WEST END FLOOD MITIGATION STUDYCOLUMBIA COUNTY

FINAL PUBLIC MEETING MARCH 10, 2022

This study has been financed by grants from the Commonwealth of Pennsylvania, Commonwealth Financing Authority and the Department of Community and Economic Development.

WelcomeCOLUMBIA COUNTY BOARD OF COMMISSIONERS

Chris Young, ChairmanRichard Ridgway

David Kovach

SEDA-COUNCIL OF GOVERNMENTSTeri Provost

Director, Housing Rehabilitation and Flood ResiliencyGeralee Zeigler

Program Analyst, Flood Resiliency

COLUMBIA COUNTY RESILIENCY OFFICEEric Stahley

Columbia County Resiliency Officer

Study Team

Columbia County – Study SponsorSEDA-COG – Study Administrator

Brozena Consulting Services, LLC

TOWN OF BLOOMSBURG

HEMLOCK TWP

MONTOUR TWP

West End Flood Study Area

Floodplains of Fishing Creek in Town of Bloomsburg, Hemlock Twp & Montour Twp

~500 parcels~350 structures

Purpose & Goals of Study

Identify and Determine Best Structural and Non-Structural Flood Mitigation Alternatives:

• Provide flood resiliency - reduce long-term risk to loss of life and property damage

• Minimize future flooding impacts on Community • Identify possible funding sources• Reduce impacts of increasing flood insurance premiums

Overview

Overview of Study - Major Tasks• Inventory of Parcels & Structures - Mailed Surveys, Field Survey, First

Floor Elevations, Parcel Data• Stakeholder Meetings to Obtain Input• Hydrologic & Hydraulic Modeling of Fishing Creek• Identified Flood Mitigation Alternatives• Evaluated Flood Mitigation Alternatives – Impact, Cost-Benefit

Analysis, Funding

Flood Mitigation Projects Considered

Non-Structural Mitigation Projects• Residential Structures in Floodway – Acquisition/Demolition• Residential Structures in Floodplain – Acquisition/ Demolition, Elevations

or Mitigation Reconstruction• Commercial Buildings – Wet Floodproofing• Other – Emergency Access Roads, Floodproofing Wastewater/Utility

Systems, Emergency Action Plans, Additional Stream Gauges, Ordinances

Structural Mitigation Projects• Levee/ Floodwall Systems• Channel/ Floodplain Modifications

Typical Non-Structural Mitigation – Elevations

Non Structural Mitigation – Mitigation ReconstructionExample Rebuild with An Elevated Home at Same Location

Analysis of Flooding Impacts

Structure Flooding Analysis – Flood Lee

• Historical Accounts – High Water Marks

• H&H Modeling, First Floor Elevations, GIS Mapping

• Structure Flood Depths - utilized for evaluation of Mitigation Alternatives, Benefit-Cost Analysis, and FEMA Criteria for Funding projects

MONTOUR TWP

Analysis of Lee Flooding Depths–above 1st Floor Elevation

FISHING CREEK

HEMLOCK TWP

Analysis of Lee Flooding Depths–above 1st Floor Elevation

Analysis of Lee Flooding Depths–from 1st Floor Elevation

BLOOMSBURG

Analysis of Lee Flooding Impacts from 1st Floor

TOTALSBloom Hemlock Montour Project Wide

Basement Only: 16

Basement Only: 3

Basement Only: 1

Basement Only: 20

0' - 2' 83 0' - 2' 12 0' - 2' 2 0' - 2' 97

2' - 4' 91 2' - 4' 5 2' - 4' 2 2' - 4' 98

4' - 6' 34 4' - 6' 2 4' - 6' 3 4' - 6' 39

6' - 8' 20 6' - 8' 0 6' - 8' 1 6' - 8' 21

8' - 10' 7 8' - 10' 0 8' - 10' 0 8' - 10' 7

10' - 14' 29 10' - 14' 0 10' - 14' 0 10' - 14' 29

Total: 280 Total: 22 Total: 9 Total: 311

No Flooding: 17 No Flooding: 13 No Flooding: 15 No Flooding: 45Total

Evaluated: 297Total

Evaluated: 35Total

Evaluated: 24Total

Evaluated: 356

FEMA Funding Criteria Non-Structural Mitigation

FEMA Pre-Calculated Benefit Acquisitions: $323,000 per structureVoluntary Program

