The mild storm that dumped heavy rain and melted a lot of mountain snow earlier this week has boosted several Eastern Oregon rivers above flood stage, but Baker County has fared better than its neighbors.
Flood warnings are in effect for several rivers in the region, including reaches of the Grande Ronde in Union County, the Imnaha in Wallowa County and the John Day in Grant County.
Sections of several highways were closed due to flooding as of this morning, including two stretches of Highway 26 in Grant County,
Neither of Baker County’s two major rivers, the Powder and the Burnt, is under a flood advisory.
But both rivers are running relatively high due to the combination of heavy rain and balmy temperatures that accelerated the melting of a deep snowpack.
No significant flooding has been reported, nor any water-related road closures, Baker County Roadmaster Jeff Smith said.
“It could slow up raining any time,” Smith said with a chuckle on Tuesday morning.
The storm that started Sunday had passed to the east by Tuesday morning, after dropping more than an inch of rain in places.
Colder air followed the storm, which turned rain to snow at higher elevations and slowed the snowmelt.
Among the areas where water has spilled onto roads is a place prone to flooding during spring — the Burnt River Canyon Road between Bridgeport and Durkee in southern Baker County.
The gravel road, which runs beside the Burnt River for several miles, remains open, Smith said.
Like its fellow Snake River tributary, the Powder River, the Burnt River is blocked by a dam.
But there’s a difference, and it’s a significant one.
Unity Reservoir, on the Burnt River about 4 miles north of Unity, has a much smaller capacity than Phillips Reservoir on the Powder River about 16 miles southwest of Baker City — about 25,000 acre-feet in Unity compared with Phillips’ 73,500 acre-feet.
Wes Morgan, who manages the Burnt River Irrigation District and oversees the dam’s operation, has been preparing for a glut of snowmelt this spring.
But the reservoir has continued to rise, and by early this week it was about 80% full.
At that level, and with water continuing to pour into the reservoir in prodigious volumes from the Burnt River’s three main forks, Morgan had to release more water from the dam lest the reservoir fill.
When that happens, he has no choice but to release water at the same volume as it’s flowing into the reservoir.
Morgan said he boosted the release rate to about 670 cubic feet per second (cfs) on Tuesday. That volume, combined with the flow of tributaries below the dam, caused the river to top its banks in the Burnt River Valley.
But the situation would be more dire if the reservoir were full.
Morgan said the total inflow into the reservoir on Tuesday was about 1,300 cfs — about 1,000 cfs of which was tumbling down the North Fork of the Burnt River.
Smith said he appreciates Morgan’s efforts to reserve room in the reservoir to capture some of the water.
“He’s done a great job of holding it down,” Smith said.
He said Morgan phoned him Tuesday morning advising him to have a crew put up “high water” signs along the Burnt River Canyon Road, however.
Morgan said he also sent a warning to downstream residents letting them know that the river level would be rising.
In the past he made a lot of phone calls, but these days, Morgan said, he can accomplish much of the task with a single group text message.
Smith said he also has received reports of areas of high water in the Pine Valley near Halfway, but no roads have been damaged or closed.
As for the Powder River, which flows through Baker City, Jeff Colton, who manages the Baker Valley Irrigation District and operates Mason Dam and Phillips Reservoir, is releasing almost no water through the dam — just 7 cfs.
With the reservoir at just 28% of capacity, Colton can store almost all of the inflow rather than release it into the river.
But even with a relative trickle flowing through the dam, there was quite a bit of snow below the reservoir, and the heavy rain that fell on that snow Monday and Monday night caused a rapid rise in the river downstream from the dam starting early Tuesday.
A river gauge in south Baker City, near Wade Williams Elks Memorial Park, recorded a rise from about 183 cfs at midnight Monday to a peak of about 400 cfs around 9:45 a.m. Tuesday.
The Powder receded after that, and as of 7 a.m. today it was at 230 cfs.
Even at its Tuesday morning peak, though, the river was well below flood stage of 667 cfs.
See more in the April 10, 2019, issue of the Baker City Herald.