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This document should be referenced as:Desbonnet, A., P. Pogue. V. Iee and N. Wolff. 1994. 1'egetated8uffers in rhe Coastal Zrme � A St<mmary R»»i ew and 8<hliogra-phy. Coastal Resources Center Technical Report No. 2064.University of Rhode Ishmd Graduate School of Oceanography.Narragansett, RI 02882. 72 pp,

ISBN 0-938 412-37-x

LOAN COPY Oddly

Vegetated Buffersin the Coastal Zone

A Summary Reviewand Bibliography

Alan Desbonnet

Pame!a PogueVirginia LeeNicholas Wolff

CIRCULATING COPY

Coastal Resources Center

Rhode Island Sea irant

University of Rhode Island

July $994

ISBN 0-938 412-37-x

' IAI TA . RIM!LR .FC .'f RTf R

5

Acknowledgments

We are grateful to the many people who provided material and insights forthis manuscript: Dr. Art Gold � Department of Natural Resource Science. Univer-sity of Rhode Island; Grover Fugate, Dave Reiss, Mark Imperial, Jeff Willis, andJim Boyd - Rhode Island Coastal Resources Management Council: Scott Millar-Rhode Island Department of Environmental Management. We also gratefullyacknowledge the Pell Library staff at the University of Rhode Island GraduateSchool of Oceanography for collecting many manuscripts and publications thatwere difficult to find. Comments, suggestions, and critical review ot the rnanu-script by Peter Groffrnan, New York Botanical Garden, Institute of EcosystemStudies; Heather Crawford, Connecticut Sea Grant; Elizabeth Gibb» and TonyCorey, Rhode Island Sea Grant; and Laurie McGilvray, National Oceanic andAtmospheric Administration, Office of Ocean and Coastal Resource Manage-ment. greatly improved the finished document from earlier versions,

Table of Contents

ffer

nt Guidance....Manage me

AcknowledgmentsI. Introduction.

~ Definition of vegetated buffer,,~ Multiple benefits.

11. Vegetated Buffer use and Effectiveness: A Review.a Nonpoint Source Pollution Control.~ Critical Variables Affecting Pollutant Removal.

Surface Water Flow.,

Groundwater Flow.

SlopeSoil Characteristics.

Pollutant Characteristics��

Vegetation Type .CI rasscs.

Woody-stemmed Speci es.Buffer Width,

Remot al of scdimc nt and suspended solids.Remc» al of total and nitrate-ni trogenRemoval of total phosphorusPerformance standards.

~ Wildlife Habitat Protection.

a Erosion and Flood Control,

5 Historical and Cultural Preservation.a Scenic and Aesthetic Enhancement.

S General Guidelines for Multiple-use Vegetated Buffers..~ Implementation Approaches to Multiple-use Vegetated Bu

The "Ideal" Buffer.

Contour.

Vegetatt'on�111. Use of Vegetated Buffers in the Coastal Zone,

8 Application and Approach.~ Public Perception,~ Management and Maintenance,~ An Example: Rhode Island's Coastal Buffer Progratn�a State Coastal Buffer Programs; A Summary.

IV. Selected Bibliography.V. Appendices.Appendix A - The Rhode Island Coastal Zone Buffer Program,Appendix B � The Rhode Island Coastal Zone Buffer Program:

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I. Introduction

Recent events. such as algae blooms: fish kills;closure to harvest of finfish and shellfish stock»;increased coastal developnient, tourism, and recre-ation; loss of tidal wetland» and wildlife habitiit; andscenic degradation of coastal vicwshed», all haveincreased our awareness ol the nccd to preserve.protect, and restore our nation's coastal resources.The prohlems observed along the coastal zone arenot the result of any single event, but rather are 'iresult ot' multiple changes that. when added togetherover time. have lrayed and split the threads that linktogether ecosystem functions. In response, rnanage-ment schemes and regulations are developed that wehope will slow the rate of ecosystem change,smooth the frayed threads. and splice back togetherthe severed links. One such management effort canbc the application ol vegetated buffers for use in thecoastal zone. Vegetated buffers have been applied inthe f'ields of forestry and agriculture to moderatenonpoint source degradation of water courses, inwildlife management to improve and providehabitat, and in landscape architecture to improvevisual appeal. While great emphasis is being placedon the use of vegetated buffers to abate nonpointsource degradation of waterway», none of the aboveuses are exclusive of the others. It makes both goodsense and good economics to pursue a multiple-useapplication of the vegetated buffer concept incoastal ecosysterns,

lt is the intent of this document to formulate

concept» and ideas pertaining to the development ofvegetated regions along the coastal zone that pro-vide multiple benefits once implemented. It is notthe intent of this review to provide the specificdetails, or provide critical comparison, of runoffsources and buffer efTects when located on specifictypes of soils, for instance. There are many reviewsof this type available in the published literature.This review differs from other published reviews ofvegetated buffer uses in that it attempts to synthe-size a broad spectrum of buffer benefits, effective-ness, and the variables that determine effectiveness,

~ Definitiort of vegetated bufferOf the variety of definitions found in the litera-

ture Table I!, all include the concept of a vegetatedbuffer acting as a transitional zone between differ-ing land uses, and/or as a barrier to, and filter of,

surface ~ uter runoff, As a result ot their associatiiin

with reducing the impact of development andlimdscape;ilteration on water resources, vegetatedbuffers,ire now being routinely employed as a toollor ntanaging the environment. Vegetated buffersare often iinpleitiented. for instaiice, to mitigate theel'fects of nonpoint source pollution by removingpollutants froin runoff through plant and inicrobialuptake. microbial degradation and conversion,physical trapping, and chemical adsorption. Philhps l989a! describes vegetated butchers as "one of theinost effective tools t'or coping with nonpoint sourcepollution." The U.S. Environmental ProtectionAgency EPA, l993! states: "...constructing vegeta-tive treatment systems, will he considered in allcoastal watershed pollution control activities."Statements such as these give signil'icance to the useof vegetated buffers. and further contribute to theiradoption and use for the control of nonpoint sourcepollution in current resource management schemes.

Resource managers are beginning to viewvegetated buffers as one method of v orking towardcompliance with recently drafted National Oceanicand Atmospheric Administration NOAA! and EPAnonpoint source pollution control measures. Thepractice of implementing vegetated buffers, how-ever, has generally focused upon their use as a "bestmanagement practice' BMP!. Overall, there is alack of understanding with regard to developingvegetated buffers to provide benefits beyond v hat atypical BMP can provide. For instance, EPA �993!states: "The term I > egetared buff'rf is currently usedin many contexts, and there is no agreement on anysingle concept of what constitutes a buffer. whatactivities are acceptable in a bulfer zone, or what isan appropriate buffer width." This statement empha-sizes the lack of general understanding and thecommon confusion concerning the use and effec-tiveness of vegetated buffers as a resource manage-rnent tool,

Further confusion arises from the distinction,noted in Table I, between a vegetated filter strip anda naturally vegetated area. Filter strips are typicallyconsidered a BMP engineered for a specific pur-pose, such as sediment removal, Forested buffers,on the other hand, are typically natural areas leftalong stream and river banks to mitigate the cfl'ectsof logging on in-stream trout and salmon habitat.These practices are commonly considered separateentities one edge of field filter strips! and the

other edge ol stream forested huffers! � despitetheir similarities in purpose. Together they make upa range of functional use» greater than either consid-ered alone.

This review incorporates information taken fromboth vegetated filter strip and forested buff'er stud-ies, since the use of both is important in developinga general understanding of the effectiveness ofvegetated buffers. particularly from a multiple-useperspective. When thc term "vegetated buffer" isused in thi» document. particularly with regard tomanagement implications for the coastal zone. itspecifically refers to naturally vegetated areas thathave been, or are being, set aside along the coast-line, whether grassy or wooded, When reference ismade to designing vegetated buffers where theypresently do not exist, the intent is t ! develop avegetated area that mimics native vegetation appro-priate to the same locale. Our choice of the term"vegetated buffer" keeps with its original use todesignate naturally vegetated areas, but we developfurther the concept of multtple use and multiplebenefits for this versatile management tool, asadapted from information on both natural andengineered vegetated buffers.

Table l. A selection of dettnitions for vegetated buffers.

8 Multiple benefitsVegetated buff'ers often produce many benefit»

that are neither well-documented nor originallyintended. They can bc used for providing wildlifehabitat; for promoting vi~ual diversity; for birdwatching. hiking, and picnicking; for preserving theintegrity of histori<.'al and cultural sites; for floodzone management by settmg development backfrom the immediate banks of waterways: and forprotecting structures from storm damage. Establish-ment of vegetated buffers throughout the coastalzone also can help provide for the long-term eco-nomic viability of the resource by maintaining anaspect of the natural wilderness of the coa~t thatdraws people to the shoreline.

Vegetated buffer programs. however, are rarelydeveloped to fully consider the multiple benefits anduses that they offer to resource managers and to thegeneral public. The "single use jsingle benefit"approach used more often tends to alienate somesector of the public that does not view that singleuse/single benefit as a priority. Public awarenessthat the vegetated buffers support multiple benefits

pollution control, wildlife habitat diversification.and scenic improvement, for instance � may leadto more effective implementation, as well as giving

Referenceat rey and Bradley, 1982

Dillaha et al., t 9 6a

Soil onservation Service, l989

Chesapeake Bay Local Assis ance Act,f990

Brown et al., 1

Palmstrom, 199 l

Comerford et al � l 992

Dodd et al., t993

EPA. f993

Definition7ones of undeveioped vegetated land extending from the banks or high water mark o awarer course or water body o some porn landward. Their purpose is to protect thewater resources, including wetlands, they adjoin from the negative impacts of adjacenttand usc,Bands of planted or indigenous vegetation used to remove sediment and nutrients fromsurface runoff.Strips of grass or other vegetation that trap pollutants from land areas before iheyreach adjacent water bodies.An area of naturat or established vegetation managed to proteci other components of aResource Protection Area and s ate v aters from significant degradation due o landdisturbance~.Transitional areas between two different land uses where one mitigates the impactfrom the other,intended to provide a neutral area to lessen he impact of man's activities i.e.,fertilizer use, on-site sep ic systems, urban runoff! on sensitive resources.A barrier or treatment area protecting adjoining areas from the o f-site effect~ of somedisturbance......stnps of land in tran~i iona areas between aquatic and upland ecosystems From a

water quality manageinerii perspective. ripanan buffers can be defmed as areas designedto mtercept surface and subsurface flov from upland sources for he purpose ofimproving water quality.Strip~ of vegetation separating a water body from a land use that could act as anonpoint source.

greater incentive for voluntary adoption and partici-pation in such programs,

Before vegetated huffers can become an effec-tive multiple-use management tool, however, theirvariable uses and effectiveness must he hetter

understood by resource managers, who can thendevelop programs to maximize the benet'its andminimize the shortfalls for their use along thecoastal zone, The implementation of vegetatedbuffer areas in the coastal zone can directly assist inpollution control, habitat diversification, and visualbeautification. The application of multiple-use vege-tated buffers, however, will hest be implemented ata watershed scale to protect the rivers and streams,and in effect, the entire ecosystem, from which the

coastal zone ultimately derive» its health. Anythingless than a system-wide approach will result, as ithas in the past, in only partially solved problems,The implementation of vegetated buffer programs.however, regardless of the environment in v.hichthey are applied or the care and effort taken in theirdesign and development. can neither take the placeof, nor tully mitigate, the effects of poor landmanagement techniques. Vegetated huffers shouldbe considered a tool that can assist in the restoration

of coastal and watershed ecosystems once soundland management practices have been developedand put into general practice, and not as an inexpen-sive technological savior to mitigate poor land andother natural resource rnanagernent practices,

II. Vegetated Buffer Use andEffectiveness: A Review

5 Vonpoint Source Pollution ControlNonpoint source pollution of our nation's

water wavs ls of rnaj<ir c<incern fol tlat ur",ll res<!ur<.'espolicy and management. The U.S. FPA recentlyestimated that 50 to 70 percent ot' the nation'sthreatcncd or impaired surt'acc water» were beingadversely atf'ected by agricultural nonpoint sourceinputs, and that five to 15 percent of thrcatencd orimpaired surface water» were being adverselyaf'fected by urban runoff lGritfin. 199 I !. Concern isalso growing for thc degradation of groundwaterdue to nonpointsource impacts, which has implica-tion» with regard to subsurface recharge to streams.rivers, lakes, and estuaries, as well as t<i drinkingwater supplies. A nati<inal survey of' wells con-ducted by th» U.S. Ge<ilogical Survey t'ound thatnearly 6,5 percent contained nitrate concentrationsin excess of the EPA-established safe drinking waterstandard of I 0 mg/I nitrate-nitrogen Madison andBrunett, 1985!,

Recent estimates of the impact of nonpointsource pollution have pushed torward a new era ofregulation to abate water quatity degradation.NOAA and EPA have both drafted ncw guidelinesfor regulations to limit nonpoint source pollutantimpact on surface waters, Under the purview ofSection 62I7 of the Coastal Zone Management Actand Section 3 I 9 of the Clean Water Act, the man-dated regulation of nonpoint source pollutants willbegin in earnest.

The control of nonpoint sources of pollution.however, will not occur as easily as for pointsources, which can usually be clearly identified,quantif red, acted upon. and monitored for cornpli-ance to discharge standard». Nonpoint source», bytheir very nature, are most often diffuse. cryptic, noteasily monitored, and in many ways not fullyunderstood. A f'urther problem is that, even when anonpoint source is clearly identified. it is often notthe sole cause of any observed degradation of waterquality or habitat. Instead. it is usually a result of thecumulative impact of many nonpoint sources withinthe area.

Although numerous problems are inherent incontrolling nonpoint sources of pollution, abatementmethods arc being developed and implemented

al<ing w rtcrcourses thr<>ugh<rut th» world. Many <if hese;<re engineered control nreasures designed torni igatc ih» oft'-site impacts ol developmentcate tr bus lrls, sett lrng Iiorr<ts, and gr'tssy' swalcs, forinsurrcc. Thc implement.<tion of' vegetated buftcrs;ts HMPs h;ts generally been practiced by resourcenianagers with the intent ol removing sediments andatt'rched pollutants from runot'f water. This practiceis welt-supported and documented in thc literature,where numerous studies can be found that describe

the design and eft'ectiveness of' vegetated buffers asa BMP. Other measures employ increased planningto abate thc impacts of future development, Rezon-ing. cluster development, setback.s f'rom water-c<iurses, and defining naturally vegetated areas <sbuffers are sor»e examples of planned mitigationmeasures. Naturally vegetated buffers have typic;<llybeen applied as habitat preservation measures,except within the. field of forestry, where they havebeen extensively applied for sediment control.

ln order to assess the potential value of imple-menting vegetated buf'I'ers as a nonpoint sourcepollutant control measure, the many variables thataffect how buffers rcntove pollutants from runoftmust be understood. A better understanding of howvegetated huffers work, and what factors limit theiruse and effectiveness as pollutant removal mech;>-nisrns, will assist in evaluation and implementati<inof practicat and functional vegetated bufters.

~ Critical Variables Affecting PollutantRemoval

Vegetated buffer» are typically employed v,iththe primary objective of removing sediment and itsattached pollutants from surf'ace water runoff. Pol-lutant removal is primarily achieved by slowing thesurf'ace water flow that trarrsports sediments, allow-ing time for the sett! tng of scdimerrts and thc pollut-ants adhered to them. The effectiveness of a veg-etated buffer in removing pollutant.s, however. willvary according to a number of conditions, such as:

~ Soil type in the butTer~ Depth of the water table in the buffer~ Type, density. and age of vegetation in the

buft'er

~ Poltutant concentrations contained in thc

runo 'f water entering the buffer~ Land usc and size of areas drainr'ng into the

buffer

~ llydrologic regitne of the area within andadjacent to thc buffer

~ Width of thc buf'fer

~ Residence tinie of water in the butter

~ The path of runoflw;itcr into and through thebuffer

Due to the inherent variability in the conditionsthat determine the effectiveness of vegetated buffer»for the removal of pollutants, no single "best buffer"has been identified lor widespread application.However. with better definition of those variablesthat determine buffer effectiveness, a hetter under-standing can be gained as to what conditions, ingeneral. promote pollutant removal efTectiveness.

Surface Water l low

ln order for a vegetated buffer to cffcctivelyremove pollutants and seditnents, the surface waterflow through the vegetated buffer must be slow,shallow, and uniform Broderson, 1973; Dillaha etal., 1986a!. Surface water runoff should progress asshallow "sheet flow," and not become channelizedas it moves across the buffer area. Slow flow allowsfor pollutants � which are often adsorbed tosediinents � to settle out and become incorporatedinto surface soils Lee et al., 1989!. Settling will bemost pronounced in runoff that contains large-sizedsediment particles, and less pronounced in thosecontaining fine silt» and particulates, which oftenrequire long retention times and very slow flows inthe vegetated buffer to effectively settle. Slow flowalso promotes utilization of nutrients by plants,assist~ flood control by allowing water to percolateinto the soil, and reduces erosion within the bufferarea, Rough surfaces, which better reduce flowvelocity and promote sheet flow, result in greaterpollutant and sediment removal than smooth sur-faces Flanagan et al� 1986; Williams and Nicks,1988!.

Field tests, however, indicate that naturallyoccurring vegetated buffers are generally incapableof inducing sheet flow from storm water runoff dueto the natural tendency of water to move in discretechannels, Dillaha et al. �986a! rcport a range of 40to 95 percent reduced efficiency of sediment, nttro-gen, and phosphorus removal in vegetated bufferswhen runoff flow through the buffer area deviatedfrom shallow sheet flow. Channelization of flowthrough the buffer was cited as a major problem and

limitation to buffer eff'ectiveness during the reviewof riparian buffers implemented on agriculturallands in thc state of Virginia, Nearly all the veg-etated bufiers inspected needed some form ofmaintenance or engineering to reduce channeli-zation of flow, and to incrc ise effectiveness in theremoval of sediment and pollutants from surfacerunof'f. The natural tendency of'water to move indiscrete channels may be one of the greatest impedi-ments to successful buffer implementation fornonpoint source pollution control. particularly whenimplementing nonengineered vegetated buffers.

When depth of the surface water flow is suchthat vegetation in the buffer is submerged. effective-ness is reduced. As submergence increases, filteringefficiency of the buffer declines to zero Karr andSchlosser, 1978: Barfteld et al.. 1979!. When stormevents occur, such as sudden thunderstorms, precipi-tation can often be extremely heavy. submerging thebufl'er and allowing an initial heavy flow of pollutantsinto receiving waters. All vegetated buffers may exper-ience temporary ineffectiveness during thunderstormsor similar events that bring heavy precipitation.

Groundwater FlowAs surface soils become saturated, ~ater may

move vertically rather than horizontally through thesoil layer and enter into the groundwater rechargesystem. The net movement of groundwater dependson soil type, subsurface impermeable layers, geol-ogy, hydrologic regime, and slope, Groundwatercarries soluble pollutants that have passed throughsoils in percolated water. As it eventually recharges tolakes, rivers, streams, and coastal waters, it can be-come a source of pollution to surface waters. Ground-water may also move into subsurface aquifers anddegrade potable water supplies. In areas such as thecoastal northeastern United States. groundwaterrecharge can be a signif'icant source of nitrogenenrichment to coastal waters Valiela et al., 1992;Weiskel and Howes, 1992!. Leachate from septictanks, leaking underground storage tanks. landfills,and accidental spills can all enter the groundwatersystem, eventually entering coastal waters.

Vegetated buffers, however, may only be able toremove a limited number of pollutants from ground-water � nutrients and some metals, for instance,Oils, inost metals, and pesticides will generally notbe effectively removed by vegetated buffers oncethey have entered the groundwater recharge systein.

Furthermore, vegetated buffers located over deepwater tables are not usually effective in the removalof pollutants from subsurface flow, Deep groundwa-ter flows can move over considerable distances and

over relatively long time frames Hynes, 1983!. andat depths where plant root systems are unlikely toreach them. Areas that are recharged from deepgroundwater flow» often receive pollutant inputsfrom distant sources that may have originateddecades ago. A time lag may therefore developbetween both cause and effect, as well as between

the implementation of abaternent measures and anyobservable effects,

Nutrient uptake and utilization by plants can bea major pathway uf nutrient removal from ground-water supplies in a vegetated buffer. In areas thatcontain a shallow aquaclude a subsurface imperme-able soil layer!. subsurface flow may be morehorizontal than vertical, increasing the likelihood ofgroundwater being reached by the roots of overlyingvegetation. In a forested area located over a shallowaquaclude less than four meters deep!, Peterjohnand Correll �984! reported an 80 percent removalof nitrate from surface water flow, and Correll andWeller �989! reported an 84 to 87 percent removalof nitrate from groundwater. In these instances thesubsurface aquaclude kept the groundwater avail-able to the root systems of plants in the buffer foruptake, as well as keeping it available to denitrify-ing microbial communities.

A major pathway for nitrate removal in ground-water is denitrification. The process of denitrifica-tion, which converts nitrate to nitrogen gas, which isthen released to the atmosphere, is reliant upon theexistence of a microbial community of denitrifyingbacteria. The microbial cornrnunity is partly reliantupon anaerobic conditions � a circumstance inwhich no free oxygen is present. The oxygenpresent in nitrate NO,! is utilized for metabolismby the microbial community, and nitrogen gas isreleased to the atmosphere as a metabolic by-product. A further limitation to this process is theavailability of a source of carbon organic material!to support the microbial community Obenhuberand Lowrance, 1991!. Soils that are poorly drainedand rich in organic materials will typrcally provideconditions that promote denitrifrcation,

Areas with a shallow water table, such aswetlands and areas with poorly drained soils, mostreadily provide the conditions conducive to the

removal of nitrate contained in both surface and

groundwater supplies, A series of related studies byGold et al. �991!, Simmons et al. �992!. andGroffman et al. �992!. reported that nitrate removalwas greater in areas with shallow water tables thanin those with deep water tables during both dormantand growing seasons. Ambus and Lowrance �991!found that 68 percent of the denitrification theyobserved occurred in the top two centimeters of soil.A shallow water table keep~ groundwater close tothc surface and in the area where carbon sources

i.e., organic leaf litter! are most likely to promotethe growth of denitrifying microbes. Correll andWeller �989!, based on biomass removal estimatesfor nitrate-nitrogen, suggest that denitrification maybe the most important nitrate removal mechanismfrom groundwater in forested areas.

There is, however, some concern that use ofvegetated buffers to treat surface water runoff mayactually increase groundwater nitrate and othersoluble pollutant concentrations by promotingpercolation into soils. Gold et al. �989! andWeiskel and Howes �992! have both reported thatnitrate can readily travel through soils and intogroundwater supplies with little or no removal intransit, This may be true for many soluble forms ofpollutants, particularly in areas with highly perme-able or very well-drained soils Schwer andClausen, 1989!, Under some soil conditions � wefl-drained, sandy soils, for instance � the vegetatedbuffer could slow surface flow, promoting rapidpercolation of surface water to groundwater. andactually degrade potable water supplies or coastalwaters, It is presently unclear, however, to whatextent this event occur», and further study is neededto determine if and when vegetated buffers promotegroundwater contamination.

SIopeAreas of steep slope do not allow for long

retention time of runoff water, and since pollutantremoval is at least partially time-dependent i.e., toallow plant uptake and denitrification to occur!,steep slopes reduce vegetated buffer effectiveness.Furthermore, steeply sloped areas negate the veloc-ity-reducing effects of surface roughness, andthereby promote erosion. Even though a steeplysloped area may be thickly vegetated, it may beineffective at removing sediments and pollutantsbecause it promotes erosion and channelization ol

flow through the buffer area, Thc shallower theslope, the longer the residence lime. the slower the1 low, and the greater the ability of se<finrent andpollutants to settle and be re»1oved fron1 the runoff'.