• Project deemed eligible when project cost is less than $323,000• If project costs is greater than $323,000, need to show Benefit-Cost Ratio

(BCR) > 1

~90% Residential Properties in Floodplain will qualify under FEMA Pre-Calculated Benefits

• 25% Local Share required with FEMA FMA and BRIC programs; HMGP no local share

FEMA Funding Criteria Non-Structural Mitigation

FEMA Pre-Calculated Benefit Elevations & Mitigation Reconstruction: $205,000 per structureVoluntary Program

• Project deemed eligible when project cost is less than $205,000• If project costs is greater than $205,000 need to show BCR > 1

Other funding required when:• The homeowner desires a higher elevated home resulting in a greater costs than

covered by FEMA (BFE + 2’ or Flood of Record Elev.)• If BCR is less than 1 (using FEMA Benefit-Cost Analysis) not eligible• 25% Local Share required with FEMA FMA and BRIC programs; HMGP no local share

Benefit–Cost Analysis (BCA)

• FEMA Methodology • Calculated Benefit-Cost Ratio (BCR) for each property and for total Aggregate • Inputs included Building Replacement Value, Square Footage, Modeled Depth of

First Floor Flooding• Considered Site Conditions (structure type, basement, USACE Generic Depth

Damage Curves determined expected damages and costs based on range and frequency of flood events)

• Mitigation Costs (Levee, Acquisitions, Elevation or Mitigation Reconstruction)• Incorporated Environmental and Social Benefits

BCA used to determine Cost Effectiveness

Flood Mitigation Alternatives

Montour TownshipHemlock Township

Town of Bloomsburg

Non-Structural Flood Mitigation Alternatives Evaluated For Each Municipality

Flood Mitigation - Non Structural Mitigation Actions

Montour Township• FEMA Buyouts – Voluntary• FEMA Elevations - Voluntary• RV Park – Emergency Action Plan • 3 Sanitary Pump Stations – Dry Floodproof• Construct Emergency Access Route from Reading St to Jackson St

across RR Montour Twp• Ordinance Revisions – Floodplain Management• Evaluate County Building for Floodproofing

Flood Mitigation - Non Structural Mitigation ActionsMONTOUR TOWNSHIP EMERGENCY EVACUATION ROUTE VIA JACKSON STREET

ESTIMATED COST = $125,000

Flood Mitigation - Non Structural Mitigation Actions

Hemlock Township

• FEMA Buyouts - Voluntary• FEMA Elevations - Voluntary• Emergency Access Road – Hassert to Laurel Street• Ordinance Revisions

Flood Mitigation - Non Structural Mitigation ActionsHEMLOCK TOWNSHIP - EMERGENCY EVACUATION ROAD

ESTIMATED COST = $600,000

CONNECTS HASSERTLANE TO LAUREL DRIVE

REQUIRES LAND OWNER COOPERATION

Flood Mitigation - Non Structural Mitigation Actions

Town of Bloomsburg

• FEMA Buyouts - Voluntary• FEMA Elevations - Voluntary• Wet Floodproofing Commercial Buildings • Emergency Evacuation Notification Siren (by W. First Street)• Fishing Creek Radar Gauge at Railroad Street• Fairgrounds – Additional Floodproofing• Ordinance Review – Floodplain Management

Flood Mitigation - Non Structural Mitigation Project

Susquehanna Flood Warning & Response System

Flood Mitigation - Non Structural Mitigation Project

Is There a Better Way?

