Dry weather to slow Lake Dillon’s filling | SummitDaily.com

Dry weather to slow Lake Dillon’s filling

SUMMIT COUNTY – Drier-than-normal weather in May – particularly in the Blue River Basin – has prompted Denver Water’s Marc Waage to lower Dillon Reservoir level predictions for the summer.

At the end of May, Waage predicted that with normal precipitation, Dillon Reservoir would be 91 percent full by July 1. Now, he said, the reservoir should fill to 90 percent. Dillon Reservoir and the water in it are owned by Denver Water, which supplies municipal water to about 1.2 million customers in the Denver metro area.

Waage said he still expects the reservoir to fill completely by Aug. 1, particularly if rainfall – and in some areas, snowfall – stays at normal levels. As of June 9, the reservoir was 78.9 percent full.

What concerns him, however, is reservoir level predictions if Summit County experiences another dry summer.

In May, Waage predicted that with dry summer conditions, Dillon Reservoir would be 98 percent full by Aug. 1. Now, however, he predicts it will fill to 88 percent if Summit County experiences a dry June and July.

It’s even more severe in other Denver Water reservoirs, including Wolford Reservoir, 6 miles northwest of Kremmling, and Williams Fork Reservoir, 40 miles east of Kremmling.

Denver Water officials want to keep Dillon Reservoir as full as possible this summer. That means water the agency owes Green Mountain Reservoir downstream will be repaid with water from Wolford and Williams Fork reservoirs.

Dillon actually supplies water to Denver. The other two reservoirs mitigate water held for Denver, but owed to the Colorado River.

If the area sees the normal amount of precipitation this summer, Waage estimated Williams Fork Reservoir would fill to 98 percent of capacity, and Wolford Reservoir would fill to 74 percent of normal. If Colorado has a dry summer, however, Waage predicts those two reservoirs will fill to only 51 percent and 54 percent of capacity, respectively.

Dillon Reservoir is filling quickly not only because of heavy late-spring snowfalls, warm weather that melted snowpack and steady afternoon rainstorms, but also because Denver Water customers have done their part to conserve water, Waage said.

The agency set higher water conservation goals this summer and will encourage customers to save even more water than they did last year.

“So far, they’ve met the challenge,” Waage said. “That’s really helped out with Dillon. All our plans are to continue with mandatory water restrictions all summer long. It’s going to be needed.”

Denver Water, which diverts water from Summit County through the Roberts Tunnel to the North Fork of the South Platte River west of Grant in Park County, hasn’t used any Summit County water since May 12.

And cold weather has slowed snowmelt in most of the county so inflow streams to Dillon Reservoir aren’t at the near-record-setting pace they were two weeks ago.

On June 1, Waage said, water flowing into Dillon Reservoir from Tenmile Creek and the Snake and Blue rivers reached the third-highest peak since the dam was built – at 2,713 cubic feet per second (cfs) collectively.

By comparison, in 1995, when Summit County experienced a 100-year flood, flows into the lake totaled about 3,460 cfs.

Metereologists say El Nino, a disruption of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe that often results in below-average precipitation in parts of the West, has broken up, and more regular weather conditions might be on the horizon.

“They can’t predict any tendencies in the weather right now,” Waage said. “But climate (forecasters) said last fall we’d have a pretty wet fall, a dry mid-summer and a wet spring. They were right on.”

Jane Stebbins can be reached at (970) 668-3998 ext. 228 or jstebbins@summitdaily.com.

Support Local Journalism

Support Local Journalism

As a Summit Daily News reader, you make our work possible.

Now more than ever, your financial support is critical to help us keep our communities informed about the evolving coronavirus pandemic and the impact it is having on our residents and businesses. Every contribution, no matter the size, will make a difference.

Your donation will be used exclusively to support quality, local journalism.


Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.

User Legend: iconModerator iconTrusted User