High Country Snowmelt = Increased Spring Runoff

GRAND COUNTY, Colo. (CBS4)- All the spring snow that fell in the high country last month has started to melt which is causing a lot of runoff along the Front Range.

The three consecutive days of very warm temperatures across Colorado at the end of May and beginning of June have contributed to the increased snowmelt.

The runoff at Lake Granby was rushing at 1,800 cubic feet per second on Tuesday.

Northern Colorado Water told CBS4 they need to discharge the water out of Lake Granby in Grand County to accommodate all the incoming snowmelt.

In Lake Granby there is only about four feet left of storage capacity but there is still an estimated 100,000 acre feet of snow yet to melt in the area that will drain into the lake. That is not enough space for all the snowmelt.

In a typical year, Northern Colorado Water will release about 75 cubic feet per second from Lake Granby during the early part of June. This year, 1,800 cubic feet is rushing out of the lake because of the above-average May in terms of precipitation.

That cold water rushing down is creating an unusual effect.

"Because of the influx of all of this very cold water, it's cooling down the air directly beside the water and producing what we call a localized area of high pressure. That high pressure is producing some wind so it's actually gusty right next to the lake," said CBS4 Meteorologist Justin McHeffey.

The snow depth across the mountains above 10,000 to 11,000 altitude is still measuring 50 inches deep in some pockets. Once all of that snow starts melting, the spring runoff will only increase.

There are four endangered species of fish located upstream near Grand Junction that also benefit from the increased spring runoff.