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  • New Living River Report tracks changes in conditions of the Lower Santa Cruz

    Oct 07, 2014 | Read More News
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    A newly released report by the Sonoran Institute and Pima County provides new research-based insights about one of Arizona’s most vital river corridors, the Lower Santa Cruz River.

    Lower Santa Cruz RiverThe Lower Santa Cruz River flows year-round through northwest Tucson and Marana, Arizona, with most of the water coming from two regional water reclamation facilities. This stretch of the Santa Cruz provides the longest length of river dominated by effluent in the state.

    The report and project, A Living River, aims to measure, track and communicate water quality and environmental improvements in the Lower Santa Cruz that may result from recent major upgrades by Pima County to its wastewater infrastructure.

    “This first report captures baseline conditions of the river prior to the completion of the upgrades to regional reclamation facilities,” said Claire Zugmeyer, the Sonoran Institute’s project manager for the Santa Cruz River. “Over time, we will be able to chart the changes, and see how the health of the river is responding to the upgrades.”

    Pima County Regional Wastewater Reclamation Department recently invested $605 million to upgrade the quality of effluent it releases into the river. These improvements are expected to have a positive effect on the aquatic environment.

    "The improvements we made have been a win-win-win for everyone,” said Jackson Jenkins, Director of Regional Wastewater Reclamation. “The project was completed well ahead of schedule and $115 million under budget. While many communities across the nation are challenged with aging and failing infrastructure, Pima County’s state-of-the-art infrastructure produces exceptionally high-quality reclaimed water, which benefits the Santa Cruz River and our community.”

    This report establishes baseline measures of 16 indicators of river health along a 23-mile stretch of the Lower Santa Cruz. It is important to note that the research findings were made prior to the completion of the upgrades to the reclamation facilities. Key findings include: 
    • A lot of nutrients were being discharged into the river, contributing to mucky bottom conditions and murky-looking water, as well as odor.
    • Effluent flowed the entire 23-mile stretch of the Lower Santa Cruz to Trico Road and beyond.
    • Non-native Western Mosquitofish, but no native fish, were found between Ina Road and Trico Road.
    • The size and diversity of typical streamside plants was relatively high near Camino del Cerro, Ina Road and Trico Road.


    Lower Santa Cruz River“The Lower Santa Cruz River has a vital water resources role in the recharge of treated effluent as well as natural stream flow,” said Suzanne Shields, Director of the Pima County Regional Flood Control District. “The associated riparian habitat and wetlands along the river provide value to the overall ecosystem, serve as a biological corridor and important migratory bird habitat, and improve our quality of life.”

    The project was funded with a four-year, $307,000 wetland health grant from the U.S. Environmental Protection Agency. In addition, the Regional Flood Control District and the Regional Wastewater Reclamation Department supplied matching funds and in-kind contributions. A group of 14 technical experts representing a variety of stakeholders provided their time and insights to select indicators of wetland health and help guide the project.

    “Rivers are dynamic, with conditions influenced by many factors including amount of rainfall, depth to groundwater, and adjacent land use,” said Zugmeyer. “We are fortunate to have a great recreational path right along the river – The Loop – so people can easily check out the flowing stretch of the river and watch the changes unfold.”

    To find reports, project updates, and more information about the Living River Project, please visit www.tiny.cc/lscr.

    Founded in 1990, the Sonoran Institute inspires and enables community decisions and public policies that respect the land and people of western North America. The Institute is a nonprofit organization that is working to shape the future of the West. For more information, visit www.sonoraninstitute.org.

    Established in 1978, the Regional Flood Control District strives to use forward-looking floodplain management practices to minimize flood and erosion damages for all county residents, property and public infrastructure. Regionally, the District is involved in the management of water and natural resources as part of the Sonoran Desert Conservation Plan. For more information, go to www.pima.gov/floodcontrol.

    The Regional Wastewater Reclamation Department provides design, management and maintenance of the sanitary sewer system. The department treats more than 90 percent of the community’s wastewater and is responsible for the operations of 3,400 miles of sanitary sewers, 30 pumps stations and nine treatment facilities. For more information, visit www.pima.gov/wastewaterreclamation.