On May 13, 2013, the Chesapeake Bay Program (CBP) Water Quality Goal Implementation Team accepted the final recommendations of an Expert Panel to establish new protocols for determining allowable pollutant removal rates associated with Urban Stream Restoration. The new protocols represent an order of magnitude increase in allowed removal credit and provides the impetus for localities to shift resources toward urban stream restoration in order to most cost-effectively meet nutrient removal goals outlined in the Chesapeake Bay TMDL. Table 1 provides a comparison of old, interim, and newly approved removal rates and the cost per pound of pollutant removed. Example calculations are presented in Section 6 (pg. 42- 44) of the Panel's recommendations.

In 2011 the Panel set interim removal rates to be used until final rates were established and approved. Interim rates were based on preliminary review of available research information and may still be used for historic projects or to estimate potential removal for projects during the planning stages. Beginning in early 2012, the Panel began a comprehensive review of research regarding pollutant/nutrient removal associated with BMP Urban Stream Restoration projects. Upon completing this review the Panel decided to abandon prior approved CBP removal rates in favor of a system which recognizes four different protocols for defining pollutant load reductions:

The Panel felt that applying one set of removal rates to all stream restoration projects was neither "practical (nor) scientifically defensible." Instead, the Panel chose a tiered approach in which multiple protocols may be applied to a project to gain additional removal based on the level of restoration achieved by an individual design. The protocol framework establishes a mechanism for localities to receive credit for stream restoration projects and details the requirements for project acceptance. Additional information on the development of these protocols and requirements for credit allowance may be found in the report titled "Recommendations of the Expert Panel to Define Removal Rates for Individual Stream Restoration Projects."

For more information, please contact Nathan Staley, Mike Rolband, Frank Graziano, or Brian Chromey.

¹$750/lf was used to conservatively approximate costs associated with urban stream restoration.

²Numbers presented in this table assume that restoration with in-stream nutrient cycling is achieved (Protocols 1 and 2 applied). The pre-construction channel used in this example was assumed to have a 15-ft bankfull width with 4-ft high eroding banks covering 50% of the project area. Analysis assumes moderate near bank stress and BEHI scores for use in the USFWS bank erosion curve. Banks were assumed to be fine-grained material with a bulk density of 1.2 ton/cu. yd. A removal efficiency of 50% for stream restoration practices was applied. All banks of the post-construction channel are assumed to achieve a bank height ratio of 1.0.