It has been a rough year for operations at the Shoshone hydropower plant in Glenwood Canyon.
First, ice jammed the plant’s spillway in February, damaging equipment that required repair. The plant came back online in July but was able to generate electricity for only a few weeks before the Grizzly Peak Fire burned down its transmission lines.
According to the plant’s owner, Xcel Energy, the electricity impacts of the outages at the 15-megawatt generating station have been minimal, and the utility expects the plant to go back online this week. But while the electric grid can manage without the plant, the outage presents a much bigger threat to the flows on the Colorado River because the plant has senior water rights dating to 1902.
This means that any water users upstream with junior rights — which includes utilities such as Denver Water that divert water to the Front Range — have to leave enough water in the river to meet the plant’s water right of 1,250 cubic feet per second when the plant is running. When the Shoshone makes a call, the water makes its way through the plant’s turbines and goes downstream, filling what would otherwise often be a nearly dry section of river down toward Grand Junction.
A Shoshone call keeps the river flowing past the point where it would otherwise be diverted, supporting downstream water uses that would otherwise be impossible on this stretch of river. But when the plant is down, as it has been for most of 2020, that call is not guaranteed.
“Historically, what the Shoshone plant has done is kept a steady baseflow, which makes it easier for irrigators down here to be able to divert their own water right,” said Kirsten Kurath, a lawyer for the Grand Valley Water Users Association, which represents agricultural water users. “When the river goes up and down, it takes a lot of operational effort.”
The Shoshone water right also supports important nonconsumptive water uses. It provides critical flows needed for fish habitat and supports a robust whitewater-rafting industry in Glenwood Canyon. When the river drops too much below 1,250 cfs, it can create for a slow and bumpy ride.
“Customers get off and think, ‘Ugh, it would have been more fun to go to Disneyland,’ ” said David Costlow, the executive director of the Colorado River Outfitters Association. “Much lower and you are really scraping down that river and at some point you just pull the plug.”
The nearly year-long outages at Shoshone have many on the river worried. When the plant is down for repairs or maintenance, it does not make its call on the river allowing users upstream — including those that pipe water to the Front Range — to begin diverting. The Shoshone call can be the difference between the water remaining on the Western Slope or being diverted to the Front Range. Long outages, such as this one, reveal the vulnerability of the water on which so many rely.
“It’s a critically important component to the way that the Colorado main stem water regime has developed over more than a century now,” said Peter Fleming, the general counsel for the Colorado River Water Conservation District. “It’s sort of the linchpin or the bottom card.”
Water interests on the Western Slope have made some headway in recent years to maintain the status quo on the river even when Shoshone is down. Most of the major junior water-rights holders upstream of the plant — including Denver Water, Aurora and the Colorado Big Thompson Project — have signed on to the Shoshone Outage Protocol (SHOP). When the protocol goes into effect, as it has this year, these diverters have agreed to manage their diversions as if the Shoshone Plant — and the call — was online.
The agreement has been in operation for about a decade, helping to maintain flows during periods where the plant has undergone repairs or maintenance. The agreement was formalized in 2016 with a 40-year term. While the outage protocol has staved off major drops in the Colorado River flow over the years, the agreement is not as secure as water users that rely on Shoshone’s flows would prefer.
“SHOP is the best alternative that we have right now, but it doesn’t completely restore the flows,” said Kurath. “And one of the other problems right now is that it’s not permanent.”
For water users downstream of Shoshone, SHOP has three major issues. First, it is only guaranteed for 40 years, which for water planners is considered a short time frame. Second, the agreement does not include every upstream diverter, meaning that it doesn’t completely restore the flows to the levels where they would be if the Shoshone plant were on. Third, the agreement allows some of its signatories to ignore SHOP under certain water-shortage scenarios.
Despite the drought this year, the conditions never reached a point where SHOP’s signatories were able to opt out of the protocol, so the agreement went into effect when river levels dropped. But even though SHOP worked this year, the long outages at the Shoshone plant highlight the uncertainty of the plant’s future.
“We’ve always been nervous about it,” Fleming said. “It’s an aging facility, it doesn’t produce a ton of power, and we don’t know how long it’s going to be a priority to maintain and operate.”
The River District has been working to negotiate a more permanent solution for the Shoshone water rights for years. They have considered everything — from trying to buy the Shoshone plant outright to negotiating with diverters on the river to make something such as SHOP permanent.
The Shoshone outages have given these efforts renewed importance. In a recent board meeting of the River District, Fleming said that resuming talks with Denver Water that had stalled during the pandemic is a top priority.
While Fleming would not elaborate on the specifics of the ongoing negotiations, all options have the potential to impact many water users on the river — even those who aren’t at the negotiating table.
“We don’t approach this like we have water rights that we don’t have,” Costlow said. “But our business depends on water, and it depends on water levels that make water fun.”
This story ran in the Nov. 13 edition of The Aspen Times.