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Arizona Water Resources and Issues. Border Governor’s Conference - Water Table May 8, 2006. Geographic and Socioeconomic Profile. Area and geographic boundaries 114,000 sq mi 6 th largest state in U.S.
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ArizonaWater Resources and Issues Border Governor’s Conference - Water Table May 8, 2006
Geographic and Socioeconomic Profile • Area and geographic boundaries • 114,000 sq mi • 6th largest state in U.S. • Bordered on the south by Sonora, on west by California and Baja California, on north by Utah and on east by New Mexico • Elevation range 70 feet – 12,633 feet • 51 groundwater basins in Arizona
Geographic and Socioeconomic Profile • Population • 15 counties; 87 cities and towns • 5.9 million inhabitants (2005) • 2nd fastest growing state in U.S. • Socioeconomic conditions • Principal activities: manufacturing, finance, commerce, mining, agriculture, tourism • 2.9 million employed (4.4% unemployment)
Hydrology • Climate • Characteristics: warm temperatures, aridity, seasonal precipitation, high year-to-year variability, strong decade-to-decade persistence • Average annual rainfall ranges from 3 inches in Yuma to >36 inches along Mogollon Rim • Average daily temperatures range from mid 90s (F) below 500 feet elevation to the high 50s (F) above 8,000 feet elevation
Average statewide Arizona monthly precipitation, (bars; left-hand scale) and temperature (line; right-hand scale) 1971-2000
Water Supply of Arizona Colorado River 2.8 MAF Salt River 0.9 MAF Groundwater 3.5 MAF Gila River 0.3 MAF
Hydrology • Surface Water • Colorado River Water 2.8 maf • 1.3 maf on River • 1.5 maf Central Arizona Project (CAP) to central Arizona • Salt and Verde Rivers (Phoenix) • 0.9 maf • Gila River • 0.3 maf • Local surface water sources • Little Colorado River, San Pedro River, Upper Verde River
Hydrology • Groundwater • Recharge rates vary significantly by area • Deep, productive, good quality aquifers in many areas of central and southern Arizona • Thin, unproductive, deep or poor quality aquifers in many systems in northern Arizona (Arsenic, Total Dissolved Solids)
Arizona mean, high capacity and low capacity reservoir levels from 1971 through 2005, expressed in percent of total reservoir capacity
Demand Sources: ADWR, UofA, USGS
Border Profile • Two thirds of Arizona’s border is under federal jurisdiction as national monuments, forests, wildlife refuges, bombing ranges or are tribal lands • Significant agricultural and urban water use is therefore restricted to area near Yuma and to the communities of Nogales, Sierra Vista and Douglas
Yuma BasinCultural Water Demand-2003 • 1.09 million acre-feet used in 2003 by agricultural, municipal and industrial sector • Well pumpage and diversion of Colorado River contract water • 96% Agricultural Use • Use not expected to increase • 72% surface water • 3.5% Municipal Use • Rapidly growing communities of San Luis, Yuma and Fortuna Foothills • 85% surface water • .5% Industrial Use • 69% surface water
37,000 people; population concentrated in Nogales and along the Santa Cruz River Large fluctuations in temporary residents Nogales, AZ population 23,000 Nogales, Mexico population 300,000 Santa Cruz AMA Demographics Amado PIMA COUNTY SANTA CRUZ COUNTY Tubac Rio Rico Nogales
Santa Cruz AMA Demand All water uses 10,300 AF 8,600 AF 7,300AF 1,500AF 25,800 AF 537 AF
Douglas BasinCultural Water Demand - 2003 • 60,400 acre feet of groundwater • Irrigation Non-expansion area • Most of basin is an Irrigation Non-expansion area • no new lands can be irrigated with groundwater • 89% Agricultural Use • Water use is increasing • 11% Municipal Use • Demand is increasing slowly
Government Framework and Management of Water Resources Laws governing surface water are distinct from those governing groundwater • Surface water • Prior appropriation doctrine • “First in time, first in right” • Groundwater • Beneficial use doctrine • Unlimited ability to pump, so long as use is “beneficial” and “reasonable” (outside AMAs) • Ability to pump constrained by system of rights and permits (inside AMAs) “Subflow” subsurface water subject to surface water law
Government Framework and Management of Water Resources • Federal Agencies • Bureau of Reclamation • Administers Colorado River Basin Project Act and Colorado River Contracts. • Responsible for construction of major water supply development projects • Environmental Protection Agency • Federal oversight of surface water and drinking water quality programs • Oversight of state efforts to regulate solid waste landfills and hazardous waste sites • Army Corp of Engineers • Conducts flood control studies and dam, levee and channelization projects. Regulates placement of dredged or fill material into waters of the U.S.
