The Cloverleaf Trust, doing business as the Riverbend Hot Springs, applied for a new appropriation of 400 acre feet a year of hot springs water about three years ago. Of the seven parties protesting the new appropriation is T or C Properties, doing business as the Sierra Grande Lodge. It hired Hydrologic Consultant Tom Myers, Ph.D., of Reno, Nev., to write a technical memorandum to determine if there is enough hot water to support the new appropriation and if it will impair existing water-right holders.
Myers’s conclusions are, “First there is no water to be appropriated within the basin. Even without considering irrigation rights, existing groundwater rights exceed discharge from the [hot water] basin by at least three times. The proposed groundwater right would substantially increase the overdraft.”
Myers also said Cloverleaf’s technical memorandum, written by James Witcher, a geologist in Las Cruces, miscalculated the hot springs basin recharge and discharge because it failed to consider climate change.
The “travel time from the point of recharge to discharge,” Myers said, is about 4,000 to 11,500 years, based on “uncorrected” carbon dating done by New Mexico Tech Earth and Environmental Professor Mark Person in a 2013 study for the City of Truth or Consequences.
“The existing discharge is a product of a wetter period with more recharge thousands of years ago and climate change going into the future will further decrease the recharge,” Myers said.
A Jan. 29, 2019 court decision ruled that climate change must be part of a new-water acquisition calculation, Myers said, citing Aquifer Science, LLC, v. Scott A. Verhines, NM State Engineer, et al.
Myers’s second conclusion is that pumping 400 acre feet a year from the Riverbend’s 240-foot-deep well will hurt the other commercial bath houses, depriving them of their beneficial use, temperature being part of their senior water right.
Pumping “would draw a very large amount of hot water directly from the source of geothermal water that supports the heat for other wells within the Hot Springs District of Truth or Consequences,” Myers said.
The 400-acre-feet-a-year “diversion is for much more water than is pulled from the basin by any other commercial well, which would have an inordinate effect on the distribution of heat supporting the geothermal water,” Myers said.
Speeding up the discharge of hot water from deep below by pumping, tapping that deep reserve before it rises naturally to shallower wells is not the only cooling effect the new diversion will have, Myers said.
Water from the Rio Grande will seep into the aquifer, also cooling the commercial baths, thus depriving them of heat.
“The subsequent drawdown would pull water from the Rio Grande,” Myers said, “which will mix with and cool the geothermal water supporting existing uses.”
Myers arrived at his conclusions by creating a “Conceptual Flow Model” of the Hot Springs Underground Water Basin. He reviewed the literature on the basin, considered “details of the existing wells and diversions,” and “downloaded recorded groundwater rights and points of diversion data” from the Office of the State Engineer’s website.
Among the literature, he cites C. V. Theis, who did a four-year study of the hot springs ending in 1941. He also cites Person, who studied it in 2013. Myers compared their recharge and discharge calculations, separated by about 70 years.
Theis said the discharge from the hot springs was “2,100 to 2,534 acre feet per annum,” Myers noted, and Person said discharge ranged from “1,738 to 2,389 acre feet per annum.”
The decreased discharge could be due to “differences in the water level in the Rio Grande or substantial pumping of the geothermal resource,” Myers said, “which could change the gradient controlling groundwater discharge to the Rio Grande.”
Myers only gives Person’s recharge figure, not Theis’s, which is 2,461 acre feet a year from the deep bedrock portion of the aquifer, the source of the hot water, which “approximates the discharge to the Rio Grande,” Myers said.
Myers compares the water temperatures Theis and Person recorded, which are 3 degrees to 10 degrees cooler than 70 years ago. He theorizes the water cooled for four reasons:
- The wells were deeper in Theis’s time.
- Pumping has “probably depleted the heat source below its point of discharge because deep geothermal groundwater production creates a drawdown, which increases the gradient for flow into the bedrock aquifer from above,” Myers said.
- “This gradient change either draws water from above, including from the Rio Grande, into the alluvium and bedrock, or reduces discharge from bedrock into alluvium and the Rio Grande,” Myers said.
- Different well locations were tested, since those originally measured are no longer in use.
Myers added up all the water-right appropriations in the Hot Springs Underground Water Basin and found “More than 12,200 acre feet per annum is claimed for diversion.”
Even if you subtract the 5,908 acre feet a year appropriated for irrigation, “which is probably supported by a different groundwater source,” Myers said, “groundwater rights exceed 6,300 acre feet per annum. Groundwater rights exceed the total discharge from the geothermal aquifer by approximately three times.”
And this doesn’t take into account climate change, Myers said, which means the over-appropriation is drawing on recharge more plentiful 4,000 to 11,500 years ago that has since diminished.
“There is no water available for additional appropriation,” Myers concluded.