Achieving sustainable urban watersheds through incentive-based decentralized stormwater mitigation

Background/Question/Methods Many US cities are struggling with aging and undersized stormwater management systems, outgrown by sprawl and infilling and no longer sufficient to meet current water quality laws. Residents in watersheds with centralized stormwater management systems are little more than “taxpayers”, with no involvement in mitigating a problem they contribute to beyond their checkbook. However, a growing number of cities are moving towards decentralized stormwater management systems, which maintain water storage and infiltration throughout the watershed using combinations of stormwater management tools, such as permeable pavement and water-retaining landscaped areas. Decentralized systems result in more natural hydrologic dynamics for the watershed and improved ecological conditions in the headwater streams, and more directly connect property owners with the source and solution to stresses in their watersheds.

Results/Conclusions Here, we present a method for extending a decentralized system to private property through the use of economic incentives for on-site stormwater mitigation practices. These practices, such as rain gardens and rain barrels, can represent substantial storage capacity when installed on many properties throughout a watershed. We used an economic auction to distribute rain gardens and rain barrels in Cincinnati, Ohio, throughout a small (1.8 km2), residential watershed where the majority of impervious surface occurs on private property. We have monitored the hydrology, water quality, and biotic assemblages of streams in the watershed before and after installation of stormwater mitigation practices. We argue that a voluntary program of economic incentives to distribute decentralized stormwater management practices on private property encapsulates all of the social, ecological, and economic dimensions of watershed sustainability. The approach may represent an ecologically effective and economically efficient approach to mitigating urban stormwater runoff and improving aquatic ecosystems, and encourage people to view themselves as active participants in the state of their watersheds.