Horseshoe Draw Sediment Control and Stormwater Recharge Project
Horseshoe Draw is an ephemeral stream channel in the Upper San Pedro River Basin that drains approximately 10,700 acres. The recharge project receives accelerated runoff that originates in the San Jose Mountains in Mexico. Before the project was constructed, a large head-cut had been steadily eroding Horseshoe Draw upstream of its confluence with the San Pedro River. An 8-acre detention basin now collects and slows the runoff, enhances infiltration to the aquifer, and improves downstream water quality.
The project has multiple goals: to prevent further erosion of a healthy sacaton grassland, control excessive sediment and E. coli from being flushed into the San Pedro River, as well as enhancing groundwater supplies by recharging stormwater underground into the aquifer. Monitoring results from 2019 show that the project detention basin doubled the amount of time that stormwater flows to the channel downstream of the basin, allowing additional time for infiltration and doubling the amount of recharge.
The Horseshoe Draw Project is located on the San Jose Ranch, on the east side of the San Pedro River, and is managed by Cochise County. Project studies and planning were conducted in 2015-2016, with design and construction completed in 2017. Project operation also began in 2017. Ongoing surface water monitoring began in 2016, one year before project construction, and groundwater monitoring began in 2018.
Click here to read the December 2019 Horseshoe Draw Project Fact Sheet.
Before the project was constructed, a large head-cut had been steadily eroding Horseshoe Draw upstream of its confluence with the San Pedro River. This video was capture with drone survey technology that allows us to compare changes in geomorphology, or the shape of the draw, before and after construction: