Final snowpack survey winds up on the low side

May 09, 2013 07:51 am

The final snowpack survey for the Grande Ronde Basin has come in at 25 percent lower than normal for this time of year.

“A few days ago the snowpack was at 73 percent, and the sites are showing, on average, 70 percent,” said Mike Burton, district conservationist with the USDA’s Natural Resources Conservation Service in La Grande. “We’re low.”

The only survey that Burton and his associate do at the beginning of May is up at Anthony Lakes, where he reports the snowpack was at 82 percent of normal.

“We’re short,” he said, “but not as short as the rest of the state. South of us the whole southern strip of counties in Oregon are all showing low numbers.”

Owyhee was coming in at 21 percent of normal, and Burton said they are already limiting stored water for irrigation there, which will significantly affect cropping sequences.

“When you look around that southern swath of counties, they are coming in pretty low and some people there will have to make some significant choices,” Burton said.

Stream flows have reflected the low snowpack measurements. This spring has not produced the huge peaks in precipitation that have occurred in years past, so there has been no “normal” flooding this year. 

“When we have a lot of low-elevation snow or high-water content snow and then get rain on top of it along with windy conditions, the Grande Ronde Valley has no place for it to go,” Burton said. “The Rinehart Gap puts a control on the valley, and the water just has no place to go. So it consolidates all that lower elevation moisture on the flood plain. We didn’t have that this year.”

Since the Wallowas had a reasonable snowpack this year, Burton said he expects Catherine Creek to rise a bit as it usually does in June, but not with substantial flooding.

Burton said the low snowpack will have some impact on the area, but it will not be substantial. If there are two low years back-to-back, then the area will see substantial changes, but this summer, the region can expect to have 25 percent less moisture unless the area gets typical May and June rains.