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Mission View Wash Drainage Improvements

Study status:  Completed

Few drainage facilities exist in downstream areas, which include portions of the City of Tucson and the City of South Tucson. Therefore, most stormwater flows are, and have historically been, conveyed in the streets. As the streets have insufficient capacity to contain all but the smallest of flows, adjacent commercial and residential areas may experience periodic flooding. The Mission View Wash Detention Basin Project includes design and construction of a regional detention/retention basin east of Park Avenue, south of 36th Street, west of Kino Boulevard and north of Interstate 10. The Tucson Stormwater Management Study identified that 44 existing homes will be protected from flooding, and roadway flooding would also be reduced, resulting in safer driving conditions, upon completion of this project.

This flood control project is part of a much larger evolving multi-purpose project that provides flood damage reduction, and park and open space benefits in the surrounding community. The approximately 23-acre detention basin is located in the center of the area so that after subsequent development, the entire project site will drain to the basin. The basin will be terraced so that recreation facilities can be installed at a later time.

The depth of the basin below the adjacent development will vary between 10 feet at the headwall of the outlet structure at the southwest to less than two feet at the natural channel bottom in the east. Flows will be conveyed from the basin through a 60-inch reinforced concrete pipe storm drain to the Tucson Diversion Channel south of Interstate 10. During a 100-year- flood event (the 1% chance storm) or smaller flows, storage within the basin will eliminate the contribution to the flood peak for the downstream properties. The maximum time needed to drain the basin completely will be approximately 24 hours during a 100-year flow event, or shorter during smaller flow events.

The total estimated cost for this project is $7.3 million.

Maps

The following maps are available: