Water use restricted, spawning threatened
By Ann McCreary
With rivers and streams dropping to seasonal record low levels due to drought, irrigators in the Methow Valley and around the state are facing water cutoffs much earlier than normal this year.
The dropping water levels may also be bad news for fish returning to the Methow watershed to spawn.
About 60 irrigators in the Methow Valley have been notified by the state Department of Ecology that they may have to curtail their water use. The irrigators have water rights that can be restricted when streamflows drop below certain levels set by state law. The water users are required to call a hotline to find out if they can irrigate.
“We typically might start regulating [water use] in September or near the end of the irrigation season,” explained Joye Redfield-Wilder, a spokesperson for Ecology.
“It’s just that this year it’s very early. We’re not really expecting it to bounce back because of the snowpack. It melted early. It’s gone,” Redfield-Wilder said.
The irrigators impacted by the water restrictions are individuals who hold interruptible water rights, which are often acquired to supplement other water rights. Many people use these interruptible water rights to irrigate pastures, gardens or lawns, said Redfield-Wilder.
“It’s not [affecting] the irrigation districts. These are not people who are relying on these rights for major crops. The importance here is to protect the creeks from going dry and protect senior [water rights] users,” she said.
The requirement that irrigators call a hotline went into effect this week for irrigators on the Methow, Colville and Little Spokane rivers. Last week about 80 irrigators in the Okanogan and Similkameen river watersheds began calling the hotline and have stopped watering, according to Ecology.
Historic low
Water levels in the Methow River and in rivers around the state are at or near record low streamflows for this time of year, said Katherine Rowden, hydrologist for the National Weather Service in Spokane.
On June 23, the Methow River was at a historic low for that date in 56 years of recording water levels. The river read 1,350 cubic feet per second (cfs) at the Pateros gauge. The next-lowest reading for that date was 1,390 cfs in 2001.
“The average time we’d see these flows is near the end of July. We’re a month ahead,” Rowden said.
“Our lowest stream flows don’t come until September and early October, so this is just setting the stage for what we could see for annual low flows later this summer,” said Rowden.
Unfortunately the heat wave shows no sign of abating. “The climate outlook for the summer is a high probability of above-average temperatures,” she said.
Ironically, streamflow levels in the Methow River rose slightly over the past week, as hot weather at high elevations melted away any remnants of mountain snowpack and brought down water from year-round glaciers.
“We’re getting snow and glacial melt that normally wouldn’t be coming down until August. It’s a temporary boost. Next week I’m sure it [streamflows] will be right back down,” Rowden said.
For native fish that need cool water and pools for spawning, the prospect of dwindling streamflows over the summer is “really alarming” said Jennifer Molesworth, a fisheries biologist with the Bureau of Reclamation. “By the time we get to August and September it’s not going to be pretty,” she said. “Low flow means less habitat.”
Lower water levels combined with hot weather, particularly if the nighttime temperatures don’t drop significantly and help cool the water, creates a dangerous situation for salmon.
“When stream temperatures get over 70 degrees, they can become a migration barrier for salmon,” said Charlie Snow, a fish biologist with the Washington Department of Fish and Wildlife.
“Right now the Okanogan River is 77 or 78 degrees. All the sockeye and Chinook [that migrate up the Okanogan] will be stuck in the Columbia River, which is great for fishermen but not for salmon,” Snow said.
Impacts on fish
Some parts of the Methow and Twisp rivers traditionally go dry by late summer, but if that happens earlier in the summer, it can impact survival of young fish and the ability of adult fish to reproduce, Snow said.
“When the stream goes down it makes really dense rearing [for juvenile fish], and when water is hot it can lead to an increase in disease. It can be very detrimental,” Snow said.
Adult fish returning to the Methow watershed to spawn could face tough times if rivers and streams keep warming and shrinking, he said.
Spring Chinook, which start spawning in August, and summer Chinook, which start spawning in October, will be holding in smaller pools of warmer water, making them more susceptible to disease and increasing competition for spawning areas.
In addition, when the water drops the fish can become isolated in pools, surrounded by dry riverbed. “Or they can spawn and the water can drop so much that the redds become dewatered,” Snow said. “Some areas that provide good rearing and good habitat won’t be used at all.”
Bull trout, which remain in the Methow watershed and are one of the last species to spawn, are often stranded when water levels drop, he said.
“In the Twisp River in particular a lot of stranding goes on, even in a good year, There could be quite a bit of mortality,” Snow said.
Steelhead, which are on their way toward the Methow watershed now, may “sit out in the Columbia and not enter the Methow until late fall or spring” if water temperatures in the Methow are too warm, Snow said.