A slope ol less than I5 percent reportedlyalhrws for adequ;lte rctet1tion titne arid pOllu an rem<rvaf, while stccpcr slopes may not he suitable1'or vegetated bufTers due to thc sh>pes' erosionpotential and lack ol' adequate retention time Schueler and Bley, 1987; Niewswand et al.. 199 !:Palmslrom, 1991!. Clark �977! gives some ex-amples ol minimum buffer width» for water qualityprotection according to slope and soil crodibility: herecommends a minimum width of' 10 meters for

areas with no slope on slightly erodible soils,extending to 50 meters for 30-percent slopes onseverely erodible soils. Trimble and Sartz �957!suggest adding an extra 0.6 mctcrs of vegetatedbuffer width for each one-percent increase in slopewithin thc vcgctated buffer for minimum ef'fective-ness, and a 1.2-meter increase per one percent slopeincrease to attain greatest water quality protection.Broderson �973!, in a study of the effectiveness offorested buflers to remove sediment from runoffbefore the runoff enters a stream, suggests thatfifteen-meter huffers are sufficient at slopes lessthan 50 percent, and a maximum 66-meter buffer issufficient for extremely sloped areas. Comerf'ord etal. �992! note, Crom a review of the literature, that.slopes greater than 30 percent generally allowinadequate retention time in a vegetated buffer forany SignifiCant denitrifiCaliOn tO occur,

Slope of the area prcccding the vegetated bufferalso «an affect pollutant and sediment removal.Steep slopes leading into a flat buffer area oftentend to cause the bulk of the transported sediment to

Poorly drained

Wett4ratned

0 5 10 15 20 25 30 35 40 45 50¹trogen Remavar kgtNtha!

12

Figure 1. Nitrogen removal invarious poorly drained and well-drained soil types. Nitrogenremoval is more than doubled inpcrorfy drained soils compared towell-drained soils. Sandy soilsprovided poor nitrogen removalregardless of soil wetness. Datafrom Groffman and Tiedje, 1989a.

be deposited on the leading edge of the bul'fcr area.forming a burnt Magct c et al�1986: Robat andSabol, 1'!8! r. Once,'< berm is t'ormed at the leadingedge ol' the vegetated buffer, water wrll be chan-neled around the buffer, rendering it useless. Even-lu;illy lhc berm will he breached, causingcharrnelization ol flow into the vegetated buffer,increasing errrsiOn and reduCing buffer effeCtivCness1'or pollutant and sedinren removal.

Soil Characteristics

Soils with high permeability generally providegreater filtration of sediment and attached pollutants Chescheir et al.. 1988; Lee et al.. 1989!. Once thepollutants enter the soil layer, they can becomeincorporated through physical, chemical. andbiological intcractrons. However, highly permeablesoils, such 'ts sandy soils. may allow for the rapidmovement of water into the groundwater rechargesystem. The movement may be so rapid that noremoval of' pollutants is allowed by plants, and onlyminimal removal by physical and chemical adsorp-tion, particularly for dissolved forms of pollutants,

Figure 1 shows that well-drained soils are onlyhalf'as effective for the removal of nitrogen aspoorly drained soils. Sandy soils provided the leastnitrogen removal. regardless of drainage capacity.Fhrenfeld 1 987! found that nitrogen from septicsystem leachate moved greater distances verticallythan horizontally through the permeable sandy soilsof' the Ncw Jersey Pinelands, where the nitrate-ladenseptic leachate quickly percolated below the rootzone of' buffer vegetation. ln some soils, vegetatedbuf'fers that are not located directly in the septicsystem leach field plume will be ineffective inremoving nitrate. The contaminants contained in

septic system leachate can readily enter ne;trbywaterway» under these conditions.

Poorly drained soil» generally relain w;tter longenough. itnd of'ten under conditions favorableenough. that pollutant removal is accomplishc<f,Figure I prcscnts a range of ttitrogetl-retnoval datareported by Groffrnan arid Ticdjc �989a! for avariety of soi! types and conditions, Poorly drainedsoils were found to he more than twice as effective

as well-drained soils for the removal of' nitrogen.Poorly drained soils that contain a higher >rganiccontent are more apt to promote thc growth andmaintenance of denitrifying microbial cotnmunitiesand hence greater nitrogen rcrnoval Vicho!s. ! 983;Peterjohn and Ct>rrell, !98'>; Crrt>ffntan et al�1991a!. In cases where long residence time occursin saturated, organic soils. nitrogen removal may behigh Cooper. !99 !!. These conditions are typicallyfound in salt nlarshcs. wetlands. and wet forests. all

of which have been repeatedly reported to expresshigh dcnitrification potential, Saturated, organicallyrich soils, theref'ore, can be useful in the removal ol

both soluble and sediment-bound pollutttnts. whilesandy soils may be most effective in removingsediments and bound pollutant», and soluble formson! y margina! ly.

Soils rich in clay content are often relative!yimpermeable, and removal of pollutants fromsurface water» by soil percolation can be low,Scheuler and Bley ! 987! do not recommendvegetaled buflers as effective p >!!utant removalmechanisms in clay-rich soils. Mixed clay soils,however, as shown in Figurc I, often arc ef'I'ective inthe removal of pollutants, Clay soi!s often have highaffinities for binding positively charged pol!utants,particularly metal», by actittg a» a cation negativelycharged! exchange site. Provided the clay soils arenot compacted, and runoff over the area is slow,pollutant removal via chemical binding may hesignificant �irschky et al., ! 989!. Chemical re-moval, however, is finite; once metal.s are adsorbedto soils, they can be freed for transport by furtherchemical or physical disturbance of the soil layer,and may be moved during the next runoff event. Aranking of' stability of soil-bound metals given inBaker and Chesnin !975! shows that copper has thegreatest tendency to remain stable once adsorbed.Zirschky et al, !989!, experimenting with copper,nickel. zinc, cadmium. chromium, iron, lead, andmanganese, found that only copper and zinc were

cor»istently rentoved, Other metals may therefore»ot be effective!y rentt>ved f'ron> surf;t«e runtrff byvegetated hulTers. even in hu ' 'ers w ith condit i<msc<>nducive lo metals remova!.;tnd other methods

rnity ttced to hc cxp!oft d t'I Iernovitl of nletitls ts ofnutjor concern.

Po! ltltattt Characteristics

M my stttdies indicate th;t most pollutants;utdnutrients trartsportcd hy surface runoff are;tttachedto sediments, This tends to be true for metals

Zirschky et al.. ! 989!, peslicides I.ake;tndMorrison, 1977!, phosphorus Karr;tnd Schlosser.1977: Chescheir el;tl,. ! 988: Lce et al,. ! 989!, and

some fornls of rtitrogen Karr and Schlosser, 1977;Cheschcir ct a! .. 19881. Nitrate, however. h ts lessaffinity to sediments. and is most often tound in tdissolved phase Chescheir et a!.. 1988!. Run<>ff thatcharacteristically contains pollutants bound tosediment need only move through a huf'I'er abl» ttrremove the sediment load. When runof'f characteris-

tically carries pollutants in dissolved or so!uh!eforms. the buffer area will need to promote lortgretention times in order for tho~e pollutattts to beeffectrvely adsorbed to soil» or utilized by plant andmicrobial communities.

The effectivene~~ of pollutant remova! wi!! herelated to the concentration ol pollut;tnts enteringthe vegetated butter lrom outside sources, Much t>fthe reviewed literature reports testing buff'cr ef'fi-ciency in response to sources that have s cry hi hconcentrations of incoming p<>llutants, particularlysediments and nutrients. For instance. Fdv ards et al.

�983! measured concentrations of t >ta! suspendedsolids. nitrogen. and phosphorus entering grassedbuffers from a cattle feedlot to bc: ! 0.200 mg/1 TSS:705 mg/I N; 2 m~jl P. In most ca~es. very favor-able removal efficiencies were reported. despite ahigh input rate. In the Fdwards et al. ! 98~! study,removal rates of 87 percent TSS, 83 percent tt!, and84 percent P were recorded after the feedlot run >ffhad moved through a settling basin and sixty metersof grassed buffer, Thi» may suggest that vegetatedbuf'fers treating more "average" concenlrations of'pollutant inputs»ri r!Irr produce even gre«tcr rcntovalefficiencies than those reported in t!re puh!ishedliterature see Schueler ! 987!. for example. foraverage concentratit>n» of varit>us po!!utants c<>n-tained in urban runoff water!.

ln c >ntrast. ':v'ich >!s ! 983! rep<>rted that re-

rnoval ef'I'iciency for nitrogen and phosphorusdecreased as loading of those nutrients into awetland treatment area increased. Reuter et al.

�992! rcport similar results. The U.S. Anny Corpsof Engineers �991! suggests that, despite reportedhigh removal efficiencies for pollutants in vegetatedhuffers, high pollutant loading rates into the butTermay result in degradation of adjacent sensitive waterbodies, For example, Castelle et al. I 992! reportedthat 55 percent of the assessed buffers implementedto protect wetlands that bordered residences usinglawn maintenance systems showed impacts fromt'ertilizer applications. The syrnptorns ranged fromincreased wetland plant growth to wetland plantdeath from nitrogen toxicity. Under high pollutantloading condition». the percentage of' pollutants nuIremoved may be sufficient to cause degradation ofwater quality and other resources. This is furtherexemplified by the study of Edwards et al. �983!,in which, despite high removal rates 87 percentTSS, g3 percent N. 84 percent P!, the pollutant loadleaving the sixty-meter grass buffer was high 988kg TSS, 63 kg N, 15 kg P!, as were concentrations�,g40 rng/1 TSS; 260 mg/1 N; S I rng/1 P!. Althoughhigh pollutant removal rates in vegetated bufferswill certainly reduce loadings to receiving water,they may not necessarily equate to protection ofwater quality.

Over time, a vegetated buffer may become"saturated" with sediments and pollutants, reducingoverall removal efficiency. Eventually the buffercould become a source of pollutants to adjacentwater bodies. lt is well known that physical distur-bance can cause pollutants trapped in a vegetatedbuffer to become available for transport out of thebuffer area, However, not enough research has beenconducted on vegetated buffers to adequately assesseither the conditions that lead to saturation withpollutants or the circumstances under which an un-disturbed vegetated buffer becomes a pollutant source,

Karr and Schlosser �977! note that pollutantscontained in surface runoff are generally bound tosmaller-sized sediment particles, such as silts andclays, and that the effectiveness of any vegetatedbuffer will partially depend on how well it removessilts and clays from runoff water. Clay sediment inrunoff generally exists at very small sizes, and Karrand Schlosser �978! report that, as particle sizedecreases, the buffer width required to remove agreater percentage of those particie sizes increases

dramatically. Wong and McCuen �982! similarlyfound that disproportional increases in buffer width

t'rom 33 to 66 rnetcrs � were required to in-crease sediment removal efficiency of a grassedbuffer from 90 to 9S percent. The largest sedimentparticles are generally deposited within the first f'ewmeters of the vegetated buffer. leaving the fine siltsand clays in suspension. For example, Neibling andAlberts �979! reported that only 37 percent of clay-sized sediment and particulates were removedwithin a 0,6 meter width of grass vegetated buffer.while 91 percent of the total sediment load wasremoved within the same effective buffer width,Wilson �967! found that most coarse-grainedsediment was removed in 3,3 meters, most. silt in 15meters, and most clays by 90 meters in a buffervegetated with Bermuda grass.

Relatively narrow buffers, provided they pro-mote shallow sheet flow through the buffer area,will effectively remove coarse-grained sedimentsand their associated pollutants. Wider buffers,however, will be required to remove smaller-sizedparticles of sediment and the pollutants adsorbed tothem, Pollutants in dissolved forms may requireeven greater buffer width to be effectively removedby chemical interactions. plant uptake, or microbialtransformation.

Vegetation TypeThe vegetative ground cover within a buffer

serves multiple purposes with regard to overallbuffer effectiveness by removing pollutants, provid-ing habitat, and creating aesthetic appeal, The type.density, and age of the vegetative ground cover playa large role in detertnining the effectiveness ofpollutant removal, the habitat value to wildlife, andthe overall aesthetic appeal of the vegetated buffer,The vegetative ground cover contained in a buffercan he inanipulated, often in a cost-effective man-ner, to better achieve the goals for which the veg-etated buffer was implemented. For instance, thevegetative cover in the buffer could be inanipulatedto enhance the removal of various pollutants ofconcern, thereby providing some flexibility toresource managers for achieving their specific goals.

Table 2 provides a range of removal ratesreported in the literature for nitrogen, phosphorus,and sediment in both grassed and forested buffersand over a variety of site-specific conditions.Nitrogett was the most widely reported pollutant

with regard to removal in vegetated buffers. Theremoval rates provided in Table 2 trtay be useful toresource managers for estimating potential nitrogenremoval in irnplernented buff'er», based upon vegeta-tion and other general characteristics. In the eventthat pollutant loadings were able to be estimated,actual removal rates for a proposed vegetated buff'ercould be estimated, based upon Table 2 and site-specific data, and the buffer area modified in orderto achieve the desired pollutant removal goal.

The removal rate value» for nitrogen presentedin Table 2 are graphically presented in Figure 2 tovisually show the range ol nitrogen removal rates ingrassed and forested buffers. The range of nitrogenremoval rates represented in Figure 2 shows that,overall, grassed buffers have greater nitrogenremoval potential than forested buffers. Forestedareas, particularly wet forests, are frequently notedin the published literature to be more effectivenitrogen removers than grassed areas. In Figure 2,however. grassed buffers are shown to have thepotential to remove nitrogen at a rate approximatelythree times greater than that of forested areas, Thepotential for forested areas to remove nitrogen maybe underestimated in the presented data. since someof the grassed buffers were treated with directnitrogen applications fertilizers!, thus providing agreater representation of their overall nitrogenremoval potential, Studies conducted with forestedbuffers generally did not include fertilizer treat-ments; therefore, their range of potential nitrogenremoval may be underestimated. However, unfertil-ized control plots of Kentucky bluegrass utilized byMorton et al. 1 988! had removal rates of only 2,0kg/N/ha/yr, which is considerably lower than thelowest removal rates reported for forested areas seeTable 2 and Figure 2!. Furthermore, fewer studiesfor grassed buffers reported removal in kg/ha/yrthan for forested buffers, and the average removalrate for grassed buffers may more closely approxi-rnate those for forested, given gre~ter representation see Figure 2!.

Grasses and woody-stemmed specie~ are de-scribed separately below because of the uniquecharacteristics of each type, as well as the differ-ences each group exhibits in the removal of sedi-rnent and pollutants from runoff. Furthermore, theliterature on the two types of ground cover is verydifferent, Most of the work completed for gras~buffers comes from studie~ of vegetated filter strips

where thc primary pollutant of concern is sediment artd its adsorbed pollutant load!. The results ofgrassed buffer studies are generally reported aspercent removal and typically have treated source;ireas with a high pollutant load. Studies of woodedbuffers generally have focused on naturally forestedareas, with the removal of nitrogen the primaryfocus, Nitrogen removal typically is through bio-logical rather than physical/chemical pathways,such as denitrification and plant uptake and storage.Forested buffer studies less often reported sourceareas that contained high pollutant loads, andgenerally treated logged or urban areas rather thanlive~tock and agricultural areas. The result is verymuch two separate bodies of knowledge, whichhave taken tv'o separate paths of study, This makesf' or some difficulty in directly comparing grassedand forested buffer studies. as the methods andreporting of results are generally different. Enoughof each, however, has been reported in similar unitsthat some preliminary comparisons can be made andrelationships proposed.

Grasses

Grasses tend to be very effective in reducingoverland flow, as well as being effective nutrientand sediment removers. Removal rates reported inTable 2 and used in Figure 2 show that grassed buf-ffers treated with fertilizer applications can removeup to 290 kg N/ha/yr, Despite high reported removalrates and efficiencies, it is often unclear how this re-

lates to water quality protection. Morton et al. I VHN!found nitrate leachate concentrations leaving fertil-ized plots of Kentucky bluegras~ to be well belowthe EPA drinking water standard of 10 mg/l nitr~te-nitrogen, Nitrate concentrations ranged from 0.51 to4.02 mg/I, with the higher values found leavingheavily fertilized. overwatered experimental plots.The results of thi» study suggest that home lawnfertilization practices may not always pose a directthreat to drinking water supplies. Although thesereported concentrations do not appear threatening topotable water supplies, concentrations at the upperportion of the range could, when combined withother sources of nitrogen, contribute to eutrophica-tion of coastal waters. This may be particularly truein the temperate coastal zone, where soils aretypically composed of glacial till and sand, whichoften allow rapid movement of groundwater tocoastal water~ with only minimal removal of nitrogen.

js

Tahle 2. Retnovat rates for iarious pollutants in vegetate t bttffers. The values reported for removal in gras«ed buffer« »layhe high relative t i tore«le t hut'I'cra because n ixl received direct tert tiger trcatilicnlx, ra here»« t ircste<t hufferx did rait. Rctlloviilra ei t'or fore«lcd h<it'I'crs tta! herc '<irc hc undcrcstiinalcd v ith regard lo their actual re»los«1 potential. j I kilograin = 2.2p<iui ds; I hectare = 2.47 i cree 1

DetailsRemoval RateReferenceV TR ! it'.4f:hrcii tclil, I '!K7 ! S - tt l kg iV+a/7 i tl,<rd<v<io<t «ctiand gc ing sep ic ank Ie«chuteEhreii feld. I '!K7 Sh k V/h </> r Pt<ic <Ipl il'i<tgl:I'I llig gepllc I,'<ilk Ic«ella <

Oak upland gc tiiig scp c lank Ic;ich;itcEhrcn I clif. 19h7 rt - <9 kg 5/ha/y rPeter!i>hri K C'or c I, 19M.Pal<rag<i, I91 l

77 kg V/ha/>i"! ! kg 4'/ha/y r

Mid-A I«otic co«xt,il plain forci ice«On;hiird grani; sewage w,rite treiuedPlan uptake and « r

Fail ci iil. I '!8 < 'olc K Rapp, 19!t I

Ah<rvcgr<rond pl,'nit vi<irugc iri rip;irian ares sDci'li l'i'1 Ic,i�<iii l� I'I p,'il'I«11 fr relly

LO'wl a»ee <"I al .. 19!ta<L<iwrance Ct al.. 19Kac

S I.!t kg Nd i ,'> r.3!.S kI. N/ha/y r

Kc»tuel y hlucgra» control pin Kc»luck v htucgra». iivcrwatercd i»rd fertilized

! kg t< /h l vi22 kg 4'/h.r/yr

Mar orr c al., I<!I KIvtor <in ct al.. 19R8

13cnnuda grasx on iandy soil« wrih repeated harvestingRipanan torest treating agricultural v aterahed

�r<i«n K Th<imav. I 9137 90 kg 4/haPe erjnhn K C'orrelt, 19!t4 I I kg/ha piirticul.itc organic C

0.�. kg/11« iirli�1<II I»!ii V2.7 kg/h;i ni rate V

Riparian ores treating agricultura! ««terxhedRipariaii fiircst trc«ting agricultural watershed

Pc eri<rhn A C<irrelt, l<!t�Pe erlohn <3< C'<irrcl!. 19 <4

AS kg/ha nitrii C V ingr<iundv aicrI ! kg N/I a/y r

Somcv, hai p<x>rly drained loampoorly drairied loam

Gr<iftnian <y< Ticdjc. 9139«Grot'1'rn,in <S< Ticdj», 1!t 9a

11 kg N/hu/yr24 kg V/ha/y

Or@fin an K Tied jc, 198<!aOrotfrnan K Tied jc, 19! 9«

W el I-drained cl ay � loamSomev ha poiirly drained ct,<y � loiirn

It kg V/ha/yr17 k i ht/h /yr

irotlnian K Ticdlc, 1989 iCirottlt «n &. T edlc, I !K<!a

4 ! kg N/ha/yr !.h I g 4/ha/yr

Poorly <trairicd clay - � in«inWell-di «i<i<at van<1

Grnt'I'm«n K Ticdlc. 19I 9,< .irntlnlali «< Tlcdjc, !9 9«

I.h kg . v/ha/ytI I. S I g V/ha/v r

Somewhat p<xirl! drairied iandPooi ly dr«I i<'.d valid

3 I g 'i/ha/day3 i g 4/ha/duy

Well di:tined aerohic forci soil with iiitratc addedV<xrrlv drained aerobic t'oreg vo l v.ith nitrate added

Gnit tfn ln c al, 1991«Groftman e al., 199! a inlttman c al., 19'! la inil1m«n ct al., 199 a

7 ! ! 9 g Q/ha/daya, S 3 7 ~ V/h;</d;<y

Tall ti acu<' iin acriihic voii w i h nitrate «ddedRue gr;<ii on aerobic voilwith nitrate added

I. I g N/ha/dayI, 4 !A g !v'tha/day

Well-druincd «naerobic forest soil. no nitrate addedWell-<trained anaerohic forest ~oil. ni rate added

Or<iffman cl al.. 19'! I a i»it'I'nian c «I, 199 a

P<xrrty drained «naerohic forest «oil, no nitrate addedPonrly dri»ned anaerohic f<ircvt soil, nitrate added

ir<>ffm; n el «I., 199 iiCirol fman ci al., 199 a

I 3.1 g V/ha/dayI,4 g N/ha/day

firn 1 »an e al., !9'! I a inil'Irnuii c «I., I'!91<

T«ll fescue <iri a»aer<ihic a<»l, no nitrate addedTall feicu< or> «n«enihic v<>d. »i rate «dded

I .1 g V/h«/d, v17,2 !tt g 4/ha/da>

Rccd canary grass on anaerobic vail. no nitrate addedReed caesar! graia on anaerobic coil. nitrate added

irol'fm«n c «I.. i 991«Groffman et al,. I' 91«

I. ! g N/h«/day! 5.2 3 g iv/ha/day

Warwick K I litt, 19!ttt

Warwick K Hill, 19 tt

Sandy ied men»

Organic aedimcnts

Watercress hcd de ritual and iedirnenti

Recit ca�« r< grani.' tc<< «ge w;isle tl'eater}

Warwick K Hill. 9!ttt

Hook K Kardox. 1977I 05 . -3 19 pg 4/nt-/dai

it<� kg X/ha/yrRhode« ct al., 198s1 e nunyo i, 1991

< c«n of I I I high-alii »dc <vc mead»«samples

!4»ixiih ttin» cgra i in lgm" weft-dra ncd ploi: urea treated

!,34 I � 7,26s g 4/hr/acre99..3 / 37.s ku V/ha

Sh,t / 2 !, r kg .'i/ha

7 .9 / 4 .9 kg 5/h«

.cmunyon, 1991

Lcm»»yon, 1991

!�.6 / 3 t.a kg V/ha !rchard grain in I S<n- «el -dr«<ried plot; urea treated I / ~C.7 kg 5'P,< Perrcni at rycgrass in I sm - well-drained plot. urea treated

IA

Pe er!oh<»r, 19'! I

0, !SM!.c!pg N/m-/day

!. � 1.2 ! pg .'i/m-/day

Riparian I'nresi rea ing agric»1 ural v atershed

Well-dr«ined lo«m

O<ilrriv<iil gr«xw lli I Sr<1 well-itr oned plo ; urea tri.'a ail

Kentucky hluegraii iri I Sm- Nell-drained pio : urea treated

Table 2. Retnoval rates for various pollutants in vegetated buft'ers. Continued

29.1 / 18.5 kg N/ha

37 � 41 2 rng N/m-/ ta>

Lemony m. 1991

Hill & Sanmugadas, 198.S

Hill & Sanmugadax, 1985 48.hour xtrcatli sl:dintent tnclll s 'll'onX 3 � ~ ~ 3 mg N/m -/daySchellinger & Clausen, 1992 0.72 kg/m-/yr TKNSchellinger & Clausen, 1992

OSPHOR VS3.0 kg/ha total particulate P Riparian forest treating agricultural v,atershedPeter>ohn & Correll. 1984

3,8 kg P/ha/yr

0.15 kg/m-/yr TP

Lowrance et al.. 1984cSchellingcr & Clauscn, 1992

Schellinger & Clausen, 1992 0.12 kg/m-/yr Dissolved PSchellinger & Clausen, 1992

Cole & Rapp, 19810.09 kg/m-/yr Ortho P

S.6 kg P/ha/yrSEDlMENT & OTHERPeter!ohn &. Correll. 1984 4.1 kg/ha/yr ol particulates Riparian torest treating agricultural watcrsh«dSchellingcr & Ctausen, 1 992 1.13 kg/m -/yr TSS

Figure 2

Figure 2. Ranges of nitrogen removalfor grass and forested buffer s. Theheavy litle contained in the barrepresents the mean of the data thatconstitute the range. Data laken frotnTable 2. [1 kilogram = 2,2 pounds; 1hectare = 2.47 acres I

Grass

Forest

100 150 2X 250Nitrogen Removal kg/N haryrl

Lemunyon, 19'

Lemunyon, 1991

Lemunyon. 1991

t~ nun yon, 1991

Nt'! / 34 1 kg N/ha

6S.Z / 33,5 kg N/ha

78.2 / 37.'1 kg. N/ltn

4fk5 / 11.7 kc N/hii

R««d canary gniss in 'I 5m- sell-dr tined pl it. iirc;i tr ;ii«d

Swee v«mal grass iri 15in- w«0-drained plot: ur ".i tr ai«d

1aff fescue in i 5ni- v cll-drairied plot. urea treated

t3ig hfucstcnt in 1 sm- well- trained ploi; Urc I tl ." I«d

Sv iichgr;iss in I 5m- well-drained plot; urea treated4-lloiir sti' "nn sc fin en ncllhat ton

22.9 X 7 6m mixed species grass hnl'f«r: 2'4 slope

'.9 X 7.fnn mixed species grass buff'cr: 't slope

Aboveground plant storag« in riparian forestsZZ.9 X 7.6m mixed spec cs grass but'fer: 2'< s!opc

ZZ.'! X 7.6m mix«d species grass buff«r; Z� slope

Z2.'! X 7.6mntixed strecies grass buffer: ZS slope

%1can ol' l4 temperate deciduous I'oresix

22.9 X 7.6m mixed species grass butTer: Z F slope

Grasses are desirable as part ol thc vegetativematrix that constitute» lhc vege ated buffer. They aregener;lily able to respond rapidly to increasedconcentrations of nutrie»ts. grow rapidly anddensely, and typically grow well tn nearly allclim ttcs. Thickly planted. clipped grasses provide;ldense. obstructive barrier to horizontally flowingwater. Thi» increases th» toughness of the terrain.which reduces flow velocity, promotes sheet flow,and increases seditnent and adsorbed pollutantremoval efficiency. This also increases residencetime in the hulTer, which promotes uptake of nulri-ents hy plants, Low-cropped grasses, however. maynot be adequate in areas that experience frequentflooding. as they are rendered temporarily uselesswhen submerged. Grasses that are to be used as partof thc vegetated matrix of the buffer should there-fOre be left in an unCut conditiOn, Or al least nOt Cutbelow a height of three or four inches. A worst-casegrassed buffer wouM bc one that is highly mani-cured and cltpped Iow. rcscrnbling a golf courseputting green. These become flooded very easily,thus being rendered useles~ as a pollutant filter.Medium height, thickly growing grasses representthe ideal for a grassed bull'er area.

