After years of drought, more water in the San Luis Valley’s rivers is a welcome change, but it comes with a price.
With higher stream levels comes a higher obligation that must be paid to downstream states. Colorado Division of Water Resources Division Engineer for Division 3 Craig Cotten reminded Valley residents of that fact during his report on Tuesday to the Rio Grande Water Conservation District board.
When the forecasts increased for the Rio Grande and Conejos River systems, so did the curtailments on irrigators, he explained, because Colorado’s obligation to New Mexico and Texas also increased.
Cotten said the annual forecast for the Rio Grande has increased every month since May because more water is expected now than forecasters predicted this spring. The May forecast for the Rio Grande was 475,000 acre feet. In June the Natural Resources Conservation Service (NRCS) increased the projected annual index for the Rio Grande to 545,000 acre feet and this month bumped it up even higher to 590,000 acre feet.
“That’s up significantly from what we had projected earlier on in the season,” Cotten said. The obligation to downstream states from the Rio Grande is 158,400 acre feet from that new 590,000-acrefoot forecast. With the water that has already been delivered , estimated deliveries for this winter, and a contribution from the Closed Basin Project, the water resources division is projecting it must deliver about 22,000 acre feet during the remainder of the irrigation season. To reach that goal, the division is curtailing irrigators 25 percent, which is significantly higher than curtailments earlier in the irrigation season. Curtailments in April and May were 7-10 percent, with curtailments increasing to 15 percent in June, 21 percent by July 3 and 25 percent July 4th.
“That’s just because of the increased forecast amount and needing to deliver quite a bit more to the downstream states,” Cotten said.
“We are watching that pretty closely,” he added. “Depending on the monsoon season, if we do get a significant amount of rain and rain events, there’s a possibility we may have to go up a little higher than that.”
Curtailments on the Conejos River system are even higher. Since July 4, the curtailment on the Conejos has been 32 percent with only the #1 and #2 ditches in priority right now, according to Cotten . The curtailment on April 1 was 12 percent, decreasing to 6 percent by April 4 and 1 percent by May 7, but then increasing to 14 percent on June 7 and jumping to 27 percent by June 21.
“Curtailment of the ditches is indicative of raising the forecast every month,” he said. The projected annual index for the Conejos River system was 185,000 acre feet in May, 210,000 acre feet in June and is now estimated at 220,000 acre feet.
Of the 220,000 acre-foot annual flow , the Conejos River system owes 57,000 acre feet to New Mexico and Texas. To reach that goal, the Conejos will have to send about 8,000 acre feet downstream during the remainder of the irrigation season, according to Cotten.
Cotten shared the threemonth precipitation outlook from the National Oceanic and Atmospheric Administration for August, September and October.
“For the first time in quite a few years we are in the above-average range,” he said. “It’s looking like we are going to have a pretty good monsoon season.”
Temperatures during that three-month period will be another court case where the fine could top that.
“We are watching the well meter usage and metering and making sure everybody has active and accurate meters on their wells,” he said.
In his report to the Rio Grande Water Conservation District board on Tuesday, District Engineer Allen Davey said both the unconfined and confined aquifers had shown some improvement recently, but the basin has a long ways to go to re-establish the kind of aquifer levels the state legislature mandated, reflecting the levels of the period from 1978-2000 .
The confined aquifer, or deeper aquifer, has improved this last year by an overall total of about 2.66 feet in the wells included in Davey’s study. He said if the weather returned to a wetter cycle, with improved run off, irrigators would not need to pump as much, and the aquifers would naturally improve.
He added, “If we have bigger water years and the pumping stays the same, the aquifer will recover, and if the pumping is reduced, the aquifer will recover more.”
Since 1976 the unconfined aquifer, or shallow aquifer, in an area representative of the area now covered by the first groundwater management sub-district has declined a total of more than one million acre feet. Davey said the study area showed some improvement this spring with the aquifer level increasing by 105,000 acre feet during June, for example. “equal chances” of being in the average range.
Cotten said his office has had to file four or five court cases in the last month or so against well owners who did not comply with the well use rules, specifically not turning in well usage numbers or not having valid well meters in place. Fines could range from a few hundred dollars in simple cases to thousands of dollars. One irrigator is looking at a fine of more than $8,0000, Cotten said, and his office is currently working on He reminded the group that the target level required by legislators is -200 ,000 to -400 ,000 acre feet for a fiveyear running average.
“Right now it’s about 500,000 acre feet below that -400 ,000,” he said.
He said it’s like gas in a vehicle’s tank, and the more the vehicle uses, the lower the gas level is.
“What we need to do in order to recover is reduce the amount of ‘driving’ we are doing ,” Davey said. “Well users need to ‘drive’ less, pump less water, irrigate less land.”