Environmental Restoration and Detention in Tucson, Arizona: A Work in Progress

Storm flows from Arroyo Chico and its tributaries cause severe and frequent flooding to the central part of the City of Tucson, Arizona. Urban encroachment severely limits the rights-of-way needed for traditional flood-control measures such as channel improvements or levees. Further, the residents and their elected public representatives prefer maintaining the riparian characteristics of the local watercourses and the historic character of the surrounding neighborhoods. Consequently, stormwater detention is the method of choice. In cooperation with the U.S. Army Corps of Engineers, the City of Tucson and Pima County have developed a two-part regional detention project for Arroyo Chico. The first part, a multiple detention basin system integrated into an existing 18-hole municipal golf course is complete and operational. The second, and ongoing, part includes a multiple detention basin system located farther down in the watershed. The design of the lower, or "Park Avenue," detention basin includes mitigation, environmental restoration, and recreation. There are several configurations that provide opportunities to incorporate different types of habitat restoration and recreation. The project is a good example of siting a multi-objective flood control/restoration project in an urban area with a scarcity of open space. The challenge is to accommodate federal flood control design and environmental standards, as well as the desires of the local community.