Thc usc of' grasses in vegetated buffers hasmany rnaintenanCe benefltS. MOWing i» relativelyeasy, and thc clipping» can be readily collected f' or amore pertnanent removal of nitrogen and otherpollutants from the buffer area, Considering thatgrasses � particularly thickly growing coversare also effective at reducing runoff velocity, theymay be used with the additional effect of promotingslow, shallow sheet flow of runoff' into a naturallywooded buff'er area. Although grasses are effectiveas vegetated buffer species, they lack the versatilityrequired of rnuhiple-use buffers � for preservingwildlif'e habitat or prolnoting visual diversity, forinstance � and generally are not suitable for use asthe only cover within a multiple-use vegetatedbuffer area. Grasses therefore are suitable as part ofthe vegetated matrix that makes up lhe buffer area,or as ground cover in the area immediately preced-ing the naturally vegetated buffer.

Woody-sremmed SpeciesWoody-slemlned species generally have deeper

and more well-developed root system» than grasses,and when the root system is greater than two feetdeep, the vegetated buffer may be effective for the

tenloval of pollutants from groundv ater I:hrenfeld. 91�; Groff»lan et al.. 1991b!. In general, hardwoodspecies are better nitrogen removal mechanism»than are conifer species Spur and Barnc», 1980kbut the overall rcmov;tl of pollutants will varyaccording to characteristics of' the forested buffersite � such as vegelative composition, depth to thewater table, and hvdrologv.

For wooded buffers, poorly drained forest plotshllve been I'Ound tO prOvide greater denitriflcatiO»than svell-drained f'ores plots hy creating betterliving;tnd grow h conditions for denitrifying mi-crohes, «8 well as by keeping water within the organ-ically enriched surface soil layer and close to rootsystems ol resident vegetation Correll, 1991; Groff-rnan et al� 1992!. Figure 2 shows removal rates ashigh as N% kg N/ha/yr have been reported for nitro-gen removal in t'orcsted areas. The range of nitrogenremoval rate» for forested buff'ers is small. suggest-ing that retnoval and storage in these sites are, onaverage. fairly consistent. With regard to plantuptake. Ehrenfeld �987! found that brush speciesdid not show an increased nitrogen content in thepresence of septic system leachate, while hardwoodand conifer species did. This suggests that specieswith shallow root systems may of'ten be incffecliveat removing nitrogen from groundwater supplies,except in poorly drained areas where groundwaterremains near surface soils. Areas with a deep watertable will need to rely on deep-rooted species torealize any nitrate removal prior to recharge fromgroundwater supplies to nearby waterways.

There is considerable variation in the docu-mented nitrate-reducing capacity of forested buffers,depending on site and climate. Whole-watershedstudies cotlducted by Peterjohn and Correll �984!and I owrance et al. �984a.b! report high levels ofnitrate removal from surface water within fore~tedbuf fers of mid-Atlantic latitudes, while work. con-ducted by Warwick and Hill �988! noted very littlenitrate removal in northern latitudes Ctlnada!,Warw'ick and Hill �988!, however. did note thatreduced nitrate removal at their study site may havebeen at least partially due to minimal retention timeof runoff during their experiments, and that in-creased retention lime of runoff water in a forestedbuffer should increase nitrate removal efficiency.

Groffman et al, �992! and Simmons et al.�992!, in companion studies, noted that nitrate-nitrogen reduction in a vegetated buffer is domi-

t8

nated by plant uptake during the growing season,but that soil microbial denitrification i» the domi-

nant nitrate removal mechanisnt during the dormantseason. Denitrification during the dormant seasonwas a result of a higher seasonal water table thatallowed nitrate-laden waters to rcinain near surface

soils, which are richer in organic content and a!lowfor inicrobial denitrification, Ciroff'man et al.

�99!b! reported that nitrate rcrnoval decreased by64 percent between the growing and dormantseasons in their study of vegetated buffers in Rhodeisland, while Correll et al. ! 992!, during a study ofvegetated buffer» in Maryland, reported 97 percentnitrate removal rates froin groundwater in the fal! growing season!, declining to 81 percent removalin winter months dormant season!,

These findings suggest that, at least in temperatelatitudes, seasonal variability in vegetated bufferscan be expected, Actively growing vcgctation willbe effective at nutrient removal during summermonths, when coastal waters are typically most su»-ceptible to nutrient inputs. During the dormantseason of vegetation, at least in areas where ground-water can rise near the soil surface, denitrificationwill continue to remove nitrate, but possibly at a re-duced rate, Cold weather months, however, mayresult in vegetated buffers becoming ineffective as theground freezes and becomes generally impermeable.

Although not as simple as mowing the grass, se-lective harvesting of' woody-stemmed species is pos-sible, thereby permanently reinoving nutrients fromthe vegetated hut'fer system Lance,!972; Leak andMartin, 197S; Todd et al., 1 983; Lowrance et al�1984c; Ehrenfeld, ! 987!, Should a vegetated buffernot be periodically harvested, eventually the nitro-gen stored in plant tissues will reenter the systemthrough decomposition. Woody-stemmed speciesare good long-term nitrogen sinks, but removal ofthe entire plant also removes the nitrogen uptakeand storage mechanism. As trees are removed fromthe buffer area, they will need to be rep!aced for con-tinued nutrient removal at a more or less steady rate.

Ehrenfeld �987! noted that most priinaryproduction by trees is converted to leaf materials,and Peterjohn and Correl! �984! found that 81percent of the nitrogen uptake in a riparian bufferwas returned to the forest f!oor as leaf litter at theend of the growing season, Removal of leaf litterfrom vegetated buffers may therefore be consideredan effective permanent nitrogen removal mechanism

in buffer managerncnt schemes, The removal of leaf'litter, however, result.s in the los» ol organic/detrita!inaterial to soil» in the vegetated buffer, changingone of the conditions � high organic contentthai promotes the growth of denitrifying microbiafcoinrnunities. Thc positive or negative effects of leaflitter rentoval may be site-specific e,g., presence ofa high water table!.

Stiffer WidthBuffer width variability is one of the mosi

versatile tools available to the resource manger.Other variables that affect the efficience of veg-etated buffers in the removal of po!!utants are oftenunchangeable, or at least may not be altered in avery cost-effective manner. Buffer width, however,i» often easy to manipulate in order to better achievethe desired affect e,g�water quality protection!.

Table 3 lists vegetated buffer widths reported inthe literature to be adequate for genemfized purposes.

The range of buffer widths runs from twometers to nearly 200 meters, with a variety ofvegetai.ion types reported. These data are presentedgraphically in Figure 3, showing the overa range ofvalues reported to be adequate to protect waterquality in several categories of water bodies. Thevalues contained in the table and figure suggest thateven relatively narrow buffers less than � meterswide! have some reported value as a resourcemangement tool for the protection of water quality.Based upon mean values reported by category,however, forty-five meter buffers appear adequate toprotect water quality in general, at least withinfreshwater systems and areas where sediment andadsorbed pollutants are the major concern,

Table 4 presents a range of pollutant removaleffectiveness values, according to buffer width,reported in the literature, Although values for theremoval of other pollutants may have been given inthe publications cited, those presented in Table 4sediment, total suspended solids TSS!, nitrogen,nitrate, and phosphorus were reported mostfrequently, and were felt to provide the best range ofvalues for review purposes, Also provided in thetable, when given in the original manuscript, isinformation on runoff po! lutant! source. vegetationtype s!, and s!ope of the buffer,

What is immediately obvious is the variabilityin pollutant removal over bath the range of bufferwidths and within similar buffer widths summerized

Table 3 Recommended vegetated buffer»'idths for pollutant removal. giving the desired eA'ect of the itnplementedbuffer. The repor cd values are generally intended as ntinimunt hul for wicfth values lo, eh!eye the desired purpiise- ~ I Ilieter�3.28 fce i

Width m! objectit c SpecifiesAuthor! s!Ozark Mts

2-10Ahi>la. t!'� 5-20Scheulcr and BIcy. 1987 Grassed buffer

Lov slope; rural land7-12

Fores ed bu f'fer

in: Cuinerli>rd et «l., 19'

Martin et al.. 1985 10 Fi>rcs ed bufferProtect water quality frt>nt clear-eut�

10- 19 Road runt>ff sedimentTriinhle k Sartz, 1957 106- 1Florida Div, Forestry, 1990

12-2412-83 Fores cd

15Phillips, 1989bin: Comerford ct al., 1992Cor!te >f; l.ynch, 1985 20- 30Clark, 1977Moring, 1982 Fores cd buffer

Protcc sire;im waicr quality 1'rom log inFimaii ct al., 1'�7 Forested 'buffer90'/r !'I;11>i>s al of TS8USACE. 1991 Griissed buffer

in: Comcrford ct al.. 1992

in: Comerfi>rd et al.. 19> 31Phillips, 1'!8'!h 40-80Clark, 1977

Clark. 1977in: Conterford et al., 19' 91

1'hillips, I'!89b tinder all conditionsPriitect streunt water quality1>� Pme lands habitat! f�

178

20

In: Cunicrfortl ct al. I '!92Ah >hi, 990

iii: Comer ford ei ul., ! 992Palm strum, 1'!'!!Doyle ct al., 197511'I'. c. i>ltief t>rd c'I al., 1992

Clark, 1977

Swill, 1986

in: Coiner ord et ul.. 1992in: Comer ord et al,. 1992in: Comcrford et al.. 1992in: Comerford et al.. 19<

Roman >1'z C>oc>d, 198313rown et al.. 1990

15-6015 - 103

Maint;iin s rcant «h;innel siahilitySt ca it liablta pi'otcc iott

R iver/hike pri> ecti<ul1 o>v level pollut;int rcnti>vul

General pu0>use use icneral purpose use

Protect v uter quality tr<>m animal v astesProtect general s> «ter quality

Protectwatci quality ll'olil ground-basedhcrhieidc applications

G cite ra 1 putp >sc use

Pro cct general v uter qual »Protect v;ii cr quality I'ioin loggirig

Protect general v�itcr qu;i! ii!Protect small streuin watet quality

Protect general v,atcr qua!it!Moderate ero>ton protcctii>n

Protect water quality from pesticidesProtect get eral v, uter quality

Severe cri!sion protcc ionProtect water quality from loggingProtect v ater quality from lngging

Protect s;ilmon egg and juvenileeleve! >p it i eii'I

Protect mater qu,i l it y 1'riim;ii ri;i! h orbit idsapp1 i ca it>its

Pnitec large stream/river water qualityPro e .t general water qualityPrt>tee general water quality

Protect general water qua i yProtcc private residences froin aerial

herb c ide applications

Wetland pn>tee i or>Protect wetland water qua! itl

0~4 slope over slightly erodiblesoils

<10cd> slop:Primarily stre ants>de

Forested bu 'lerFores ed buffer

'Well-drained soilsForested buf crFt>rested hu I terForested buffer

Forested bufferPoorly drained soils

30'. slope over scvcrcly crodib!csoil s

in Table 4. Thi» variability in vegetated buffer pol-lutant removal eff'ectivcness is a direct result ol th»

site-specil'ic conditions previously discussed, Mostof the reported pollutant removal values come frotnstudies that have utilized hufters vegetated withgrasses to treat runoff t'rom sources rich in p<illu-taftts � n'tanure. sewage spf"ty, and fecdlotsfoi in-stance, The range ot value» tor rcntoval effectivenesspresented in Table 4 may therefore bc biased towardthe treatment of'extreme pollution sources, cotnparedto what may be considered typical f' or runoff waler.Furthermore, studies of grassed buffers have providedmost of the data sumfnarired in Table 4, with the resultthat forested buffers are potentially underrepresentedwith regard to pollutant removal ett'iciency.

The data presented in Table 4 are graphicallyshow~ in Figure 4 through Figurc 8 for sediments,total suspended solids, nitrogen, nilrate, and phos-phorus. An associated 'best fit" curve a logarith-mic function using percent removal as the depen-dent variable � is also provided to show the mod-eled rclalionship between buffer width and pollutantremoval efficiency. The relationship between bufferwidth and polutant removal agrees with thosepreviously developed by Karr and Schlosser �978!,Wong and McCuen I982!, and others, in whichremoval efficiency increases rapidly up to a certainbuffer width, after which large increases in bul't'erwidth arc needed to improve removal efficiency byeven a small amount, It i» important to note that thedata used to construct the graph» in Figures 4through 8 do not come from a single, controlledstudy, but from a wide variety of studies reported inthe literature. The studies werc conducted at a

variety tif sites and treated different pollutant

Figure 3

st!ut'ccs with differing input concentr;ttions seeTtblc 4!. The relationships between percent remov;tlanti vegetated buffer width given herc. therefore,integrate buffer eff'ectiveness over a range providedin tltc literature, 'tnd are to be interpreted as general-ircd. or;iverage, pollutant removal efTect iveness.

Aemoval of sedi mertf and saspeftded solids8etfin'tents 'tre readily removed from surface

water runotf moving through vegetated bull'ers, Thisi» evident from Table 4 and is further exemplified inFigure 4, which shows that removal efficiencies aretypically high. even for relatively narrow vegetatedbut'f'ers. From the modeled relationship. a vegetatedbuffer of even two meters in width could be ex-

pected to remove about sixty percent of the sedi-ment load entering the vegetated buffer, A twenty-five-reefer-wide vegetated buffer could be expectedto retnove about eighty percent of sediment inputs.Only slight increases in removal efficiency withincreasing buffer width are noted for buffcrs greaterthan 25 ttteter» wide. Overall. vegetated bufferwidth must increase by a factor of 3.5 in order toachieve a I 0 percent increase in the removal ofsediment i» the vegetated buffer. Although themajority of data that was used to develop the curveshown in Figure 4 comes from grasscd buffers, thcfcw reported values that come from forested buffersare high. particularlv at larger butTer widths.

The pattern noted for the removal of totalsuspended solids TSS; Figure S. following page! invegeiated buffers is similar to the relationship seenf' or thc removal of' sediment. In vegetated buffcrs sixmeters in width, the expected removal eftfciency forTSS is about sixty percent, Eighty percent removal

Rivers snd Lakes

stream

Gensrst

Figure 3. A range of vegetatedbuffer widths reported in theliterature to be adequate for theprotection of water quality invarious water body types. The rangerepresents buffer widths noted in theliterature, as reported in Table 3. TheGeneral category contains bufferwidths that were reported to protectwater quality, but were not specific toa type of water body. The heavy linecontained in the bar represents themean of the data that make up therange. I I meter = 3,28 feetl

0 t0 20 00 40 50 60 70 80 90 100Buffer Width m!

Table 4. A summary of pollutant rernova! effectiveness vaiues according to»idtb of the vegetated buffer. Removalefficiency values are giien as percent rentoval ltir each o! the van«os pi!litt inti treated in the v«getated huNer � iediment,TSS, !otal nitrogen, total phoiphorui. «nd nitrate-niirogen. ! I nteter = 3.28 I' t.ct i

P iv�3Author!i!D«vie ct .il., 1977 OSsictliltng & Alberti. 1979 0.6

70.678

S7 C'r8 82'ir«4

9S9 99 ra62r,,4,0 68ci

O'er83c 31rr 87 i 76't. 67r 4.6

17 i'c72'7 41cr 63963ci

6.1 90C I96c»7.6I Sr»7.616'Pr 18%a 7 r/

9,1 19 "ir95c 9,1 77q 80�

7!% 17 A78Cr 78'7r

53'rS ] / 459

a 8 err2ttrt 'i Sca 15 4S'ir

97rrrI S.2 99c!I S.2 46c/r

62rr19 90�Young ct al., 1980 213

75C rYoung et al., 1980chwer & Clau.ien, 1989 9SCS

Young ei al,. 1980 93ci '27.466%27.4 87r 88%

84%83rd27.4 81%31% 29 11

71%69'» 629 61 r

90rr45

87% 84%

50r !SSC/ 909 97,521597ri

85r/ 3 l-42�

97' 98%

22

'Ncthling & Alberti, 197'!Ncihling & Alberti. I'�'!Doyle et a I., I 977iilcthltng & Alberti. 1979Iyoy le et «1., 197SD iylc «1 «! .. 1977Young ct al.. 1980Dill«ha ct al,. 1988Dillaha ct al .. 1988Dillaha et al.. 1988M«gctte et al., 1987Dillaha et al., 1986h!i!eibling & Alberti, 1979h!eihling & Albens, 1979Doyle et a!�1975Schellinger & C!«usen, 1992ScheHingcr & Clauicn, 1992Dillaha et al., 1988Dillaha et al.. 1988Dillaha et al.. 1988Dillahaet a!., !9 6bMagettc et al., 1987Thompiori et al., 1978Bingham ct a!., 1978Mannering & Johniori, 1974Doyle ei al .. 1977hake & Morrison, 1977Peterjohn & Correl!, 1984

Young et al.. 1980Young et al.. 1980Edwards et al., !983Doy!e et al., 197SPatterson et al., 1977Thompson et al., 1978Wong & IVlcCuen, 1982Wood«rd, 1988Edwards et al.. 1983Baker & Young, 1984Karr & Schlosser, 1978Karr & Schlosscr. 1978Karr &. Schlosier, 1978Lowrance et al.. !984Jacobs & Gillam, 198SRhodes et al., 1985Reuteret al.. !992Schipper et al., 1989

Vol!utant Removal I%1Width m!,'i tdatwnt 8 S

Ttuhle 4..k»ufnmttry «f p«IIU tun r»ttt tvtul »ff w ixet!e»» xt!lt!c» t CL'«r�1!!g arri<-ICLH,>r«L<>II

I l!,l ilk I k ~ t.> r»u>1»rc Jppl >«Jlu>ti!!d>TV »id»un' T<ht1 d gfav<

!airy manu>e On;hlird graLLI'<iuliry manure

I mT/h,i: ir;i<el<, Lilt-loam L»II<l!dnv nldnufc

Fi>re<teil nnlOuts

Feveuc < < rye rni XMilk hltuve «J<te 'i>m

!r<hdrd grav<C-year, 0-h<>ur <tom> Limuiati<>ti

1'«ed li» run«It

iravely. Lilt-l<>um L<» IL

Natural. mixedMoved through 2 «iinxe«uli<c .'If!m !/F<iFeedli>t eff!uent

FCf ill lief<

7<! h h J undivturhed >< ater<hed

Man-mude grdvel

F<>re<led pine<<age '<pfu!'

Run»ff 41ure»1!.»11 '»1.»l»le

H,ir«<>II!lure <<Ill!.ir< L»il

ni Ji >lireH.ir«t Ill

I!;urx r»i»>ure1!JIT< nl.in»r«f!d'lf< 'ICC<lliit1!,IIT> «I,III<>f<'1!.1lf't n ltlll'»I<'!;lily i»,miirc

1!.»i< fn.ill»TL'< rill ir Cil < nip!dud

8,'IT» Lil tl

1!.»i< yllnl ful'llilf1!,t>ry yaril runi>tl

!,lir< nldriur»1!alrx «l.'uluf<'

.' I gr I< u! lul'u! I alii'll I1-Ccdli>l «in»f1

1!iilly nluflule1 ><Iuid ddir< >va<le

Fertilircd ieldrun«I'f

l»g»t u I lnn if liv I< L< uc

< I'l,lv<l if.i<<

Il.li<I'I'»I;<1/Li,! »h

I !TL hard g ra<<<!> «h.iril gr,iLLFufc<l/L«f Uh

F v«ue A rye Itu'<FCvelle <>k e!'e n'» X

!r«hurd gran< !r«h:ird gmv<

Fcv< ueHIUC Tuvv >«dFl >le vt/L>LL L<xl

. <>rg>hum/gra<<Fev«ue

F»fe>>t/>>«fuhFev< ue

Gr»LLLBermuda grass

F >fC<led»reLet!and

!th<irikl i»I/l<d

1-ttl iii,lf<«gl.itr'likl <C<lrr»C»l<I'<ir L I,« -i>r<d p<iitii le<I-i» < IJL vired p;uli< I< L

'k'I iii I'/I> JI ii'I L>t>li

itl'l«el'tll,'Ileil tl»«cki. I I ill I k!>>Ill> tt>.»>ur«>ppli«at>in>

II! lkkl k. a n>unur«,<ppli<xitiiir> trav«ly, Lilt-I<it»» L<>il<

P<><IT y I'h'»lie<, <UTI'1<i' vai»plCp<k>f 1 drl»«C<!. Lu LuffJ«<' <at»pl«

I'ul«»filiate< It<<Av ii!!, uk! kg/ill< T>1:ilE»n: 'i>pl'h<'.'Uli>ll

X-year, 0-h»ur vton11 <in>uldt»>»'l-year, 4-h»ur Ltnn» <irnulatii>n

.'iett ling bavin. th«n thriiugh f> ! m <if graLLhu I I e r

occurs at about sixty meters of' buff'er width, beyondwhich improved reniovat elf'iciency is slight withincrcascd buffer width. l'or TSS rcntoval, an ap-proxitnate incrcasc in buffer width by a factor of 3,f!provides a lA percent increase in removal eff'iciency.The greater vegetated buffer widths required forTSS removal, ct»npared to sediment removal, mayhe due to smaller-sized particles and a gteateramount of particulate matter, which in generalrcquircs greater buffer width to be adequatetyremOvCd frOnl SurfaCC water runOft'. As with sedi-

ment removal, the few included forested buffer

vatuc» are high for the removal of TSS f'rom runof'f'.

