Originally Published: September 19, 2012 9:59 p.m.
PRESCOTT - An agreement that obligates Prescott and Prescott Valley to put several million dollars into expanded groundwater examination in the Big Chino Sub-basin got unanimous local approval this week.
On Wednesday afternoon, the Prescott City Council and the Prescott Valley Town Council jointly approved an agreement with the Salt River Project (SRP) that calls for years of groundwater monitoring and modeling in the Paulden-area Big Chino Sub-basin.
The SRP board approved the agreement earlier this month.
Representatives from all three of the participating parties praised the cooperative effort that went into drafting the agreement.
Prescott Valley Mayor Harvey Skoog, for instance, emphasized local officials' ability to work with SRP. "There was a time when we were challenged in that department," he said.
John Sullivan, associate general manager and chief resources executive for SRP, said the agreement would lead to information that would be useful for future Big Chino decisions.
"We're going to learn some things about the Big Chino that we don't know yet," Sullivan said, citing the capacity of the aquifer and its relationship to the Verde River as examples of that anticipated information.
Basically, the agreement obligates the three parties to spend a combined $4.3 million over the next eight years for new monitoring wells in the Big Chino Sub-basin, and for a new "nested" groundwater model that would refine the larger U.S. Geological Survey model on the area.
The monitoring plan will involve the drilling of nine shallow monitoring wells and two deep wells, and will cost about $3.07 million. The schedule calls for installation of five stream gages during the first year, with the well-drilling occurring in the second, third, and fourth years.
The model - estimated at a cost of $1.25 million - is scheduled to get under way in the third year and continue through the sixth year. Among other things, it would include aquifer storage analysis, geophysics, water level data, and a final report.
Prescott City Manager Craig McConnell noted that the model would use information from the expanded groundwater monitoring, and likely would be done by a consultant after a request for proposals (RFP) process.
The agreement requires SRP to pay one-third of the cost for the monitoring and modeling, with Prescott and Prescott Valley taking on the remaining two-thirds. The two communities would further split the cost on the 54.1 percent/45.9 percent Prescott/Prescott Valley breakdown of the total project costs.
After the meeting, Prescott Mayor Marlin Kuykendall said the agreement means that the Big Chino Ranch pipeline construction is still nearly a decade away.
"This agreement takes about eight or nine years," Kuykendall said. "And that's a minimum."
Plans for the Big Chino Water Ranch have been under way since 2004, when Prescott and Prescott Valley teamed up to buy the ranchland northwest of Paulden, with plans to pump and transport thousands of acre-feet of water through a 30-mile pipeline to the tri-city area.
While officials projected early on that the pipeline construction would get under way by about 2009, a number of issues, including the economic downturn, have combined to postpone the project.
This week's agreement follows through on a settlement that the three sides approved in February 2010, which effectively ended the litigation that had been going on for years between the Phoenix-area utility company and the two area communities.
SRP, which claims senior downstream rights to Verde River water, had long maintained that the large-scale pumping in the Big Chino, which is near the headwaters of the Verde, could harm the flow of the river.
This week, Sullivan said the agreement's monitoring and modeling would "give us a better understanding of what the connection truly is." He noted that two theories exist on the matter - either that the Big Chino supplies 86 percent of the water for the Upper Verde River, or that an underground "clay plug" or playa deposit restricts the flow of Big Chino water into the Verde.
The future of a possible plan to mitigate any impacts to the Verde River would depend on the outcome of the upcoming monitoring and modeling, Sullivan said. "If an impact is identified, I anticipate a mitigation agreement," he said.
But local water advocate Howard Mechanic said after the meeting that he doubts that the new model would show anything different from what is already known about the Big Chino Sub-basin.
"I don't think (the new modeling effort) is needed to show the effect on the river; I think that's already in," Mechanic said, maintaining that science already has shown that pumping from the Big Chino would affect the Verde River.
Even so, Mechanic foresees some positive impacts from the monitoring and modeling. "This will set an example to the other users (of water in the Big Chino)," Mechanic said.
Tom Slaback, another local water advocate, told the two councils that the monitoring and modeling effort is "getting the horse before the cart." Rather, he suggested that a mitigation plan should come first.
Representatives from Prescott, Prescott Valley, and SRP have been working since the 2010 settlement to come up with the proposed agreement.