Oro Valley Water Utility Community Sustainability March 16, 2019 Peter A. Abraham, P .E. Water Utility Director
WATER UTILITY MISSION MISSION: To maintain and acquire suffjcient water resources to ensure the community has an adequate, safe and reliable water supply to sustain the Town’s quality of life and support residential and economic development. Town of Oro Valley
WATER UTILITY YESTERDAY 1993 – Voters approved creating Water Utility May 1, 1996 T own purchased 2 private water companies Canada Hills Water Company & Rancho Vistoso Water Company thus creating the Oro Valley Water Utility (OVWU) 9,800 service connections serving a population of over 26,000 Solely dependent of groundwater as the only source of supply In 2005 the OVWU began reclaimed water deliveries for irrigation purposes thus reducing the T own’s sole dependence on groundwater In 2012 the OVWU began delivering of a portion of the T own’s Central Arizona Project (CAP) water entitlement thus further reducing the T own’s dependence on groundwater Town of Oro Valley
WATER UTILITY TODAY T oday the OVWU… Is no longer solely reliant on groundwater as a water resource (In 2018 44% of water demands were met with sources other than groundwater) Has over 20,000 water service connections Serves a population of approximately 45,000 residents Has two water service areas – Oro Valley & Countryside Has a water resource portfolio that includes groundwater, CAP water and reclaimed water Has successfully operated the Water Utility for 22 years Employees 40 full time personnel Town of Oro Valley
WATER UTILITY GOALS AND OBJECTIVES Water Quality - Provide safe and reliable water service Customer Service - Provide excellent and responsive customer service. Water Utility Commission – Support the citizens advisory group to Council Water Resources – Develop and maintain a diverse water portfolio Water Conservation – Continue to develop conservation tools and incentives Drought Preparedness – Plan for curtailments in resource availability Fiscal Responsibility Continue to successfully operate the Water Utility Enterprise Town of Oro Valley
WATER RESOURCES – DIVERSE WATER RESOURCE PORTFOLIO Groundwater (1 AF = 325,851 gallons) Legal right to pump 13,384 AF/Yr. (Assured Water Supply) 2018 OVWU pumped 5,573 AF/Yr. Central Arizona Project (CAP) water Allocation = 10,305 AF/Yr. 2018 OVWU utilized 7,667 AF/Yr. (2,094 delivered) Stored unused CAP water allocation in underground aquifer storage facilities Reclaimed water entitlement depends on effmuent generation (Approx: 2,500 AF) TOVWU utilizes most of its effmuent entitlement 2018 OVWU delivered 2,321 AF of reclaimed water Water Resource Goals Groundwater – Preserve and protect existing groundwater supplies CAP water - Increase deliveries to match pace with growth Reclaimed Water – Look for Cost efgective ways to increase deliveries Town of Oro Valley
WATER RESOURCES – Aquifer Storage & Recovery Town of Oro Valley
WATER RESOURCES – RESOURCE UTILIZATION BY YEAR
DROUGHT PREPAREDNESS The Water Utility prepares for drought by: Preserving and protecting its groundwater supplies and availability Maintaining a robust groundwater pumping capability Utilizing reclaimed water for irrigation and construction purposes Storing unused CAP water for future use Entering into agreements with agriculture to fjrm groundwater availability Participating in local and state-wide steering committees and advisory groups to ensure Oro Valley’s interests are represented How does drought afgect the Colorado River system? What does it mean for Oro Valley? Welcome to the Lower Basin Drought Contingency Plan.