Removal nf total and nitrate-nitrogenThe removal efficiency ol' vegetated buffers for

nitrogen varies considerably, particularly within therange of narrow buffer widths. This is very evidentfrom both Table 4 and Figure 6. Removal efficiencyof nitrogen in anine-meter-wide vegetated bufferis expected, from the modeled relationship, to beaboutsixty percent. Removal efficiency increaseswith increasing buffer width to about 80 percentremoval at sixty meters of buffer width, after whichpoint the rate of removal of nitrogen per unit in-crease in buffer width slows, An approximateincrease in vegetated buffer width by a factor of 2.6is required to achieve a 10 percent increase innitrogen removal el f'iciency.

The nitrogen removal efficiency data used inTable 4 and Figure 6 are mainly from studiesperformed in grassed buffers, and therefore may notadequately portray removal efficiencies of forestedbuAer», However. the scatter in the forested bufferdata included in Figure 6 appears as wide and asvariable as that noted for grassed buffers.

Nitrate removal is variable, but generally low,according to the data given in Table 4 and shown inFigure 7, for all buffer width», The modeled nitrateremoval-to-buffer width relationship shown inFigure 7 suggests that approximately 50 percent ofthe nitrate present will be removed in buffers of onehundred meters in width. The modeled relationshipfor nitrate removal suggests that increased removalwill only occur given enormous increases in veg-etated buffer width. lt i» unclear if the low removal

efficiency of nitrate tn vegetated buffers providedby this model is due to thc data being generallyfrom grassed buffers, which are often less than idealdenitrification sites, or if the relationship between

buffer width and nitrate removal is simply inappro-priate. Considering that nitrate removal predomi-nantly occurs through biotogicat rather than physi-cal or chemical ntean», site-specif'ic variables, such;i» denitrif'ication potential. ntay need to be consid-ered in order to better estimate nitrate rentoval invegetated but'fers.

Removal of total phosphorusThe data given in Table 4 and modeled in Figure

8 suggest that the removal efficiency of' phosphorusin vegetated buffers is quite variable, and relativelylow at very narrow buffer widlhs. Buffer efficiencyincreases rapidly to twelve meters of buffer width.where approximately sixty perce~t phosphorusremoval is achieved. Buff'er efficiency improveswith added buffer width, until approximately eightypercent removal is achieved in an eighly-five-meter-wide vegetated buffer, Greater phosphorus removal,a» with other pollutants. is achieved only with largeadditions of buffer width after this point, Overall, anapproximate increase in buffer width by a factor of2.C is required to achieve a l0 percent increase inphosphorus removal,

Although phosphorus is reported to bc typicallybound to sediments. it is generally bound to smaller-sized sediment particles Karr and Schlosscr, 1977!.Since smaller-sized particle» and particulates aretypically not as eAcctively filtered out by vegetatedbuffers as coarse-grained sediments, this may resuttin the differences noted between sediment and

phosphorus removal efficiencies, as seen whencomparing the removal patterns in Figure 4 andFigure 8. The forested buffer data given in Figure 8appear tO be aS vari'able and ~Cattered a» thOse fOrgrassed buffers.

Performance standardsFrom the values given in Table 4, and the

modeled relationships seen in Figure 4 throughFigure g, an estimated removal standards matrixwas constructed Table 5!. Other than for nitrate. thematrix suggest~ that. on average, 50 percent overallpollutant removal can be expected to occur invegetated buffers five meters wide. Seventy percentremoval efficiency can generally be expected to oc-cur in vegetated buffers of about thirty-five metersin width, while eighty percent removal efficiencymight be expected in buffers of about eighty-fivemeters in width. Vegetated buffer widths between

1DD

BDe

60L

D0

Figure 5.

a

60

K re<e 40

Figure 4. Relationship of percentremoval to buffer width for thetreatment of sediments contained inSurfaCe water runoff. An approxin1a eincrease in vcgctatcd buffet v idth hy 0factor of 3.5 is required o achieve a 10percent improvernen in removal ofsediment. The rnos efficient vegetatedbuffers, based upon width-to-remova!ratios, will be about 25 meters in wid h,after which large additions of buff'erwidth are required to achieve only smallincreases in sediment removal efficiency.The modeled iinc is: rf removal = [�.6! 3" In width in meters!! + 55.H]. Data arctaken from Table 4. [ I meter = 3,2!t feet[

Figure 5. Relationship of percentremoval to buffer width for the treat-ment of TSS contained in surface waterrunoff. An approx ima e increase invegetated hutTer wid h by a factor of 3.0 isrequired to achieve a 10 percent improve-ment in removal of TSS. The most etficicntvegetated buffers, based upon width-to-removal ratios, will be about 6 ! meters inwidth, after which large additions of bufferwidth are required to achieve only smallincreases in TSS removal efficiency. Themodeled line is: % removal = [ 8,34 "!n width in me ers!! + 45.1 [. Data aretaken frotn Table 4. [I meter = 3.'2!t fcct[

50 10D 150 200 25D 300Buffer Width lrn!

50 100 150 200 250 3DOBuffer Width re!

250 and 550 meters will be needed to achieve 90�99 percent overall pollutant rentovaf effectiveness,

The matrix given in Table 5 may be useful inestimating Ihe potential overall removal of a veg-etated buffer for a given buffer width, or for estimat-ing the removal of a given buffer width for a spe-cific pollutant ol'concern, These values should beheld in light ol the site-specific conditions in andaround the actual buffer area, and buffer v'idthadjusted according to best professional judgment forbest estimating a buffer width to achieve the desiredremoval efficiency.

5 Wildlife Habitat ProtectionFor the purposes of this review, the tenn "wild-

life" refers to both animal and plant species. The useof the term wildlife, with regard to its animalcomponent, is generally meant to encompass allexcept large mammals. This is particularly true atnarrow buffer widths, but large mammals maybecome part of the vegetated buffer complex as thewidth of the buffer increases, providing moresuitable conditions and space for large mammals.

The vegetated buffer concept has reached itsgreatest application for wildlife habitat protection inthe development of "greenway," "stream corridor,"and "habitat corridor" management programs. Thesepractices generally set aside vegetated strips alongrivers and streams to promote good water quality,maintain wildlife habitat, and provide wildlife travelcorridors. Current paradigms suggest that increasedenvironmental diversity and complexity promoteincreased biodiversity see Wilson, 1988!, There-fore, the establishmem of vegetated buffers can beviewed as one step in maintaining local ecosystemsand promoting regional biodiversity. The followinghighlights some of the potential benefits to wildlifeof vegetated buffers, as noted by Groffman et al.�991 b!;

~ Increased species diversity: mixed habitattypes promote greater diversity

~ Increased foraging sites: mixed vegetationprovides greater food availability

~ Wildlife dispersal corridor: wider buffersprovide a better travel corridor

~ Escape from flooding. Hibernation sites

~ Breeding and nesting sites: wider buffersreduce nest parasi tism

~ Decreased disturbance f'rom neighboringareas

~ Decreased predation: wider buf fers furtherreduce predation

It is dilTicult to be specific about the value towildlit'e of vegetated buff'er» as habitat, since thevegetative makeup of the buffer area will ofte~determine what species will use it, as well as hovthey use it. The habitat value of vegetated buf'fcrsfor different animal and plant species will also bedetermined by width of the buff'er, proximity toother required habitat types, proximity and densityof' predators and competitors, and proximity of eachorganism to others of its species. Furthermore, noisedisturbance from developed or developing areasaffects habitat quality and use. The greater thcdisturbance, the greater the buffer required to reducethe impact upon the use of adjacent environmentsby wildlife. In some instances, buffers may need tobe established around habitat areas in order for themto he successfully utilized by wildlife. This will bemost critical in areas that are highly developed andcreate a lot of disturbance noise, t'or instance.The value of narrow buffers as habitat will thereforebe directly related to the amount of disturbance theyreceive froin adjacent areas.

Table 6 provides a summary of buffer widthsreported in the literature considered to providehabitat for various broad wildlife categories: thissummary is presented graphically in Figure 9.Several authors for example, Tassone, 1981: Cross,1985; Triquet et al., 1990; Groffman et al., 1991b!note that vegetated buffers that are contiguous toareas of natural vegetation are likely to support, orbe used by, a greater number of species. Even smallvegetated buffers can be enhanced in value by beingclose to undisturbed areas that more fully satisfyspecies-specific resource requirements.

From thc reported values in Table 6, whichrange from 15 to 200 meters, it is difficult to deter-mine a "best size" buffer width for general wildlifehabitat. It has been noted that 15-meter bufferwidths provide habitat under certain conditions, andit may be that widths inuch less than that will notprovide adequate space � bird nesting site» forin s tance � for res i den tspec ies. 8 uffers l ess than 15meters wide, however, may provide adequate habitatfor the temporary activities. such as resting orfeeding, of bo h resident and transitory species.

26

Figure 6.

Figure 7

00

0TI

37

Figure 6. Relationship of percent removalto buffer width for the treatmenl of nitro-gen contained in surface water runoff.An approximate increase in vegetated bufferwidth hy a factor of 2.6 is required to achievea ! 0 percent improvement in removal ofnitrogen. The most efficient vegetated bufl'ers,based upon width-to-removal ratios, wi! I beabout 60 meters in width, after which largeadditions of buffer width are required toachieve on!y sma!! increases in nitrogenremoval efficiency, The modeled line is; %removal = [�0.5 " In width in meters!! +37,4[, Data are taken from Table 4,

! Figure 7. Relationship of percentremoval to buffer width for the treat-rnent of nitrate contained in surfacewater runoff. Unlike the other modeledpoilu ant retnoval-to-buffer width relation-ships, that for nitrate is suggested to beinappropriate. Nitrate is typica!ly removedby biological processes rather thanthrough physical and chemical means, andthe variables that control denitrificationmay better determine the removal ofnitrate in vegetated buffers than doesbuffer width. Data are taken from Table 4[ I meter = 3.28 feet!

0 t0 20 30 40 50 $0 70 00 90Buffer Width m!

0 5 10 15 20 25 30 35 4! 55 50Buffer Width m!

Figure tt. Relationship of percent removalto buffer width for the treatment ofphosphorus contained in surface waterrunoff, An approxi nrue increase in vcge atedhutfer wid h hy a factor ot '.5 is required toachieve a I ! percent irnprovcnten i» re novalof ph<tsphorus, The ntost et'ticient vegetatedhuff'ers, hased upon wi<hh-t<!-removal ratios.will bc bc ahou 75 mc ers in width. afterwhich large addi tons of bufter wid h arerequired o achieve only small increases inphosph<trus rcrnova! ctl ciencv, The modeledlinc is l< removal = [ l0.3" In «idth inn<eters!! + .t4.1I. Data arc taken front Table 4.l I <neter = .' .28 feet]

000E<c 00

2«. Cj<<

oe 20

00 10 20 30 40 50 60 70 $0 90

Bvtfar Wt< th tm!

Butfer Width Im % Removal TSS l<<'i trogen Phosph«rusNitrateSediment

Table 5. l:sti nated removal standards matri« for speeiftc pollutants as taken from the modeled relationships shown inFigure 4 through Figure 8 t'or vegetated buffers. In general. greater than 50 percent removal standards can hc met withvegetated huff'crs about 5 meters wide, The 80 percent removal ca egory general!> narks the optimal width-to-removal ratioboundary, above which the <ncrease in removal elficiency for a given increase in buffer v td h is small. l I meter = 3.2 t'ect l

Many studies have determined buffer widths forwildlif'e habitat by determining species-specificneed» such as those for rare, threatened. orendangered species and then applying them tobuffer width requirements. Few»tudies, however,have determined overall needs for multiple-speciesuse of buffers, and fewer still have studied usepatterns of wildlife for existing or newly establishedvegetated buffers that are part of a multiple-useresource management program. It is thereforedifficult to determine how buffers of various widths

and vegetattve makeup, once implemented, will beused by wildlife.

However, if current paradigms are correct, thenwith regard to value of vegetated buff'ers to w ildlile.bigger is better, and some i» better than none. Largebuffcrs may be required in areas where speciespreservation is a major focus of vegetated bufferdevelopment, while smaller buffers may bc ad-equate in other areas, particularly where morecontiguous stretches of habitat are nearby, Largerbuffers will provide a greater diversity of resourcesover the long term for wildlife in general, whilesmall patches will provide "island" habitats in thelarger mosaic, The greater the diversity of availableresources, the greater the potential for the long-tennsurvival of the targctcd or intcndcd wildlife species.as well as for incidental users,

Some caution, however, is noted in a summaryby Groffman et al. �991b! of vegetated buffers aswildlife habitat. The author» note that sharp con-trasts between habitat types, such as engineeredbuffers, may promote the growth of weed spccics.The weed species could invade nearby naturalareas,replacing resident vegetation with opportunistic andtransient species, This was reported by Dillaha et al.�986a! to be a common problem in vegetatedbuffers assessed in the state ol Virginia, Weedspecies have been known to invade nearby habitat»,thereby reducing the habitat value of the buffer, Thisis a most important consideration if the vegetatedbuffer is established for the protection of rare.threatened, or endangered species, and may also bca consideration in the development of small buff'ersthat represent island patches.

This suggests that care should be taken indesigning and designating vegetated buffers next tosensitive areas, or where rare or endangered specie»live. In these cases, the vegetated buffers could hedeveloped to graduate into the sensitive habitat.

rather than providing a sharp contra»t betweenhabitat types. In some case» where no buff'er exist»,a sharp contrast may be unavoidable, and transientwildlife may be the major users of thc vegetatedhuff'er area. Wider buffer» will provide less contrast.»incc they wiII produce a larger gradient betwcetthabitat». and will become habitat thcmselve», Some

routine as»cssment and maintenance practices maybe required to maintain habitat value and keep in-vading species from overtaking implemented buffer».

~ F.rosion and Flood Control

Vegetated buffers employed as erosion controlsare generally applied as best management practice»to mitigate the off-»ite impact» of development andconstruction activities. However. by their verynature, vegetated buffer» can assist in reducingerosion even when not specifically designed for thatpurpose. Since vegetated buffers slov the velocityof runoff How, as well as dissipate flow and reducechannelized flow, they will reduce the probability oferosional problems downstream of buffer areas.

It wa» previously noted, however, that vegetatedbuffers can become clogged with sediment remov edfrom surface water runoff, Vegetated buffer» that areemployed specifically for erosion control � forinstance. to control sediment movement fromconstruction sites � may need to be rehabilitatedafter construction work if they are intended ocontinue functioning as a multiple-use buffer.

Vegetated buffer» also have value for floodcontrol, and have been employed for this purpose.They control flooding by reducing flow velocity,allowing absorption and storage of water in soils,and by moving water from surface to subsurfacewatercourses. Vegetated buffers also mitigateproperty destruction by maintaining some undevel-oped land along waterways and keeping developedor developing areas back from floodwaters, »tormsurges, and extreme high tides.

The capacity of the buf'fer area to provide floodcontrol will depend on rainfall and runoff intensity.soil characteristics, hydrologic regime, and slope ofboth the buffer and the source of runof'f water. Even

under ideal conditions, the ability of a vegetatedbuff'cr to control floodtng vvilf be related to thewater source area, A buffer that is»mall relative to

the water»ourcc area will have only limited abilityto control Hooding. When bul'fer» are applied vi ith aprimary intent of flood contn>I. v. ater-holding

'I'able ti. Recommended buffer width» for wildlilfe habitat. Thc rcpi tcd « d hv arc ge»cr;illy i» c»dcd;i» 1»ininiui» v.iliic» ii pniv dc hc tci rcd habit,ii re i»rrci»C» hi »lect hi' give rl iihlCC l vc. [ l lite er = .t. H ICCI i

lipectttcaAuth ir »l l%'id h m! t!bjcct tv cRip.irian» i ureaL cncra av ian habit »ri uel cl a ., I

Hh» cr cl a . IVH 'riiieel «C an habitat rom hi»-in Cnailv di lurhanicv

ycn»cly gniv,iiig mini specie~ hu er

Wildli c traicl corridorTan~inc, I VH '!Hh»lcr el;il, I uH7 tyei»CIV gtii'» ti'tg I liked iipee le' hill Ci'Priileel we land h.ibilal Iroin high-

in C11»1 V divlirrhailCC»thiv ard and Allen. I UH'I Iencral » ildhtc hahiuil

1 aav inc. IuH I rCCding allC» Ior rag i 'nl ~ lcnii iv t. 11 l'I <

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W i Klcd 11pal'lan;�."1iiialuf tl vcgt,'1'iliiin

1»all mam na ahiialPn'ilcel at Ill ie'141»1 dli C habitat

47riivv. 19trr i inan cl al., I vu I h ul »

Wellaii habit;ii protectionfhvcric aoiigbird cii»1111»iiil'1

�Htni»net U .!Schculcr, I

Riparian Ion v V,, . ACE, 99 or ill bul large mainnia v

Vigttre 9.

Figure 9. Ran tee of buffer width»noted in lhe literature to provideeffective habitat for»everal broadcategoric» of wildlife. 'Vhc range» if categoric» repre»en ed by a circlear »e from one study, and thereforemay n n he very repre»enta ivc ifthat particular categ iry, 'I'worep irted value» make up the range»hown by each of the h irizon alhar». Data are taken from Table 6.[ l meter = 3.28 feet I

Bree gng SlidAH K ceti

Lertte Mammals tensret W htl te

so 80iten Is e Butter Widths ml

capacity of the buffer uea w ill need to be deter-rnined, and proper width applied to the buffcr inorder to store the water received during a givenstorni eveiit,

~ Historical and Cultural Preservation

While vegetated buffers are best known for theiruse in preserving and protecting water quality andwildlife habitat, application of coastal buffer zonesmay also have value in preserving and protectinghistorical and cultural sites. In Rhode Island, forinstance, many of the important archaeological sitespertaining to Native American» such as summerencampments and trading sites � are within 200f'eet of the coast. The satne tnay be true for othercoastal states. If' so, establishing coastal vegetatedbuff'ers can preserve potentially important sites forfuture archaeological study.

~ Scenic and Aesthetic Enhancement

Aesthetic and scenic qualities of vegetatedbuffers often provide an "extra" value or benefit tothe major purpose for which the vegetated buf'ferwas designed. As noted in Mann �975!, Simeoni�979!, and Forman and Godron �986!, landscapeswith high visual diversity are generally more ap-pealing than nondiversified landscapes. Designedplanting of trees and shrubs within the buffer areacan enhance visual diversity and thus aestheticappeal. As the vegetated buff'er attracts wildlife,such as songbird», visual and biological diversityarc both enhanced. In areas previously cleared ofvegetation, reestablishing native species can assistin rebuilding the ~ense of "wilderness" often associ-ated with coastal expanses, It is this sense of isola-tion and wilderness that makes coastal regionsattractive to those who visit.

The aesthetic value of vegetated buffers is, how-ever, mostly based on subjective factors, and there-fore not fully transferable in implementation prac-tices. Although no criteria for aesthetic values ofvegetated buffer» exist, aesthetics will continue to beincluded as an intrinsic value of vegetated buffers thatare implemented for natural resource management.

5 General Guidelines for Multiple-useVegetated Buffers

Although the conditions determining the actualeffectiveness of a multiple-use vegetated buffer willbe of a local and/or site-specific nature, some

general guidelines can be developed for the use ofvegetated buffers, Table 7 provides a generalizedoverview of the pollutant removal effectiveness-take~ from the modeled relationships and as pre-sented in Table 5 � and wildlife habitat value,taken from Table 6 � for a range of buffer widthsfor multiple-use vegetated buffers. The eft'ectivcncssof vegetated buffers for pollutant removal. as wellas for wildlife use, is presented as increasing step»ol bultei width.

Using the generalized set of buffer widthspresented in Table 7 for developing and implement-ing a vegetated buffer policy requires that localconditions and intended uses be taken into consider-

ation. The buffer widths listed in Table 7 are meant

to be useful in a general sense for planning pur-poses. For example, the table values may be overlylarge if removal of sediment is the intended effect,and if the area of buff'er implementation is veryconducive to sediment removal. Sitnilarly. the tablevalue~ may be too small if the removal of inetals isthe intended effect and the proposed buffer areaoverlies impermeable soils on steep siopes,

From the values presented in Table 7, a mul-tiple-use vegetated buffer of five meters could beconsidered a reasonable minimum-buffer-width

standard. A five-meter-wide vegetated buffer willprovide approximately 50 percent sediment andnutrient removal except for nitrate!. While avegetated buffer of this width may not provide goodoverall wildlil'e habitat, it may be sufficient toprovide resting and feeding areas for both residentand migratory species. A five-meter-wide multiple-use vegetated buffer can be practically imple-rnented, except in areas of very dense development,and these exceptions could be reviewed as a vari-ance to general buffer policy. A five-meter-widevegetated buffer could be established as a ininimumgoal for the restoration of already developed areas.Establishing a minimum buffer width will alsomaintain or improve the scenic and aesthetic qualityof the area, and will act as nondestructive, naturalfencing between public waters and private uplands,

It should be kept in mind. however, that a five-meter-wide vegetated buffer removing approxi-mately 50 percent of pollutants and sedimentcontained in surface waters may not meet minimumperformance standards in all instances. If an ap-proximate performance criterion of 80 percentremoval is desirable. then a 75-meter-wide veg-

etatcd bufTcr may bc the acceptable minirnui». Thisbul'fer width will also provide minimum generalhabitat value. If protection of' habitat f' or significantspecies isto lie tile man! purp lsc of the vegetate<ihuf'f'er. then 2 X! meters may be the mininium accept-able buffer width. This width will also provideapproxiiitatcly 90 percent removal of sediment;mdpollutants. A» minimum buf'fcr width increases. how-ever, conflict may arise in areas where small-sizedland parcels or extensive development already exist»,

For general-purpose bu fer» that will providesome value as wildlife habitat, a minimum width of'

15 inctcrs is suggested. A vegetated buffer of thi»width should bc implemcntable in most areas thatare only modcratcly developed, Vegetated bufTers ofI S meters should provide some water qualityprotection for inost waterways e.g., approximately60 percent pollutant removal!; will of'fer minimalwildlife habitat value and greater visual and aes-thetic appeal; and can provide a natural physicalbarrier bctwccn public and private propcrtics.

For areas that are undeveloped, or arc character-ized by large lot sizes, buffcrs of 50 meter» or morecould be applied to ensure that sonic areas areproviding general wildlife habitat. Buffers of thiswidth could hc applied to all publicly owned lands,such a» state parks, recreation area~, and conserva-tion areas, For areas that are considered critical, or

provide habitat for rare, threatened, or endangeredspecies, the bufTer width could be extended to 100meters or inorc to ensure sufficient habitat diversityand isolation from disturbance, and to promote thelong-term survival of these species and their eco-system. The minimum acceptable width will bedetermined by the function or functions of the vege-tated buffer. Resource managers may need to definepresent and future uses for thc regions under theirpurviev . and then develop minimum multiple-usevegetated buffer width» for the goals and use» desired,

8 implementation Approaches to Multiple-use Vegetated BuNer

One approach to multiple-usc buffer implemen-tation is applying a fixed vegetated buffer widthalong all waterways. For instance, a vegetatedbuffer of 2S meters in width could be requiredbordering all waterways. This approach. accordingto Table 7, would provide approximately 70 percentoverall removal of ~ediment and pollutant~. andprovide minimal general wile}life habitat. Along

m in> areas. however, a 25-meter vegetated bufferm;iy niake some dcvefopabfe lots unusable due tosite constr;tints, and may not give sensitive re-sources adequate protection. Shifting the fixedwidth to higher or lower values alleviates problemson one end while creating them at the other. Thi»approach has many limitations, but has been used byresource manager» in vegetated bufTer programs.

