Releases from Stagecoach to Yampa River become more important as climate warms

Colorado Water Trust has released more than 600 million gallons into the waterway since 2012

 

Steamboat Pilot, August 4, 2022

Near the end of July, flows into Stagecoach Reservoir from the Yampa River dropped below 40 cubic feet per second for a few days.

That threshold is important because it helps, in part, determine how much water flows out of the reservoir and continues downstream to Steamboat Springs. If the flow coming in is more than 40 cfs, then at least 40 cfs is usually discharged at the bottom of Stagecoach Dam.

If the inflow drops below 40 cfs, the outflow generally would as well, leaving less water for critical fish habitat below the dam and in the river in general.

But on July 22, the Upper Yampa Water Conservancy District released reservoir water to bolster the river’s outflow — part of a 10-year deal for water releases with the nonprofit Colorado Water Trust meant to protect the health of the river.

“If the flows that are coming in drop below 40 cfs, we make sure the flows coming out of Stagecoach stay at or above 40 cfs,” said Alyson Meyer Gould with the Colorado Water Trust. “We basically try to prevent it from really tanking below the dam.”

The long-term deal is one of the first in the state and was made possible by a 2020 state law allowing such agreements. Before, groups like the Water Trust and Upper Yampa district needed to rehash out a contract each year.

As Meyer Gould put it in a July news release, snowpack and rainfall has become a “roll of the dice” in Colorado, and the hope is this reservoir water can be used to augment the river when it gets a “bad roll.”

Meyer Gould said 2021 certainly was a bad roll.

The snowpack in the Yampa River Basin peaked before the end of March and precipitation from May to August in Steamboat amounted to just 64% of the average over the past 30 years.

The second half of the year was the hottest ever in Colorado, and tree ring studies have revealed that human-caused climate change has made the last 22 years the driest since at least A.D. 800.

To support the river, the Water Trust released 1,850 acre-feet of water — more than 600 million gallons — from Stagecoach. At times, more than half the water in the river was there because of releases.

But this year has been different. While the snowpack wasn’t impressive, spring precipitation slowed melting, and there was still snow in the basin until June 23, according to the Natural Resources Conservation service. Monsoon rains have further buoyed the river, with Steamboat measuring more than 10 inches of rain from May to July.

While not necessarily a good roll, this year doesn’t seem like a bad one.

“I think it is on the low side of average,” said Emily Lowell, the district engineer for the Upper Yampa Water Conservancy District. “Runoff was pretty average, and I think monsoonal rains this summer have made it sustain that average.”

But even in a close-to-average year, releases from the reservoir are still needed, though not to the same extent. Since the first releases at the end of July, inflows and outflows have both stayed above 40 cfs and more of the trust’s water hasn’t been needed.

The 10-year deal can be extended twice, essentially lasting 30 years. While releases for environmental purposes are limited to five of every 10 years, the water trust has other mechanisms to release water that meet the legal definition of a “beneficial use.”

Putting water in the river for the sake of having water in the river generally isn’t considered a beneficial use. Neither would be adding water to ensure the river stays open to recreation.

The Water Trust can release water for hydroelectric purposes, as well as to send water to the Steamboat Springs Wastewater Treatment plant. Each has the same benefits as an environmental release.

In addition to adding water to the river, water coming out of the reservoir is colder than what goes in, too.

A new water temperature gauge above Stagecoach measured over 70 degrees on Thursday, Aug. 4. Holly Kirkpatrick, spokesperson for the Upper Yampa district, said water currently being discharged is being drawn from the bottom of the reservoir, which is generally about 55 degrees.

Meyer Gould said these releases will become increasingly important to maintain the health of the river as climate change continues to bring hotter and drier conditions to the West.

“I don’t know what that is going to look like in terms of volume,” Meyer Gould said. “But I think that there are times when, if we can keep things from drying out — especially in terms of major fish kills — then yeah, I think that is going to be something that we try to do year in and year out.”

 

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Steamboat Pilot
by Dylan Anderson
Original Article