Colorado River System Colorado River system is 1,450 miles long, runs from the Rocky Mountains to Gulf of California Holds 4-5 times the river’s annual fmow Provides water to seven US states and Mexico Upper Basin States: Colorado, New Mexico, Utah and Wyoming Lower Basin States: Arizona, California and Nevada 7.5 MAF/year for each Supplies water for approximately 40 million people Supplies water to over 5 million acres of agricultural production Capacity to generate more than 4,200 megawatts of hydropower Enough power to serve 1.3 M people Supports Arizona’s $250B economy
Lake Mead Water surface elevations of Lake Mead determine annual delivery volumes to the Lower Basin States Lake Mead specifjcs:
Lake Mead & 2007 River Shortage Guidelines Lower Basin Colorado River entitlements: California: 4.4 MAF/YR Arizona: 2.8 MAF/YR (1.2 MAF/YR on river users & 1.6 MAF/YR CAP) Nevada: 0.3 MAF/YR Colorado river system began experiencing drought conditions in 2000 In 2007, Secretary of Interior adopted the Colorado River Interim Guidelines for Lower Basin shortages Shortages are dependent on the surface water elevation of Lake Mead 2007 River Shortage Guidelines only applies to Arizona CAP, Nevada and Mexico Reductions occur in a priority order
2007 River Shortage Guidelines
Lower Basin Drought Contingency Plan (LBDCP) Why LBDCP?: Hydrological studies estimate that the Colorado River is over- allocated by 1.2 MAF/YR (Structural Defjcit) Conclusion: 2007 River Shortage Guidelines are not enough to protect Lake Mead (625,000 AF/YR between Arizona CAP, Nevada and Mexico) LBDCP Goal : Reduce the risk of Lake Mead water surface elevations declining to critically low levels and protecting the highest priority users Priority users include Municipal , Industrial and Indian Priority water Accomplished by reducing deliveries to all Lower Basin States, BOR and Mexico, not just Arizona and Nevada LBDCP will not prevent a Tier 1 shortage unless Upper Basin Hydrology improves in 2019 and 2020 The LBDCP builds on the 2007 River Shortage Guidelines by taking reductions sooner and subsequent reductions are larger than the 2007 River Shortage Guidelines Reductions under the LBDCP will occur in priority order within Arizona
Lower Basin Drought Contingency Plan (LBDCP)
LBDCP (AZ) vs. 2007 River Shortage Guidelines (AZ) LBDCP (AZ) vs. River Shortage Guidelines (AZ)
LBDCP (AZ) vs. 2007 River Shortage Guidelines (AZ)
What does LBDCP mean to Agriculture in AZ Agriculture that is not mitigated by higher priority CAP users will have their CAP allocation reduced or cut altogether Pima County agriculture is self-mitigated and not afgected Priority Pima County CAP users store water in Pima County agriculture Groundwater Saving Facilities (GSF’s) LBDCP Tier 1 reductions mostly afgect Pinal County agriculture Pinal County does not have the GSF agreements with higher priority CAP users Pinal County is third largest farming County in Arizona 80% (275,000 AF/YR) of the CAP water allotted for agriculture is delivered to Pinal County CAP water makes up about half of Pinal County’s total agriculture water supply Under a Tier 1 LBDCP shortage Pinal County agriculture would rely solely on groundwater unless a higher priority CAP user mitigation plan were to be implemented
Groundwater pumping and Arizona’s aquifers Pinal County is dominated by an agriculture economy. What afgect will Pinal Counties anticipated increased groundwater pumping have on Arizona? The 1980 Arizona Groundwater Management Act resulted in the creation of 5 AMA’s where groundwater pumping was heavily relied upon. Phoenix & T ucson AMA make up 80% of the state’s population. Consumptive demands are primarily agriculture, municipal and industrial. Primary goal of Prescott, Phoenix, T ucson and Santa Cruz AMA’s is safe yield by 2025. T ucson AMA has achieved safe yield. Active management areas represent aquifers that are NOT hydraulically connected. Pinal Counties potential groundwater depletion operating plan should have no afgect on the T ucson AMA.
What does LBDCP mean to Oro Valley? Oro Valley Water Utility has a subcontract with CAP Oro Valley’s CAP allotment is part of the Municipal Priority Pool The 1.2 MAF structural defjcit is eliminated prior to cuts to the M&I priority pool If Lake Mead drops below 1,025 FT, delivery reductions up to 7% could be experienced by the M&I priority pool For Oro Valley, a 7% cut would equate to a 721 AF/YR reduction 10,305 AF (current allotment) – 721 AF (possible reduction) = 9,584 AF/YR In 2018 the utility used 7,667 AF of it’s CAP allocation. Stored the rest in aquifer storage for future use. T own buildout will utilize 8,500 AF/YR of CAP allocation. Contingency Planning: Utility has accrued more than 22,000 AF of long term storage credits Utility accrues between 2,500-3,000 AF of long term storage credits/year Oro Valley has access to 600,000 AF of AZWB water in the TAMA. Utility is a member of the CAGRD Utility has a well-established conservation ethic Utility continuously explores ways to build and diversify its Water Resource Portfolio
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