A variatiiin of the fixed-width vegetated bufferapproach is tha recommended by the U,S. Forest.Service in a recently published booklet describingriparian buffers see Welsch, 1991!. In this case, avcgctated buff'er has a ininiinunt v idth of 28 meters,and consists of three zone», The zone closest lo thc

water is of a fixed width five meters! and allowsfor no alteration of the buffer, The second, or

middle. zone has a minimum width �7 meters! butcan he expanded based upon local or site � specificconditions or to achieve a given effect e.g.. rarespecies protection!. I imitcd use. such as sclcctiveharvest of tiinber. may be allowed in this zone of thebufTer area, The third, or inost inland zone. abuts adeveloped or disturbed area and possesses a mini-mum w idth � meters! that can also be expandedbased on local conditions. This inland zone mightconsist of lawn in a residential setting or hay field inan agricultural setting. This approach alleviates someproblems by allov ing greater buffer widths to be ap-plied as needed. but still may be restricted in itsapplicability in areas where small lot sizes are common.

A further modification of the fixed-width

approach to vegetated buffer implementation issetting a realistic minimum vegetated buffer widthbased upon lot size or land use. A minimum widthcould be established for small lot» or high-densityresidential areas so thc buf'fer will provide somebenefit for pollutarn rcinoval and/or habitat whilenot inordinately restricting use of property. Theminimuin vegetated buffer v.idth could then beexpanded as lot size and/or land use changes toprovide greater benefits of pollution removal andhabitat provision, while not overly restricting use ofprivate or public lands, One example of this ap-proach is that developed by the ~tate of Rhode Is-land, which is provided in full detail in Appendix A.

An alternative to a fixed-width vegetated bufferis a vegetated buffer tailored to each site, using amodel to generate a buffer width based upon avariety of data, but dependent upon site-specificconditions, This approach is often data-intensive.

f't!hfe 7. A summary <!f pnllula nl remu> at effecti> enesx t<nd «ltd fife t>uhf rut > it tue <if > el etuled hu A'erx ueav!rdlnl> tridth. '1'hc tet!v> i < it!C<etttet>r,trC;1< ,'ll <C t tri 1 I;tl IC S . rl l t'iihl t ..>It l rellect C�:Inge itl fX!tttt<,tt!t rel>> s.tt Ct'ICC ll eltc";inst Il<lllfC h >h>tar >.1 trc ii r tiring, u 1 1th I' thC ! Cgei.rt ' 1 hiiftCI. l lti '<Ci = .t.'X tCC11

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Apprr>i>II>l,ite ! ! »'i veil>'>lie>U .I>lit pi>i <it.ill reniir>;I

hut does result in;i given htrff'cr width that v< if 1hct cr;Ippr<>xirnate a sf>ecitic pert<!rr»ance staftdar<l,Thc modcle<f approach, h iwevcr, will ottly hc asgixxl >tx tfte st < specific fat;t troin which thc»rode lis run. fligh <fuafity d.tta f<>r use in a nt xkl willOl eit be eX f!eris<'VC te.g... time p it toto C !llectittg it hwhich may lirrlit its <iveriill pr;ictic; lily for getter;iluxe in res<iurce m<in;igeine»t programs. I-'urther-m»n., rn<ixt modeled appr<>aChex <denly Consider O»evegetate<1 huff'er benefit � poilu ant removal, 1'<>rinxtanCe � arid neglec other potential henct'! tx.Mitt!y ol' lhc existing huffer delirrcati<ir'I ttt<xfcfs wt.'rcdevelop<rd to mitigate conxtruclion irrtpacts,;tndtheret'ore rnai nol be readily applic;thfe in eslahlixh-ing mulliple-uxe vegetated buf'ferx in;tlrcady devel-oped or un<leveloped itfe'tx, 4 f urth .'i Itin>tat<on Iothc site-xpeCific modeled apprOach ix that regulatoryx aff vs tl1 bc re<fuired <> delineate vegetated bufferxon a case-hy-case has!s, which could heciimc imeC<!nxumtng. frurthermore. pcrrnit applicants will n >the ahl» to incorporate vegetatestlo all development requiring a permtt,;inth the permit applicant and lheperrni ling <tg>ency.

[!capite i s lin» ;1 i<>r!s, tlie tn<Xfefing,tpproaeh isot tc» considCred he nt<!xt aecuralc and dependahl»rrieth<id <>1 dclinctitirtg vcgc a ed huf'f'cr widths, tindis cOntmo»ly used hy rcgul;t ory agencies A strictlyin<xfefc<f;tf>pr<iach, hecause it is hascd s<>lclv uport"real" dat;t, Ic;ives less r xim for argu»ten ol' rc-<fuired f>uf'fcr w'i<llhx tother h;in whether i!r nol hcinput <la a or the;tctu;il lnodef ts appr<!prr;ttc!;<md tx hcrel<!re gener;<lly vicvved ax more "just! fi thfe."Since;t strictly n»xfclcd approach iv very "hlack-and-w, hite," it is geircrally intlexihle. and may limitI'ull it!!pter!ten a i !r! ol multiple-usc vegetiltedhuffrers hi' resource nl;tnagei s. Uvlng a rn<!<fele fappr<!ach t<! det«rntine huffcr widthx o achieve agivcf1 polfutarlt re<11<!val xtaft<fafd. and then Ievrew-ing the m<xlcled 1>uf'f'er width using best pro 'ehsi<>naljudgment to achieve other bencf s e.g., provisionol' wildlife hahi atl may provide more ffevihility anda het er multiple-use vegetated huffer program.

F-;. ch appr<iach lth go<xi;in dclcrnline wh.tt ra<le-olfs are th» m<ist rcason-ahle ar!d thc nu!s acccp ahle. <!Xtx;tnd hcnet'i xwill have lo he weighed and exantined in ligh of the

uncertainty, restrictions, and flexibility inherent ineach of the diffcrcn ;tpproaches.

The "Ideal" Buffer

Although it i» not possible o develop a "onebest' vegeta ed buffer flnr all purposes, i i» possibleto describe the components of an "ideal- vegetatedbuffer for multiple usc. If the vege ated buffer isintended to reduce pollutant inpu s to waters fromnonpoint sources. provide wildlife habitat, andestablish a visual and physical barrier, it is possibleto develop a general description of an ideal veg-etated buffer. This description may prove useful increating vegetated buff'ers that will pcrfortn withinexpectations and provide the rcsul s for which theywere established.

Contour

The ideal multiple-use vegetated buflcr f' or theremoval of pollutants, regardless of width, would berelatively flat in contour in order o promote ~hallowsheet Aow through the buff'er. This would increaseresidence time. allow greater absorption of waterinto the soil layer, and reduce the probability ofchannelized flow. The vegetated buffer would nothave any gulticd or channelized areas within it.Similarly, the landscape surrounding and leadinginto the buffer would not promote channelized flowinto the buff'er area, and would have adequatevegetation or engineered design to reduce sedimen-tation at the leading edge of the buffer zone, Fngi-neered designs might include the installation oflevelspreaders, or mechanical grading of the soils toproduce a less steep slope. and/or alteration of the-preferred" direction of surface flow to promoteshallow sheet flow into the buffer.

VegeradonIdeally, the vegetation within the multiple-use

vegetated buffer would consist of a mix of species.The leading edge of the buffer might consist of athickly growing grass maintained at a height ofabout four inches. Beyond thc grassy area wouldgrow a mix of trees, brush, and possibly nativegrasses. The species of trees would have well-developed root systems capable of exploitingnitrogen stores traveling in groundwater, particu-larly in areas that are serviced by septic systems.Brush or woody-stemmed understory species wouldalso provide a well-developed root system and

canopy. Wherever possible, wetlands � bothcoastal and inland � would be incorporated into thebuffer ttrea. These areas mos of en provide heconditions that are conducive to denitrification, aswell as often providing valuable habi at. Further-more. upland buffcrs vsould be designated aroundwetland areas to provide habitat lor the ntanyanimal» that use wetlands as feeding and f'oragingareas hut rely upon the upland~ for breeding sitesand refuge from predators,

Vegetation specie» growing in the buffer wouldbe native, or species that are known to grow insimilar habita and climate. Ornamental species maybe appropriate, provided they will not exclude oroutcotnpe e native species. Many state agencies ornongovernmental organ i zat ion s � land trusts,universities, and botanical socie ies � have put ogether p;trnphlets that list and describe plantspecies native to a region. These publications wouldbe consulted when planning a vegetated buA'er tobest ensure an indigenous cover within the bufferarea, This is importan for en~uring the longevity ofthe vegetation in the buf'fer. for providing adequatecover and forage for resident species, and forpreventing problems associated with invasion~ ofnonnative species.

To provide greatest value to wildlife, the idealbuffer would contain a mix of vegetation that fruitson a progressional schedule in order to provide avariety of feed types over the greatest length oftime. Vegetation in the buf'fer would be as randomlydistributed as possible woody vege alton inter-spersed wi h areas of grass to provide increaseddiversity within the buffer habitat landscape. Veg-etation of vartous heights and canopy thicknesswould provide thc greatest diver~ity to avian wild-life, and would promote use by the greatest diversityof bird~, as wella» other fauna. Some bird species� herons and osprey, for example � require largetree~ as nesting sites, and providing some large treesin the vegetated buffer would promote the nestingactivitie» of these and other species,

For aesthetic appeal. a mix of' vegetation wouldprovide visual diversity, Although some tall tree~within the buffer area v ould be kept to providecanopy habitat. short trees and brush would bedispersed throughout the buffer to allow waterviews from areas Iandvvard of the lead 'ng edge ofthe buffer, Ba~ed upon vegetation type and pollutantuptake rates, the buffer area would be determined to

remove a given portion of those pollutants ofconcern, and then aesthetically tlt into the landscapebased upon development patterns and paths ofsurface water flow,

The ideal multiple-use vegetated buffer wouldbe designated in existing natural area». Designatingvegetated buffers composed of existing vegetationassures the habitat value of the buffer to the supportof native species. Designation of preexisting veg-etated areas as buffers is also more economical since

the costs of design and engineering are avoided.

Although the ideal vegetated buffer may not berealized under most circumstances, the concept ofthe ideal buffer is useful as a reference or goalduring design and implementation phases. lt canhelp ensure that the buffers that are eventuallyimplemented will contain the most desirable traitspossible, given natural limitations and site restric-tions, and thereby be the most practical. The closerto the ideal a given buffers becotnes, the moreclosely it will serve its intended purpose and pro-vide the anticipated results.

III. Use of Vegetated Buffers inthe Coastal Zone

~ Application and ApproitchVegetated buff'er» hold the promise ot being an

effective multiple-use management tool for sustain-ing the diverse uses o the coastal zone, The rangeof multiple-use vegetated bu Tcr widths, five to 2 �meters or more; see Table 7!, provides resourcemanagers with a set of tools that can be appliedaccording to developmental conditions along thecoa~t. It also allows flexibility with regard to pur-pose and use of the multiple-usc vegetated bufferarea. Adopting some form of' vcgctated bufferprogram that applies minimum buffer widths ac-cording to existing or potential development anddensity, as well as applying wider buffer zonesaround areas of critical concern, can result in thedevelopment of a contiguous, or nearly contiguous,hand of vegetated land bordering the coast. Such aprogram will assist in reducing the nonpoint sourcecontribution of pollutants flowing into coastalwaters, provide a diversity of wildlife habitats,provide for the protection and enhancement ofscenic and aesthetic appeal of the coastal zone,promote flood and erosion control, and provide avisual and physical transition zone between publicand private coastal propertie~. Development of sucha program is realistic. equitable, and feasible.

A coastal zone buffer policy can be readilyestablished using a variety of available resource».U,S, Geological Survey topographic map», townzoning maps, aerial photographic survey results, orGeographical Information System» GIS! databasescan readily be used to interpret conditions along thecoast, and then to establish vegetated buffer widthsfor a given region. Habitat for rare, threatened, orendangered species; areas particularly prone toerosion and/or flooding; areas bordering poorlyflushed estuaries or significant shellfish beds; andareas of particular historic or scenic significancemay be identified as critical resource areas bycoastal managers, and larger buffer widths imple-mented to provide for a greater degree of protectionand/or preservation.

Although the removal rates presented in Table 2cannot be used directly to provide a required widthfor implementing a vegetated buffer, they can beused to estirnatc annual removal rates for a given

area of vegetated buft'er. If estimates of pollutantinput to the vegetated butler can he arrived at ��through nonpotnt soui'ce loading tnodefs. fol' lli-~tance an estimate of removal ef'ficiency c.in heobtained f' or a given buffer area. Given the rapidityof thc growth aiui sophisticiltion ol'norlpoint soulceloading model» and computerized geographicinf'ormation systems, it is not unrealistic to imaginecalculating pollutant loading» to the coastaf zone,lociiting sensitive habitat areas or especially scenicor otherwise "special" area~, deterininin ~ thevegetated buffer area required to provide expectedbenefits, and then de~igning the location. extent, andconfiguration ol' the vegetated buffer,

Some coastal areas. sui'.h as historical seaportsand coastal village~. gain much of' their charm andambiance by their location directly on the water. Irisuch instance~. a vegetated buAer may be inappro-priate. and other ways to mitigate nonpoint sourcepollution impacts and create wildlife habitat, itpossible, may need to be considered, Resourcemanagers will have to evaluate the various uses oftheir coastal zone. decide on a vegetated bufferapproach, and then define where and hoss to imple-ment the vegetated buffer program.

8 Public Perceptionlt is important to acknowledge tha humans arc a

species that utilize» the coastal zone for a varicl! ofpurposes, This must be not only considered, butincorporated into vegetated huffer policy. Designand implementation of a coastal vegetated bufferzone program that disregards human use of thecoastal zone is bound to meet both resentment «nd

resistance, which could potentially be great enoughto force the abandonment of the usc of this impor-tant management tool for preserving and pro ectingcoastal resources.

Establishing a program that utilizes vegetatedbuffers for multiple use pollution control, wild-life habitat, scenic improvement would help inmaking the program more appealing to a wider aud-ience. Furthermore. a multiple-use approach to acoastal vegetated buffer program would make hcresults of its implementation more "real" in the eyesof many. Increased scenic improvement, or greaterwildlife sightmgs. are both very tangible, very visi-ble, and very real public "benefits" of a multiple-usebuffer program. Certainly they are more tangiblethan increased pollutant removal. which is o tcn in-

visible to, and mi»under»to<xi by, thc general public,The ideal hul fcr prograin. however, woultl bc

<itic that 1.'i ilcccptablc to the lilrldowfici wllo t!i bc<rigre<fuc»ted t<i "doriatc" tlie I'ringe ot' coa»tal acreagef<ir thc benefit <it the public. Certainly the privateI;indowner will garner»oine hcnel'it I'r«in the pro-grani � incrca»cd wtldlif'<.' »ightings «n<l thc prc»-ence of a natural liarrier between hi» personal l;ind»and th<isc ol' thc public, for in»tancc � hut resent-ment due to land u»c liniitation» i» ol'tcn f'clt hyprivate landowners. Given»<ime leeway for nianipu-lation ind u»c ot the buff'er area, mo»t land<iwner»will feel Ie»» threatened by the program'» inl'ringingup<in their rights ol <iwnership and u»c.

~ Management ant} MaintenanceRegulatory agcncie»»hould develop a vcgeuited

buffer use, maintenance, and management fxiokletthat outlines to abutting lan<lowner» what is pcrmi»-sible within the buffer, infomtati<in source» for theproper maintenance and management of the bufferarea, and a calendar and schedule of recommendedor re<fuired maintenance procedure». An as»e»»mentof implemented buffer» by Castelfc et al. �992!reported that 95 percent of the a»ses»ed bufters»bowed sign» of alteration after their implementa-tion, In all ca»es where the buf'I'er wa» part <>I aresidential lot, the buffer wa» eventually replacedwith lawn hy the homeowner. Thc author» suggestthat a lack <il clear use and management objective»for the buffer. as well a» a lack ol' buffer monitoring,resulted in the high alteration rate. A strong publiceducation program implemented with the adoptionof the buffer policy into the regulatory frameworkwill go a long way toward helping landowner.under»tand why the buffer» were e»tahlished andhow landowners can use and maintain these area».This t» supported by the findings of Castelle et al.�992h who note that buffer» on the property oflandowner» who understo<xl the purpose of thebuffer» were less affected by homeowner manipula-tion and impact than those buffer» on property of'landowners who had little or no understanding ofbu ffer purpose.

The management of coa»tal zone multiple-uscvegetated buffer» will need to balance landowners'rights to use of their property with maintenance ofthe purpose for which the buffer wa» originallyimplemented. Winding trails and footpaths would beallowed within the vegetated but'fer to provide

acce»» to tltc water'» edge, and the trail» v<«ul<f bcchecked <I<id mi<lflliililc<'I oii il rug<if<<I hil»i» f<irer<1»i<in of pf<!ill<i ion «I chanttcfized flow <br<nighthe buff<.'r area. A» <iccasi<inal picnic t;ihle. garcbo.or siltii lal ll»c»trucl lire tnt ghl he sultiihle 0 <itiiri»<iinc v<'gct,'<ted b<lffcrs, provided it pr<!lnolcsneither;i l«»s of eff'<.ctivene»» n<ir overu»e ot' thehuf'fer as a travel zoiie to tin<1 from th»»tructurc.Areas that have buffer» estahli»hed to protect criticalhabitat <ir signific;mt wildlife may not be»uitahlcf'<ir any manipul;ition for recreational u»c. SuchIn;inlpul;itl<1 Pilaf hilvc I<i be asse»»ed <in a c;i»e-by-casc basi» iri order to ensure that hc origirial intentfor which the but'fcr wa» e»tahlished is not ~e<ipar-dl/ed. Appeii<.'fix 8 provide» an exalnple of <I iiiul-tiple-u»e vegetated huf fcr nianagement and mainte-narice progriiin. This example i» taken from thcRh<idc I»land C<iastal Re»ource» Managenieri!Prograrii . RMP!. and was developed to co<nple-ment the vegetated buffer p<iiicies lor the»tate <ifRh<xfe l»land CRMP Appendix A!,

All w<xidy-stemmed species of vegetationwouM be pruned arid trimmed on a»chedule t<i pr<i-mote vigorou» gr<iwth and utilization <if nutrient».A» trees and bru»h mature, or a» individual plant»»uccumb to n;itural causes. selective harve»tingwould maintain a vigorou»ly growing and diver»eplant coinmunity. Leaf litter rind other organic dcbri».pr<ividing hat it does not prc»ent a hazard or liinit<ither intended use» <!f the buffer area, would not heremoved from the huff'er area. The breakdown of

leaf litter provide» a natural »ource of carbor the pr<x:e'is<if dcnitrificiition. Con»idering that c<ia»tal wat r»are generally nitrogen-sensitive, and nitrate i» areadily u»able form of nitrogen in marrne v ater», thepromotion ol' denitrif ication in coastal zone veg-etated buffer»»hould bc considered a priority. Gra»»clippings may or may not be removed trom the buf'-fer area, and worn <ir thin spots may be over»ceded.Although neither fertilization nor watering of thebuffer area would be needed a» a regular maintenanceactivity, either or both might be appropriate in estab-li»hing new buffer area» or re»toring exi»ting one»,

8 An I'.xatnplet Rhode 1»land's CoastalBuffer Program

An example of multiple-u»e vegetated butterpolicies that have been developed for use in thecoa»tal zone of Rhode Island is provided in Appen-

dix A. It applies various-sized. fixed-width veg-etated huffers, based on the summary given in Table7, for residential lands: a fixed-widlh buftcr on areasof concern or signilicance; and a case-hy-caseapproach to other development, such as industrial,residential subdivisions, and comnlercial uses.

The Rhode Island example insti utes vegetatedbull'ers along the entire coastline of the stale, whiletaking into consideration land parcel size andexisting coastal development patterns. 'I'he prograntstrives to strike a balance between land use by thehomeowner and protection of coastal resources, Thewidths of the established buffcrs are determined

according to lot size and Coastal Resources Man-agement Council CRMC! water type. The CRMCwater type is a destgnation of the predominant useof coastal waters i,e� I-Conservation Areas; II-LowIntensity Boating; III-High Intensity Usc; IV-Multipurpose Waters; V-Commercial and Recre-ational Harbors; VI-Industria! Waterfronts andCommercial Navigation Channels!. Special mea-sures e.g., wider buffers! are applied along areasthat are considered critical or sensitive, such a»wetlands or habitat that is used by rare, threatened,or endangered species,

The vegetated buffer policies and regulationsare limited to residential area» existing and infill!and allow for limited use of the buffer areas so that

homeowners are not unduly denied use of theircoastal property, These policies and regulations areused as guidelines for other types of development commercial/industrial!, but the Ainal determinationof buffer width for development other than singlefamily residential is performed on a case-by-casebasis by CRMC staff engineers and biologists tomitigate any potential impacts to the coastal zone,

The Rhode Island vegetated buAer program wasdeveloped to provide for multiple uses and multiplebenefits. During development of the program, it wasquickly realized that implementing vegetatedbuffers that would provide both high pollutantremoval and high quality habitat was not practical inall coastal areas, Attempting to implement suchbuffers would either lead to the proposed program'snot being adopted, or to requests for variances onnearly all permit applications.

Given this, a program was developed thatbalances the landowner»' rights and the CRMC'smandate to "preserve, protect, and where possible,restore ecological systems." Narrow buffer widths

are applied on small lots so as not to cause the lotsto become unusable, and with the realization that

pollutant removal will be limited and habitat valueminor. A» lot size increases, wider buffers arc

implemented. increasing their value for pollulantremoval, wildlife hahital. and visual appeal.

In all cases. «nd for all lot sizes, wider bulTers

are implemented where they border water~ whoseprim;iry use has been designated Type I � Conser-vation. or Type II � Low Intensity Boating. Thereasoning i» that these types of waters require ahigher degree of protection and preservation in or-der to maintain their designated primary uses. Widerbuffer widlhs are also applied when the area receiv-ing the bufter abuts an area of critical concern. specialsignificance. or scenic or historical importance.

The actual regulatory program, as adopted bythe state of Rhode Island, is included in Appendix Aexactly as it appears in the slate'» regulator> coastalprogram documentation. Appendix B includes acomplementary vegetated buffer maintenance andmanagement document created as part of the veg-etated buffer program implemented by the RhodeIsland CRMC.

~ State Coastal Buffer Programs:A Summary

This review of coastal state~' programs, poli-cies, and/or regulations that could he used to estab-lish vegetated buffers along the coastal zone con-cems itself only with those that are a part of lhestates' Coastal Zone Management Programs. Poli-cies and regulations applied by other state agenciesare mentioned when the state CZMP defaults to

other programs to avoid replication, or when noCZMP has been established for a given state.Finally, despite the fact that the shores of the GreatLakes are considered under the federal coastal zone

management program, this review restricts itsell to adescription of those states bordering saltwatercoast lines,

Table 8 provides an overview and summary ofthe differences among states' policies. regulations.and requirements for the establtshment of vegetatedbuffers along the coastal zone. A similar dcscrip ionof state buffer policies has been put together inCastelle el al. �992!, but pertains strictly to wet-lands and buffers around wetland~. Reader~ with a

particular interest in wetlands may v. ant to reviewthat document. The program descriptions given here

;ire based on a review of publi»hed state program»and/or discussions with state agency personnel. Anyerror», omissions, or misinterpretation» are those olthe authors.

Of thc twenty-three state program» reviewed,four had buffer program» applying to thc entirecoa»tal zone a» an element of their state coastal zonemanagement prograins. Two other states had bufferelements that pertained only to a certain portio~ ot'their coastal zone. Nearly all state» had some fortnof mitigation procedure that could he applied duringthe permitting process to establi»h vegetated buffer»in the coa»tal zone, Construction or septic systemsetbacks, which could be used to e»tablish vegetatedbuffer», were reported by most states. althoughmany reported those to be established by townrather than state regulations.

The various setbacks and buffer policies beingused by state coastal zone management programsthat could establish vegetated buffers range from 20feet to 300 feet of'buffer width excluding thepossibility of no buffer!. This represents a range ofbuffer effectiveness from Table 7! from fiftypercent pollutant removal and poor habitat value toeighty percent pollutant removal and good generalwildlife habitat value, No state program had policiesor regulations that provided greater than 80 percentpollutant removal, and none provided buffer widthsthat were in the category from Table 7! consideredexcellent as wildlife habitat, although either or bothcould potentially be achieved during case-by-casebuffer development.

