There are many issues related to water resources facing our region. Global warming will affect our climate and our water needs. Increased demand for electricity in a warming climate increases water demand for both electric power plant cooling and for irrigation to landscaping that will become increasingly stressed as temperatures rise. Increasing growth projections raise concerns over water availability as we enter another year of drought.
What is the situation…
Tucson residents utilize water from 3 primary sources: groundwater, Colorado River (CAP) water, and effluent (treated wastewater).
The groundwater comes from an aquifer that lies beneath the city. The aquifer is a porous layer of sand, gravel, silt and clay that exists at various depths beneath the ground. Water in the aquifer collected there over thousands of years from rain and snowmelt runoff draining from the watershed and soaking into the ground – a process called natural recharge. The groundwater is pumped for delivery through a system of wells located throughout the Tucson-metro region.
Read the Our Water Resources: Groundwater fact sheet for more information.(pdf)
Resources to learn more about watersheds:
Arizona Cooperative Extension Arizona Watershed Information website
Arizona Cooperative Extension Master Watershed Steward Program
AZ Dept. of Water Resources Tucson Active Management Area website.
Colorado River water is delivered through the Central Arizona Project (CAP). Beginning high in the Rocky Mountains of Colorado and Wyoming, the Colorado River provides water for 7 states, including Arizona, before it enters the Sea of Cortez in Mexico. Tucson’s portion of Colorado River water is about 44 billion gallons each year. The water is delivered to Tucson through the Central Arizona Project canal, a 335-mile long channel that begins near Lake Havasu, passes through the Phoenix area and rural Pinal County, and ends about 15 miles south of Tucson. Construction of the canal began in 1973 and took more than 20 years to complete.
Most of the Colorado River water delivered is put into recharge basins in Avra Valley at the Clearwater Renewable Resource Facility. The water sinks into the earth and blends with the native groundwater in the aquifer. The blend is then recovered by a number of wells and treated before delivery to Tucson Water customers. The use of this blended water reduces our reliance on groundwater and has allowed a number of wells to be shut off, allowing the water table to recover from over-pumping.
Read the Our Water Resources: Colorado River water fact sheet for more information. (pdf)
Central Arizona Project website
The Water Information Program website maintains a list of media stories about the Central Arizona Project.
Effluent is wastewater that has been treated and can be re-used to offset the use of potable water. There are a number of good reasons why wastewater effluent is a good resource for Tucson. Effluent is the only source of water we have that increases as population increases. Because the City of Tucson owns much of the effluent that flows from Pima County’s 2 municipal wastewater treatment plants, Tucson Water does not have to pay for this alternate water resource. Finally, effluent can be used to replenish the groundwater in our region.
Read the Our Water Resources: Effluent fact sheet for more information. (pdf)
Tucson Water’s Reclaimed Water website
Tucson is located in the Sonoran desert, an area that averages only 12 inches of rainfall each year. Long-term drought and limited water resources put access to water at the forefront of regional planning.
For decades, groundwater was the only water source in Tucson, coming from wells drilled throughout the metropolitan area. Groundwater has been pumped faster than nature can replace it through natural recharge, causing the water table in some places in central Tucson to drop more than 200 feet. Over pumping can cause a number of problems, including potential damage to the environment and the threat of land subsidence (sinking). In order to meet the community’s water needs without risking these problems, the City now delivers a mix of recharged Colorado River water and groundwater. This has allowed many of the most overtaxed wells to be shut-off. However, Colorado River water is also a limited resource.
Tucson’s portion of Colorado River water is about 44 billion gallons each year. Although we are currently only using about 20 billion gallons of our allocation each year, the Colorado River is under great stress and the future could bring changes in the amount of water it can provide to us. Six other western states all vie with Arizona for water from the Colorado River. The water allocations to these states account for almost all of the water flowing in the Colorado. In addition, years of drought in Colorado have many scientists and water professionals concerned about the long term water levels in the river and the availability of water to fulfill all of the water allocations.
