Cochise County flood-control briefing covers recharge projects, USGS monitoring and Army Corps watershed study; supervisors question recharge yield

County Engineer Jackie Watkins and staff briefed the Board of Supervisors on flood-control district activities April 29, describing monitoring and recharge projects, grant-funded investigations and planned repairs to detention and recharge infrastructure across Cochise County.

Watkins presented a portfolio of projects that includes the Palominas recharge and infiltration work (now in year nine of monitoring), a Coyote Wash recharge project north of Highway 90 estimated at about $6.5 million with grant funding, repair work at Horseshoe Draw detention basins, the 3 Canyons recharge research effort (funded in part by an Arizona Smart grant application) and a USGS stream-monitoring program the county shares that Watkins said costs the county about $125,000.

She said the county is working with partner cities on several projects: Riverstone is a recharge project the county is funding in part and that the City of Sierra Vista is designing; an intergovernmental agreement with the City of Bisbee accompanies a $2 million Bisbee grant to extend pipeline infrastructure and acquire a recharge site that would support baseflows in the San Pedro River.

The briefing also covered planning for Lehi/Leslie Canyon ponds (design to meet Arizona Department of Water Resources regulatory-dam requirements), watershed studies for the Wilcox Basin funded with a grant (Watkins cited a grant of approximately $187,000 and a design cost estimate near $299,000), and ongoing monitoring that the county said helps shape project choices (for example, Watkins said infiltration trenches have performed better than dry wells in some Palominas locations).

Supervisors asked multiple substantive questions during the discussion, including whether recharge basins materially raise regional groundwater levels and how any recharge credits or allocations might be used. One supervisor who was not identified by name in the transcript said, "Testing and monitoring do not produce water," and expressed skepticism that localized recharge projects would substantially raise aquifer levels countywide. Other board members asked about potential off-site uses of recharged water and whether recharge work could enable water transfers.

Watkins and staff responded that some recharge projects are intended to improve local baseflows and groundwater levels and to mitigate localized flooding; she also noted that certain projects use federal or state grant requirements for acquisition and construction and that projects near the international border may affect regional flow patterns. She explained that some projects are sized to slow the rate that flood flows leave channels — turning a two-hour pulse into a 24-hour release to increase infiltration into coarser gravels and thereby enhance local recharge where geology is favorable.

The board discussed operational matters: the flood-control district supports the National Flood Insurance Program (NFIP) permitting that homeowners need for federally backed loans; the county maintains sandbag supplies at road yards and provides sandbags as a public service during flood events; and the county continues to seek Army Corps of Engineers watershed study grants, including work for Rucker/Elfrida where a multi-stage Corps watershed study is proposed.

Watkins and staff emphasized that the session was informational and no formal votes were taken. Supervisors also discussed the flood-control district’s revenue — Watkins said the district receives slightly more than $2 million annually in taxes and that large projects can cost multiple millions, which necessitates saving balances across years to fund big capital projects.

Ending: Supervisors asked staff to provide additional maps and materials (floodplain overlays, maintained-road layers and project area maps) for follow-up briefings; no policy change or appropriation occurred at the work session.