Alabama

The state of Alabama has a 40-foot constructionsetback requirement, but it is only applicable to landalong the shoreline areas immediately on the GulfCoast; it does not include back bays and cove».The application of the 40-foot setback is meant toprotect beach dune systems and is measuredfrom the dune credit. Vegetated buffers may be estab-lished through local zoning regulations of coastaldistricts but are not a requirement of the statecoastal zone program.

Alaska

ln the state of Alaska, separate requirements forcoastal vegetated buffer areas may be establishedthrough local government mandate» for each re-gional borough. Regulations exist that require

leaving vegetation along coastal areas being logged,but thc actual vegetated width preserved i» deter-mined on;i c;i»e-by-case basis. On «ity- and slate-owned I;ind». a l �-foot no-cut zone i» required,while on private property there is a 66-foot no-cutzone. Thi» relates to timber harvest areas only. andas noted above. is subject to modification on a ca»e-by-ca»e ba»i», Vo statewide coastal zone programbuftcr requirement currently exists.

California

The»tate of California buffer program focuse»on wetland habitat protection. The program require»a ininimum 100-foot buffer around coastal wetlands,with additional width required if adjacent land~ arebiologically significant, if sensitive wildlife inhabitthe buffer. if the area is highly susceptible to ero-sion, or if proposed development poses significantpotential impact. The I I0-foot buffer. however, isused as guidance only, and may be negotiated on acase-by-case basis, Buffer regulation~ may exist atlocal levels of government, and may be more or les»stringent than the l00-foot buffer guideline sug-gested by the state coastal program. Vegetatedbuffers may be applied to riparian areas whencoastal program jurisdiction is exlended into water-sheds that drain into sensitive coastal areas,

Connecticut

The state of Connecticut coastal zone programhas policies that promote preservation of vegetatedcoastal area» but has no statewide requiremeins.lmplementaliOn Of vegetated buf'ferS Or COnztructionsetbacks along the coast may occur through zoningregulations and requirements at local levels of gov-emmcnt, Construction setbacks that do exist in localzoning ordinances may vary by town throughout thecoastal zone of the state. New vegetated bufferpolicies and regulations are being drafted by stateregulatory agencies, While these new policies aregenerally focused on riparian systems, their applica-tion may be extended into the state's coastal zone.

Delaware

In the state of Delaware, establishment ofvegetated buffer» in the coastal zone is not a re-quirement of the coastal zone management programbut may occur at the local level, according to localzoning regulation». State CZMP staff may requirethe establishment of a vegetated buffer during the

Table ft. A listing of buffer and setback widths that coastal states have established through their coastal zone tnanage-ment programs. Vl denotes the wid h is mandated. while R denotes that the width is recommended onl>. l 1 toot = 0.305 meters l

'Setback Width is atua t. ommentsBuffer Width Yilatus'State0 r; Applies to iulf

t. oust oltl1Primarily 1'or dune protection and

preservationA labor»a

App!ies only to timber harvestopelatlolls

100 cityA!are !itnds:fih' private propcny

Alaska

I X!' around wetlands Mainly for hahitat preservationThrough local ordiitunces

utiforniaConnect i cut

5 r !rom ineini highv. ater inark

A!so through local ordinances

Through local ordinances

Delaware

FloridaNo CZMP at presentGeol gl a

Hawiiii 00' t'rom shorewardvegetation line; Z !' if

hardship shown

Applies to all is!ands in theHav inian islands group

Through local ordinancesLOll is I altaMaine Also has a buffer manugcrncnt

program7S' a!Ong entire Coast;

SO alung sei1sltiVewetland areas

Case-hy-case on non-Chesapeake Bayshores

100' along ChesapeakeBav shore

Mary land

ln process of deve lopmemVlassiichusc ItsRarely; case-by-caseMiss I as ippi

The definition ot wetlands includesthe entire NH coast

100' along wetlandsNcwHampshire

Only along sensitive areas; loca!zoning supersedes state

0-3 X!' on a case-b> -casebasis

New Jersey

Vegetation not required in thesethack

75' from v'et!ands 1 a0'in New York City' !

'New York

Vegetation not required in buffer

Through local ordinances

30' amund significantwalel s

hlorthCan1! t i!at!rcgon

New huffer program heiiigrev ieweil

50' 1'roni the coastallea ure

0-20fr on a case-hy-casebasis

Rhode ts!und

Only applicable in coastaldunes; vegetation not required

South Carolina Variable, according toerosiona! rates

Ci'lv!P being developedTexasVirginia Nnt required along other siate

coastal areas1 xr a!ong Chesapeake

Bay shoreThrough! oca 1 ordinancesWashington

permitting process on a case � by � case basis. Furlher-rnore, a 50-foot construction setback from the edgeof a water body or wetland is required, and may actas a vegetated buffer, The state coastal zone pro-gram also requires the use of vegetation for shore-line stabilization as a first choice during the permit-ting process. Rip-rap or other engineered shore! inestabilization structures may he allowed wherevegetation proves inefficient or impractical. A majorfocus of the program is the creation of wetland areasas the shoreline stabilization structure of choice.

Florida

In the state of Florida. vegetated buffer» may beestablished in the coastal zone as part of the permit-ting process on a case-by-case basis, or as mitiga-tron requiretnents due to proposed developmentimpacts. Furthermore, requirements for vegetatedbuffers may exist at local levels of governmentthrough implementation of construction setbackregulations i' or dcvclopmcnt along the coast, State-rnandated setback» in the coastal zone relate only torequirements for the setback of septic systems fromcoastal wetlands.

GeorgiaThc state of Georgia has no statewide require-

ments for the establishment of vegetated buffers,and at present is not a participant in the federalcoastal zone management program. A MarshlandProtection Act may create vegetated buffer» in thecoastal zone adjacent to protected marshes or as themarsh itself!, but the primary purpose of the Act isto protect marshlands, not create vegetated buffers,The Shoreline Protection Act gives state regulatoryagency staff some discretionary power to establishvegetated coastal buffers through the permitting andreview process.

Hawaii

The state of Hawaii has policies and regulation»within the state coastal zone program to establishvegetated buffers along the coast. For all of theHawaiian island group, a 40-foot shorelme setbackis required, beginning at the shoreward edge of thecoastal vegetation line and extending inland. Thebuffer is generally r'ntended to remain in an undis-turbed state, but certain uses are allowed, and vari-ances may be sought for limited development withinthe buffer. In cases in which hardship can be proven,the mandatory 40-foot setback buffer can be reducedto 20 feet. Each of the islands in the Hawaiian islandgroup may develop its own regulations with regardto the shoreline setback, but the width may not beless than the 40 feet mandated by state regulations.

Louisiana

The state of Louisiana has no statewide policiesor regulations that establish vegetated buffers in thecoastal zone. Vegetated buffer areas may be estab-lished on a case-by-case basis as part of the statepermitting process. When established, buffers areused to protect significant habitat or resources bymoving development activities away from theresource to a region of rnirumal impact.

Maine

The state of Maine, as part of its ShorelineZoning Act, has implemented a coastal vegetatedbuffer establishment program. The coastal zoneprogram mandates a 75-foot minimum vegetatedarea, measured from mean high water, along theentire Maine coast, The buffer must be kept in avegetated state, with no more than 40 percent ofexisting trees in the buffer being harvested every 10

years, Pruning and other maintenance proceduresare allowed, but complete renioval of gritsses orunderstory in the bul'f'er is prohibited. A vegetatedbuffer 250 feet wide is required along areas border-ing sensitive wetland». The larger buffer width isimplemented to provide added protection to wild-life. especially waterfowl. while the minimumbuffer width of 7S feet i» impletnented for protec-tion of water quality and visual appeal,

The buffer applies to new construction only. andpreexisting lots are exempt I'rom the 7S-foot buff'errequirement. Preexisting lots may not expand bygreater than 30 percent, may not expand tov ard thewater's edge. and if outside the 75-foot buffer zone,may not extend into the buffer area during expan-sion. Local zoning ordinances may require a greaterbuffer width than the minimum 75-foot buffer

mandated by the state program.

MarylandIt is the policy of the Maryland coastal zone

program to promote the establishment of vegetatedbuffers along the coast, and buffer» may be requiredon a case-by-case basis, particularly around wetlandareas. As part of the Chesapeake Bay Program. allland l 000 feet inland of the shoreline of the Chesa-peake Bay and its tributaries is subject to a 100-footbuffer requirement, The buffer requirement may bewaived if "good conservation practices" are em-ployed at the shoreline site, Furthermore, the bufferrequirement i» only applicable to new developinent� existing development and previously platted lotsare "grandfathered" to preexisting requirements.Other state programs share the cost of buffer stripimplementation with farmers actively using landbordering the Chesapeake Bay and its tributaries.

The major emphasis of this policy has been intidal tributaries of Chesapeake Bay. The emphasis innon-Chesapeake Bay portions of the Marylandcoastal zone has been on stabilization of the coastby promoting plantirig and preservation of vegetatedareas. Vegetation within the buffers along the coa~thas focused on grass species, while woody�stemmed species have received greater emphasisa! ong tidal tributaries.

Plummer �993! provides a more comprehen-sive review of Maryland buffer policics and regula-tions. as well as a review of impletnentation withinthe coastal zone program.

42

Massachusetts

The state of Massachusetts coastal zone pro-grarn does not currently have policies or regulationsthat establish vegetated buffers along the coast.Establishment of vegetated buffer areas may occurat local levels of government through zoning ordi-nances and regulations, or may be established on acase-by-case basis through the coastal zone programpermitting process. The state coastal zone program,however. is in the process of developing a bufferzone program, which is presently being drafted.

MississippiThe state of Mississippi coastal zone program

has no statewide policies or regulations that estab-lish vegetated buffers in the coastal zone. During thepermitting process, however, vegetated buffers thatconsist solely of tidal wetlands may be establishedto protect significant resources and habitats, Theestablishment of vegetated buffer areas applies onlyto tidal wetland environments, and does not apply toupland areas adjacent to the coast.

Jersey huft'er policy and regulations, as well asimplementation examples.

New York

The general policy of the state of New Yorkcoastal zone program is to protect significant coastalresources and habitats, and therefore vegetatedbuAer areas may be established during the permit-ting process on a case-by-case basis, The statecoastal zone program encourages the protection and/or planting of vegetation along the shoreline, butdoes not require it as parr ot the program mandate,

Through the regulatory program of the Depart-rnent of Conservation. a construction setback

regulation exists that may establish vegetated bufferareas. The regulations require a setback fromwetland areas of 75 feet �0 feet in New York City!.The setback regulation does not require that thebuffer area be vegetated, but encourages the use ofvegetation. Local government may develop andimplement vegetated buffer policy and regulationsaccording to local zoning ordinances.

New HampshireThe state of New Hampshire coastal zone

program, through state wetlands regulations, re-quires the establishment of a 100-foot vegetatedbuffer around coastal wetlands, beginning at themean high tide mark. Although the buffer area is arequirement, activities can still be conductedwithin the buffer, provided that proper permits havebeen issued.

New JerseyThe state of New Jersey has a coastal zone

program element that may be used to establishvegetated buffers along the coast. The programelement requires a buffer width of 0 to 300 feet,determined on a case-by-case basis, and is depen-dent on the potentiai impact to water resources fromthe proposed development activity. The bufferprogram applies to private property, and to allactivities conducted in the coastal zone by any stateagency. The buAer program, however, is onlyapplicable to those areas of the shoreline designatedas significant or sensitive areas. Furthermore, localplans and zoning ordinances supersede the statecoastal buffer program, and do not have to beconsistent with state coastal zone policy. Plummer�993! provides a more detailed review of New

North Carolina

fn the state of North Carolina, the portion of thecoastal zone that lies within 75 feet of the water' s

edge is subject to permit approval for developmentpurposes, Vegetated buffers may be establishedthrough the permitting process on a case-by-casebasis. When buffer areas are established. they neednot be vegetated as a requirement. but vegetation isencouraged. A 30-foot buffer is required aroundwaters that are classified as high quality and/or ofhigh significance, but the buffer need not be veg-etated, The 30-foot buffer requirement is mosttypically used to protect public water supply water-shed areas. Local zoning ordinances may require theestablishment of vegetated buffers along the coast.Phillips �989d! reviews some local-level bufferrequirements in North Carolina.

OregonThe state of Oregon has several statewide

policies that require local governing bodies to beconsistent in their planning and zoning efforts.Statewide policies to preserve and protect signifi-cant coastal habitats, cultural and historic resources.and scenic qualities may result in the establishmentof vegetated buffers along the coastal zone throughlocal adoption and implementation. Areas marked

44

for preservation and/or restoration in estuaries mayalso be viewed as vegetated buffers,

Rhode islandThe state o Rhode island coastal zone program

has a policy for the establishment of vegetatedbuffcrs, hut it is implemented on a case-by-casebasis under the purview of'program staff'. Whenapplied, the buffer is rncasured from the inland edgeof the coastal feature as defined by the program!,with buffer width based on potential impacts ofdevelopment and the sensitivity and use of theadjacent land and water, The state coastal zoneprogram also requires a minimum 50-foot construc-tion setback, but local zoning ordinances or regionalSpecial Area Management Plans may require theestablishment of a buffer area, or require a greatersetback distance.

The state of Rhode 1sland has developed a morecomplete vegetated buffer program, a final versionof which is included in Appendix A. Adoption of theprogram occurred during early 1994. Appendix Bcontains a copy of the vegetated buffer managementand maintenance document that accompanies thestate's buffer program.

South Carolinaln the state of South Carolina, vegetated buffers

may be established on a case-by-case basis along orwithin critical or sensitive areas, such as saltmarshes. Typically, the program regulates activitywithin the critical or sensitive areas, rather thanestablishing buffers around them. The coastal zoneprogram also has jurisdiction within a setback areainland of coastal dune systems, The setback width isdetermined by erosional rates, and although veg-etated buffers could he estabhshed within thecoastal setback, the focus of the program is toregulate activity in the setback area rather than toestablish it as a buffer area. The overall intent of thesetback is to protect property hy removing structuresfrom erosional zones along the coast.

Texas

The state of Texas is in the process of develop-ing its coastal zone program, and therefore atpresent has no policies or regulations that establishvegetated buffers along the coast. The program thatis in development recognizes the value of coastalbuffer zones, and several policies within the draft

program deal with the concept of vegetated andnonvegctated! huffers,

VirginiaThe state ol Virginia has a buffer program

applicablc to the shoreline of the Chesapeake Bayunder the Chesapeake Bay Preservation Act, but theprogram does not apply to other coastal areas in thestate. The coastal zone program recommends the useof vegetation and vegetated buffer areas for shore-line stabilization and other uses, but it is accorn-plished on a voluntary basis by property owners,

Along the shores of the Chesapeake Bay, theChesapeake Bay Preservation Act requires a 100-foot vegetated buffer along all shoreline that drainsto or is adjacent to the Chesapeake Bay. The pro-gram does provide for limited use within the veg-etated buffer, and variances may be sought to utilizelands within the buffer area, No variances will beprovided that result in less than a SO-foot vegetatedbuffer remaining along the shoreline except foragricultural uses!,

Water-dependent uses such as rnarinas anddocks � are generally allowable within the 100-foot buffer area, Agricultural land uses that abut theshoreline may seek a smaller vegetated buffer widthof 50 feet. and a 20-foot buffer may be allowed foragricultural purposes, provided that a managementplan has been developed and is actively beingimplemented. Plummer �993! provides a morecomplete review of the Virginia Chesapeake BayPreservation Area Program. as well as implementa-tion examples.

WashingtonThe state of Washington coastal zone program

recommends the use of vegetated areas for shorelinestabilization and other purposes, but does notrequire their use. Each of the coastal counties in thestate is required to develop its own master plans andzoning ordinances, which may, but are not requiredto, include regulations for the establishment ofvegetated buffers at a local level.

IV. Selected Bibliography

Thi» bibliography represents a search of lheliterature lor works that relate to vegetated huffers.The selected bibliography presents <t wide range ofsubjects, ranging from pollutant removal research tothe aesthetic and scenic value o vegetated buffers.The selected works are definitely biased towardsresearch oit pollutant removal efficiency ol veg-etated buffers, The reason for this is twofold: I ! thebulk of the published literature is the results ofresearch with lhis a» their focus, and �! in light ofthe recent emphasis on control of nonpoint sourcepollutants, this porlion of the literature is extremelyvaluable in pursuing the use of vegetated bull'ers asa nonpoint source control mechanism. However,the selected references presented here represent areasonable introduction to thc diversity of uses ofvegetated buffers as a multiple-use resource man-agement tool.

Several bibliographies, some annotated, aregiven in the following list of literature references,One of special note, however, is that compiled byDr, David Correll at the Smithsonian Environmental

Research Center Correll, 1993!. Thi» biblrographyis specific to the literature regarding forested buff-ers, and is indexed according to the parametersresearched in each citation given. Thc bibliographyalso contain» references culled from international

sources, and provides a robusl compendium ofresearch in forested buffers,

Adams. L.W. and L.E. Dove. 1984. Urban wetlands forsiorinw uter control and wildlife enhancement. NationalInstitute for Urban Wildtife. Columbia. MD. 15 pp.

Ad<>ms. L.W. and D.L. Lccd leds.!. 1987. Inrrgrar<ng nrunuiul >ion<re in rhe inerniP<>!ihm enl ironrrienl. Naiiollal institutefor Urban Wildlife. Columbia, IVtD. 249 pp.

Adams, I .W., T.M. Franklin, L,E. Dove. and J.M.Duff'ield. 1986, Design considerations tor w ildlif'e in urbans orniwuter management, Ti ansa< lions of' rhe <Vur h Ameri< untrii ldhf<' u>ul f>la<ural kes<wi'<'es <niferen< e 5 I:249 � 2s9.

Ahola, H. I 99<!. Vegetated buff'er zone cxaininat iona onthe Vantaa River basin. Aqua Fermi< a 20 I!:65-69

Allen, I.H. 1979. Role ot wetlaml plants in erosioncontrol ot' riparian shorelines, In: P.E. Greeson, J.R. Clark, andJ.E. Clark leds,!, War and Fun< ri<ins and I'alaes The Srare ofOur Urrd< >sra<>dirrg. American Water Resources AssociationTechnical Publication No. TPS79-2. pp. 403 � 414,

Ambus, P. and R. Lowrance. 1991. Comparison ofdenitr ificarion in two riparian soils. S<>il S< ieiirisr S<a ieri ofAm< ri ur>>al 55:994-997.

Anacostia Restoration Team. 1992. A current assessmentof urban hest management practices: Technique~ of reducingnonpoint source pollution in the coastal rane. MetropolitanWashington Council of Goverrrmenrs. Wash>ngton. DC.

Anderson, B.W. and R,D. Ohmarr. f985. Riparianrevegetation as a mitigating proces~ in stream and riverrestoration. In: J.Gore ed. 1, 1he kesrorari<in of Rivers andStreams Butterworth Publishers. Boston, MA. pp, 41 � 80.

Anderson. M.P. 1984. Movements of contaminan s ingroundwaier: Groundwater transport, advection. and disper-sion. In: National Academy of Sciences. Ground><urerC<mrvrrri nuri <in. pp, 37 � 45,

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I'lumrner. J.t.. I<!<J >. Vcgct,>t>vc huff«fv;>i<»>g «o.i»alwatcric A iaxc xtudy <>f the 'hcviipcakc Hi>!i 'r>tii,il *re >Pfogfafn M >vier v ' if SC>cncc thc'v>v. Ienlv > II'Iivcl v>ly. lernvon,!ii>uth ' >rolin,>. I,tl pp,

Vi>rtc>, I W, I !X I. phc wetly n<J «dgc as a c in>n>unite ar>d tv v aluc I<> wildlitc. In' Fr< r< ri'ilrn e> <~J ld<' < Iiif>< i'il '<in/ri-<uii i rni t rflurnf< 'I uli« i i nil dfinrue<'lllrlrl I revh> >terSoiietv. Navarre, vIN pp I C 'l

I <'Iwcf. J I . I !XS, N>trogen- a>Id water-uvc Ctliiici>i!' iilvevefi>l I:<x!l-vcilvini gfavve'< I'Ci.'i:Ivlng ainu'ii'if>i>>I>i 11>tratc l !i' !yeafv. Ac!'rininlf> J<nrrll<ll 77; I X'> I<!',

P<>v cr, J.lr and J S.! chcpcrv. I<IX !. Nitraic io»t,nn>n;I-t>i!n <>f gr<!undwatcr in Nnfth AnICrlca .tkl'ii I<ill<fr. I:< rl'i>afrm>. < !ff nitri>gcn.Ad>'rffrr r fili'fili in t <ll<'r Prrfhi'ur< 6 1, 5 X!

Prcul, H '. and !.J. '.ichrocpter I 96X. I'ravel of niir<igenin vn ls jr!alaiI< l I'rillnllrni 'rinlrril F'ril<'rallnn40. II--IX.

kaflne!. J W .. M Bfunef. Ui>d J.H. I.evcnv>X!. I'A I . Thcimportance of edge in the vtfucture «i>d dyn~micv ot torcvtivtandv In: R.L. Burgevv and D.M. Sharpe Iedwl, I:nlr'>lfilund I!ynarn>afrd I~n I < ape> Springer-Veriag. New York, iNY. pp. 67 -<J%.

Ravn>uvven, W !. I<!9 k Predict>ng vivuat buffer vtripx ina f<>revted <:UViri!nn>ent. Jr>urnui rid I.iuer-m< lrl 3d:X I- <>4.

Reikkhi>w, K.II.. J.B, Butcher, «nd '.i! . Mania. I JXSPollutant runoff m<idelv: Selectii!n and Uve in dccivi«n niaking.I '<lfri kr>ln<r« i II><lfrtrn 21�!: IIIC- IMC.

Reppcrt. k I., W Siglco. I'. Sr,ikhii. I . Mc»<>i.in, .ind Mc! crx I<7<! Wctl.>nil v.>lu< i: 'iii«cptv .>r>d Jncth<xtv tiirwell,iiidv Ci ill>i,>liiiii i>JIC<t Sli!te< Afn!V iifpv iil I'neir>CCfvlnvtiliitc Ii» %,<t<'r kent<>i<rccv k<'vc.irch kepi>I> No. 7 >.k I I I X!Pl>.

kciiicr, J I, T I!liihan. >rxl I'.k. Iol<ti>><if>. I<X>' I'hc uvciil < ctliinilv tiir nuti >Ci>t ren>O< al Iron»UJ t,u;C ru»<ilf it> a «!l<titin>ate r 'g>ii>1 <il' 'al>lnriii.i revultv I'ruin .I nc>< I! iiifiv>>Uiti'dWCII'If><'I at I.:ike I ih<ie .Ir»il n<il ii/ f ni'J« inln<'lrl<ll .If'>nil irrii rir 36,4'<

kh<iilcv. J.. '!>rt Sk.iu, f! Iccnlcc..>J>d I! Hf«<J> IUH,~Qu.><II>I>i.i>>> iit i>it>">IC i>P'lake h! r>Par<a» I'Orevlv < id«c liiii lv I� '.>i'I iiixlivliirhi;d he<>d<<atcfv ,'ltcrvhc t l>1: k kJohnvon, ' I! lichclt. I! k. I'alt in, p I'. IJ<illii!tt. and R.II.I I >fort.' I C92lv in kiln>i i<in Ii«!< > ill'lii'I illnl I ll<'ll !9<Vitae<'!I ><'JIIX<' rifi< i!ink I 'rnifhr'fine I '«'i. L'UIICd Sl'Itei I!epar>iiiei>t <ilAgriiul I ure. I:i>rent !ieri'ice 'i enei at I'ii hi>>i,il kcfx!rt R ,' I-I I>. k<iik'< ytounril>J> I'Ofcvt .Ui 'I Ri<i'IXC I'.vpcr> nc>>1 St;it>i>i>Port 'ol}i>>v, ! pp. I 7C I 7h.

