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Chesapeake Stormwater Network
New Guidance for
the Prevented
Sediment Protocols
Josh Running Lisa Fraley-McNeal
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Poll Question #1
Tell us a little about yourselves…who are you representing today?
▪ Local government
▪ Private sector
▪ Regulatory agency
▪ Non-profit
▪ Academia
▪ Other…tell us in the chat box
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Poll Question #2
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Who are you watching with today?
▪ Just me!
▪ My spouse/significant other
▪ My children
▪ My pets
▪ Some combination of the above
Poll Question #3
What best describes your experience with the prevented sediment protocol?
➢ I have designed or constructed stream restoration practices for Protocol 1 credit
➢ I’ve done watershed planning that involved P1 to meet pollutant reduction goals
➢ I review and/or permit projects that received credit using P1
➢ I conduct research on stream restoration projects
➢ I am an interested party just trying to stay up with the latest and greatest
➢ Other
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Today’s Speakers:
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David WoodCSN
Lisa Fraley-McNealCenter for Watershed Protection
Josh RunningStantec
Agenda
1. Group Background and “The
Charge”
2. Recommendations Overview
3. Bank Armoring
4. Site Specific Data Collection
5. Monitoring Guidance
6. Modeling Guidance – Calibrating
BANCS
Safety
Moment
How Quickly Things Change!
COVID-19 has altered the way we
live our daily lives
Social Distancing, wash your
hands, watch out for your
neighbor
Group Background and “The Charge”
Group 3 - Protocol 1
History of CBP Stream Restoration Crediting
• Expert Panel Report approved in 2013
• Report was revised after a “test-drive”
period in 2014
• Changes in how streams and
sediment are simulated in Phase 6
watershed model in 2017
• USWG approves SR Protocol FAQ
document in early 2018
• 5 Groups formed to revisit Protocols in
mid-2018
Key Elements of the Original Report
• 3 Protocols to address different pollutant removal pathways
• Qualifying conditions to define eligible practices
• Emphasis on functional uplift and comprehensive restoration
• No “mud-slinging” at other design approaches
Background
The Stream Restoration Protocols
4. The “tweener” Dry Channel RSC
1. Prevented sediment 2. In-stream denitrification
3. Floodplain reconnection
Protocol 1: Prevented Sediment
• Step 1: Estimate the rate of streambank
sediment erosion
• Step 2: Use soil nutrient concentrations to
determine N and P rates
• Step 3: Multiply by 50% to determine final
credit (unless monitoring shows better rate)
Background
Revisiting Stream Restoration
The USWG formed 5 groups to revisit the stream restoration expert
panel report:
• Group 1: Verifying Stream Restoration Practices
• Group 2: Outfall and Gully Stabilization Practices
• Group 3: Establishing Standards for Applying Protocol 1
• Group 4: Adjusting Protocol 2/3 to Capture Floodplain Restoration
• “Team” 5: Floodplain Reconnection with Legacy Sediment Removal
Background
The Group: Membership for Group 3Overview
Table 1. Membership for Group 3
Name AffiliationDrew Altland RKK
Lisa Fraley-McNeal Center for Watershed Protection
Joe Berg Biohabitats
Rich Starr Ecosystem Planning and Restoration
Josh Running Stantec
Matt Meyers Fairfax County, VA DPWES
Bill Brown PADEP
Jeff White MDE
Josh Burch DOEE
Reid Cook RES Consultants
Aaron Blair EPA
Tess Thompson Virginia Tech
Joe Sweeney Water Science Institute
A Few Provisos…
• These are Bay guidelines… final authority on any and all
regulatory/permitting issues remains with the appropriate
local/state/federal agency
• Memo was approved for urban stream restoration
practices. New guidance is being developed for NRCS
practices.
• Grandfathering Clause: New recommendations take
effect July 2021
Background
Recommendations Overview
Group 3 - Protocol 1
Why The Need?Overview
One of the fastest growing BMPs – hundreds of miles in the pipeline
Several key concerns based on past 5 years of implementation
experience:• Observations when comparing defaults to onsite data in different geologies
• Over-reliance on default rates (idea for use as planning only)
• Need for a clear “bank armoring” definition
• Need for guidance on monitoring and modeling methods to improve
consistency across practitioner community
The Recommendations
• Clear definition of bank armoring
• Emphasis on site-specific data collection
• Clear guidance for monitoring and modeling
approaches
• Recommend ways of “calibrating” BANCS
assessments
Overview
Bank Armoring
Group 3 - Protocol 1
Bank Armoring: Original vs. Group 3 Memo
Original Expert Panel definition/guideline was only
one sentence:
“Projects primarily designed to protect public infrastructure by
bank armoring or rip rap do not qualify for a credit.”
New Group 3 Memo bank armoring definitions,
crediting methods are more expansive to include:
• Non-creditable
• Creditable with Limits
• Creditable
Bank Armoring
Non-Creditable
Definition: Highly engineered, permanent structures used to protect critical infrastructure and stabilize banks.
• Concrete Retaining Wall• Sheet Piling/ Planking• Gabion
• Engineered Block Walls• A-Jacks• Dumped Rip Rap
• May not be used unless required for critical infrastructure protection
• Any length of banks using these techniques must be subtracted from total restored length
• May require mitigation to replace lost function
Bank Armoring
Creditable with Limits
Definition: Large rock or boulder structures that harden a limited portion of a bank or bank toe in a localized area.
• Angular Rip Rap for bank protection or localized toe protection• Boulder Revetments• Non-biodegradable soil stabilization mats• Imbricated Rip Rap
• May be used on up to 30% of total bank length
• Any use over 30% is subtracted from final load reductions
• Should only be used in areas of high shear stress (outer bends, etc.)
