The 23-mile-long pipe that siphons water from Dillon Reservoir to the Front Range has run dry thanks to decreased water demand from the metropolitan areas near Denver. 

This has allowed Summit County to keep more than 6,000 acre-feet of water in Dillon Reservoir, and officials with Denver Water, which controls the flows out of the reservoir, say it will help support more recreation on the Lower Blue River. 

The outflow to the Blue River currently hovers around 1,050 cubic feet per second. That rate is around 175% of the historic outflow for the last week of June. Last year, outflow was at 56 cubic feet per second, which sits at the historic minimum. 

For comparison purposes, a basketball is about one cubic foot. So to put the current flows into perspective, people can imagine 1,050 basketballs flowing past them every second. 

Commercial rafting operations typically require flow rates above 500 cubic feet per second. 2023 marked the first weekslong commercial rafting season in Summit County thanks to above-average precipitation this spring and reduced demand from the Front Range. 

Over the next week, the spillway should release flows between 900-1,200 cubic feet per second, and Denver Water forecasts don’t call for the flows dropping below 500 cubic feet per second until mid-July.

The commercial rafting season was nearly ended by a downed tree across the commercial stretch of the river, but locals banded together to remove it and save the season despite the danger posed by the situation.

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As of Monday, June 26, all 10 of Denver Water’s major reservoirs were full, causing free river conditions on the South Platte River.

Multiple swift-water deaths have caused public safety groups to urge caution while recreating on and near rivers. Officials advise folks to never use plastic tubes or vessels that aren’t commercial-grade rafts, and only experienced rafters should attempt to navigate High Country rivers due to their increased flows, natural obstacles and terrain traps.