Reclaimed water, or effluent, is the City’s only truly renewable water source because it increases as population increases (the more people there are using water, the more waste water the community generates). Tucson Water maintains and develops infrastructure to deliver reclaimed water to a number of sites throughout the City, such as golf courses and parks. This water source should be utilized wherever possible. However, in order to make reclaimed water available to residents for landscape irrigation, Tucson Water would need to expand its infrastructure and construct an extensive reclaimed water delivery system completely separate from the one that currently brings drinking water to homes. In addition, existing homeowners would need to separate their irrigation system from the rest of their plumbing system, to prevent the possibility that reclaimed water could mix with potable drinking water.
These issues make water resources an important part of regional planning. Explore the resources below for more information about regional water planning.
The City of Tucson Mayor and Council and the Pima County Board of Supervisors initiated a multi-year study of water and wastewater infrastructure, supply and planning issues (WISP). The ultimate goal of this effort is to assure a sustainable community water source given continuing pressure on water supplies caused by population growth and the environment. Documents and other information from this effort can be found throught the hyperlink above.
One of the policy outcomes of the City/County Water and Wastewater Study described above was the City's formal adoption of a Water Service Area Policy in August of 2010. The Water Service Area Policy establishes a water service boundary for Tucson Water based on economic, social and environmental considerations as recommended in the Study. For more information, visit the Tucson Water’s page at the hyperlink above.
Drought Preparedness and Response Plan
This plan was developed in compliance with HB2277 passed by the Arizona State Legislature in 2005 requiring all Arizona water providers to develop a drought preparedness and response plan. Because Tucson Water supplies water from the Colorado River (CAP), the criteria for declaring different stages of drought do not only consider local conditions, but also conditions affecting the Colorado River. As the severity of drought increases, water restrictions may also increase.
Long Range Water Plan- Water: 2000-2050
Our growing desert community has some tough choices to make. Tucson Water’s Long Range Water Plan lays out the challenges and opportunities we all face if we want to ensure a secure water future for our families and ourselves.
Emergency Water Conservation Ordinance
In order to ensure Tucson Water can maintain adequate water supplies to provide for life safety, and fire protection, an Emergency Water Conservation Ordinance was approved by Mayor & Council on March 20, 1995. The Ordinance gives the Mayor & Council, the Mayor, or his designate the authority to declare a water emergency and to implement mandatory water conservation measures targeting non-essential uses.
Pima County Drought Management website
Pima County Drought Management Plan (pdf)
The Pima County Regional Wastewater Reclamation Department (PCRWRD) provides design, management, and maintenance of the sanitary sewer system for all of Pima County, including the conveyance system and treatment system. The department manages three metropolitan wastewater treatment plants and eight outlying facilities.
Pima Association of Governments Watershed Planning
PAG’s Watershed Planning Program focuses on ways to preserve or improve the water resources in Pima County's watersheds.
Arizona Statewide Drought Program
All areas of the world experience natural cycles of drought. However, Arizona is especially sensitive to drought impacts. Because Arizona is an arid state, water is scarce here even during years of above-average precipitation, and population growth continues to increase our demand for water. The future of the state will depend on the wise water management choices we make today. Governor’s Drought Declaration (pdf)
Drought status reports http://www.azwater.gov/dwr/drought/DroughtStatus.html
Arizona Drought Resources from Arizona Cooperative Extensionhttp://ag.arizona.edu/extension/drought/
Arizona Department of Water Resources
This state agency has jurisdiction over much of Arizona's surface and groundwater resources. The site includes extensive information on surface and groundwater basins, water management issues, a searchable version of the Groundwater Site Inventory (GWSI) database, and agency contacts.
Arizona Water Banking Authority
The AWBA web page supplies information on recent announcements about the Water Bank, biographies of the Authority members, links to Water Bank publications, the history of the Water Bank and links to other related web sites. The "Bank Ledger" section contains both planned and actual delivery tables and graphs for the entire state, AMAs, and irrigation districts
Arizona Water Protection Fund
The AWPF web page provides details on the projects funded by the Water Protection Fund, as well as recent announcements, the history of the Water Protection Fund and information on the Water Protection Fund Commissioners. The funded projects are in a database that can be searched, or project summaries can be selected by clicking on a map of the state.
USGS Arizona Water Science Center
The U.S. Geological Survey (USGS) Web page for the water resources of Arizona is your direct link to all kinds of water-resource information. Here you'll find information on Arizona's rivers and streams. You'll also find information about ground water, water quality, and many other topics.