Scottsdale Water proactively planning for future Colorado River uncertainty
As negotiations continue over the future of the Colorado River and the operating rules governing the Central Arizona Project beyond 2026, Scottsdale Water is continuing to take proactive, forward-looking steps to ensure the community maintains safe, reliable water service well into the future.
While the Colorado River system is expected to face additional reductions in the coming years, Scottsdale’s long-term planning, diversified water portfolio and ongoing infrastructure investments position the city to adapt to evolving conditions.
Staying ahead of uncertainty
Last year, Scottsdale Water assembled a cross-disciplinary team of subject matter experts to evaluate potential impacts associated with future Colorado River shortage scenarios.
The CAP Supply Shortage Sub-group, comprised of professionals from water engineering, water quality, water production, process control, water optimization, water policy, and wastewater collections and reclamation, meets regularly to evaluate multiple supply reduction scenarios and operational strategies using decades of institutional knowledge and technical expertise.
During the group’s regular meetings, the team analyzes data, reviews infrastructure capacity and operations, and evaluates how Scottsdale’s water supplies and delivery systems can be strategically managed and, if necessary, rebalanced to meet customer demand under varying and unknown future scenarios. Drawing on decades of combined utility experience, the group continues identifying practical strategies that preserve reliability, operational stability, and long-term water security.
“One of our primary shared responsibilities within Scottsdale Water is to plan for uncertainty long before it becomes reality,” said Thyra Ryden-Diaz, interim senior director of Water Resources. “We achieve this by continuously evaluating operating conditions and implementing informed strategies that are carefully coordinated with highly developed infrastructure projects and associated support systems. Our infrastructure needs to satisfy a wide range of conditions and scenarios to provide the necessary water quantity, quality and reliability needed for Scottsdale to thrive.”
Ryden-Diaz said Scottsdale has spent decades planning, designing, constructing, and operating complex water supply and delivery systems that emphasize flexibility, redundancy and reliability. While the potential scale of future Colorado River reductions presents unprecedented challenges across the Southwest, Scottsdale’s ongoing planning efforts are focused on ensuring the city remains prepared for a wide range of reasonable outcomes.
Building Multiple Paths to Reliability
To reduce dependence on any single water source and strengthen long-term reliability, Scottsdale has adopted a comprehensive five-spoke approach to future water security. The strategy includes demand management, advanced water purification, conveyance of groundwater from the Harquahala Irrigation Non-Expansion Area (INA), the proposed Bartlett Dam expansion and evaluation of emerging water solutions. Together, these initiatives are designed to diversify Scottsdale’s water portfolio, increase local water resiliency, and position the city to adapt to future reductions in Colorado River supplies.
Turning plans into projects
Scottsdale also continues to make measurable progress on established initiatives designed to ensure a reliable and resilient water future. While several initiatives remain in planning or development phases due to their scale, such as advanced water purification and the Bartlett Dam expansion, Scottsdale continues to make measurable progress by bringing new wells online to expand access to aquifer resources and strengthen long-term water supply reliability.
City staff will return to Council with additional recommendations as key studies are completed.