Securing Verde River headwaters
An agreement in 2010 between SRP, the City of Prescott and the Town of Prescott Valley will help protect the flow from the Big Chino aquifer into the Upper Verde River Springs and headwaters to ensure that a critical water supply is protected for generations to come.
This, in turn, helps increase the certainty of the Verde River to support the wide range of recreational, agricultural and municipal uses along its 170-mile course that reaches from its headwaters to its confluence with the Salt River near Mesa, Arizona.
Comprehensive Agreement 1, signed in 2012, is a three-part plan to monitor, model and mitigate, as needed, impacts from groundwater pumping in the Big Chino Sub-basin. The Big Chino aquifer is believed to contribute over 80% of the source headwaters of the Verde River near Paulden, Arizona.
A portion of Prescott and Prescott Valley’s future water supply may be derived by pumping water from the Big Chino aquifer under an exemption from the Groundwater Transportation Act. Comprehensive Agreement 1 is aimed at ensuring that pumping by the communities under the exemption will not impact the historical flow from the Big Chino aquifer into the Verde River.
The aquifer releases 14,000–18,000 acre-feet of water into the Verde River annually. During the dry summer months, this can account for 10%–15% of the Verde’s total baseflow as measured above Horseshoe Reservoir.
Under terms of the agreement, ongoing monitoring and data collection inform a groundwater flow model developed as a tool for predicting future impacts to the Upper Verde Springs.
The model will also be used to identify triggers and continuously determine if mitigation is needed to offset impacts of pumping to the Verde River headwaters. The agreements between SRP, Prescott and Prescott Valley ensured that all parties could address their primary concerns of enhancing available water supplies for the two municipalities while protecting the flow of the Verde River.
The aquifer releases 14,000–18,000 acre-feet of water into the Verde River annually. During the dry summer months, this can account for 10%–15% of the Verde’s total baseflow as measured above Horseshoe Reservoir.
Under terms of the agreement, ongoing monitoring and data collection inform a groundwater flow model developed as a tool for predicting future impacts to the Upper Verde Springs.
The model will also be used to identify triggers and continuously determine if mitigation is needed to offset impacts of pumping to the Verde River headwaters. The agreements between SRP, Prescott and Prescott Valley ensured that all parties could address their primary concerns of enhancing available water supplies for the two municipalities while protecting the flow of the Verde River.
A partnership of monitoring
A long-term monitoring plan developed in 2012 and fully funded by the parties has resulted in 12 additional streamflow measurement sites; the collection of gravity and geophysical data; an assessment of existing wells for monitoring purposes; annual crop surveys; and the creation of the Big Chino Sub-basin Groundwater Model and Report (in development) to model the complex hydrology and geology of the basin.
SRP, Prescott and Prescott Valley are working like-mindedly toward an important achievement critical to sustaining water supplies for all Arizona communities and users that rely on the Verde River.
A partnership of monitoring
A long-term monitoring plan developed in 2012 and fully funded by the parties has resulted in 12 additional streamflow measurement sites; the collection of gravity and geophysical data; an assessment of existing wells for monitoring purposes; annual crop surveys; and the creation of the Big Chino Sub-basin Groundwater Model and Report (in development) to model the complex hydrology and geology of the basin.
SRP, Prescott and Prescott Valley are working like-mindedly toward an important achievement critical to sustaining water supplies for all Arizona communities and users that rely on the Verde River.
