River flows fourth lowest on record


ALAMOSA — On a less positive note, this year is the fourth driest year on record for the Rio Grande.

On a more positive note, next year should be better.

Division of Water Resources Division 3 Assistant Division Engineer James Heath shared the latest on river flows and precipitation projections during Tuesday’s Rio Grande Roundtable meeting in Alamosa.

“It’s worse than 2003 but better than 2002 and better than ’77 and 1902,” Heath said. “It is a significant drought.”

The annual index flow for the Rio Grande at Del Norte will be about 285,000 acre feet, Heath explained, making it the fourth worst year on reported record. Of that, only 72,000 acre feet were required to go down river to New Mexico and Texas to meet Rio Grande Compact obligations. The Rio Grande will over deliver about 13,500 acre feet this year, giving the river a credit it can use in the future.

“That’s not anybody’s fault,” Heath explained. “We have set zero curtailments from the beginning.”

He added that if next year is a better water year, which it looks like it will be, that credit can be used to reduce curtailments to San Luis Valley irrigators.

The Conejos River system is faring about as well this year, with the annual index flow projected at 139,500 acre feet, or about half the average flow, Heath said. The obligation from that flow to downstream states is 25,000 acre feet, but just as in the case of the Rio Grande, the Conejos River is going to wind up with a credit, having over delivered about 3,500 acre feet.

Between the Rio Grande and Conejos River systems, the over delivery will amount to about 17,000 acre feet this year, Heath said, which gives Colorado a healthy credit with its downstream Rio Grande Compact partners.

Regarding temperature and moisture predictions from the National Weather Service, Heath said temperatures in the next few months are predicted to be warmer than normal for the Rio Grande Basin while precipitation is predicted to be above average for this region from September through November. He said the rain is not likely to come in the next 10 days, “but hopefully after that, more rain.”

The long-term precipitation forecast calls for “equal chances” of above normal precipitation for this region, Heath added. That is in the February through April time period, so hopefully next year will yield more snow, he said.

Rio Grande Water Conservation District General Manager Cleave Simpson also addressed the drought conditions. He said this is the first decade in recorded history when the Rio Grande (measured at the Del Norte gauge) never hit 700,000 acre feet and the first 20-year period where the Rio Grande never exceeded 800,000 acre feet annual flow.

He reminded the group of Valley water leaders that the Rio Grande Water Conservation District has measured the unconfined aquifer since 1976 (roughly in the portion of the basin where the first water management sub-district now lies) and specifically tracked the decline in the aquifer levels since the historic drought of 2002, which dropped the aquifer by 400,000 acre feet alone. (The aquifer levels in that study area have declined by about a million acre feet since 2002.)

Simpson said he was hoping the decline this year would be less than 200,000 acre feet. “Since January of this year we have lost 160,000 acre feet,” he said, adding that September is generally the lowest of the year, and that month has not been factored in yet.

It just illustrates how much of an impact that Rio Grande flow at Del Norte has on the aquifer, Simpson said.

He said Sub-District #1 has been using a variety of methods to bolster the aquifer including conservation, the Conservation Reserve Enhancement Program (CREP) and fallowing. Those efforts have resulted in about 350,000 acre feet of recovery to the aquifer. However, to meet sustainability levels required for the sub-district, it will have to recover 800,000 acre feet in the next 12 years, “and it’s a significant challenge for us.”

The impact is broader than the hundreds of irrigators in Sub-District #1, Simpson pointed out. He said the Valley’s economy is built on irrigated agriculture, and drought conditions coupled with mandated recovery requirements will cause fundamental changes in that agricultural economy, consequently affecting the entire Valley community.

“It seems undeniable to me there will be impacts to the community going forward,” he said.

Caption: Division of Water Resources Division 3 Assistant Division Engineer James Heath concludes his report on Tuesday with some better news about future precipitation forecasts./Courier photo by Ruth Heide

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