I am writing to provide three comments on Guidance Memo No. GM23-2004 – Accelerated Release of Nonpoint Source Nutrient Credits for Stream Restoration Projects.  

1. The justification for the release of 50% of the credits prior to the occurrence of a bankfull flood event or end of Year 1 monitoring is justified based on crediting guidance that allows only 50% of the estimated nutrient load reduction to be applied as credited nutrient reduction ("50% efficiency").  The decision to only allow 50% of the estimated load reduction be "counted" as credit was made to provide a "factor of safety" or margin of error, in recognition that the load calculations are estimates.  This factor of safety provides a conservative estimate of the likely achieved load reduction to provide additional assurance that water resources are improved.  I served on the committee that made this decision for the Chesapeake Bay watershed TMDL.  Increasing the initial credit release from 25% to 50% is less protective of water resources, not more protective.  Therefore, the "50% efficiency" is not a justification or basis for an increase in the amount of credits initially released and is instead simply the maximum amount allowed by SB 187.  
2. Having conducted an assessment of over 60 stream restoration projects and more than 500 instream structures, it is evident that a major failure mode for instream structures is when stream flows exceed bankfull discharge and cause erosion behind structures, at the interface of the bank and the structure.  Since most structures are built to the bankfull stage, the greatest risk of structure failure is during floods that exceed the bankfull stage.  Therefore, it is recommended that accelerated credit release only be allowed if there is at least one flood that exceeds bankfull stage, rather than just meets bankfull stage.  
3. While having the accelerated criteria be applicable only to low-risk projects is more protective of water resources, it is possible that this requirement will encourage conservative designs that utilize large rock structures that prevent natural channel adjustments.  It is important that the criteria for what constitutes a "low risk design" not discourage innovative designs that could produce more ecological benefits than traditional, form-based, static designs.  My research has shown that projects constructed in urban watersheds or watersheds that have recently undergone urbanization have greater risk than projects in rural watersheds or watersheds with stable landuse/land cover.  Additionally, projects with more frequent floodplain access (lower relative bank height and higher width-to-depth ratio) are more likely to be successful.  

I am happy to discuss these points further and/or share my research findings.

Best regards,

Tess Thompson

Associate Professor

Department of Biological Systems Engineering

Virginia Tech

DEQ should pause approving and funding stream restoration projects until their true nutrient reduction benefits have been studied and quantified.  A water monitoring study on Taylor Run in Alexandria, VA, completed in March of 2022, indicates that stream restoration may not improve water quality or reduce nutrients flowing into the Chesapeake Bay.  On the contrary, the study showed that most of the nutrient pollution flows into Taylor run from the upstream watershed.  So, a reengineering of this small urban stream would have done little to reduce the nitrogen, phosphorous, or sediment pollution in the Chesapeake Bay.  Worse, the use of construction equipment in the stream bed and stream valley would have likely increased sediment pollution flowing into the Bay.  As a result of the study, the City of Alexandria abandoned its plans to "restore" Taylor Run.  A few important takeaways from the study are listed below.  

• When evaluating nutrient reductions from a stream restoration project, do not rely on pollution reduction estimates derived from the Bank Erosion Hazard Index (BEHI) method.  They overstate nutrient reductions.  
• Stream bank soil sampling might give a better estimate of potential nutrient reductions from the proposed project, (but as we later learned, these estimates might also be badly inflated).  
• Water quality monitoring is the only way to accurately quantify nutrient reductions for a proposed stream restoration project.  
• Base nutrient reductions on good measurements and sound science.  

A copy of the Taylor Run final report has been forwarded to Tyler Monteith as an attachment to be included in these comments.  

Many environmental advocates have voiced concerns about the invasive and destructive nature of so called "stream restorations" which may do little restoration, but instead, a surprising amount of damage.  One advocate, Ken Bawer, has created a video on a stream restoration in Gaithersburg, MD that captures the concerns of many environmentalists.  Please take a moment to view this insightful video at: https://youtube.com/watch?v=NvTvPnG6Qs8.  

Given these concerns, it would be unwise and a poor management decision to accelerate the release of nutrient reduction credits for stream restoration projects.  

Virginia's streams and the stream in the rest of the Chesapeake Bay watershed are probably not the major source of nutrients degrading the Chesapeake Bay.  Nonpoint source pollution, transported by these streams to the Bay, is a problem that needs to be addressed, however.  

The Virginia DEQ is in a unique position to conduct water quality monitoring projects that clearly show the sources of nonpoint source nutrients that pollute the Chesapeake Bay.  It has the manpower and expertise to: 

• Conduct Taylor Run like studies that carefully quantify the benefits, if any, of a stream restoration project.  By monitoring at the upstream and downstream ends of a proposed project, DEQ can determine whether the stream is the source of the nutrient pollution or the upstream watershed.  
• Conduct water quality monitoring studies that clearly show where the nutrient pollution is coming from.  

Rather than reengineering streams, the Virginia DEQ should focus its manpower and resources on funding stormwater Best Management Practices (BMPs) in Virginia watersheds.  BMPs slow, filter, and sequester stormwater.  The upstream watershed appears to be the source of the nonpoint nutrient pollution problem.  Let's focus our efforts on the real problem.  

Thank you for the opportunity to comment on this proposed guidance document.  We would be happy to continue a dialog with the DEQ on this important matter.  

Sincerely, 

William Gillespie and Russell Bailey