BISBEE — The eastern half of Cochise County has been grappling with serious groundwater problems for years, but last year the people of the Wilcox and Douglas Basins got a chance to do something about it.
Voters have passed a proposal to establish an Active Management Area within the Douglas Basin. It requires that drilling of new wells and deepening of existing wells be stopped, and that wells with a pumping rate of 35 gallons per minute or more must be metered to measure and report groundwater withdrawals. Arizona Water Resources Authority. Homeowners with wells pumping 35 mpg or less are not subject to these requirements.
Countermeasures have failed in the Wilcox Basin, which has suffered the most from falling water tables.
To understand groundwater issues in the state, the Center for Water Resources Research at the University of Arizona, a unit of UofA’s Collaborative Extended System, held a seminar on the challenges it faces with the Douglas and Wilcox basins of the Sulfur Springs Valley.
About 200 people participated in the online seminar.
Recognizing the different water resource status, priorities and values of each county, the WRRC worked with local experts to guide content and access existing water-related data, said WRRC Alumni Outreach Assistant. One Taylor Simmons said: The Cochise County Technical Advisory Board was led by Extension Agent, Kim McReynolds of Cochise County Natural Resources, and Randy Norton, Extension Interim Regional Director for Cochise and Graham Counties. Information was received from local and regional stakeholders with deep knowledge of the regional characteristics of Cochise County waters.
In 2022, the WRRC will partner with the Cochise County Cooperative Extension to produce a water fact sheet that will help illustrate key challenges and solutions and provide a basic understanding of water supply and demand, McReynolds said. said. We look at the future of groundwater, covering topics such as county water supply and demand, water management challenges and opportunities.
Mary Ann Capehart, formerly of the UofA Water Wise Program in Cochise County, provided an overview of the county’s water needs, stating that approximately 91.8% of the water used is for agriculture and 6.7% is used by homeowners. made it clear that On average, the average household uses about 80,000 gallons of water per year, or more than 6,600 gallons per month, according to the Southern Arizona Water Utility. Livestock uses about 0.4% of water.
From 1991 to 2014, water consumption increased from 37,000 acre-feet per year in the Douglas Basin to 50,000 AFY, Capehart said.
Those with entitlements excluded from the previous designation of non-expanded irrigation areas will continue to submit the specific requirements established by the ADWR and submit the required documentation within 15 months of election date to continue pumping groundwater. should be submitted, she said.
ADWR will appoint an Area Director to oversee the Douglas AMA and develop management objectives within two years. The governor appointed her five-member board to the Groundwater Users Advisory Board for a six-year term. ADWR’s management plan will seek public comment upon completion.
“If the groundwater abstraction rate is approved, the rate will be capped at a maximum of $2 per acre-foot per year, and the funds will support efficient use by water users and help the AMA meet its water management goals.” said Capehart.
In the Wilcox Basin, the situation has deteriorated significantly as water use increased from 133,000 AFY to 180,000 AFY. One acre foot of water is equivalent to a football field covered in water to a depth of one foot, said Capehart.
In addition to lowering groundwater tables, she said the Wilcox Basin is also the most rift-prone area in the state due to pumping “well above the recharge of natural mountain fronts.” When groundwater is removed, the ground above it collapses, creating subsidence and fissures that disrupt transportation as roads cave in, affecting utilities and even damaging homes.
The study, Capehart said, has reduced the distance to groundwater in the Wilcox area by 50 feet in some areas and 331 feet in others.
That happens as large industrial farming wells go deeper than 1,000 feet, she continued. Deeper wells draw groundwater from areas near the aquifer, creating a cone of depressions. Her one such cone is below the Kansas Settlement area near the massive Riverview Her Dairy and extensive grain fields.
The Wilcox Basin has a 2,290-foot well. Pumping rates of 2,000 to 1,400 gallons per minute reduce groundwater.
Most homeowners are faced with the decision of whether to deepen a well, haul water, or sell their home at a cost of $27 to $58 per foot, Capehart said. .
Recent droughts have not provided enough rainfall to make up for the difference between pumped and naturally replenished rainfall.
“When wells dry up and land is sold, the loss of customers will affect the area,” said Capehart.
Cochise County Environmental Projects Coordinator Mark Appel spoke about progress in the San Pedro Basin on the western side of the county. This watershed includes the 57,000-acre San Pedro Riverbank National Conservation Area under federal protection. This is a 40-mile-long wild habitat that contains many endangered flora and fauna.
To protect SPRNCA, partnerships have been formed between local, county, state and federal agencies, including Fort Huachuca, to protect groundwater, he said. The Upper San Pedro Partnership kicked things off and made some great strides.
Sierra Vista built its largest water reclamation project in 2002, using treated sewage to recharge nearly 2,700 acre-feet per year while creating a welcoming habitat for birds, other animals and bird lovers. provided.
The Cochise Conservation and Recharge Network is another smaller consortium. These include the county, Sierra Vista, Fort Huachuca, The Nature Conservancy, Hereford Natural Resources Conservation Area, Bureau of Land Management and Bisbee, Appel said.
CCRN has three completed projects and others are still in the planning stages, he said.
The county’s first project was on 265 acres of land in Palominas, slated for a subdivision near Palominas School, an area that receives large amounts of sheet flow from the Huachuca Mountains during the monsoon season. A large basin collects rainwater and releases it slowly downstream into a series of 13 recharging cells. These cells return water to the subsurface in various ways. It can recharge approximately 98 acre feet per year.
According to Appel, cells with infiltration trenches (10-foot-deep trenches filled with gravel) did the best job of storing water underground and outperformed dry wells. .
Then came the Horseshoe Draw project, which aims to prevent sediment movement and erosion from reaching the river. A large headcut was steadily eroding the Horseshoe Draw upstream of its confluence with the San Pedro River before the project was built, Appel said. The recharge project is an eight-acre retention pond that will collect and slow runoff, promote infiltration into the aquifer, and improve water quality downstream.
The Three Canyons Preserve has permanently eliminated water pumping for agriculture, saving approximately 2,500 acre feet of water annually.
In the Sierra Vista region, three projects are still waiting to harvest rainwater from streets and roads for recharge and flood control.
Also planned is the Bisbee Drainage Project, which will transport treated wastewater as close as possible to the San Pedro River on the border with Mexico to correct the reduced flow from the south, restoring 200 acre-feet per year. I can.
The Babocomari Floodplain Protection Site consists of three parcels with conservation easements that collectively protect the 488-acre Babocomari riverbank and floodplain, plus a 104-acre parcel currently owned and managed by Cochise County . Estimated annual savings of 9 acre feet.
Apel noted that the CCRN project will provide more than 6,000 acre-feet of water benefits in 2021, and more than 41,000 acre-feet of water benefits since 2015.
WRRC continues to hold seminars across the state on a variety of water topics. To view the list, go to: wrrc.arizona.edu/calendar.
