Click the link to read the article on the Boulder Reporting Lab website (Tim Drugan):

This winter dropped a lot of snow on the mountains above Boulder. Our reservoirs are in good shape for now as Boulder Creek babbles. But that’s not our only water source. 

Boulder and many other cities along the Front Range rely, at least in part, on water from the strained Colorado River. Younger cities with fewer senior rights for local water sources — like Superior and Erie — rely on it almost entirely. 

Because every city is responsible for its own water portfolio, as the Colorado River becomes a potentially unreliable source, wholly dependent cities could be far worse off than others. This isn’t a far-fetched idea. A Colorado State University study shows that for every degree Fahrenheit of global warming, flows of the Colorado River decrease by 4%. And already, the Windy Gap Project — responsible for supplying a portion of Colorado River water to Front Range cities — sometimes doesn’t provide any water at all. 

Yet for now, many municipalities in the Boulder County area seem reluctant to even discuss sharing water. 

“Right now, we’re all trying to do the best job for our [own] residents and our customers,” said Melanie Asquith, the water resources manager for the City of Lafayette. “Everybody’s situation is different. Everybody’s storage is different. Everybody’s rights are different.”

Interviews with water managers across the county revealed potential stage-setting for a “Mad Max” situation. Each municipality is concerned only with securing water rights for its own residents. This means that unless the mindset in Colorado changes to one of greater collaboration, it’s safe to assume future droughts will hit some communities harder than others. And those hard-hit communities may be on their own. 

“The citizens and businesses of Louisville are paying their water bills to ensure their supplies are covered — not necessarily Lafayette’s or Broomfield’s or anybody else in the region,” said Cory Peterson, the City of Louisville’s deputy director of utilities. “There’s not a regional or state presence that would do those types of activities. That’s just the way the system is set up.”

Where do Boulder County communities get their water from?

Peterson of Louisville said a foreshadowing of droughts’ impacts in Boulder County happened in 2001. 

“You had some communities that were doing very aggressive water restrictions, had very low water supplies, and were really struggling to make it through,” Peterson said. “And you had other communities that had very light restrictions and had, I don’t want to say an easy time, but they were able to manage through those impacts.” (We saw a lesser instance of this last summer when Lafayette imposed year-round water restrictions while Boulder didn’t.)

This has led to water resource managers up and down the Front Range to chase water diversity to ensure they’re not the worst off. If one water source fails, it’s good to have another to lean on. 

“Our biggest gift is our diversity, that we are not wholly dependent on the [Colorado River], that if we had to rely only on eastern water, we could do it,” Asquith of Lafayette said.

Age matters for water rights

Because of the way Colorado water rights work, it pays to be old. The “prior appropriation doctrine” — summed up as “first in time, first in right” — heavily favors cities that started getting water for their residents earlier. Being first has landed them “senior” water rights from local sources like Boulder Creek or St. Vrain Creek. 

“Longmont is fortunate that a majority of the water rights in our water rights portfolio are very senior water rights,” said Wes Lowrie, a water resources analyst for the City of Longmont. “We feel very strong in our ability to meet our future demands for Longmont.”

Boulder, Louisville and Longmont have senior rights to local creeks, requiring them to get only a third of their water from the Colorado River. That insulates them from future uncertainty on the Colorado River and provides some resilience against climate change through diversification. Lafayette gets less than a quarter of its water from the Colorado River. 

Pretty much all of Erie’s water, on the other hand, comes from the Colorado River. All of Superior’s does as well.

California, Nevada and Arizona recently reached an agreement to temper their use of water from the Colorado River. With federal assistance, the worst repercussions of overuse from the river will hopefully be avoided, for now. But Colorado wasn’t a part of the recent Colorado River agreement, because Colorado is part of the Upper Basin states: those using water above parched Lake Powell. Unlike the Lower Basin, Upper Basin states have thus far used less water than is available to them. But that could change as the river reduces more. 