Ritter, W.I'. «nd k.p. I:. >xthuri> I <!XX A rev >cw iil<le>>It>'ll>CUI>o11 >n on vile wavtcw ate> lfcatinciit vV'vien>vI'ri> iriilrm< nl«l I'rillnlfrrn 51I I I:0<! *I

kilter. W.I:;ind A.J'.M. 'h>n>vide. I<!X4 Ii»pari i!t t,u>dUvC i<>i gri in>id-w'I tci lu'll II V >11 voulhcfn l!e lii v are i l < urn<I!<'<Jlrr 22,1X g7

kohhat, A iind J.k. Sahol. I'JXX. Summ;iry Rcport: 'I'heliteriituri review <it cvoli>giial hcnet'itv ol' Ihc 'iinvcrvi>tiiii>kcverve Program. An>ef>ian Managen>crit Sy vteinv. IniPrepaie t li!r 'lir>>ted Sli>tcv J.nv>ro>>n>en at Protection Agc>>vy,!Ii >cnic-Pi>liiy integration Branch. Wavh>r>gton, IX'.

k<q>crv, i<ililcn Ik I falpcrn, Ini. 1<!XX. Wetland hut terdc linea»i>n n>ethixi. Prepared lor Ihi Div»i<! JJ i!t 'iraxialke'<oufcev New Jefvcy Departn>cn> i>l Rnvironincnt.>l I'r<!tei-l> >n. Ircnton. NJ 6+ pp.

kor>ian, O'.T. and R.I.:. !<x>d I<!I '> Huftcr delincati<inmi>del l<!r N«w Jersey Pincli<ndv wetlandv. Rutgerx 'nivcrviry 'enter tor 'i>avtal and I.nv iri>nmcnlal Stud>ev. Divivi<!n <ilV>actin> tv Reve >rch. Rutgcrv L:niveriit! 'New Brunswick, NJ,

kom n. '.T. and k.t'.. ' x!d. 19XI W tl;ind >f lhc NewJervey P>f>ctandv. Vatucv, functi<uiv. In>p>itv and a propoxcdbutter del>neatu!n model. 'enter lor Coavial and I-:nv>ron acr>-tal Studies. Rutgcrv Un>veracity. Nev Brunvw>ck. NJ.

Ryther, J.A. and W,M. Dunstan. I971. Nitrogen, phosph<!-rui, and eutrophication in thC coavt d marine environmentS .lrnii 171 III JX-1 II3.

Sit<i. I-: !;<nil I W. ' Undy I edv J. I<!tt7. I'rri< ri <fine> rifll1< !>'!!If!r!>Inn> rrn,>fr«' fn>>I<I<' Muriilkr nn lrl I rir< ifi i <in<iI I ilirIII>hi>1i<!fi V >..>7. IJ>xt>tote il p<irevtkcvouri:cv, I r>ivcfv>ty W;>hah>ngton Se;>ttle, WA. 47 I pp.

xch lcl<'r. J, Nt,>f><I!<f 1 f3fo«n I <><I' [Jc<II.»'»>g .'in<1Pf»ICCI>llg ll< cl <c!fr><i<!f< lier << �<IIII<.'. kti c'i i .3 f !' la I fi

!i<hcllilikcr, i.k,>nil J. 'I,»i<en I'tu' l'cgc>,II«c III clircU>nici>I <it <I,»I < h.>f»y.'»i lr rut tt,tl rr//' tl! ttritttttc'tlfct/ Et it/tt92 2f -kt

X< hitter. IJ h1 I'txx fille<'I< i!l prc>r<',ill>icnl iil hrf'.h«,><flit>»It ii» <Ill >I»'I ol «CII,»>t'» < I» I 3 kc .IIIII

han IC I !. 8 '4 I! IC l .!I tp I « I I t»l 'll, tki'irri t t i'< 1cchrliciil f uhl C,<II<!ll Xeric' iil Ihc A»IC> 1<.il> 33 IICIk C <c c> I I'L C < A s xc H. I.t I I I � M I !. pp,

!i<hipper, I. A . w J, 1!ycI, f' i, f3,>r«!r>..i»fc!Ere» IC li'Iv,ill<'� h< <'IC»»Ill>CUT»!l>»1 .>h!f<'>I xcv Cf >rf>Xr,<!» wvvlc»1 Htirlrrkrt«t/ 33rtifc'1 29 IX I IN7.

Scfll<i<<cr, I.J;i iff. I'JN I.i. 'A'I>lcr qu.IIII< <»<fr< I<'<>Ill>rill m.>le<~he<i <'litt i»ghr>re IJ»!< fit f<'t kt'<rtt<t Cr HI J/<' tt f7, E 3 QI!

Xchlo<icr, I J. Uncgc>.!I>i»tUnnnel »>ofph»l»fry iriipiu:I iin <p.>IIl>CT»<»l !< >ICI4ut>}>ly tl'I t<gf>CUIIUTUI <<Urclxhe<I< l.tii itrrttttt<'ttri l .3/< tt< C<'nt<utt 5.',3 J

yhc ><I.»>, J.'!f,Encl k h. Il>lych;If4<Ix<f1 icl«ilrilx Iri irrc,>1»lh>N Iriin> c!,>i i>l Vl;ii» v r<>c> <l>c<I< ./ir tt ttrtl/ tti ttrrnnir'ttt<tl >it<I/t i IA' I 1 I I >f!

.'ihtilcr. J.h . I' f >A';»<Icli<h, II. i Ru<vcl. anil k f3 I'iclI'>X ' I3»I I<'I t'citl<'v»1 v CII'»i

hliivlci. J f< . P I:. KU><ICI>ch, ff, i Ru<xcll. »nil k AJi'»ih»I Ic>X'<. <!,<>I.'II «CIIU»<'ls Vie>!i>»' <fCI>1'I<.'.III<»r.I»<I< - 1.«1 I 4<«Jcr<cy tc!I>fic»II»r;>I I<<pc »nci>l .'i>iili<iiif'iihli<,iriiii! "i<! 3'-A l !II -I I -X.! kutycrs f '4>< crc II<I31>ills<< ICEr, c J.

.'iliiiri, II I I IIX'.3. M.>l». IIC»>C»I gc!;>li,»>>.tl <If»<Ii»c I>i k k. John«!», '.I!. />Chcll, f! k. f!'<>Ion. pf' I'i!lliiilr..I»<l k I J. I I.l»ll <' Ic<ii >. ki/!92tt'trttt I.i iri'I'<fi't T'I < ttil I/I<'ttM tttrtucnii-tit ki'irrni ilttte rrtt//ti fttiL' l ile<1 Xl <lciI >cp.>f1»92<'t>1 ol Agf>C>tllutc, I ol'cvl Xcrv>CC ieflt.'f'Ill 1<ichl»<.tlkclii!r> k <<5- I 'll, Riicf,y MO»»I.>i» f I!< c<1;inCC I:.aper >n>cn>.'il,<»>. I-iin c!ll»>i, ' !. pp '.� ' ! '.

!'In>hcrlc!II. 17..>n<l J. 'i!x I 'JX7. <!i»ctcnc«i i»><CT<.ill»» Coffl<IOT<. ritt<i't ii tiirtt //ii!/irc'I I ! I 71.

.iChi!»C<<">I<J- i!X, .M. I uXX. I3<>1 n<l,<fico»I Ihc prulc -I»in i!t n» ure rcicrVC< Htcr<r ic tii < 3f3,4X E AI >,

!ichuclcr, f'k. I'J<J'. A currcii> axxcvvl>>Cni of' ufh,ui h <In> >tlclj<'n>C» prie>ICc< Mell<'Ip<1 iil> Er>>ru<h>nt'Ion '<>»neil <il iiiv i rr>nicnlx. 4;<ih> t>X>on, f X .

!ichucl<r, I k I'tx7 ' on r»II>t>y, ufhi»i r<»loll. A pr,ic>><.il»IU»util IOI 1>IU»IE»'!X,>II t <Icwtjn! >fr ufh.in l3MI'S 'MCIT<!pi!IIIIIII>/It Iih»rgl<!ii <X»1< II <1'I !» <CIT>l»i:»Ix. Ni<c ht»gli»l. JX

Xchuclcf, I k., f'.A. Kiinhle, Uti<f .'< A ffcr,ily lenti.'UTICI>1 rv '<c<rrnlc II <if llrhan heut>'if'.cn>c»I pfuc»<'c <Tcchni<IUC< Ii!r re<loci>>f. 4<>n-ix»n> iouree p !llu»on ir> thec !uwl'll lone fJCpl. »I I.rivi»»1>1'Ien'IUI I'fc>frfu»E<. Ifclro/x!III.»1Wuihinfr>on 'i>uii<» I iil tiivcmincnlx Wuih»>f;lc»1, I X .

hchUCIcf, T.R <»>lev i!fk Ii'C< UIU.>I>ng Compl> in<.C v, ilh lhc III A rule in Ihc 'hc<upcrlf,cI3;>y <.ri>ical UrCU, 'MCIT<!IX!III;u>WU~h>fig><!n »Utl< Il OI iovernmentv Depar>n>cnl Of f=n< irunr»c»IUI Proyfi»ni.9,'Uxh Ingrun, f X '.

.'ichor,Cr. '.f3. Un<J J '. 'It<»we». I<JX<! Vefelu>i<C lil>CrIfcu>l>le»>»l dUIfy I» ilf h !u'rc << U< C< I 13:44 !- 4 '! I .

«'.»II, 1. BI>.in>»n lhc»<el'lun J I1<!<v If',TU>< Ifl>> 1<�1 <y<ICI'I! Ptrti i'i'cl tie! rrf et i/tttc't tt<rft<ttt t/ rrtijc' I'tti I' rill /Jc'>i'lirptttct! i iti /.J 33 >/t'cc< <'I '/rt<trttienr <ttt / /'tt/t.» trit MC!IX!urrE<'. Au<rr,iIi;i.

!ih;<Il'<r, C�. 19XI Minimur>i p<!pulali»n iieet liif xpccic<L<!n<CrVali<!n. Rtrr.'!I Inn t 3f: I 31-1 34.

S»r><iii>i, A I ... Jr 1<>7'J. A ilu<Jy Ol rcf:><>»,>I <IC<clc!pnIC»I.Ilc!nf'. IhC i<!urh <h<irc reg><!r> Ol kh<XIC I<I;»i<I, uiinlr U i i<u;Il11!pl'txlch h<>'re C< i'rll»g CIEv >fun»>c»1'll I iu;Ii>f<. Wf.cf 'i »I!3< ie»LC Ihc»i, .'iirricll I. »!vcf<iiy Iih:x:a. N'>'. 7' pp

l»1»ic�<. k. .. A J. col<I..»>rf. I i>lln> iri. I <I<JNrir,ilc <3uir>ic< in rifi»i iiu> I<ifc<l< in!<irl<lv i>rcr <lu< i.Jrrt nit/ rrl / rti ttrrtttttc'ntrt/ f >nit/it< 2fl4>i't!! > ! !!.

!II,<Icl. J %1. I»iX7, f!C»I>rllic.ii>i»> in.UJ»>let «!! I .I»lv l»t1<lcnc<' I hyXfc!u»<l« III<'I t11>1,<I<' .'92l!/!it<'i/ itttil / ttl'ttrrttttti' !it/ Mtr trr/!t P/trc',<c%- I Eci ' I J<t 7

.'ii».ir Xiii. k. ' IC<J !. I'JX I/tr I ntut I!/ 33 t/rttt./!el!i '!!t»L i!urt/ 'tt/ttttrt/ 3ultti I'uhI!<her~.for.i<v.!, NJ

4»>I>h. I I </X'J. $1>c I itic> <lfip coflet:pr. M,'»liluilti>IX<<.'I>cf LILI'lli> < II'I II>C 4>'ITlitk<' I I<!re<I. In' k. f J. f311fr f."!. +.I3kn!hr>, CI,!I IC<'I< i, l.rrti if attr/ 33 l lit/<' M ttt tkrt nt< tti itt 4c'I</ tic/urril - 'll Hrtt i rttt ci «/lrtrr/ ' M,»r>c rhgr!« ilrur.il I.<pcf!-nicnl .'ir.'ilii!r> kcpiirl 3 3 !,

<»>iirh. k I .U> I J.f3 J!ull IIIXX Det»>fificz IO» ii> 4 xUi><l,inS4 I/>71 lll7X

Xc!il '»f>ic <,>><on '!Cf v icc I ux't. <>»<Cr< UI«iri p El<1<Liesr»f1 l,i <lv liif < cL' '>i>re !p<. 3 n»cCLIII<tfe 6'Isf>ll>UI<ti>, IX

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62

1 nl'tcd .i<ate'i I'.nv II'iiililierli.'ll f'ri>tcc 1 li'fl Ageilcy. 1954.k '/tilt< f t lt><'i '92>,Y<rti/>rnltt <in<i< r' i'lrl//iti'i<It> iti I/i ' iI ' .i tiovernn>eut I <1<ltlllg tytllce Wilihiilg iln. !X'.

I i'>lied ht.ue< l i>i iri>111>leg 3ke<t</I< / tirr i tri iiii /r iith trr un /j i t er itti - iri irtri r<t<nttt<rtt v V.'<t»>n,d lcchni< «I liiliiriii.it<i»> Rervicc !h<hhc;>t«n>

P�84 I N'~ >45 .'>Prlng ti<'Id. YA

1'nit-<ill lit I'logic<>I 5e<'ricei.I '.it'6 i. !!ep;>itu>en iil tile trl'teriiir Waihu>gtiul, IX In><11Ill'

!irh;ui, I., R V !'Nc<l, and !l.ll. >huger . Jr. 1<!7.!..u<dicape ec<'iliigi Birr.'>'r ii'tir r 3712! 119 I'7

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Appendix AThe Rhode Island Coastal Zone

BuA'er Program

Adopted Aprii 1994, RI CRMP

bcxIiiM4} befbk~k

Amend Section 140. C to read ai tnllov,i:

"C. Se backi iha! I es end a minimum dii ance ol'eiiherfifty Srt!! feet from the inland boundary nt' the coaital featureor twenty-f'ivc�5! feet inland of he edge ot a Coaital ButterZone, whichever ii further landward. !n areas designated bythe Council ai Critical Err>sion Areasg Table 2!, the minimumdii ance ot thc ictbacl shall be nnt leii than 3 ! irnei thcca!culated average annua! eroiion rate for leii than t'nurdwelhng units and not less than 60 timei the ca!culatedaverage annual erosion rate fnr projecti propoiing more than 4dwelling i unit s.

SECTION 150 COASTAL Bl JFFFR ZOIVLS

A, DefinirionI. A Coastal Buffer Zone ii a land area ad!acelit to a

Shoreline Coas at! Feature that i», or will be. vegeta ed wi hnative ihoreline ipecies and which acti as a natural transitionzone between the coast and adjacent upland development. ACoai al Buffer Zone ditferi from a c<mitruction ie back Section l40! in that the ictback es abliihei a minimumdiitance bc ween a ihore!ine fea ure and conitruction activi-tiei. while a buffer zone ei ab! iihci a na ural area adjacent to ashore!inc feature that muit be retained in, or reitored to, anatural vegetative cnnditinn f igurc 2!. The Coastal Bu!TerZone ii generaily contained within thc ci abliihed construc-tion se back.

Figure 2 An ekamp!e of the application of a COaStalBuffer Zone.

kUUUaUU U Ur<'UU«rU<r UU aUUU

CoaFea

Un I

B. Findings1. The estab;ishrnent of Coastal Buff'er Zones is based

upon the CRMC'i legislative mandate to preserve, protect and,where posiible, restore ecological systems.

Vegc a cd butter zonci h;ivc beer applied i<v britiiianagei»ent !iraC ieei v, i hin the fields iif tore itri aiidagri< ul turn since hc 1 95 s to priit«c in-i rc<«n h <fr i :its ! riii»dcgrad' liat lr> 1hi: Illpu ol ii.'diilli'rl illlil !1 ! ficll s �>eshiirilicict al t<!<�!. Morc recently, vcge a cd buffer r<rnev h,ivc g,iincdpopularity ai a bci rnanagerncnt priv:tice I'or thc conrriil aniliibitleiiiel11 ol 11<inpninl in tee poilu it<i i Cori iiriillliiicd lull<i!and are niulinely applied in bo li engineered and na ur<iliettingi Deibonnet et al !<1<!.t: EPA I<!<�!.

3. Coaital ButTer Zonei provide muliiplc iiiei iiiiilmultiple banc i i o hoic areas v,here tliey tire iipplicd{Dcibonnet et al ! <!<�!, The multiple uiei anti bencli i olCoaital Buff'er Zonei include:

al Prrrre< ririn <>f Bi<ter grrrdrrv: BufTcr tones along 1heperime er of cuai al v ater b<i<frcs can bc effective ll'I trapplrlgicdimen i, pollutant~ including oii, detergents. peiticidei.herbicidei. iniec icidei, wood prciervativ«i and iithcrdomeitic chemicals!. and abiorb ng nu rien i par icularlyni rogcn! from surface v'ater runot'tand groundwa er t1ov,.lhe efteCtiveneiS nf vegetated bufferi ai a bait m,in;igeincii practice f' or the contrn! of nimpoint source runoff ii <tcpcndentupon hcir ability to reduce the ve!<reit> of runoff ll<iw io,iliiivfor thc deposition of iedirnenti, and the ti! ration and bi<iliigi-cal rernnval of nutrienti v'tthin hc vegc ated arc:r. !ii gun<.riil.the effcetivenesS Ot'any vegeteded butter ii re!ated O i width.i! ipe. ioil ype, and reiiden species of vegcta inn. Ff lee ivcbutfcri tor nonpoin source p<i!!ation coritro!. v< liich rcmoi c atleast 51!o<, and up to 99<J, of ie<1imeriti and riutricnti cn eringthem, range fram I C feet to QX! feet in v idth.

The remova! of pollutants cari be ot' particular irnpor1ancein areas <tbutting poorly Bushed ei uariei thar are rhrca1encdby an or<cess of nutrients or arc contaminated bi runoft' v,<der.iuch as the South Shore Salt Pondi and lie <!arro«River.1 arge. v:ell flushed v:a er bndiei, iuch ai rs<arragansc B,i>.are alio suiceptible tn nonpoin iourcc p<illu ant inpuii, an<1can be ieverely impac ed by nonpoiiit s<rurce pollutant i ui hasbeen doc omen cd in itudiei completed for thc varraganieitBay Pro!ect.

tb! Prrrr<'<'ri«n vf Cons i rciidcii andmigratory ipeciei. Sornc ipecrei v,hich uie coai iil hiifterzonei are now relatively uncommon, v.hite o hcri are coniid-ered rare. threa cncd or endangered. Theic p!an s and ariimalsare eisen ial to the preiervation of' Rhndc !iland'i valuablecoastal ecoivs em,

Thc c fee iveness of vegeta cd bufferi ai v< ildlile habi atis dependent upon buf'fer v,idth and iegelation tvpe. !ngeneral the wider the buffer the greater iti value ai vv i!dittohabi at. Larger buffer widthi arc typical!i needed tor vpecicithat are mnre seniitivc lo diilurhancei e.g.. noise i. Further-more, those bufferi that poiieii vege a inn nail< c o he 'ileiprovide more v;i!uahle habi at for ius aining residen ipccie .A diveriiiy of plant ipecici and v pci lc.g.. grasses. shrubsand trcci! promotei biodiveriit> v i hin the hut't'cr arc.i. and th<'region overall.

Water UeeCat ~ et

Reerdertttal Lt>t Typeal xe 3,4, 8 a

tet tt ! 8

Ty >e'ta2

Rett<< red Su ertt

15255075

100125150

< t 0,00010,000 � 20. 00020,001 � 40.00040,001 � 50.00060.001 - 80,00080,001 � 200,000

~200 000

255075'! 00125150200

C. Policies

D. St<tttdarrfs

66

c! Prote< <ion of SCent'< «>rd.4exth<ti< Czr«riity: Orle Of he primary gaa!s of thc Council is o preserve. protect, andwhere possible restore the scentc value of the coastal region inorder to retain the visual drvcrsi y and unique visual charat tcrof thc Rhode Island coast as scen hy hundreds of thousands ofresidents and tourists each year frotn boats. bridges. and suchvantage points as roadways, public parks, und pub!ic beaches Seclton 330!, Coastal Bufter Zones enhance and protectRhode Island's scenic and visual aesthetic resources ah>na thecoast. Ctvastal huffers also preserve the natural character ofthe shoreline, while mrtigating the visual impacts of coastaldevelopment. Visual diversity provides for both contrast andrelief between the coas a!and inland regions. leading togreater aesthetic value ol' the landscape,

d! Frosi<>rr Controi: Coastal Buft'er Zones provide anatural ransttion zone betv een the Open cOast, shore!mefeatureS and upland development. Natural vegetation wi hln aCoastal Buffer Zone helps to stabilize the soil, reduces hevelocity of surface water runoff, reduces erosion of thc soil hyspreading runoff water over a wide area, and promotesabsorption and tnfiltration through he detrital !eaf! layer andunderlying soils. The extensive root zones often associatedwith buffer zone vegetation also help prcvcnt excessiveshoreline eros an during coastal storm events by stabilizingunderlying soils,

e! Flo<rd C<rnrroi: Coastal ButTer Zones aid in floodcontrol by reducing he velocity of runoff and by encouragingint titration of precipitation and runotT into the ground ratherthan allowing runoff to f!ow overland and flood low lyingareas. In addition, Coastal Buffer Zones often occupy lheHood plain i self and thus add to coastal flood protection.

f! Protection of Histori < arrd Ar < kaeologi<oi Resources:Coastal Buffer Zones protect areas of cultural and hrstoricimportance such as archaeological sites by helping preventintrusion while protecting the sites' natura! surroundings.

I The establishment of a Coastal Buffer Zone is basedupon lhe CRMC's legislative mandate to preserve, protect and.where possible, re~tore ecological systems. The determinationof the in!and boundary of the Coasta! Buffer Zone mustbalance this mandate with he property owner's rights todevelop and use the property,

2. The Council shall require Coastal Buffer Zones inaccordance with the requirements of his section for thefollowing: a! new residential development; b! commercia! andindustrial development; c! activities subject to Section 300.gand Section 300,13: and d! inland activities identified inSection 320. For existing residential structures, the Councilshall require a Coastal Buffer Zone for category "A" and "B"activities when the R IDEM requires the tnodiircalion arexpansron of an existing septic system or when the footprint ofthe structure is expanded.

3. The vegetation within a buffer zone must bc eitherretained in a natural, undisturbed condition, or properly

managed in accordance w ith he standards contained in thissection. In cases «herc na»ve Hara vegctati<m! does not ex stwithin a buffer zone, the Council mav require res oral>oncft'orts which inc!udc, but arc no limited to. replanting thef. oastal Buffer lone v:ith native plant species.

4. Coastal Buffer Zt>nes shall remain covered v, ith nativeflora and in an undisturbed s alc in order to promote theCounct!'s goal of presers ing. protecting, and restoringecological sys cms. However, hc Council may permit minoralteration~ to Coasta! Buffer Zones that l'aciirtutc thc continuedenjoyment ol' Rhode Island's coastal resources. All a!tera tonsta Cons al Buft'er Zones or ultera ions to the natural vege ationtr.e.. areaS nOt preven ly maintained in a landscaped condit On!wr hin the Caunc!I's jurisdiction shall be conducted inaccordance with the standards contained in this section as wellas all other applrcable policies and standards of the Council.In order to ensure compliance with these requirements. theCouncil may require applicants to suhtnil a Buffer ZoneManagement Plan

Table 2a.Coastal Suffer Zone designations for residentialdevelopment.

S. In order to enhance conservation, protect water quahty.and maintain the low intensity use characteristic of Type I and2 waters, greater buffer widths sha!l be applied along thecoas linc ahu ting these water ypes.

