MONTE VISTA—Water returned to the Rio Grande from the city’s wastewater treatment facility replaces more than the town depletes from its wells, members of the city council learned Thursday.
Kate Ryan of Berg Hill, Greenleaf and Ruscitti attended the meeting to explain settlement concepts that have been developed with the state engineer to ensure the city can comply with any filed groundwater rules. The concepts were developed after the city opposed Rules Governing the Withdrawal of Groundwater in Water Division No. 3 (Rio Grande Basin).
Ryan explained there were four concepts Monte Vista is hoping to attain in regards to proposed state groundwater rules. The first is a settlement term that enables the town to get credit for accretions to the Rio Grande from its wastewater treatment facility.
“Without this settlement term, a significant portion of Monte Vista’s accretions would go unused because it puts more water in the Rio Grande than it owes for replacement of well depletions,” explained Ryan in a memo.
The second concept is that limits on pumping will be recorded using five-year averages as the city will be required to limit pumping to 1978-2000 levels. “If Monte Vista is responsible for making a greater contribution to the confined aquifer than is required in a single year, it can take credit for that contribution in the next five years...Confined aquifer users will get a 10 percent upwards adjustment in withdrawals they are allowed to take in order to make up for faulty math by the state engineer,” wrote Ryan.
Monte Vista will be able to provide actual estimates for lawn irrigation return flows in the future under the third concept. “Lawn irrigation return flows offset the amount of water a municipality owes a replacement water attributable from well pumping because when water is pumped for lawn irrigation, some of it flows into local streams. Right now the state engineer assumes that lawn irrigation flows are a set amount,” she said.
The final concept is improving modeled data. “The state uses historical well pumping data input into what it calls the RGDSS Groundwater Model to calculate delayed stream depletions attributable to past pumping that Monte Vista will have to replace to the Rio Grande pursuant to its plan for augmentation,” she said. According to Ryan, Bikis Waters Consultants have provided the state with improved data for the model so that the city will not have to replace more water than it owes.
The Monte Vista City Council unanimously approved the concepts to represent the interests of the city.