Severe drought may soon become more common in Eagle County. Water providers have a plan

Every year brings different water conditions in Eagle County. With climate change, the promise of full rivers in the summer may become even less certain.

To prepare for future drought years, the Eagle River Water and Sanitation District and Upper Eagle Regional Water Authority have a new water shortage response plan.

“The goal of this plan is to provide water security, to ensure that we can provide our core services,” said Justin Hildreth, the district’s water resources engineer, when presenting the plan to the district board for approval on April 10. Among the core services included in the list are safe drinking water and water for structure fire suppression.

According to the plan, “a water shortage occurs when the (district/authority) lacks the physical or legal water supplies needed” to provide their services and maintain required streamflow levels. This can happen when there are extended calls from older water rights, (like the Shoshone water rights on the Colorado River), when stream flows are low for long periods and when local reservoirs (Eagle Park Reservoir and the Black Lakes) have low supply.

The district and authority boards approved the plan during their April 10 meetings after learning about the plan during Feb. 27 work sessions.

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Preparing for a water shortage starts early

“We are always monitoring for drought conditions,” Hildreth said in February.

One of the best early predictors of a drought scenario is if the snow water equivalent measure has not reached an average of 15 inches across the Vail, Fremont Pass and Copper SNOTEL stations by April 1. “That directly relates to Eagle Park Reservoir, that relates to the flows in Gore Creek and the flows in the Eagle River,” Hildreth said.

This year, the average was just shy of 16 inches across the three stations on April 1.

“That’s good news,” Hildreth said in April. “We’re seeing early melt off at the Vail Station because it has been so warm, so we are tracking that. We do think Eagle Park Reservoir is going to fill up, so we should be good for this year, but we are tracking the climate, because if we have a really warm spring, we could have an extended in stream flow in the summer.”

The second indicator of a severe drought year is if peak flow in the Eagle River at the Avon Wastewater Treatment Facility measures below 1,200 cubic feet per second at some point between May and July. One cubic foot per second is equivalent to about 7.5 gallons of water flowing past one point within a second.

The third indicator is when the flow drops below 100 cubic feet per second at the same station. When that happens between May and July, it signifies that the critical period is coming soon. “The drier the year, the earlier it is going to be,” Hildreth said in February.

The critical period refers to the number of days in which the district and authority bolster water supply for their customers by releasing water from the Eagle Park Reservoir and Black Lakes. The length of a critical period varies widely year-to-year, from zero days to weeks on end.

“A critical period lasting 30 to 50 days is associated with moderate to severe water shortage risks,” according to the water shortage plan. In 2002, 2012 and 2018, the critical period lasted more than 50 days.

As soon as district staff sees the low April 1 reading, staff will mobilize to prepare for a dry summer. “We’ll have enough time. That’s the advantage of this plan, is we’ll know in April that this is coming,” Hildreth said in February.

How does the district react to a summer of drought?

A measure of streamflow in the Eagle River below Gypsum from 1946 to today shows that stream flows vary widely from year to year, with droughts occurring roughly once every 20 years. There have been four droughts classified as “severe” in Colorado and the Eagle River Valley over the last two decades: In 2002, 2012, 2018 and 2021.

The water shortage plan is focused on short-term water emergencies, not long-term conservation strategies, Hildreth said in February. (The district has other plans in action to build in preparation for the long-term droughts, including encouraging customers to use less outdoor water by raising water rates and implementing a water use schedule, along with building Bolts Lake Reservoir as a backup water supply.)

The water shortage response plan is designed to respond to this type of one-in-20-year drought event. But climate change predictors estimate that the likelihood of severe drought could increase to one in 10 years soon.

During a severe drought event, there will be a short period in May and June when water flows in the rivers. As the summer goes on, in late July, August and September, the river will start to dry up and there will be calls on the river from other places.

Part of the problem is that the two-month dry period at the end of summer also coincides with high water use by people.

Outdoor water use, like irrigation, is 75% consumptive, meaning only 25% percent of the water gets returned to the river. Indoor use, on the other hand, is only 5% consumptive, and remains relatively steady throughout the year.

The district and authority customers’ outdoor water use is consistently highest in June, July and August, followed closely by September. In an accounting of district and authority water use between 2011 and 2022, these months alone account for 86% of outdoor consumptive use for the entire year.

Going into a severe drought, the district and authority will also ask customers to curb their outdoor water use. During a 50-day critical period, customers will be asked to reduce their outdoor water use by 60%.

Those who do not adhere to the limitations may face financial implications. “Fines are probably the biggest stick we have,” Hildreth said in February.

The first set of drought fines will be proposed in the district and authority’s 2026 budget packets, which will come before the boards in the fall. (The fines are intentionally not written into the water shortage plan to allow for the flexibility to adapt them to the climate conditions each year.)

If necessary, the district and authority can release water from Homestake Reservoir and the Eagle Park Reservoir to augment the river and bolster in-stream flow, but these sources are not meant for regular use.

“We want to be as conservative with managing that reservoir so we can have it last as long as possible,” Hildreth said in February.

While releasing water from the reservoirs one year will not cause harm, the risk is that if a lot of water is released and the following winter is a low snow year, the reservoirs may not refill completely, worsening the problem for the following year. “Statistically, there is a good chance we have two years in a row of a problem,” Hildreth said in February.

The water shortage response plan is designed to be updated regularly. The district and authority will revisit the 2025 plan in 2030.

“These trigger points are really only designed for the next 5 to 10 years,” Hildreth said in April. “We are going to come back and update this plan as conditions change, whether it’s the construction of Bolts Lake, dealing with the climatic conditions. It’s supposed to be a living document according to the state’s standards.”