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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #171125
Title: WATERSHED-LEVEL BMP SELECTION AND PLACEMENT IN THE TOWN BROOK WATERSHED, NY

Author
item GITAU, MARGARET - PENN STATE UNIV.
item Veith, Tameria - Tamie
item Gburek, William
item JARRET, A - PENN STATE UNIV.

Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2006
Publication Date: 12/29/2006
Citation: Gitau, M.W., Veith, T.L., Gburek, W., Jarret, A.R. 2006. Watershed-level Best Management Practice Selection and Placement in the Town Brook Watershed, New York. Journal of the American Water Resources Association. 42(6):1565-1581.

Interpretive Summary: Optimal scenarios for Best Management Practice(BMP) selection and placement were determined for the Town Brook Watershed, a 3700 ha watershed that is part of the New York City water supply. The scenarios were determined by combining phosphorus(P) losses as simulated by the Soil and Water Assessment Tool(SWAT), BMP effectiveness estimates from a BMP tool, and BMP costs in an optimization using the Genetic Algorithm. Results from the optimization favored the use of nutrient management plans, crop rotations and contour strip cropping, alone or in combination, as well as riparian forest buffers, with the BMPs being placed where they offered the greatest benefits in terms of reducing both P losses and costs. With the optimal BMP scenarios, P losses could potentially be reduced by an average of 60% over time, with the most effective scenario having a cost-effectiveness of $24 spent/kg P removed /year, an improvement from the basic scenario ($34 spent/kg P removed /year).This study showed that P losses could be reduced substantially even when BMPs were applied selectively (that is, to selected high P-loss areas). Selective implementation of BMPs, however, did not always offer the most cost-effective solution. This study demonstrates the importance of evaluating potential BMP solutions before BMPs are implemented, and offers a means by which alternative scenarios can be evaluated. The study can now be extended to the larger New York City watersheds, as well as to other watersheds for which BMPs are being considered.

Technical Abstract: There has been on-going implementation of Best Management Practices (BMPs) within the Town Brook Watershed (TBW) as part of a watershed-wide BMP implementation effort to reduce phosphorus (P) losses to the New York City water supply reservoirs. Currently, there are no quantitative indications of the effectiveness of these BMPs at the watershed scale. Additionally, BMPs come at a cost, thus the need to search for the best way(s) to select and place BMPs on a watershed so that maximum pollutant removal is achieved at minimum cost. This study determined optimal BMP selection and placement for the TBW by combining simulations of P loss by SWAT, BMP effectiveness estimates from a BMP tool, and BMP costs using a Genetic Algorithm (GA). Optimum scenarios favored nutrient management plans, crop rotations, and contour strip cropping, alone or in combination, and riparian forest buffers. With these BMPs, simulated P losses were reduced by up to 60%, with a cost-effectiveness of $24/kg P removal/year compared to the $34/kg P removal/year associated with the current basic BMP scenario. This study demonstrates the need for determining and evaluating potential BMP solutions prior to implementation and offers a means of generating and evaluating these solutions.