Fontanelle Reservoir Completion Put On Hold Until Absolutely Necessary

May 28, 2019

Fontanelle Dam and it's power plant.
Credit U.S. Bureau of Reclamation

Construction on the Fontanelle Reservoir won't get started until extreme drought strikes because officials say the unfinished bottom won't be accessible until then.

Officials hoped the reservoir located on the Green River in southwestern Wyoming would be completed sooner. When former Governor Matt Mead was in office, there was a lot of talk of completing Fontanelle Reservoir, allowing it to store another 80,000 acre feet.

But the U.S. Bureau of Reclamation now says it's better to wait for an extreme drought to draw the reservoir down. The reservoir's rubble foundation — known as riprap — was never completed during its initial construction in 1965. But Jason Mead of the Wyoming Water Development Office's Dam and Reservoir Division said finishing the job while the reservoir is full would be too difficult, and draining it would hurt fish and irrigators.

"But when we get to that point in these extreme drought conditions, if you had to bring the reservoir down that far, we could then put the riprap in place at that point in time and avoid the environmental effects of trying to draw it down, and riprapping when you don't need the water," he said.

Jason Mead said at full capacity Fontanelle Reservoir could help Wyoming water users fulfill their promise to contribute Colorado River water to states like Arizona and California that rely on it downstream.

"Fontanelle could potentially be used to release water to lower basin states in exchange for allowing our water users to remain on or continue taking water out of the river. And so, it's more of an exchange," said Mead.

The reservoir was not completed in 1965 when plans to use the water for farming became unrealistic.