Spatial distribution of best management practices for stormwater management
In response to increasing imperviousness resulting from urbanization, many municipalities have used Best Management Practices (BMPs). Strategically, BMPs can be implemented using a centralized or decentralized approach. But recently, the decentralized approach is gaining more attention due to its better hydrologic functionalities in most local practices. Although it might suggest broad implementation at site scales, still little is known about locational decisions for the systems of BMPs at a watershed scale.
This study is designed to understand the spatial distribution of the systems of BMPs at a watershed scale through their hydrologic performances, economic benefits, and policy implications. A peak flow is determined to be the primary variable of interest and targeted to characterize spatial distribution of BMPs. Construction cost of regional pond forms the basis of the economic valuation. The employed analytical methods are Hydrological Simulation Program-FORTRAN (HSPF), benefit transfer/engineering cost/avoided cost methods, and policy interpretation.
The main results are that (1) it is most effective to have partially distributed BMPs in the upper reaches of the watershed (787m3/s) and the common practices - centralized BMPs in either a downstream (841 m 3/s) or single watershed (816m3/s) - are the least effective choices for peak discharge attenuation at a watershed scale; (2) savings exist between the locational differences and reduced peak discharge increases cost savings. Potential cost savings range from $3,985 to $10,671 at a watershed scale and from $0.06 to $0.15 per 0.4ha (lac). The largest saving can be obtained when BMPs are partially distributed in the upper watershed; and (3) the primary responsibility for stormwater management is with local governments and most counties and states have the advisory and informative roles. However, a federal agency has a regulatory role.
For policy implications, it is discussed that (1) functional guidelines and inner jurisdictional partnership might be useful for both resource and institutional efficiency based planning; (2) the estimated locational marginal cost ($/ac) are introduced as a policy variable to stormwater utility fee system, impact fees, and subsidy; (3) providing readily usable information through information portal would help regulatory agents and the public focus on better planning and policy alternatives.
Area planning & development
0999: Urban planning
0999: Area planning & development