Over the last decade, stream restoration has become an increasingly popular strategy for achieving sediment and nutrient load reductions. In the Chesapeake Bay watershed alone, approximately 700 miles of stream restoration projects are expected to be implemented to achieve the nutrient and sediment load reductions defined by the Chesapeake Bay TMDL. In 2013, the City of Frederick developed a watershed management plan for meeting NPDES Phase II MS4, Chesapeake Bay TMDL, and local TMDL requirements that include a set of candidate stream restoration sites. Before advancing these proposed projects, the City’s Sustainability Manager wanted to better understand the current conditions, restoration potential, and TMDL credits associated with each site. Reach-specific planning and analysis of the proposed project sites was necessary to ensure that City’s financial resources are directed to projects that offer the most benefit to the community and environment.
The City contracted with the Center for Watershed Protection (CWP) and Ecosystem Planning and Restoration (EPR) to assess six candidate stream restoration sites and to document, for each site, the existing stream functional conditions, functional uplift potential, proposed design approach, BMP potential, constructability, potential TMDL credits, and design and construction costs. As co-chair of the Chesapeake Bay Program BMP Expert Panel on Stream Restoration, the Center was well-suited to assist the City in proper application of the recommended crediting protocols.
CWP and EPR conducted rapid watershed, function-based stream reach-level, bank stability, and restoration feasibility assessments on each stream reach using the U.S. Fish and Wildlife Service’s 2015 Rapid Function-Based Stream Assessment and the agency’s (unpublished) Rapid Restoration Feasibility Assessment, as well as Rosgen’s 2009 Wildland Hydrology Bank and Nonpoint Source Consequences of Sediment Assessment. Preliminary TMDL reduction credits and treated impervious cover acres were calculated for each site following the guidance in the 2014 Recommendations of the Expert Panel to Define Removal Rates for Individual Stream Restoration Projects and Maryland Department of the Environment’s 2014 Accounting for Stormwater Wasteload Allocations and Impervious Acres Treated.
The final report summarized the assessment results and provided preliminary restoration solutions and design and implementation costs, excel spreadsheets documenting the results of the assessments and TMDL credit estimates, and an interactive GIS layer showing the locations of assessment results. This report is being used by the City as a “roadmap” to restore local streams and reduce sediment and nutrient loads entering the Chesapeake Bay from the City’s watersheds. This project helped to ensure that the City has detailed information to target implementation funding to the best possible projects and provide the initial data for post-construction load reduction accounting using the expert panel protocols.
Funding to conduct these assessments was provided by the City of Frederick as well as a grant secured by CWP from the Chesapeake Bay Trust’s Watershed Assistance Grant Program. To learn more about this project, contact Bryan Seipp at bts@cwp.org.
