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12/1/2015
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© 2014 HDR Architecture, Inc., all rights reserved.© 2014 HDR Architecture, Inc., all rights reserved.© 2014 HDR Architecture, Inc., all rights reserved.© 2014 HDR, Inc., all rights reserved.© 2014 HDR, Inc., all rights reserved.© 2014 HDR, Inc., all rights reserved.© 2014 HDR, Inc., all rights reserved.
© 2014 HDR, Inc., all rights reserved.
SCASM 4th Quarter Meeting
Stream Restoration as aBMP for TMDL Compliance
01 Overview of SCR030000 PermitSection 3.2.1.2.2
02 Making a Stream a BMP
03 Inside the Chesapeake Bay TMDL
04 Case Study – Hopewell, VA
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http://www.scdhec.gov/tmdl
SCRO30000 Permit Section 3
o 3.2.1 – Monitoring & Assessment Plans
o Section 3.2.1.2.2
• Process for Assessment
• Selection of BMPs
o Section 3.3
• Data Assessment
• BMP Prioritization
• Schedule
Beyond TMDL Monitoring &Assessment Plan
TMDL Implementation Schedule (Existing MS4)
Activity Existing TMDLs New TMDLs
Monitoring/Assessment Plan January 1, 2015 Within 12 months of TMDLEffective Date
Monitoring Plan Initiated July 1, 2015 Within 24 months of TMDLEffective Date
Monitoring Duration 2 years 2 years
TMDL Implementation Plan January 1, 2018 Within 48 months of TMDLEffective Date
Monitoring of TIP, Revisions Ongoing through Permit Cycle Ongoing through Permit Cycle
TMDL Implementation Schedule (New MS4)
Activity Existing TMDLs New TMDLs
Monitoring/Assessment Plan January 1, 2016 Within 24 months of TMDLEffective Date
Monitoring Plan Initiated July 1, 2016 Within 24 months of TMDLEffective Date
Monitoring Duration 2 years 2 years
TMDL Implementation Plan January 1, 2019 Within 60 months of TMDLEffective Date
Monitoring of TIP, Revisions Ongoing through Permit Cycle Ongoing through Permit Cycle
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Non-Structural BMPs
o Public Education
o Ordinances/Rules/Regulations
• Better Site Design
o Pollution Prevention
o Street Sweeping
Structural BMPs
o Stormwater Treatment
• Wetlands
• Wet Ponds
o Runoff Reduction
• Bioretention
• Permeable Pavement
BMPs for Consideration
What can it do for your watershed
o Stream bank erosion
o Floodplain connection
o Riparian buffers
o Water quality/Aquatic lift
What other benefits can it have
o Stabilize or improve property value
o Protect other infrastructure
o Community connections (i.e. greenways)
What about StreamRestoration as a BMP?
Sediment
Nitrogen
Phosphorus
Bacteria
Pollutants of Concern with Stream Restoration
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Bay TMDL Action Plans
Three tier process to get to full complianceby 2025
o First Permit Cycle – 5%
o Second Permit Cycle – 35%
o Third Permit Cycle – 60%
Pollutants of Concern (reductions fromimpervious)
o Sediment – 20%
o Nitrogen – 9%
o Phosphorus – 16%
Experiences fromChesapeake Bay
Cost-effectiveness of Stream Restoration
Cost-effectiveness of Stream Restoration
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Publications
Stream Restoration
Stormwater BMP Retrofits
Expert Panel Researchand Policy Development
Default Values for Planning (Virginia DEQ Guidance Memo)
Detailed Values for Design (Expert Panel)
Stream Restoration Guidance
Panel of Experts Protocol
Protocol 1
o Credit for Prevented Sediment duringStorm Flow
Protocol 2
o Credit for In-Stream and RiparianNutrient Processing within theHyporheic Zone during Base Flow
Protocol 3
o Credit for Floodplain ReconnectionVolume
Detailed Analysis
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Case Study – Hopewell, VAMarina BMP Project
Targeted BMPs
Stream Bank Stabilization
Regenerative Stormwater Conveyance
Wetland Enhancement/Expansion
Stream Restoration
Hopewell Marina BMPProject
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Targeted BMPs
Stream Bank Stabilization
Regenerative Stormwater Conveyance
Wetland Enhancement/Expansion
Stream Restoration
Hopewell Marina BMPProject
Targeted BMPs
Stream Bank Stabilization
Regenerative Stormwater Conveyance
Wetland Enhancement/Expansion
Stream Restoration
Hopewell Marina BMPProject
Targeted BMPs
Stream Bank Stabilization
Regenerative Stormwater Conveyance
Wetland Enhancement/Expansion
Stream Restoration
Hopewell Marina BMPProject
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Prevented Sediment
Data Needs
o BEHI and NBS Scoring of existing stream
o Bank Height
o Soil Bulk Density
Calculations
o Determine Erosion Rate
o Calculate Sediment Loss
• Apply Efficiency Rate (50%)
• Apply Soil Delivery Ratio (0.061 for Coastal)
o Apply ratio for N and P
Protocol 1
In-Stream and RiparianNutrient Processing
Data Needs
o Design Bankfull Section
o Soil Bulk Density
o De-nitrification Rate
Calculation
o Hyporheic Area
o Total Mass of N Loss (Tn/day)
o Covert to Pounds per year
o Credit only for Nitrogen
Protocol 2
Floodplain Reconnection Volume
Data Needs
o Storm Event that activates floodplain
• Concert to Rainfall Depth
o Amount of Storage/Treatment byFloodplain
o Rain Data for examining range ofevents
Calculation
o Rainfall depth to access floodplain
o Floodplain Storage Volume (WatershedInches)
Protocol 3 Similar Curves for N and P
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Subject to VDEQ Final Review
Summary of Results – Protocol 1
Subject to VDEQ Final Review
Summary of Results – Protocol 1
Subject to VDEQ Final Review
Summary of Results – Protocol 2
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Subject to VDEQ Final Review
Summary of Results – Protocol 2
Subject to VDEQ Final Review
Summary of Results – all BMPs
Is Stream Restoration an Effective BMP?
Yes
May not be for all situations and pollutants of concern
Best Practices are available to quantify its benefit
o Chesapeake Bay TMDL
o Gwinnet County, GA
Summary
Recommended