• RetroFIT – Charlotte-Mecklenburg, North Carolina (2016)• Full range of flood mitigation options• Funded by County Stormwater Services Flood Mitigation Capital Budget• Property owner provides financial contribution, sliding scale

• Valmeyer Acquisition – Monroe County, Illinois (1993)• Acquired 242 Properties and relocated to high ground• Completed in 2 years• FEMA HMGP, State, EDA Funding

• Isle De Jean Charles Resettlement, Louisiana (2016)• Acquired 515 acres for 120 residential properties, commercial, retail, public spaces on higher ground• State CDBG Funding

National Flood Insurance Program

NFIP Risk Rating 2.0

Changes– Changes from Zone to Individual

Rating– Zone changes smaller difference

in costs– Replacement cost is part of

premium calculation– No elevation certificates needed– Premiums reflect unique flood risk

Staying the Same– Statutory rate caps on annual

premium increases– Availability of premium discounts– Transfer of policy discounts to new

owners– FIRM’s used for mandatory

purchase and Floodplain Management

– FEMA Community Rating System discounts

National Flood Insurance Program

H&H Evaluation of Fishing Creek – Channel Modifications to Reduce Flooding

• Lee Flood is considered 300-Year Flood on Creek and 200-Year Flood on River.• Evaluated existing creek channel to reduce Base Flood and Storm Lee Flood

Elevations. Doesn’t mitigate flooding to degree necessary for Bloomsburg or Hemlock Twp.

• Railroad Street Bridge and Stream Floodplain modifications provide significant reduction for Fernville flooding in vicinity of Railroad St Bridge and can mitigate some induced flooding from levee on Bloomsburg side.

• Dredging not feasible. Rock in stream bed prevents adequate excavation.

H&H Evaluation of Fishing Creek

Fishing Creek 2011 Record Flood

2011 FERNVILLE FLOODINGAT RAILROAD STREET BRIDGE

Fishing Creek 2011 Record Flood

H&H Evaluation of Fishing Creek

EXISTING RAILROAD STREET BRIDGE – FACING DOWNSTREAM

LENGTHENED RAILROAD STREET BRIDGE WITH BENCHED FLOODPLAIN – FACING DOWNSTREAM

H&H Evaluation of Fishing Creek

BENCHED FLOODPLAIN BENEFITS:

Compensates for lost conveyance in Bloomsburg Floodplain with levee option

Allows more flow through RR St Bridge rather than through Fernville

Environmental benefits of creek to Floodplain during lower flood flows.

FISHING CREEK HYDRAULICS

REDUCTION OF EXISTING FLOOD LEVELS

Modification Alternatives Near Hock Road @ Route 42 Bridge @ Barton Street Above RR ST Bridge

Remove Covered Bridge & Railroad Bridges 2.1 FT 0.0 FT 0.0 FT 0.0 FT

Remove Route 11 & 42 Interchange Ramp Fill 0.0 FT 0.3 FT 0.2 FT 0.0 FT

Remove Existing Island 0.0 FT 0.0 FT 0.0 FT 0.1 FT

Excavate Benched Floodplain and Modify RR St Bridge

0.0 FT 0.0 FT 0.2 FT 3.0 FT

Remove Railroad Street Bridge 0.0 FT 0.0 FT 0.0 FT 2.6 FT

100-YR EVENT

H&H Evaluation of Fishing Creek

Full Floodwall/ LeveeSystem

Bloomsburg6,200 LF

Total Estimated Cost

$29 million

Structural Flood Mitigation (Levees)

Full Levee System - West End of Bloomsburg

• Length of Floodwall System – 6,200 Feet (1.2 Miles)

• Induced floodingUpstream of Railroad Street – Negligible Downstream of Railroad Street along levee length – 1.8 Feet

