Jackson Gulch may expand

Tuesday, Jan. 7, 2014 2:44 PM
Ice fishermen try their luck as children play on the ice at Jackson Lake on Saturday. The Mancos Water Conservancy is proposing adding water storage near the lake as well as a hydroelectric plant at the drop shoot downstream from the dam.

The Mancos Water Conservancy is working on expanding Jackson Gulch Reservoir to hold an additional 80 acre-feet of water.

“There’s always the need for additional irrigation in the valley,” said Gary Kennedy, superintendent of the conservancy.

The water would be stored in the depression left by the construction of the original Jackson Gulch Dam. The expansion would be the equivalent of about 26 million gallons.

The addition is very small compared with the capacity of Jackson Gulch, which tops out at 10,000 acre-feet. About 6,000 acre-feet are dedicated to irrigation, and the town of Mancos draws on the reservoir when the West Mancos is running low.

About five years ago, the conservancy considered expanding the reservoir itself but determined the gravel pit would be more feasible.

A preliminary study has been completed, and the conservancy is going to start discussions with the Bureau of Reclamation later in January. The Bureau of Reclamation will have to complete its own study.

If the expansion is completed, filling Jackson Gulch Reservoir would be the first priority, and any excess would go into the new lake.

During the 2012 and 2013 season, the reservoir was filled to only 36 percent of capacity because of low snowpack.

Currently, the reservoir is filled to about 27 percent of capacity, according to the Bureau of Reclamation. The winter average is about 35 to 40 percent of capacity, Kennedy said.