Karl A. Pereira, Thomas Meixner, and Evan Canfield1
The Pima County Regional Flood Control District is developing a multi-benefit management plan for the effluent dependent Santa Cruz River, located in Southern Arizona. In the Cortaro Road to Avra Valley Road reach, the District has ongoing maintenance problems as the result of effluent flow up against the bank protection. The District and other stakeholders are interested in multi-objective solutions that would; move flow away from the soil-cement bank protection, increase infiltration and generate more recharge for water owners, improve habitat for species of interest, and improve the recreational experience of Loop users. Channel modifications have been carried out downstream of Cortaro Road which include; bendway weirs to direct flow away from the bank protection, creation of multiple channels to increase the infiltration footprint, rock fords to slow the water. This project will evaluate the infiltration and recharge at the site and evaluate the monitoring network necessary to document increased recharge. Surface flow data obtained from USGS gages at Cortaro and Avra Valley, will be evaluated to determine the changes in infiltration before and after the installation of the channel modifications. Groundwater data from nearby monitoring wells will be evaluated to determine the possible impact on groundwater levels.
1Pima County Regional Flood Control District, Tucson, AZ