Cochise County uses high‑resolution Flow2D modeling to target Wilcox Basin recharge sites

Cochise County Flood Control District staff and their consultants presented results of a Flow2D hydrology and hydraulics modeling effort and a GIS suitability screening that together aim to identify locations in the Wilcox Basin suited for managed aquifer recharge and flood mitigation.

The work session on Tuesday, Sept. 30, included a technical briefing from Sai Miller, an engineer with J.E. Fuller Hydrology & Geomorphology, and a follow‑up screening study from Lindsey Bunting of Geosystems Analysis (GSA). Miller said the study area covers about 1,700 square miles that drain to the Wilcox playa and that the modeling effort divided that area into 13 linked models run on 40‑by‑40‑foot grid cells. "Flow2d essentially breaks up the terrain into a gridded mesh of square cells," Miller said, describing how the model routes runoff across cells and captures depths and velocities across the basin.

Miller said the team simulated a standard 100‑year, 24‑hour design storm using a type‑2 temporal distribution and ran verification tests against U.S. Geological Survey regression estimates. The modeling produces depth maps and hydrographs across the grid; Miller noted peak discharges in some cross sections…