Government Framework and Management of Water Resources • State of Arizona Agencies • Arizona Department of Water Resources • Groundwater management and administration of water rights • Technical and administrative support to the surface water adjudication court • Authority to consult, advise and cooperate with the U.S. Secretary of Interior on certain matters related to the Colorado River • Supervision of safety of dams under state jurisdiction • Arizona Department of Environmental Quality • Administers water pollution control, monitoring and assessment, and contamination site cleanup programs • Effluent reuse, groundwater recharge projects and discharge of water to aquifers or streambeds must meet water quality standards
Government Framework and Management of Water Resources • State of Arizona Agencies • Central Arizona Water Conservation District • Tax-levying public improvement district of the state responsible for Central Arizona Project system maintenance and operations, repayment obligations and creation of water resource management programs • Arizona Water Banking Authority • Stores Arizona’s unused Colorado River allotment in groundwater basins to firm up urban water supplies for Arizona to be used during times of shortages on the Colorado River or during CAP service interruptions. • May enter into interstate agreements with entities in Nevada and California to store water in Arizona
Government Framework and Management of Water Resources • Local Agencies • Have certain authorities to obtain and manage water resources locally in accordance with state and federal laws • Public water utilities • Set water rates, can enact local water conservation and water use ordinances. For example, can require effluent use on golf courses, time of day lawn watering, etc. • Private water utilities • Regulated by the Arizona Corporation Commission, which regulates water rates and authorizes curtailment tariffs when demand is greater than production • Cannot pass ordinances affecting water use or rates
Groundwater Management • There are different programs and regulations in Active Management Areas (AMAs), Irrigation Non-Expansion areas (INAs) and in areas outside of AMAs and INAs. • Statewide, all wells must be registered and drilled by a licensed well driller • Statewide, transportation of groundwater between groundwater basins is prohibited except as allowed specifically by statute
Water Management Areas Prescott AMA goal: safe-yield by 2025 Joseph City INA: No new irrigated lands Harquahala INA: No new irrigated lands Phoenix AMA goal: safe-yield by 2025 Pinal AMA goals:- allow development of non-irrigation uses- preserve agriculture as long as feasible Tucson AMA goal: safe-yield by 2025 Santa Cruz AMA goal:- maintain safe-yield- prevent decline of water table Douglas INA: No new irrigated lands
Groundwater Management – Active Management Areas • 1980 Groundwater Management Act: • Established Active Management Areas (AMA’s) – Currently 5 • Established a system of groundwater rights based on historic use and permits for new uses subject to specific conditions • Set long-range water management goals for AMAs • Will AMAs achieve their goals? What other actions are needed? • Requires management plan for each AMA • Created the Arizona Department of WaterResources to administer the provisions of the Act • Department has regulatory, permitting and enforcement power; it does not control water supplies or infrastructure
New plan every 10 years, though 2025; developed through a public process Increasingly stringent conservation requirements Include long-range water demand and supply projections Conservation programs for agriculture, municipal and industrial water users Recharge/augmentation program and water quality assessment Groundwater Management – AMA Management Plans
Groundwater Management – Irrigation Non-Expansion Areas • Irrigation non-expansion areas • Established in areas of critical groundwater overdraft-but not as severe as in AMAs • Prohibition of new agricultural irrigation acreage • Management objective to protect existing water users • 3 INAs: Douglas, Harquahala, Joseph City
Challenges: Future Water Supplies • Underground Storage • CAP and effluent • 55 Active Permits • Permitted volumes 150 af to 200 kaf/year • Most recharge facilities are located within AMAs; especially the Phoenix AMA • Conservation • Reuse • Augmentation
