Summit County Citizens Voice

Dillon Reservoir, the centerpiece for Summit County's summer recreation, is likely to fill even the rest of spring brings dry weather.

Denver Water releases latest models for Blue River Basin stream flows, reservoir levels

By Bob Berwyn

SUMMIT COUNTY — Thanks to copious snow in late March and early April, local streams should be running high with runoff well into the spring. Dillon Reservoir is likely to fill sometime in June regardless of spring weather, said Bob Peters, a resource engineer with Denver Water.

Peters last week released the latest forecast models for Blue River Basin streamflows and Dillon Reservoir levels. The only significant change from the previous month is that he expects Dillon Resevoir to fill even if the late spring ends up being drier than average.

Under a dry weather scenario, Dillon would stay almost full through July, then drop about 15 or 16 feet in August and September, with plenty of water for marina operations. And the existing snowpack all but assures that there will be some decent runoff in the Lower Blue, north of Silverthorne, where Denver Water expects flows during June to average about 712 cubic feet per second in June, dropping to about 426 cfs for July (monthly average).

Under a normal spring weather scenario (dry, normal and wet are based on runoff forecasts), levels in Dillon Reservoir won’t change much, but there could be up to two months of Blue River flows high enough for boating below Silverthorne, with average monthly flows peaking at more than 1,000 cfs in June, dropping to about 820 cfs in July.

Under a wet scenario, Dillon Reservoir would fill up by the end of June and stay full all through July and August before dipping down by about 15 feet in September, then going back up by about seven feet in October. With higher than average runoff in the tributaries above Dillon Reservoir, the Lower Blue could run as high as 856 cfs starting in May, climbing up to above 1,300 cfs in June and staying above 1,000 cfs into July — a dream outlook for boaters.

Filed under: climate and weather, Colorado, Dillon Reservoir, Snow and weather, Summit County news, Summit County snow and weather Tagged: | Blue River Basin water, Colorado water, Denver Water, Dillon Reservoir levels, Summit County News