Council approves Casita Village rezoning after flooding debate; developers had promised additional modeling and basin dedication

The Council authorized the rezoning of roughly 19.8 acres for the Casita Village at La Mariposa after an extended hearing and dispute over upstream flooding risks and the adequacy of hydrologic modeling. Pima County and city staff, the developer’s engineers and neighborhood experts debated the modeling and whether the project would raise water surface elevations offsite.

Developer commitments and ROSAC-style review process The developer agreed to several measures during an extended pre‑council process: an updated, higher‑resolution topographic survey and hydrology; submission of a CLOMR to FEMA; increased detention/retention sizing (developer committed to 120% of code requirement for retention basins); and an agreement to dedicate an adjacent 11‑acre area (the former polo fields) as a regional recharge/detention basin under Pima County Flood Control management. Developers also re‑configured the plan to move living units out of the 500‑year flood areas and bring buildings out of the 100‑year floodplain.

Why it mattered: flood risk and public debate Neighborhood groups and independent consultants, led by a hydrologist retained by Bear Canyon Neighborhood Association, said the models relied on dated FEMA hydrology and urged the council to delay rezoning until new hydrology and more advanced modeling (3‑D capabilities) could be reviewed. Developers and city/county reviewers said the project used current engineering practices (2‑D hydraulic modeling), the updated topography and FEMA/County review processes and had not created new flooded properties in the FEMA regulatory mapping; FEMA approved the CLOMR the developer submitted.

Council action and rationale The council debated the technical issues and broader neighborhood concerns and approved the zoning authorization 6–0 after staff and the developers described the additional mitigation (larger basins, CLOMR, and proposed dedication of the 11‑acre recharge basin) and after the developer agreed to move living units out of the most at‑risk flood areas. Several councilmembers said the basin dedication and river‑edge open space increased their confidence that regional mitigation measures were in place.

Next steps The zoning authorization requires the developer to meet conditions listed in the record (submitting final development plans, hydrology confirmations and compliance with FEMA/Pima County requirements) before final subdivision approval and building permits are issued. Bear Canyon and other community groups signaled they will continue to review technical submittals and to seek continuing oversight of construction work and flood protection implementations.

Ending: The vote ends the rezoning chapter but not technical review. Council members and staff said that as construction moves toward permitting, city floodplain, Pima County Flood Control and FEMA will continue to review final engineering, and residents will have opportunities to review and comment on those subsequent steps.