Federal reservoir managers began releasing water into the North Platte in eastern Wyoming, making room for heavy runoff from deep snow, but ice on the river and fluctuating temperatures will slow releases upriver.

Listen Here:

The release of water from Glendo reservoir  began Tuesday  and starts at Guernsey next week .

Bureau of Reclamation area manager, John Lawson, says the high snow pack and early reservoir releases haven't happened since around 1997.

"We're saying right now that we need to start moving water out of the system because we just can not risk waiting until late April or May to make these decisions."

Lawson says, while releases have begun on the east end of the state, in Natrona County and at Grey Reef they'll wait, due to dramatically fluctuating temperatures and the presence of ice.

"We've decided that we're not going to change the flows out of Grey Reef so we are not going to risk having increased flows cause ice movement down here.  So as  ice does move it will not be a result of any of our actions."

Lawson says they want more of the ice to clear before releasing water from the upper reservoirs.

Last year a very wet May and June led to the opening of the Pathfinder spillway for the first time in over 25 years.  Casper prepared for extensive flooding but was spared. Lawson says its too soon to say if that will happen again this year.

Snow pack in the upper parts of the North Platte Basin is at more than 130 percent of average.

That compares to about 80 percent this time last year.