When a water source is diminishing, you want a senior right on that source to make sure you get your water before it runs out. Yet some of the water coming from the shrinking Colorado River to the Front Range isn’t even close to a senior right. The Windy Gap project, a water right that provides some cities with a considerable chunk of their water, only dates back to 1968 — very young by Colorado River standards.

“The Windy Gap water right is a very junior water right on the Colorado River,” said Jeff Stahla, a public information officer at Northern Water, which manages Windy Gap. “The Windy Gap Project in some years yields zero water.”

The project — which includes a diversion dam and reservoir on the Colorado River — is just one of the water rights allotting Colorado River water to eastern cities. Originally funded by Boulder, Estes Park, Fort Collins, Greeley, Longmont and Loveland to cope with booming populations, the project started delivering water across the Continental Divide in the 1980s.

Today, some Front Range municipalities are investing further in Windy Gap water. By building a new reservoir in southern Larimer County, the cities hope to store Windy Gap water from wet years to get them through the dry ones when Windy Gap may provide no water.

Called the Chimney Hollow Reservoir, the project broke ground in 2021 and is on track to cost upwards of $700 million. A dozen different water districts are funding the reservoir to add an additional fail-safe to their water supply. Involved cities include Louisville, Lafayette, Longmont, Erie and Superior. Broomfield is leaning especially heavily on the new reservoir, voting in 2021 to foot $176.4 million of the bill. (Boulder is not involved in the Chimney Hollow project.)

According to City of Broomfield staff, this investment will increase Broomfield’s reliance on Colorado River water from 60% of their source water to 70%. Broomfield’s water not delivered by Northern Water comes from Denver Water, which also gets a portion of its water from a tributary of the Colorado River. Piped through the Moffat Tunnel, water previously destined for the Colorado River is stored in Gross Reservoir that recently began a controversial expansion project.

Yet Windy Gap water isn’t the only water coming from the Colorado River. The Colorado-Big Thompson Project, or C-BT, has been pumping water east since 1947. With its right dating to the 1930s, that water “is much more guaranteed,” according to Stahla.

Almost all cities who get Windy Gap water also get a portion of C-BT water. 

Pete Johnson, a water attorney for the town of Erie, said the town’s water comes from a mix of C-BT water and Windy Gap water with an investment in the Chimney Hollow project — all Colorado River water.

“The long term goal is to diversify the town’s portfolio,” Johnson said.

But C-BT water isn’t infallible either. “The CB-T water right, I don’t want to say it’s junior, junior,” Stahla said. “But certainly a 1930s water right is not senior in the state of Colorado.”

Setting up a Mad Max future

Robert Crifasi, a former City of Denver hydrologist and Boulder Open Space and Mountain Parks water resources administrator, and author of a new book “Western Water A to Z: the History, Nature and Culture of a Vanishing Resource,” said one of the most important steps to avoiding a Mad Max future is ensuring water availability before building new developments. Because of overzealous development companies, Crifasi said, some Denver suburbs are now reliant on nonrenewable Denver Basin groundwater. What will those communities do when the aquifer runs dry? Rely on the Colorado River?

“There is no magic bullet in any of this,” Crifasi said. “But I do think the most important action is to legislatively require vigorously integrated water and land-use planning.”

Kim Hutton, the City of Boulder’s water resources manager, said in addition to conservation and planning, there’s a need for collaboration and coordination among municipalities around water. As it currently stands, it’s every city for itself.

“Right now, with the water rights system, individual water users really are responsible for developing a supply to meet their needs,” she said.

Lowrie of Longmont, for instance, said that Longmont has always required that developers prove a reliable water source before moving forward into construction. “And that planning has served us well,” he said.

When asked if Longmont had talked about possibly sharing with other municipalities that might, in the future, not have enough water for their residents, he suggested that long-term aid would be viewed very differently than short-term aid.

 “The decision to share water on an ongoing basis might be a different conversation than if there was an emergency situation, like if somebody’s water treatment plant went out,” he said. “That’s a different scenario than saying, ‘Hey, we didn’t plan as well as Longmont, and now we don’t have enough supply.’”

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