Groundwater pumping along the Verde River has diminished stream flows by 10,000 acre-feet a year—that’s 3 trillion gallons a year, equivalent to the average annual water use of 2,500 homes. And groundwater pumping isn’t the only thing that impacts the river—surface water diversions, drought, and climate change are also putting pressure on and constantly challenging the river.
The Verde River begins near Prescott, where groundwater supports springs that form its headwaters. The river flows southeast year-round through the Verde Valley communities of Clarkdale, Cottonwood, and Camp Verde, where it is used for agricultural and home irrigation. Beginning six miles below Camp Verde is a 40-mile stretch designated as a Wild and Scenic River, ending just above Horseshoe Reservoir. This reservoir and nearby Bartlett store water for Phoenix area water users. It’s for good reason the Verde is often referred to as one of the hardest working rivers in Arizona.
Western Resource Advocates has actively worked in the Verde River Watershed since 2011 to advance water conservation, reuse, and planning to protect the Verde River and its perennial tributaries. As one of the few remaining healthy large river systems in Arizona, the Verde River is critical to people and wildlife, including otters and bald eagles, and it supports a growing recreational and tourism economy for Verde Valley communities.
As the population of the Verde Valley increases, so will the demand for groundwater pumped from wells to serve homes and businesses. The historic effect of groundwater pumping on Verde River stream flow is significant, and current and future pumping will continue to reduce flows. However, relatively little is known about the magnitude and type of well pumping in the Verde Valley since water withdrawals are not measured except by water providers.
WRA undertook a study of the water demand of wells in the Verde Valley to provide important information to water users on how wells are impacting flows and to identify opportunities to manage water use to reduce the impact of groundwater pumping. We identified almost 3,000 wells in areas that are most likely to impact stream flow. The results were surprising! We estimate that over 2,400 acre-feet a year of water is pumped from wells that may capture 70 to 100% of groundwater that after 50 years of pumping would otherwise flow to the stream and riparian vegetation. This volume of water is about 50% more than that withdrawn by the largest water provider in the valley. We also found that water used by residents, agriculture, water providers, and for large residential landscapes was of similar magnitude, suggesting that several different types of water users could explore groundwater pumping reduction strategies.
All water users in the Verde Valley have a stake in using water in a sustainable manner in order to protect local water supplies, maintain river flow, and support the local economy. The study provides specific groundwater demand-reduction strategies including information on costs, funding sources, and examples of successful programs in order to promote more sustainable groundwater use to maintain healthy rivers and streams. Our efforts to find solutions have been supported through collaboration with conservation partners as well as the cooperation of communities, for which we are grateful. Significant progress is being made in many areas. These collaborative relationships form a framework for additional future progress towards maintaining a healthy Verde River for communities and wildlife, and is a model of what can be achieved elsewhere in Arizona.
To read the Executive Summary or the full Water Demand and Conservation Potential of Verde Valley Wells Report, click here