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The Water Resources Unit


To provide leadership, technical expertise, recommendations and guidance in the acquisition, protection, and management of Pima County’s water resources consistent with Board water policy. To support regional water policies that advance a strong and diverse economy and protect natural resources. To monitor and implement drought management.

About Us

Learn more about water resources at Pima County. Visit the Pima County Water Fact Sheet

Pima County is engaged in water resources in ways you may not expect:

Land Use Authority

Through its statutory land use authority, Pima County can approve changes to density in unincorporated Pima County that increase residential and industrial water demand. The Water Resource Element of the County’s Comprehensive Plan, PimaProspers, provides the Board of Supervisors a framework to consider water use impacts before changes in land use or zoning are approved.  The building code, plumbing code and landscape codes also provide for water conservation. 

Conservation Resources

While the Sonoran Desert Conservation Plan implements landscape-level conservation, a key component is protection and restoration of riparian areas dependent on streams, springs and shallow groundwater. The biological goals of the SDCP are designed to conserve critical and sensitive wildlife habitats through the protection of in-stream flows and water quality.

Through its acquisition of conservation lands, Pima County and Pima County’s Regional Flood Control District hold surface water rights for in stream flow, stock ponds and certificated rights.  Pima County and the District also hold groundwater rights.  Board policy requires annual accounting of Pima County’s water rights. 

Reclaimed Water

The Regional Wastewater Reclamation Department operates reclamation facilities throughout Pima County serving the City Tucson, Town of Oro Valley, Town of Marana, communities in Avra Valley, Green Valley and Corona de Tucson and other areas of unincorporated Pima County. Reclaimed water is allocated to the City and Towns, with Pima County’s share used for park irrigation, riparian restoration and underground storage.

Flood Control

The Regional Flood Control District provides floodplain management throughout Pima County. Additionally, the District’s statutory authority permits construction and operation of groundwater replenishment project that enhance wildlife, recreation and riparian habitats along water course and floodplains.

Water Resources

Because water resource is all-encompassing, Pima County collaborates with municipal water providers in Pima County, as well as with local and regional partners. Among them: 

Southern Arizona Water Users Association, consisting of the largest water providers in the region, coordinates effective water resource policy and planning to reflect one voice from Southern Arizona

Arizona Department of Water Resources is the steward of Arizona water future ensuring long-term reliable water supplies to support the State of Arizona. ADWR regulates groundwater, withdrawals, monitors safe yield in the Tucson Active Management Area, implements the assured and adequate water supply rules, maintains the central repository for surface and groundwater rights and manages the state drought preparedness plan.

Bureau of Reclamation, the largest wholesaler of water in the Western United States, brings water to people and farmland. It manages the Colorado River operations delivering surface water to seven basin states including Arizona. Reclamation has announced completion of the Lower Santa Cruz River Basin Study. The study is a collaborative effort between Reclamation and local cost share partners, Southern Arizona Water Users Association, University of Arizona, the Central Arizona Water Conservation District, the Arizona Department of Water Resources, Pima Association of Governments and Cortaro-Marana Irrigation District. Pima County actively participated in the study through its membership in the Southern Arizona Water Users Association. The basin study assesses the impacts of climate change and population growth on the Lower Santa Cruz River Basin water supplies and demands. It identified four areas of concern where groundwater levels are projected to decline and identified adaptation strategies that could help offset the impacts of climate change and water demand from future population growth. The Study Summary describes the findings, goals, innovations and lessons learned.

Central Arizona Water Conservation District operates and maintains the Central Arizona Project delivering Colorado River Water to municipal and agricultural interests in Pima County. CAWCD levies a property tax to residents in Pima County to help pay the construction and operations of the Central Arizona project.

Central Arizona Groundwater Replenishment District replenishes groundwater pumped from member subdivisions in unincorporated Pima County for landowners and water providers to demonstrate an assured water supply. Do you live in a CAGRD member subdivision? If so, a CAGRD assessment is included in your property tax statement. Find out if you are in a CAGRD member subdivision by using the CAGRD Membership Locator.

Water Policy

Water policy plays a central role in the economic, environmental, agricultural, cultural success in Pima County. Several policy-level initiatives form the basis for water policy in Pima County

Board Policy F54.9 requires an annual inventory of Pima County’s groundwater rights, surface water rights and reclaimed water assets. Implementation of Pima County’s management and utilization of Pima County’s water resources is described in the Water Resources Asset Management Plan.  Reflecting the value Pima County places on its share of reclaimed water, the Strategic Plan for Use of Reclaimed Water describes the state of supplies in the region and various uses of Pima County’s allocation

In 2011, Pima County and the City of Tucson completed collaboration on a Water & Wastewater Infrastructure Supply and Planning Study to assure a sustainable community water source given continuing pressure on water supply caused by population growth. 

The Conservation Effluent Pool, established by Pima County and the City of Tucson reserves up to 10,000 acre-feet annually from the metropolitan wastewater reclamation facilities for riparian projects

Drought Management

Pima County established a Drought Management Program  in 2007 as the state struggled with sustained drought conditions. The past two decades of drought include some aberrations, however, the overall trend has been below or well below average precipitation and above or well above average temperatures in Pima County and across the state. A Local Drought Impact Group was set up to monitor the status of the summer monsoon season and convenes roundtable discussions of drought and water conservation outreach programs.

Water Quality

Pima County is committed to protecting its headwaters, wetlands and intermittent and ephemeral streams. The Board of Supervisors has provided staff with policy direction per the resolutions below:

Pima County Resolutions regarding Clean Water Act

Pima County Resolution 2017-60  and Pima County Resolution 2018-82 urge the US Environmental Protection Agency to retain protections for headwaters, wetlands and intermittent and ephemeral streams by rejecting proposed changes to the federal “Waters of the US” rule.
County Memo: Resolution 2017-60 and County “Waters of US” Comments

County Memo: Retaining 2015 Clean Water Rule

Pima County Resolution 2017-50  commits the County to participate in the Triennial Review of state water quality standards in order to protect human health and ecosystem function and oppose the diminishment or removal of water quality protections for Arizona’s Outstanding Waters, including Cienega Creek and Davidson canyon.

County Letter: To ADEQ regarding Triennial Review

Pima County Resolution 2008-209  expresses support for Army Corp of Engineers determination of the Santa Cruz River as a Traditional Navigable Water pursuant to the federal Clean Water Act.

County Memo: Clean Water Act Compliance