As we said in Part One, water conservation is very important in Yavapai County, AZ. Since 1999, no developments were granted new groundwater allocations (thus protecting the water supplies for existing homes and lots platted prior to 1999) and the only way forward for new development in the Prescott AMA is to utilize sustainable water supplies such as effluent credits or surface water.
Graser says conservation and an efficient water utility is important and the City of Prescott has an effluent recharge program, along with a tiered rate system – the more you use, the more you pay.
Prescott Valley will even sell you effluent credits if you are a developer who needs to show you have a water supply for the future. Munderloh says the town has a 65-percent waste water return, which means it is generously recharging the source of its water.
Nearby Granite Creek and Lynx Creek substantially contribute to recharging aquifers. The aquifers described in this report are not large storage pools but should be thought of as heavily saturated gravel beds.
“We have 2.9 million acre feet of water, which is about twice the size of Lake Pleasant, sitting 500 feet below the town of Prescott Valley,” said Munderloh.
Although Prescott Valley pumps its water from a large aquifer beneath the town, it indirectly benefits from the Verde River and the Big Chino Basin, if one considers that the watersheds and aquifers of the state do meet up eventually. The town taps 26, soon to be 30, wells from an aquifer beneath town. The town shuttered one well last year when it exceeded federal limits of arsenic, but in August town council approved drilling more wells and money for repair and maintenance of others.
“Six of the town wells are inactive for various reasons,” said Neil Wadsworth,
Utilities Director, Town of Prescott Valley. “The well that has arsenic issues is not considered inactive, but rather out of service. We are in the process of doing some work on it to see if the arsenic can be reduced so that we can use the well again.”
Arsenic is naturally occurring in Arizona aquifers and is also a byproduct of mining.
Prescott Valley has a robust water conservation program and has won an international award for an innovative approach to creating a market for effluent to be used for growth, rather than groundwater. Because Prescott has a much older infrastructure and hilly terrain, it has greater challenges than the newer and flatter Prescott Valley. In fact, Prescott pumps water from six wells in Chino Valley in order to meet its demand.
Munderloh said ADWR monitors over 100 wells in the Prescott AMA and has determined that water levels are declining – a condition that has been occurring since the 1960’s. The AMA is only recharging 10,000 of the 18,000 acre feet that it pumps and according to the 1980 Ground Water Act, “We have to reach safe yield by 2025. The requirement is in the statutes and the Fourth Management Plan. The Big Chino is the only legal source we have to reach safe yield,” Munderloh said.
The county has two enormous underground aquifers north of Paulden and south of Seligman, AZ known as the Big Chino and Little Chino aquifers. Yet some “water advisory groups” are quick to claim the Verde River is running dry, and locals will be out of water soon.
The naysayers say Yavapai County residents and towns are pumping too much. Ironically, in a dry season, pumping can result in a cone of depression and actually facilitate an increase in aquifer storage space and create more stream recharge. The naysayers point to a sentence in a year 2002 ADWR report that said the headwaters of the Verde River – Del Rio Springs - will go dry by 2025. But there are two problems with this notion: Lake Sullivan is the headwaters of the Verde River, and the sentence about “going dry by 2025” was removed in later versions of the report.
Naysayers will also focus on one drought year of statistics and often fail to discuss flood years and the recharge that occurs in those years and in plentiful rainy seasons like this past summer.
Whitmer points out that precipitation levels this monsoon season have been significantly above average, which has resulted in significant increases in the flow of the Verde River at the USGS stream flow gauges at Paulden, Clarkdale, and Camp Verde since July 1.
When asked if a one year synopsis of water supply in Yavapai County was a fair estimate, Keith Nelson of the ADWR said, of the most recent state model, “The model calibration is explicitly based on available data. If data indicates natural recharge has occurred, model parameters, including natural recharge, are adjusted to fit the data in a systematic and objective manner. For example, 2002 was a very dry year, so the model is calibrated to data that limit natural recharge. On the other hand, 1993, 2004/2005, and others, were relatively “wet” periods. Consequently, large rates of natural recharge input into the model, to fit available data (minimize model error). We simulate stresses to the aquifer in a seasonal manner. I think what you are saying is that each year should be treated independently, which is the way I calibrated the model.” Modeling Report 14, and others, can be found at new.azwater.gov and azwater.gov.
But the civic planners on the southwest side of Mingus Mountain are thinking long range and have invested money in an intergovernmental agreement known as the Big Chino Water Ranch (BCWR). The City of Prescott is a 54.1% partner and the Town of Prescott Valley a 45.9% partner in the BCWR. If the plan works, the towns will get about the same percentage of shared water and the contract states that they “could share” with Chino Valley in the future. They have also purchased ranches north of Prescott and Chino for use in aquifer recharge. Chino Valley has also acquired water rights in the Big Chino Sub-basin but they are not currently part of the BCWR project.
Imagine a 39-inch wide pipe running from Prescott to the Big Chino Sub-basin 30 miles north of the city. Neither town can afford to hire a contractor, yet.
The Cadillac design would cost $150 million, unless some of the gold plate is shaved. And planners admit there could be cost savings. For instance, the pipe may not have to be 39 inches wide. It could be narrower to meet needs and a narrower pipe over 30 miles, and cheaper pumping stations are of course cheaper. Regardless of price, the new water pipe and recharge plan would insure adequate water supplies for more than a century.
The investors do not have all the financing but there have been visits to town by investors from Saudi and Australia because buying into American utilities is considered a safe investment.
It is important to note that all bodies of water in Arizona are “connected.” (see ADWR map) And the Arizona Supreme Court has made two interesting rulings: groundwater and surface water are legally connected under certain circumstances, and surface water is a constitutionally protected, vested property right. So, it will be of critical importance for Yavapai County residents to see the conclusions in the report due out in 2020.
“There have been many USGS studies over the years and there have been many consultants doing studies in the little and big Chino area over the years and many different groups that have studied water in the area,” said Macy.
“The info that these groups have gathered is currently being put into a computer simulation called ‘the groundwater model.’ It will be used to understand current pumping and future pumping and the effects that the pumping will have on ground water systems.” Many water reports can be found at pubs.usgs.gov
“Prescott Valley and Salt River Project jointly fund the groundwater model project with Prescott. Prescott is the fiscal and contracting agent, per the agreement,” said Munderloh.
This will be the best way scientists will be able to say if current ground water use is sustainable over time and whether residents on the southwest side of Mingus Mountain are truly running out of water over time. And if The Adjudication lawsuit is ever settled, Arizonans will learn who really owns the water rights.
Bill Williams earned a Master of Science Degree in Journalism and Mass Communication from Iowa State University, an undergrad degree from ASU, and a Paralegal degree from Yavapai College; and wrote a book about a notorious murder trial in Prescott titled “Murder by Guile.”