Future Water SuppliesUnderground Storage - Benefits • Long-term storage • Large capacity • Little evaporative loss • Reduces risk of subsidence
Future Water Supplies-Conservation • Public outreach: • Teach Good Water Habits Statewide • Provide information on the best available conservation technologies • Provide incentives – tax credits • Voluntary local conservation goals • Promote low water use designs in landscaping • Local government initiatives: • ‘Toilet to tap’ • Domestic/commercial water-harvesting and use of ‘graywater’ • Encourage water-efficient appliances, fixtures, ordinances • Ordinances for use of effluent for large turf areas such as golf courses, parks and sports facilities
Future Water Supplies - Effluent Reuse and Augmentation • Improve treatment quality or match quality to use • Turf and Landscape Uses - some municipal and county ordinances require effluent for new golf courses and turf areas. There are also regulatory incentives • Recharge excess for later recovery • Direct Reuse – considered but must overcome public perception issues • Augmentation includes importing water where legally available, cloud seeding, constructing necessary infrastructure, securing water sources and rights, desalination
Challenges: Indian Water Settlements • 28% of Arizona Land held in Trust for the benefit of Native Americans • Many areas of the state are affected by Indian Water Rights settlements with significant implications for water management and access to water • Recently Settled: • Gila River Indian Community and Tohono O’odham 635,000 acre-feet/year to Gila River Indian Community -- Fort Yuma – Quechan • Pending settlements; Navajo, Hopi, White Mountain Apache and San Carlos Apache
Challenges - Surface Water Adjudications Definition: “A general stream adjudication is a judicial proceeding in which the nature, extent, and relative priority of water rights is determined.” Gila & Little Colorado cases are still in Phase 1 after 30+ years Gila River Little Colorado River • Court must define the legal difference between surface water and ground water before rights can be determined
Challenges - Colorado River • Of the 7.5 million acre-feet of water available to the lower basin states, Arizona’s Central Arizona Project water supply has the most junior priority. • River is over-allocated • 16.5 maf allocation vs. 13 - 15 maf actual • Drought impacts on water supply • Discussions are underway on supply augmentation, conservation and system management to meet demands and obligations
Colorado River Compact & Treaty Allocations Upper Basin (7.5 maf) Lee Ferry Lower Basin (7.5 maf) California – 4.4 maf Arizona – 2.8 maf Nevada – 0.3 maf Arizona Upper Basin – 50 kaf Mexico 1.5 maf
Mexican Water Treaty of 1944 Allots to Mexico 1.5 maf of Colorado River water per year, plus 200,000 acre-feet if the Secretary determines that surplus water is available.
Colorado River Flows Legally allocated16.5 MAF Tree rings, Upper Basin (1512-1961)13.5 MAF Lowest 20-year average(1579-1598) 10.95 MAF Tree rings, Upper Basin (1512-2000) 14.7 MAF Isotopes, Delta clams (1500-1950) 12.5 MAF
Challenges -Drought • Arizona Drought Preparedness Plan adopted in 2004 to identify drought impacts, prepare drought response and reduce drought impacts • Water providers must prepare drought plans • Drought monitoring is ongoing
Average water year (October –September) temperature and total water-year precipitation in Arizona from 1930-2002.Figure Author: Ben Crawford, CLIMAS
Challenges - Border • Issues related to the Colorado River are under federal jurisdiction and international treaty • Increasing population growth is impacting shared and limited water supplies • Limited hydrologic information for many border basins hinders water planning and management • Water quality issues in the Douglas/Agua Prieta and Ambos Nogales pose a threat to local water supplies • Lack of access to renewable water supplies to support increasing demand
Challenges - Border • Need for an integrated binational groundwater model to effectively manage the Santa Cruz AMA water resources to meet the management goal • Uncertainty about the future use of effluent generated by Mexico and treated at the Nogales International Wastewater treatment plant in Arizona and concerns about the quality of the effluent. Effluent is an important supply for riparian areas and groundwater recharge