Friday, July 1, 2011

Willow Creek Reservoir elevation: Back to normal

After a couple of months of looking pretty low, Willow Creek Reservoir's elevation will start looking up.

The reservoir's elevation will start to rise in the next few days as we go back to more normal operations for this time of year. The elevation has been lower than the seasonal average because of releases, which since April 1 have equaled more than 106,300 acre feet - nearly two and a half times the amount that normally flows in.

In a typical year, Willow Creek's pump plant moves reservoir water to Lake Granby. But in this wet year, we knew Lake Granby wouldn't have room for that water, so we let it simply pass through Willow Creek Reservoir. There was so much Willow Creek water passing through that we had to keep the reservoir elevation much lower than usual so we could be prepared for heavier runoff peaks and help protect the channel downstream.

Now that the runoff is tapering, the risk of peaking events is significantly reduced and we feel comfortable letting Willow Creek Reservoir go back to its normal elevation. Over the next few days, it will gradually rise to 8,124 feet - about nine feet higher than it is today.

During this fill period, flows below the reservoir will be reduced, but once the reservoir reaches elevation, we will start passing inflows again.

This chart shows how Willow Creek inflows (red) compare to outflows (green) this year:

2011 Willow Creek Reservoir inflows (red) and outflows (green)