Coyote Wash Urban Enhanced Runoff Recharge Project (AZ)

WEST assisted Cochise County, Arizona, with the Coyote Wash (Buena School Watershed) Urban Enhanced Runoff Recharge Project, a USDA-NRCS P.L. 83-566 grant-funded project. The Cochise County Highway and Floodplain Department contracted with WEST to develop a watershed plan and environmental assessment (Plan EA), construction drawings, cost estimates, and specifications for a new recharge facility on the 2,984-acre Bella Vista Ranch capable of recharging up to 630-acre feet of stormwater runoff per year. The goals of the project were to capture urban enhanced runoff and thereby: reduce flood risk, erosion, and sediment yield within the watershed; increase baseflows and improve riparian habitat for threatened and endangered species along the San Pedro River; and enhance water security for local communities. Recharge of the alluvial aquifer is intended to raise groundwater levels and support the declining base flows in the San Pedro River. Properly constructed and managed, the project was intended to reduce the contribution of both sediment and non-point source pollution in stormwater runoff.

The project objectives were to 1) design two off-line recharge basins in existing abandoned gravel pits to be filled by storm water runoff diverted out of the main Coyote Wash corridor; and 2) implement land treatment practices, in particular, actively managed livestock, to manage overland runoff. In this way, land surface conditions were to be modified to promote infiltration and reduce rapid runoff.