WENATCHEE, Wash. — An abnormally large mountain snowmelt in Canada is swelling rivers in Northcentral Washington and may flood shorelines along the Okanogan River from Oroville to Brewster all summer.
“Property owners with low-lying lawns and fields and folks who recreate in the river should take heed and prepare for the highest river levels we’ve seen in 20 years,” said Al Josephy, of the state Department of Ecology’s water resources program.
Okanogan River flows could be two to three times greater than normal through summer, he said.
Large mountain snowpack in British Columbia is putting tremendous pressure on Canadian water managers to maintain optimal levels in reservoirs and lakes, Josephy said.
Lake Osoyoos on the U.S.-Canada border likely will remain above normal operating levels for much of the summer, causing periods of flooding on the lake shore and farther downstream, he said.
Roughly 100 acres of pasture between Oroville and Tonasket flooded and a couple hay fields near Tonasket, said Jay O’Brien, manager of Oroville-Tonasket Irrigation District.
“Guys had first cutting down, grass and alfalfa, and had it raked but never got it baled,” O’Brien said.
The river was 1.34 feet above flood stage at Tonasket on May 25, he said. That amount of flooding is not unusually every few years but the anticipated duration through summer is unusual, he said.
O’Brien said he didn’t know of any orchard flooding.
The Methow, Entiat and Wenatchee rivers are all full and above their banks in places. Several rows of a pear orchard at the Old Monitor Bridge northwest of Wenatchee were underwater from the swollen Wenatchee River on May 30.
Pear trees can handle high water better than apple trees but neither can survive it too many days, said Howard Schell, director of field services at Chelan Fruit Cooperative in Chelan.
Roots can’t get air and if that lasts too long, trees will die, he said.
Driving from Chelan to Omak, on May 28, Schell said he saw no orchards flooded but did see low-lying hay ground flooded near the town of Okanogan.
The Columbia River reservoir behind Wells Dam had been lowered to make room for additional flows from the Okanogan and Methow rivers, “both of which are roaring torrents right now of lots of water,” he said.
John Baile, assistant orchard manager at Auvil Fruit Co. in Orondo, said company orchards along the Columbia at Orondo are OK but that he didn’t know about company orchards farther south at Vantage. They are more prone to flooding, he said. There’s a lot of silt in the river from the heavy runoff so employees are constantly checking automated irrigation pump filters to make sure they are working, he said.
Larry Letts, a Baker Flats orchardist near East Wenatchee, said the Columbia is 10 feet below the high water mark for his orchard and that his irrigation pump would be jeopardized if it reaches that level.