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interested agencies. Copies are still available by request from Ms. Julia Fonseca, Principal <br />Hydrologist, Pima County Public Works, Pima County Flood Control District, 201 North <br />Stone Avenue, 4th Floor, Tucson, Arizona 85701 -1207; telephone: (520) 740 -6350. <br />Design Concepts <br />Design concepts developed for the Rillito Recharge Project, such as integrated recharge <br />and riparian enhancement, will be carried forward in the district's Lower Santa Cruz <br />River Replenishment Project. The Rillito Recharge Project would use an inflatable dam to <br />divert a portion of the effluent and stormwater flows to off - channel basins. This project <br />would increase the proportion of effluent recharged into the Tucson basin. In addition, <br />lands acquired for this recharge project will remain available for river park development <br />and riparian restoration. Cost estimates and preliminary design of the inflatable dam and <br />fuse plugs will be used by Pima County Wastewater Management Department in <br />developing budgets for the Water Reclamation Project located on the Santa Cruz River <br />near Cortaro, Arizona. The Rillito Recharge Project studies indicate that additional <br />stream and precipitation gauges would be desirable to operate the dam to minimize risks <br />of flooding and erosion. <br />Institutional and Public Support <br />The Rillito Project Management Committee, which brought together interested academics, <br />regulatory agencies, and funding agencies, provided a model for conducting recharge <br />feasibility studies in an open forum. The district continues that tradition in the <br />Northwest Replenishment Project Committee, which is overseeing the feasibility studies <br />for Canada del Oro Wash and Lower Santa Cruz River. <br />The high degree of public support achieved by the Rillito Recharge Project is also notable. <br />Unlike many other recharge projects, this project was immediately next to suburban <br />backyards. This potential disadvantage was overcome by the team's responsiveness to <br />neighborhood concerns during the design process and the wildlife habitat and recreation <br />benefits associated with the project. The district is duplicating this close rapport with <br />neighbors early on in the process in the Lower Santa Cruz Replenishment Project. <br />Regulatory Constraints <br />If the objective is to obtain storage credits, then regulatory boundaries play a critical role. <br />The ADWR will grant credits for stormwater recharge only if it can be shown that the <br />flows would otherwise leave the Active Management Area. Thus, the greatest <br />opportunities for obtaining storage credits through recharge of small- magnitude flows <br />would seem to lie in the lower reaches of the Brawley and Santa Cruz River systems. <br />Even if credits can be granted, considerable discussion would be needed concerning the <br />methodologies to be used to quantify the increase in recharge. <br />Program Summary Report Part 111 — Demonstration Project Summary Reports 19 <br />