Research on human responses to natural hazards shows that communities tend to adopt new measures right after a disaster. Pima County is no exception. The community was primed for action by its fourth Presidentially-declared flooding disaster since 1977. A week after the floodwaters subsided, Pima County Hood Control District Engineer Charles Huckelberry presented the Board with a detailed damage report. Within a month, County staff had received tentative approval from the Bond Advisory Committee to initiate the Pima County Hood Control District's Floodprone Land Acquisition Program. This initiative provides natural flood and erosion damage mitigation, water quality assurance, groundwater recharge maintenance, and preservation of natural floodplain habitats as well as open space and recreation areas, all with the economic benefit of reduced cost of disaster assistance and emergency relief.
This effort begins with the purchase of plots of land that provide natural flood storage which reduces flood peaks downstream. One study commissioned by the District estimated flood-peaks would increase 40% if upstream floodplains were developed and channeled per conventional structural flood-control programs. Increased erosion of channel beds and banks resulting from structural flood-control projects can also be mitigated through establishing areas where natural erosion processes can continue unabated. The program also involves District purchase of flood- and erosion-prone land from private owners, to be managed for the benefit of the citizens of Puna County. Condemnation proceedings, trades, donations, and easement purchases are additional options depending on unique circumstances.
Purchased land preserves dwindling riparian vegetation for wildlife habitat and enhances groundwater recharge, which is Tucson's sole source of water. Two recent purchases, Cienega Creek and Bingham Swamp, had been identified through a state Natural Heritage Program as containing three globally rare plant communities. One of Tucson's last remaining perennial streams, Cienega Creek has been recently designated a State Natural Area and protected through restrictive covenants which run with the land. Additional District acquisitions will link the Preserve to federally-owned parklands, resulting hi protecting a continuous riparian-habitat corridor 35 miles long. The County has also entered into a 25-year agreement with The Nature Conservancy for management of Bingham Swamp. In addition, The program is returning land along major watercourses to public use by providing recreational and open space opportunities for a growing outdoor-oriented metropolitan area.
Probably the single most important achievement of the program has the completion of a locally-initiated process for relocating victims of the 1983 flood. These people lost everything in the flood and were men faced with a moratorium that prevented them from rebuilding on their homes. Using general obligation bonds, the District purchased 105 flood- or erosion-prone mobile home lots and relocated an estimated 200 residents out of the floodplain or erosion hazard zone. Over 160 structures were removed from harm's way.
The District also demonstrated the cost-effectiveness of acquisition over structural projects through purchase of the mobile home park at Cardinal and Los Reales Streets. A state agency had estimated it would cost $3,500,000 to provide a structural solution. The subdivision was acquired for $460,000.