Bank Armoring
Creditable
Definition: Structures that mimic naturally occurring streambank materials, features that provide aquatic habitat function, and limited in-stream grade control.
• Root wad Revetments• Live stakes/coir logs• Soil lifts
• Riffle-weir series• Berm-pool cascades• J-hooks and cross-veins
• No limitations on use
• Full credit provided
Bank Armoring
Site-Specific Data Collection
Group 3 - Protocol 1
Dealing with the Defaults Site-Specific
Original Expert Panel definition/guideline:• Nutrient Concentration Default Rates
• Bulk Density Example Being Used as Default
• Over-Use of Default Nutrient and Sediment Reductions
New Group 3 Memo:• Site Specific Monitoring for Bulk-Density and Nutrient Concentration
• Recommended Field and Lab Methods
• Explicit language on need to use the Protocols
• Separate section on recommendations for planning level estimates
Site-Specific Data Collection: Bulk DensitySite-Specific
Volume of Bank Erosion X Bulk Density = Sediment Load
Source: The Water Research Foundation and Center for Watershed Protection (2018)
Site-specific monitored bulk density is required prior to reporting.
The bulk density value has a significant impact on sediment load calculations.
Source: https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs143_019165.pdf
Case study bulk density
example has been used
erroneously as a default value.
Site-Specific Data Collection: Nutrients
Summary of streambank nutrient concentration values (lbs/ton of sediment)
Site-Specific
Sediment Load X Nutrient Concentration = Nutrient Load
Site-specific monitored nutrient concentration is now required prior to reporting.
Nutrient concentration has a significant impact on nutrient load calculations.
Defaults Values in the Expert Panel Report:
• 1.05 lbs P/ton sediment
• 2.28 lbs N/ton sediment
Recommended Methods:
• Total-sorbed P – EPA Method 3051 + 6010
(USEPA 1986)
• Total N combustion testing (Bremner 1996)
*Referenced in original Expert Panel Report
Recommendations for
Planning Level EstimatesSite-Specific
Default rates now vary based on project location due to changes with how sediment
delivery is simulated in the Phase 6 Model. Appendix B in the work group memo
provides steps to make the adjustment.
The default rates should never be used for project reporting to the state.
Default Nutrient and Sediment Reductions per Linear Foot of
Qualifying Stream Restoration (lb/ft/yr), Applied at Edge-of-Stream
Recommendations for
Planning Level Estimate Using BANCSSite-Specific
Bulk Density: USDA Soil Survey Datahttps://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/survey/
Nutrients:
Default Values in the Expert Panel Report
• 1.05 lbs P/ton sediment
• 2.28 lbs N/ton sediment
The planning level estimates should never
be used for project reporting to the state.
Monitoring Guidance
Group 3 - Protocol 1
Monitoring Guidance:Original vs. Group 3 Memo
Original Expert Panel allowed for:
• Use of “alternative monitoring and modeling
approaches” to estimate sediment loss along a
proposed reach
• Monitoring to be used to demonstrate better
pollutant removal than 50% efficiency
New Group 3 Memo recommendations:
• Describe bank pin monitoring, permanent cross-
sections, bank profile, and DEM differencing
methods
• Monitoring guidance to obtain more than 50%
efficiency
Monitoring
Monitoring GuidanceTo obtain greater than 50% restoration efficiency
• Directly measured pre- and post-restoration sediment loss from
streambank erosion
• Need 3 years of post-restoration monitoring before re-calculating
reduction efficiency
• Use same monitoring method for pre- and post-analysis
• Re-report the back-dated BMP and remove the original record
Monitoring
Source: http://awramedia.org/jawra/tag/fluvial-processes/
Source: Merritts et al. 2019. DEM Differencing Change Detection Analysis Report
for 3 BMP sites in the Paxton Creek Watershed, Dauphin County, Pennsylvania.
DEM Differencing
DEM Differencing
Monitoring
Source: Merritts et al. 2019. DEM Differencing Change Detection Analysis Report for 3 BMP sites in the
Paxton Creek Watershed, Dauphin County, Pennsylvania.
Bed and Bank Erosion
DEM DifferencingMonitoring
Source: Merritts et al. 2019. DEM Differencing Change Detection Analysis Report for 3 BMP sites in the
Paxton Creek Watershed, Dauphin County, Pennsylvania.
Deposition
Modeling Guidance – Calibrating BANCS
Group 3 - Protocol 1
Guidance – Calibrating BANCS
• Assessments should be performed by teams of
two experienced professionals
• Focus on most sensitive parameters (bank height, root depth/density, materials (clay))
• Develop BANCS manual, QAQC procedures
and training program for the Chesapeake Bay
• BEHI, NBS and Bulk Density guidance docs
included in appendices of updated memo
Modeling
Development of New Bank Erosion Rate Curves
• Recommends the development of two new bank erosion
rate curves for the Chesapeake Bay watershed:
Coastal Plain Curves and Piedmont Curves
Modeling
• To date, numerous data points have been collected from both
the coastal plain and piedmont...
But more data points are still needed
• Several key data needs and decisions
were identified (needle in haystack, V.High/Low)
• Development will likely take 2 years+
and additional funding
• Lessons Learned in the Catskills, NY90
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40 45 50 55 60 65 70
Ele
vation
Station
baseline
2017115
20180605
20180829
20190626
Without change there is no innovation,
creativity, or incentive for improvement.
Those who initiate change will have a
better opportunity to manage the
change that is inevitable.
William Pollard
Questions ?
Memo Link: https://chesapeakestormwater.net/download/9928/
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