By cvlopez | firstname.lastname@example.org
ERIC Harmon is the type of person Douglas County says it wants to listen to.
He’s a hydrogeologist with expertise on the San Luis Valley aquifers of the Upper Rio Grande Basin. In fact, his team completed the groundwater component of the Rio Grande Decision Support System, which is generally described in state water court documents as “an interactive computer-based system that utilizes data and computer models to help decision makers solve unstructured problems.” The RGDSS is what the state relies on to determine the impact of groundwater pumping.
Harmon is also retired and hasn’t been part of any of the presentations that the three Douglas County commissioners have heard on Renewable Water Resources and its pitch to Douglas County to partner on exporting from the San Luis Valley.
What does Harmon’s experience and expertise say about the RWR proposal? He wrote a letter to the Douglas County commissioners outlining his concerns and recommendation that Douglas County reject the RWR proposal. He has yet to hear back from the commissioners. Alamosa Citizen also asked Douglas County for a response to Harmon’s letter.
“The Renewable Water Resources (RWR) proposal to Douglas County to use ARPA funds should be rejected in favor of less risky projects,” Harmon told the commissioners. “RWR’s project would place undue risks on San Luis Valley (SLV) water users and ratepayers (water customers) in Douglas County. Why? For that, we need to get down into the weeds on the SLV aquifers.”
You can read the letter HERE.
Harmon said he has given expert testimony in the Division 3 Water Court (San Luis Valley) in the AWDI case (1991), the Confined Aquifer New Use Rules case (2006), the Great Sand Dunes In-Place Groundwater Right case (2008) and the Groundwater Rules case (2018).
“Confined aquifer tests in the SLV by my testing team were done as part of Colorado’s Rio Grande Decision Support System (RGDSS) in the early 2000s,” he said to the commissioners. “Our tests showed repeatedly that pumping impacts move outward from a confined aquifer well very rapidly, often causing drawdown (water level decline) up to ½ mile away
within one day of pump startup. At several locations, pumping a deep well caused measurable drawdown in layers much shallower than the pumping zone. This is how confined aquifers work: drawdown spreads out very far, very fast. The SLV confined aquifer is ‘leaky.’”
After he sent along his letter to AlamosaCitizen.com for publishing, we asked him a few additional questions. The exchange is below:
AC: What concerns or thoughts, if any, can you share on the drought the San Luis Valley has been experiencing going back to 2002?
EH: Conditions are never static in hydrology. The dynamic nature of water, weather patterns, and the hydrologic cycle means that conditions are always changing. But where there is a long-term drought, the job of scientists and engineers becomes harder. It means that any predictions we are asked to make may be less reliable than we would like, because we don’t always have similar historic conditions we can look back on to compare to.
AC: The streamflow measurements documented by Davis Engineering for the Rio Grande Water Conservation District demonstrate troubling patterns. Have you recently looked at those streamflow measurements? In your view what type of impact is drought, climate change having on the basin and should that be a concern with the RWR proposal?
EH: I have tried to keep up with the general hydrologic trends in the Valley, including snowpack and streamflow. I have also kept up with the trends of Unconfined Aquifer storage change that Davis Engineering has done for RGWCD for many years. It is clear that even after a number of years of self-imposed pumping reductions in the Subdistricts, there is still too little water available to meet the irrigation demand, and to replenish the groundwater storage deficit in the Unconfined Aquifer in the Closed Basin. If drought or climate change persist in the future, as appears likely, then these impacts should be of concern in any new appropriation of water, whether by RWR or anyone else.
AC: Would the change in conditions, drought persistence, declining snow melt, particularly along the Sangre de Cristo range factor into a water court proceeding?
EH: Declining snowpack, earlier and faster runoff, and drought persistence certainly are of concern in the Sangre de Cristos, as they are in the San Juans. Valley-wide, the water supply from the Sangres is considerably less than it is from the San Juans. Smaller drainage areas, the “rain shadow” effect of the San Juans before the snowstorms get to the Sangres, and differences in topography and geology between the two ranges all are factors. If asked, I would advise the water court to look very hard at all of these factors. If groundwater recharge is less in the future than is predicted, it would almost certainly have an impact on the question of injury.
AC: Commissioner Teal said at the last meeting (March 8) that Douglas County has heard repeatedly that there is a “million acre feet” of water in the SLV aquifer. How does one address that notion?
EH: I can’t find any reference to a “million acre feet” in RWR’s proposal or in the presentations to Douglas County. RWR has stated that 22,000 acre-feet per year, the amount they intend to pump, is 2.5% of the aquifer’s annual recharge. So RWR’s number for annual recharge is 880,000 acre-feet. I do not know if this is what Commissioner Teal is referring to. The important thing, however, is not the annual groundwater recharge or the volume of groundwater in storage in the aquifer. The important thing is that the Valley’s water resources are over-appropriated. As Colorado Division of Water Resources officials have pointed out, this means there is no water available for appropriation and full (“1 for 1”) replacement is required under the Rules.
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