Snow runoff not a major concern for local streams
January 9, 2009 · Updated 9:20 AM
Melt could be beneficial to salmon as crews work to remove sand
The sand, salt and other deicing measures used by local and state road crews during the recent near-record snowfall were great for motorists, but they might be a mixed bag for salmon-bearing streams and other bodies of water.
“It’s fantastic,” said Suquamish Tribe salmon recovery manager Paul Dorn. “The snow melts slowly so it helps our streams maintain their seasonal levels.”
Runoff becomes more of an issue during heavy rains, but the slowness of the snow melt creates far fewer runoff issues and concerns, Dorn said.
“The runoff is also very cool, which makes the salmon in the eggs grow at a slower rate, which is great,” he said.
December was one of the snowiest months on record for the Bremerton/Silverdale area as snows began on Dec. 17 and continued periodically through the Jan. 1 holiday, with some areas waking up to a New Year’s Day snow.
Road crews from both Kitsap County, the city of Bremerton and the Washington State Department of Transportation worked long hours to ensure roads were passable for motorists using their road clearing plans that prioritized roadways.
Fortunately for both the Bremerton and Central Kitsap school districts, the timing of the winter storms coincided with each district’s winter break as both districts cancelled classes on Dec. 18 and 19, leaving about four more snow days on each district’s 2008-09 school year calendar.
By the time classes resumed Monday, some snow remained on the ground, but the majority of local roads were free of snow and ice, although Central Kitsap School District delayed the start of classes by two hours Monday because of snow that fell Sunday night.
As the snow has begun to melt, the sand, salt and other materials used to keep roads and sidewalks clear has made its way into local stormwater treatment facilities.
“Major concerns focus primarily on erosion and sedimentation,” Kitsap County Public Works spokesman Doug Bear said. “With increased water volume and velocity, the likelihood of erosion increases.”
When dirt particles are picked up by erosion they mix with the water creating turbidity, Bear said. This is seen as muddy water where runoff enters larger bodies of water.
“There is always the concerns for the effects of large volumes of snow melting and the possibility of localized flooding in urban areas,” he said, noting that flooding presents its own challenges to water quality.
Removing sand from the roadways is a high priority for road crews and is removed in the same way it is applied, he said.
“We start with primary roads and arterials, followed by secondary roads. Our sweeping process keeps sand from being pushed into the catch basins and waterways,” he said.
In addition to sand, the county uses a 23 percent sodium chloride solution to prevent snow and ice from sticking to road surfaces, he said.
“The potential for pollution is minimal as the product is further diluted by rainfall and snowmelt,” he said, adding the Washington State Department of Transportation has done a study that confirms the solution has little potential for pollution.
“Suffocation of salmon redds (spawning nests) by sands and silt from road runoff are one possibility,” said Kitsap County Health District Water Quality Manager Stuart Whitford. “Stream flows will increase as the snow melts. Sand and silt will be added to stream beds, potentially impacting salmon redds.”
Increased fecal coliform contamination also can be expected as fecal coliform bacteria tend to adhere to sand and silts and are carried with them, Whitford said.
“Also, these bacteria can multiply in pockets of sand and silt along stream beds, creating additional fecal coliform contamination in the future,” he added.
The forecast for this weekend includes a slight chance of showers with highs in the 40s and lows in the upper 30s.