Must be Mitigated to Zero

MITIGATION OF INDUCED FLOODING

REDUCTION OF INDUCED FLOOD LEVELS FROM LEVEE

100-YR EVENT

H&H Evaluation – Mitigate Fishing Creek Impacts

Location Induced FloodingMitigation Alternatives

Excavate Flood Bench & Modify RR Street Bridge Replace all Bridges

Barton St 2.5 FT ‐1.1 FT ‐0.6 FT

Leonard St 2.4 FT ‐1.5 FT ‐1.0 FT

Scott Ave 1.9 FT ‐2.0 FT ‐1.7 FT

Hemlock St 0.0 FT ‐1.0 FT ‐1.0 FT

Flood Mitigation – Structural Mitigation (Levee)

Benefits: Protect 294 Structures (including Fairgrounds Bldgs) in Floodway, Floodplain,

Zone x Total Property value = $42.9 Million Total Taxes Generated = $657,000

Challenges: Permitting Levee in Floodway / Eliminate Induced Flooding Property Acquisitions

Schedule: Engineering, Permitting, Property Acquisition – 18 to 20 months Construction – 20 months

OVERALL LEVEE/ FLOODWALL

SYSTEM CONFIGURATION

Municipality Flood Mitigation Alternative Estimated Cost(w/ Maintenance Costs) Over Life of 

System**

Benefit‐Cost Ratio(BCR)

BCR > 1  indicates “Cost Effective”

Bloomsburg Levee System $30 Million 3.65

Residential Acquisition – Floodway & Floodplain* $45 Million 2.07

Residential Floodplain Elevation & Floodway Buyout* $42.6 Million 1.84

Residential Floodplain Mitigation Reconstruction &Floodway Buyout* $52.9 Million 1.47

Hemlock Residential Acquisition* $6.3 Million 2.39

Residential Elevation* $4.3 Million 2.08

Montour Residential Acquisition* $4.3 Million 2.65

Residential Elevation* $3.3 Million 0.63

FEMA BENEFIT-COST ANALYSIS FLOOD MITIGATION ALTERNATIVES

*Calculated with 100% participation.**Life of System for BCR calculations ‐ Levee = 50 yrs, Acquisition =  100 yrs

Funding - Non Structural Mitigation• FEMA Grant Programs

Hazard Mitigation Grant Program – HMGPFlood Mitigation Assistance – FMABuilding Resilient Infrastructure and Communities – BRIC

• US Department of Housing and Urban Development

HUD CDBG-DR

• American Flood CoalitionFlood Funding Finder, resource for flood mitigation funding information

https://floodcoalition.org/resources/floodfundingfinder/

Funding – Structural Mitigation Systems (Levee)

• FEMA Building Resilient Infrastructure and Communities – BRIC

• FEMA Flood Mitigation Assistance - FMA

• The Federal Infrastructure Bill contains billions for flood mitigation and coastal restoration from storms. The Senate version of the bill contains $3.5 billion for FEMA's Flood Mitigation Assistance program, and $1 billion for FEMA BRIC

• State

Study Summary

Study Summary• Flood Insurance – April 2022, All existing policies renewing under Risk Rating

2.0, Contact Your Insurance Carrier • Flood Mitigation Alternatives – Non Structural & Structural (Levee) Alternatives

are Cost Effective (Benefit-Cost Ratios > 1), some Non Structural require individual analysis

• County and Municipalities Determine Mitigation Alternatives to Implement• Challenges

Acquisitions/ Elevations/ Mitigation Reconstruction – Voluntary Program Commercial Properties – Funding Options Levee – Further Analysis of Impacts/ Mitigation of Induced Flooding Levee – Permitting in Floodway

Next Steps - Final Study Report to be Published

Study Webpagehttps://seda-cog.org/departments/flood-resiliency/columbia-county-flood-mitigation-studies

Send Questions/ Commentsfloodstudy@borton-lawson.com

WILL BE AVAILABLE FOR PUBLIC

THANK YOU!

Questions?