Reclamation Information Sharing Environment (RISE)

This research examines the hydrologic impacts of Grade Control Structure (GCS) installations at the Heard Scout Pueblo study site in the City of Phoenix, Arizona, USA. The site is comprised of eroded channels that convey storm flows and sediments into a downstream residential neighborhood. Baseline rainfall/runoff response conditions were established before structures were installed. Innovative monitoring equipment, including video cameras/pressure transducers; digital terrain models; sediment samplers/sediment chains; soil moisture sensors/monitoring wells; and weather stations were established, and small Unmanned Aircraft System surveys were completed. A novel layout of 30 GCS installations was designed to reinstate a historic channel - 20 structures were built in the main channel and 10 were built in adjacent locations. A surface-water model was applied to track the flow of water and potential infiltration before and after GCS installations to simulate their impacts. The model predicted a slight reduction and delay in peak flows for small events and simulated an increase in channel infiltration of ~15% over time. Weather data indicate that the HSP GCS installations created roughly a three-degree microclimate cooling effect for at least two days following rainfall events, as compared with the untreated channel.