Long Hollow Reservoir should improve water rights administration on the La Plata River

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From The Durango Herald (Dale Rodebaugh):

The water collected in Long Hollow Reservoir from Long Hollow Creek and Government Draw will supplement the often scant water from the La Plata River, half of which must be shared with New Mexico.

“We’re happy to see the project moving along so well,” Brice Lee, president of the sponsoring La Plata Water Conservancy District, said last week. “It’s been a tough year because we haven’t gotten the monsoons yet.” Lee gets water from a ditch off the La Plata River for pasture and to irrigate hay. But he’s had only four days of water from his ditch so far this spring…

Long Hollow Creek and Government Draw drain a basin of 43 square miles on the east side of Colorado Highway 140 about five miles north of the New Mexico line and about a half mile from the confluence of Long Hollow Creek and the La Plata River. The reservoir, expected to be completed this year, will have a capacity of 5,432 acre-feet and 160 surface acres…

Colorado and New Mexico share the water of the La Plata River under a 1922 agreement. Each state has unrestricted use of water from Dec. 1 to Feb. 15. But from then to Dec. 1, if the river is flowing at less than 100 cubic feet per second at the state line, Colorado must deliver one-half the flow at Hesperus to New Mexico.

Fulfilling the compact isn’t easy for several reasons:

The La Plata, which rises in the mountains north of U.S. Highway 160, doesn’t have abundant water even in its best years.

Water availability and the growing season don’t follow parallel paths. The bulk of the water – as 95 years of records show – is available from April 1 to July 1. Flow shoots from 50 cubic feet per second to 200 cfs then drops quickly to 50 cfs before trailing off. The growing season goes on much longer.

A porous river bed and vegetation siphon off water in the 31 river miles from Hesperus to the state line.

Lee said there are probably 15 major ditches off the La Plata River and many smaller ones. He estimated that 500 to 600 irrigators have a share of the flow, however small.

The cost of the project must come in at $18.6 million or less because there’s no additional funding in sight, Lee said. The source is $15 million – plus accrued interest – from what the state contributed for irrigation in the Animas-La Plata Project. The irrigation component was removed from the A-LP – a settlement of Native American water right claims – in the 1990s.

More La Plata River Watershed coverage here and here.

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