Multi-Criteria Decision Analysis for Optimal Placement of Stormwater Detention Basins and Dry Wells to Enhance Aquifer Recharge in Tucson

Abstract Submission: The City of Tucson, Arizona, faces significant water scarcity challenges, intensified by the Colorado River crisis and reduced water allocations. Groundwater is critical to the city’s water supply, emphasizing the need for sustainable management. Among emerging solutions, artificial aquifer recharge using stormwater runoff has gained attention. This approach leverages both surface and subsurface infiltration methods. Combining stormwater detention basins and dry wells—supporting both surface and subsurface infiltration—has proven effective in maximizing aquifer recharge. However, locating these interventions at a finer, urban scale is a challenge, as prior studies have primarily focused on watershed-level analysis.
To address this gap, we propose a Multi-Criteria Decision Analysis (MCDA) framework to identify optimal locations for stormwater detention basins and dry wells, using census tracts as the analytical unit. This finer scale allows for targeted urban infrastructure planning to enhance aquifer recharge. The MCDA framework evaluates key factors such as flood depths, land availability, soil permeability, infrastructure proximity, and flow accumulation patterns.
We simulate flood depths across the city using FLO-2D model, and aggregate results at the tract level, prioritizing areas most vulnerable to flooding. The MCDA framework then guides the selection of optimal basin locations to capture projected runoff.
We focus on the top 20% of basins with the highest capture potential and further enhance recharge by integrating dry wells to accelerate infiltration. This approach highlights stormwater capture as a complementary strategy to Tucson’s water reuse efforts, advancing the city’s goal of expanding local, sustainable water sources in support of Net Zero Water objectives.

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