6. In critical areas and when the property owner o«nsadjoining lots, these lots shall be considered as one lot for thcpurposes of applying the vaiues contained m Table 2a andensuring that the appropriate buffer zone is established

1. All Coastal Buffer Zones shal! be measured from theinland edge of the most inland Shoreline Coas a! ! Feature.

2. f oostui Buffer Zone Requirements i<n itic«RctrdentrulDeteioprnent: The ntinimum COaS al Buffer ZOnC require-menls for new restdential development bordering RhodeIsland'5 shore! ine are contained in Table 2a. Thc CoastalBuffer Zone requirements are based upon the size of the lotand he CRMC'5 designated Water Types Type I � Type 6!.Where the buffer zone requirements no cd above cannot be

mct. 1hc:ipplicarlt tiiay rcqiicsl,i variaiicc iri .li curit.iiii c w ilhScctuin I2 t A >anaricc i> xttq ot thc rcqiiircil hiif ter >s«t t>1'<lay hc gr. ntcd;id lilt»sir > <> cl> hy lie li xci utli e I!<r<x tor iltlic;il>PI<can has ia <> <cd the hilrdctls ill Pn>iil 1 il ttlc gri>lit«>giif a vari'itive. Wlicrc 1'I ls dc eit'lE>tied tl.'1 lie,ippllcall h'<si«it >a >st ied thc hurdcns ii pt<x>I, iir thc re<lite> e<l s;ttr a»cc»i<1 excess i>l St!'3 <it lhc rcquifcil ii iihh. 1hc <1pplic;ill<«i sh,'>llbc rcv>cwc<t hv thc 1'ull t <u»wil

<><r>n<vririlti h 'i I il'itii<Kkeu<l< nt<ui 5riu< nrr«rh<ri I:ip<tn<l tilt' I'<>«tint/it of rh<St>r«rr<tr und/<>r Sti u< tur»t F>pun<i«n I:tine S<'liri< Sv<r<ttt. When,iii cxis <»gres>dcn >;tt s rue ore dix s ri '<I<>cd lli Iahlc 'a c g . thccx>s lng s ruct ore di» s n 1' a huller rinic ur has a hotterri>nc with a v ulth less ha.<Itic <'uil' a<lielb>wing Ciiaslal Huffe< Zi>ne rcqu>rc<llcllts >h.dl itpply tiicai;h m<xli lie' loin <>I 1he rcsu'Ic1 lail s r Uc til I. <<l'i ll thcproper y's Coastal Butter /iinc equals, bu J«cs not exceed,th» value containc<l iii I'able a.

a! Where aI era tons tii a residential s ructure rcsut in1hC expattsl in ul' the s rue ure's fix> print square I'<xi age Ot'thc ground floor area cncuriipasse<t hy he >true ural 1ounda. xin «I an cxis«ng huilding I, the Ciiastal Buffer Zorie require-ment shall be extahti>hed v ith a wid h equal 1« the percentageincrease in a structure's f<x>tprint as <if April 15, I <I<Id multi-plii;d hy the value coiitaincd in Table 'a square fixit incrcaxcof foi> print/square too age as of April I S. I'994! X valueciintained m '1'ible a = Ciiastal Z<ine Butfcr kequtrcn>cnt!;

lb! Where «Iterati«ns t thc Individual Sewag» t>tstx>sat By>ten> ISM and the RIDt.M has rcxtu<red thc ni<xlilicali<iil <irexpansiiin i!f he ex is ing ISDS. thc Coastat Hut'fer Z<increquirement shall he estahlished wi h a width equal to >S'y«if he value con ained in Table 2a t. >S X value contained inTable a = C <>as al Buffer /A>ne requirernellt 1.

fhese reqiiiremenrs iinly applv h> categiiry "* ul<t Bassen s. In addition. he E.xecu ive direcuir ~hall have theauth<>ri y «grant a variance o these requirenicnts f<ir categiiry"A" assents in accordance with thc burdens of proof con ainedin Section 12th

4. C'r>urrul Buffer Z<>ne k'egrrirr'ments jnr ull C<inrnren tuluiul lndustrrol devel<ipment und ui ni ities subdae<-t tii th<regr<trements <if Se< ti«n t KI It, Sei riun .IIK! I.t, nr Se< run .320:C oas al Buffer Zones shall be de ermined on a case-by-cavebasis hy he C ouricil. Table 2a may be used as appropria eguidance However, depending on the activity proposed anJi s poten ial impac s on ci>astal resources, thc Council mayrequire a Coastal Bul'fer Zx>ne v ith a width grea er than thatfound in the Table 2a.

'S. All property abutting crt ical hah< at areas. as definedby the Rhode Island x<a «inat Heri age Program «r theCouncil, shall possess a minimum vegetated huf'fcr rone of011 feet between he <den >f>ed habitat and any development

area. The Execu ive direct«r shall have the au honty io grant a

s art aiicc i> thc>c rcquircnicnt s in;t> c<irdance v i h hc hurik nxi>I ptix>t ci>ill.lltled <11 . ncc >utt I 11.

>..XII priipcrry abut ing u:<s al 0'a ural Areas 1!ice i<inlti 4> slliitl Iiil>c ii rlliliulluill vegcl; ted iiilstiil Butlcl Ziitic

iit 'S lect tron»hc <nit>rid edge of the ciias iil feature ThcI xciuti> c ihrcctiii shit ll have thi: authiir«y u gri«ita > ar<anccto hcsc require<neo s iii iu:ciirdancc v.ith thc burdens ot prixili'i>illa'iileil in See i«i> 12 !.

7. All proper y located v ithiii thc Ix>ut>d >r<c«it;> SpecialAtea M,lrl.igcliicn <SAM'l I'lati iippri>veil bv thc Ciiuttcil shitlli»cci adilitiiuial hut'I'cr rnite require»ct>tx ci>ntaincd w iihinthese SAM plans. Wheri a SAM plan's hulfcr rune rcqu<re-<nc<t s apply, ihc hufter v idth > aloes ciin .iined in his sec i<inw ill hc c<iniparcil to ' hi >se required hy lie SAM plan. and theI,irgcr iit' thc huBer v,i<hhx applied.

'Vhc sc hacL <Sec i<in I 4 ii t'<>r all ncw residential.commercial, and indus rial s ru<nures shall exceed he CoastalBuf ter Ziine requirement hy a minimum of 'S tee tor fire,safety. tuid maintcnancc purposes. Where the 2S fixi scpara.tion distance between the inland edge of he hut'ter andc«nstruc«iin setback cannot he «htained, the;ipplican niayrequest a variance in accor<hincc with Scc»on 12�. Thef-:xecu tvc l!<rec or shall have the author< y to griui vanances1tprin .

F. Roger Itrlanagesncnt and hfrsintcnrrnce lfcgttirctncnrs

1. All alterations within established . oas al Buff'cr /~>nesor alterati<ins o natural vegeta ion i.e.. areas not presentlymaintained in a !andscaped cond>tain! wi hin the C«one il'slun>diction may bc required to submit a Buffer i~>ne Managc-rnen Plan lor the Coun<;il's appriival that is cons>>tent v ith therequirements uf this sec ion and the C ouncil 's most rccen edi iiin «f lti<ff<'r I<>tu M<tnagetn< nt fiutdun«'. Bufter ZoneManagement Plans shall include a description of «II pr<ipoaedalterat <«ns and n>ethods <if avoiding problem areas such as hepniper ptacemcnt and maintenance ot pa hv,ays. Applicantsshould consult he Council'» most recen edition of RrrfferZ<>ne <trlutr<r<,en crit fir<I<I<st <'e vrllen preparing a bulfer manage-men plan.

In order o prom<ite the Council's goal tii preserve.pr<»ec and, where possible, restore ecol<igical sys em<aCoastat Butter Zones shall be vege a ed with native flora andretained in a natural, undisturbed condition. or shall heproperly managed in accordance with Council s mon recentedi ion ot Buffer Z«ne NI<tnu,e< rnrnr Civrdunr e. Such manage-mcn ac tv ties compatible with his goal include, hut are notlimited tii:

a! .'>hr>refine rt«'< ii I'uth<: Pathways which prov tdcaccess <> thc shoreline are normally considered permissiblepr<ivided the> are less than or equal to f> fec wide and f<illi>v apath that ni<ntm<tcs eros<« i arid gullying within hc butferzone c.g.. a winding. hut direct path!. Pathways shouldavoid, or may he prohibited in. sensitive habitat area~,

including, but n»t limited to, coaital wetl indi. Pathwaii <nayhe vegetated w ith gfaiiei 'uld nl<!wcd or may !Ee iurf iced E< 1thcI <Iihed i nile»I Iiluleh.

b! l !<» C >r! i<it>i!I: SelCCtiVe trCC rein<iv.il and prunirtg;ind thinning <il n;i ural vcgclaiinn may bc all<>wed v, i bin adcl'incd c»rri<for iii »rdcr to pro!note a i icv ol hc ih<ireline.f!nly hc»iirii»ial altcrati<En nf vcgenitinn nC<'Cii;Iry <E nbtain avicv, ih;ill be uiceptabl» to hc Council. Shoreline;iccciipa hi ihal I hc locaicd wi hin view corridori to the r»aximumCareiit praetieable in Order o minimire diiturhiiiiee nf CV iitalButler lonci. View corridori ih;ill be prohibi cd in ieniitivc<ir critical habitat are»i.

c I It'ubilul >Vu»a«!near; Manageillent ol n;ltur;ilvcgc ation wi hin a buffer anne io enhance v:ildlife habitat andC<intl Ol »uiiani.'C alld n»n-na IVI,' spec les Ol vege a ion »1«y' heallowed. Homeowner control nf pest ipcciei nf vegitali<insuch ai I'unipean bittersweet and nuiiance spcciei iuch aipoiinn ivy ii normally cnniidered acceptable. Hov,ever. hcindiicrimiii;»C uiC Of herbiCideS Or thC clear-Cutting Of'vegetation ihall be prnhibited. Thc uic of I'er ilireri Iigenerally prohibited within the Coastal Buffer Zone exccp v hen used o enhance the rcplanting of native vegetation te.g..hydro-iccding! appriived by thc Couiicil. However. heClearing Or <iutright eliminatiOn Of natural vege a ion f»r suchpurpniei ai COntrOlling ieks or pollen shall nOt be perini ted,

ld!,!ttf<'rit/ p>t'!t<I!' <". S<'.!CC IVC tree I'C'»1»val. pi »11»i!and thinning Iif n, tora! vegetation witliin a <vaital Buffer/uric may bc allowed by hc C<iuncil o» a caie-by-caie b<iiiitnr prnien i<Ifeti and welfarC COnCerns C.g.. remni a nt:I<f,'miagcd tree in clnie proiimi y o a dwelling!. In <Irdcr t»prninntC Child iafe y and it!a»age peti in areai harboring Icki,tCnCCi al<mg lie inland edge of a COaital Buffer Znf!C alE<fali>ng ihOreline aeeeii paihv aVi nay be pCrmitted.

c! l'hu>'< firie Rt I r« trit>n: Thc CRMC rec<<gnizci thatihoreline r< Cre;ItiOn ii nne Of the predominant aiiracti<ini toiliving on. <Er visiting the Rhode Island Coast. Iii order tiI allov,I'nr iuch uiei. minor allerationi of buffer zonei may hepermit cd along the ih<ire! ine it they arc deter»tined <iconiiitent with Council'i re<tuirementi. These i tera ioni rnaiinclude maintaining a i nail clearing along thc ihnrc fnr picniciaMei. benches, and recreational craf'l ldinghiei, canoci, dayiailhi<a i. ctc.!. Addi ionally, the CRMC may allow imall,non-habitable ilruclurei including storage ihedi. boat h»usesa Ed gazeh<Ei v,i bin COastal Buffer ZOnei, where appropriate.Ho» ever, theic structurei may be prohibited in ienii ivc orcritical habitat areas. Due to the potential for theie i<ructufciio tntpact values provided by Coaital Buffer Zonei, theCouncil ih all exercise iigniticant diicretion in this area."

Appendix BRhode Island Coastal Buffer

Zone Management Guidance

Revised Jartttsrv 7, 1994

CRMt Coastal Buffer /one Manage nent thuidance

A. GuideBnes for preparing an appiicarion for CoasraiBuffer Zone hfanagen!carr

l. All proposals for buffer zone management must hcdesigned v, ith respect to the one or morc of the "Managemen Options" identlt'Ied in S«ction "B" ilf these guidet!nes an< must u it!zc appropriate techniques IOr managing vegetatiOn asde tned in Section "C".

2, Photograph~ «nd site plans must he suhmitted for allapplicati<ins in order o minimize the need for on-site inspec-tions. Actual field inspcc ions will only be performed whendeemed necessary by CRMC s aff. All applications should hecomplete, clear and concise. Applications which are unclear orimprecise will he returned.

3. Applications which propose acceptable alterationswithin Coastal Buffer Zones as de er!»i»ed by CRMC staft1will be processed as a "Category "A" and will reccivcadministrative approval. In cases where CRMC stat ' dctcr-mines the upplica ion to be unacceptable, an effon will bemade R> neg<>tiute a resolu ion with the applicant. If at'avorahle r«solu ion cannot be reached, CRMC statf v ill makea rccommcndati on to the Executive Director that the applica-liun be processed as a Category "B" rcvicw requiring tinaldecision by the full Coastal Council.

4. All proposals t'or Coastal Bulfer Zone managementshould involve minor altera iona which do not depreciate hevalues and I'unctiuns of Coastal Buffer Ztones as defined bySec i<>n f60 ot' he RICRMP. At a minimum, at least sixty�0%! of a buffer zone ~halt remain completely unahered.Typically, Coastat Buffer Zone Management Plans whichaffect 25% or less of a buffer zone arc more likely to beapproved. Areas to remain unaltered should be clearlyidemitied <m the proposed plans. An exception to thisrequireinent is allowed for "Suburban Coastal BufferZones" - see Section B.6 of this Guidance material.

S. Where appropriate, Coastal Bufter Zone manageinentmay be applied to Coastal Banks, However, the CRMC mayimpose greater restrictions on alterations affecting coastalhanks.

6. Tree damage and removal - in cases v here a smallnumher ot' dead, diseased, or storm damaged trees need to heremoved frotn a buffer zone, the applicant may request «nexpedited reviev. In such cases. a dcscnp ion of work and aphotograph of the area may bc sufficient for CRMC review.

B. rtfnnagen!ent opii rn! !I'i bin roa!raf buffer -r!nes:

t. Qh~rt~nA . P:tth. - Pitch ~ t htch t r ILCess O th<' shut«tine are nur!»'ltty CO»si feled;ippn>pl I.i «pathv iiys niay h«h' v'ide i>r l«vs anes iiut prOmiite <ruvion « Ithiii iti«hut'1<'IZune. Shur«tht« i<eeess paths i»uhi he dehi n«<t t«n»nn»IZCdisturbance and may he prohihi «d in sensitive hilhitat,irciis.including but not limiteit o. «Oas at v et ands. Pi!th«.!y ~ milyhv vegetated w i h gl asses and niow «c'I Or l»ay he surfaced v lthcrushed s <lne or mulch. Fec itizers may only be «llo«<d turthe initial cstahlishmen of gras<ed p.ithways. Prop«r sl eplans aust be submitted which show the loca ion il' th»proposed path throu'h he buffer zone. Applicants niay «Is<ibc r«quired to deiineatc the path on site lor C R%1C stat tinspection.

. ~V' m .y t.cttr trecr nt itt,tndh«»rind thinning ol'natur;il ! ege a»on may be allowed wiihin adet'ined COrridor in Order t<> prOmate a viev Of the shoreline.Only the minimal at!era ioii ol v«getation necess:iry to ohtairi aview shall be considered acceptahle clear cuttiri «nutallowed!. Shore inc access paths tif proposedl shiluld hclocated v'ithit! a view corridor to minimire disturhiincc withinth«buffer. Applicant< prOposing a viev COrtid<ir must pr<parea plan showing the view corrid<ir's location w lthili ihe Coav iilBuffer ZOne with res pe<'t 1O view pO n is ttx'!m 3 d v «ll liig olOther viewing area. View C >rrldOrs ure typically trapezoid<!I ilishape, heing narrow a the inland edge imd expandiri ' t!i< iir<tthe shore. On residential tots ot 2 iu:res or less, only one viev<corridor is typically considered acccptahl«. Vie«Corridor~n!ay not affect more than 25 % of the length of the CoavtalButfer Zone av measured along he shoreline feature. ViewCorr!dors may he prohibited in sensitive or critical h;>hi atilfcas

vegetation w<thin a Coastat Buffer tone io either enhanceu ildlifc hah<la or control nuisance and/or n >n-natl< «spec Icof vegeiation may hc alh>v ed wh«re it is demonvlratc<t tli;it thcex S ing «nvirOnmental COnditiuns v ill be in!prnved tor na I<«plantlife and v. ildlit'e. Additionally, homeowner contn>l olfiulsar!ee spec ietr of v«getat!on such atr Eurupean B »tern v< <.'L'Iand pols<m ivy are considered acceptable within managedportions of Coax at But'lbr 7~>nc . However. <he indis rimi-nate use of herbicides is prohibited and fertilizers may only h«used io enhance the replan log Of natl v«v «getat!un. tnaddition, niaintaining a buffer zone in;> "tandsci<ped condi-tion", or estahhshing lawn are not considered appropriatehab!tal managemen acti< it ies and are prOhihii«d. Irl Oilht !IBuffer Zones encompassing one acre <ir niore. clearing m,iyhe allov ed to establish tield e<inditi<»is which contain nativegrasses and herbaceous plants. In such caves. cl«<!ring tierf'ield establishment shall not atteci n!ore thin> 25% ot th<Coastal Butter Zone. All Butler Zone Maliagenieni pl:iriinvolving habitat managcnient within ii o.isla But'ter t iii«ilonc aerc <>r inure. ir in sensitive Or Critical habit<It;IIC.I< t asdetermine i by CRMC stat t! shalt suhl»!t a butter zoneInanageinent plan prcparCd hy;i qualified < nvlrnnnienlii!prnfexs!Onal ur bi<i!<>g»t.

70

4. Sg<fety gtL tt WSIftlrS - SefCCtive lr»» r»nloval andpruning and thinning of natural vegetation within a CoaitalBut't'er Zone !nay be allowed on a caie-by-case basis forprOven Safely and welt arC COnCerni ie.g., remOVal Of adamaged or discased tr»e in cloie proximity lo a dwelling!.order to promote child .iafe y and manage peti in areasharboring ticks. fcncei along hc iiiland cdg» of a CoaitalBuf'ter Z<inc and along ihorclinc acceii pa hi <>r shoreline ccrc:1t ion,'ifeai nlity' bc pcriri tcd lcficest must be Of ln"open" type coni ruction to permit thc paiiagc of v ildlife, e.g.split rail or iimilar!. Ciiaital Buffer Zone nianagement plansihall inctude methodi ot avoiding problem areas such ai theproper placement and maintenance of pathi.

5. ' ' - The CRMC recognizes thatihoreline recreation ii <me of lhe predominant a tractioni forliving on, or visiting thc Rhode island coait. In order to allowfor such uses, minor alterations ol Coastal Buffer Zones maybe permitted along the ihoreline it' they are determined to beconsistent with CRMC'i goaii and policies as noted in thcRhode island Coastal Resourcei Management Program R ICRMP!. Appropriate altcrationi typically include maintaininga small Clearing alOng thc shore for picnic lableS, benches, andrecreational craft dinghies, canoes, day sailb<>ats, etc.!.Additionally, where appropriate, the CRMC may allow smailf 200 sq. ft. total floor space, or leis!, non-habitable structuresincluding storage sheds. boat houses, and gazebos withinCoastal BufTer Zones. Due to the potential for these slruclurei o impact natural values provided by Coastal Buffer Zones, theCouncil shall exercise significant discre ion in this area.

ti. n - Where the CoastalBu fer Zone requirement is 25' or less as per RTCRMPSection 150, Table 2a!, the CRMC shall consider such bufferzonei "Suburban Coastal ButTer Zones". Suburban CoastalBuffer Zones may be tnanaged in their entirety f100%! byselective tree removal, selective pruning. selective thinningand restorative planting,. However, the CRMC may requiretha several tree~ bc maintained or planted o protect scenicquality.

C. ApprOprk fe reehniqtueS for n anaging regef< tiOni<gifhin a co< sr< l brzff'er zone:

I. ~f~civ T gg ggIIK<val � ln casei where the applicantwishes tO remove a few seleCt trees, trees proposed lo be cuttnust be specifically identified for CRMC staff revie~. Inmost case~, pho ographs of the buffer area may be sufficientprovided the affected trees are clearly shown in relation to thesurrounding buffer and shoreliiie. Trees may also be inarkedon-site to allow inspection by CRMC s aff. In order tominimize disturbance and allow monitoring by CRMC staff,tree stumps of fallen trees shall not be removed. CRMC staffmay make a follow-up inspection to verify that only markedtrees were cul based upon stump counts. Should the applicantwish to remove a fallen tree fro<n the buffer zone, this must beperformed in a inanner which does not disturb remainingvegetation. Selective tree removal is often a preferredtechnique for the establishmen of a view corridor.

purpOses iilvOlvei Catling bi a»Ches tfOrii rees, tice saphngsaad shrubi. F<ir certain C<iailal Buffer Zone ManagementOpt<oils. prUfllng he 1Opi Of Shruhi anil fOI'est UndergrOV lhiioppiiig! may bc appropriaue to diicourage growth in height.On level ground. ihriihi and forcit undergrowth should bepruned to a heigh of'not less than 4'-5'. !n areas where thegr<nind surt'acc deicends toward the shoreline, lopping shouldOnly be perfOrnied O a heigh lhat a! IOw i a view Of the v ater.Applicami proposing pruning must describe in detail the workpropoied, provide photographs and a iite plan. and/or narkthoic piirti<in.i ot' hc Coaital Buffer Zone where vegetationv ift be pruned on-iitc. Thc species of' vegeta ion to be prunedshould he <den <tied si»ce ionic species of vegetation cannot Olerate eXCeiiive pruning Or tnppiag, SeleC ive pruning iSoften a preferred technique tor the eilablishment of a vievc <1m d<ir,

3 bc~Lv~ILitng � Thinning ai defined for CRMCpurposei involves the ielecrive removal of' tree saptings.ihrubs and vinei occurring in bruih areas and in lhe arid<.r-growth ot tores ed buffer zones. Applicants proposinglhinning must describe in detail the work propoied, pr<iv dcphotographi and a site plan, and/or mark areas lo be thinnedon-site. Thc speciei of vegetation lo be removed from aCoastal Buffer Zone manage »en area rnui bc differentiatedfrom those ipeciei which arc to be retained and encouraged.Selective thinning ii often a preferred technique in areaiwhere habitat management will be performed.

Zone 1VIanagement, restorative planting shall be s rictl>det'ined as the pi alt ting or replanling of natural vegetationnative to the Rhode Island shoreline. However, naturalizedipeciei iuch ai Rugoia Rose may he allowed. «s dclcrminedby CRMC staff. The plan»ng ot non-native, landscape andCXO iC SpeCies, in mOil CaiCi, shall nO be»onsidercd apprOpri-ate in Coastal Buffer Zonci.

5. ~nt in � i mntt cn:e:, mowing oi egetetion w tiona Coasta! Buffer Zone shaiil be prohibited unless associatedwith the eitabliihrnent and maintenance of shoreline accesspath or approved shoreline recrea ion area. However, forcertain habitat mattagement options, annual or biannualmowing may be allOwed O maintain field VegetatiO» wheresu»h vegetation ii considered valuable to wiidlif'e and othernatural values, In such cases, mowing ~hall be confined to25% of' thc Coastal Buffer Zone area, or less.

6. Cli~ar<n - Clearing or clear-cutting of vegetationwithin a Coastal Bufter Zone shall only be aliowed for heestablishment of' shoreline access paths, shoreline recreationarcai and in certain cases. habitat management options whichare designed to maintain a field of native grasses and herba-ceous plariti. Clearing shall not affect more than 25% of theCoaital Buffer Zone area. Clearing for habi al managementih;dl not hc allowed in Coaital Buffer Zones of lesi than oneacre.

Q less l and grading shall ottty be allowed in Coastal Bufter Zoneareas for he establishment of shoreline access paths andshoreline recreation areas. Certain tninor cutting and filling,tctivities may also bc allowed on a case-by-case basis topromote these uses. Filling and grading shall not he allowedfor hah>tat management options.

Figure 10. Examp!e of an adequate buffer zone management plan drawn by owner.

1 Il' T . Vf t t 8 5 l' 4 B i l i 1 '3l - 00 i f. 3 - National Sea Grant ...

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