Long Hollow Reservoir late season augmentation water working as planned

Long Hollow location map via The Durango Herald

From The Durango Herald (Jonathan Romeo):

In the 1960s, irrigators in southwestern La Plata County had their dreams dashed when plans for a major transmountain diversion, which would have taken water from the Animas River into the low-flow La Plata River, were quashed.

The water project – called the Animas-La Plata Project – was considered the last major water storage effort in the American West. Then in 1990, the project was downsized again, removing plans for irrigation out of Lake Nighthorse.

“That’s when we started thinking seriously about this,” said Brice Lee, president of the La Plata Water Conservancy District.

Irrigators on the western side of the county have historically had to rely on the La Plata River, a generous moniker for a relatively low-flow waterway that is reduced to a trickle, and even dries up, after a short spring runoff.

Yet despite the lack of natural flows, the water has been terribly over-appropriated.

In the 1920s, Congress approved a water compact that requires the state of Colorado to deliver one-half of the daily flow of the La Plata River, measured at Hesperus, to the New Mexico state line for the use of irrigators to the south.

However, Colorado, which must live up to those terms from Feb. 1 to Dec. 1, has not always made good on that requirement for a number of reasons, including drought and water demands.

As a result, Long Hollow Dam was concocted in the 1990s, with construction starting in 2012. It cost nearly $23 million. Funds set aside from the Animas-La Plata Project paid for the 151-foot-high, 800-foot-wide dam.

The reservoir, located along Colorado Highway 140, has a capacity of nearly 5,400 acre-feet – small change when you consider Vallecito Reservoir has a capacity of 125,000 acre-feet and Lake Nighthorse, also relatively new, has a capacity of 123,541 acre-feet.

Still, the stored water in Long Hollow Dam functions as a win-win water exchange.

About 100 to 150 irrigators in southwestern La Plata County can draw and divert water out of the La Plata River farther north of Long Hollow Dam.

Then, to meet the terms of the compact, water is released from the Long Hollow Dam into the La Plata River, which takes water from Long Hollow Creek and Government Draw, tiny tributaries of the La Plata River that drain 43 square miles east of Colorado Highway 140.

Lee said thanks to strong winter snowfall and spring rains, Long Hollow Dam was able send 2,000 acre-feet to New Mexico this year. That means irrigators in southwestern La Plata County were able to use an additional 2,000 acre-feet out of the La Plata River.

“We’re pretty pleased,” he said. “We had a good year.”

The uptick in available water has had a predictably positive affect for ranchers and farmers, extending the growing season anywhere from 10 to 14 days – a vital extension in an industry that runs on margins.

“This is helping families that were drying up and getting discouraged,” said Ron Crawford, a fourth-generation La Plata County resident who is in charge of dam maintenance.

Taylor, whose father, Bobby, sold the land for the dam, said he was able to produce 30 to 40 percent more hay and grain than in years past because of the water Long Hollow Dam freed up.

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