Heavy snowfall doesn't guarantee spring flooding

By Kasey Halmagyi

Speculation about this year's heavy snowfall may have some Whatcom County residents worried about floods. And while that is a possibility, heavy snowfall may be just what saves the area from flooding.

This winter's snowfall has lead to a huge snow pack on the North Cascades. Mount Baker has even broken its record for annual snowfall with 1,126 inches so far this year, said Amy Mack, marketing and special events at Mount Baker.

Because the pack is so large, it is melting slowly. This allows the rivers to absorb the excess water without flooding. With this much snow, "It melts at a gradual rate," said Don Boyd, program specialist with the Whatcom County Division of Emergency Management.

Although it may seem contrary to some logic, if there was less snow there would be more flooding. "Three feet of snow can get saturated and melt in a 12-hour period," said Paula Cooper, manager of rivers and flooding for the Whatcom County Public Works Department.

Flooding happens when rain saturates the snow. With such a huge snow pack, it would take a large amount of rain in a short period of time to saturate it. Cooper says that's unlikely. "It could happen, but it's going to take the right series of events," Cooper said. "My feeling is that there would have to be an extended period of warm and rain."

Twice a year flood experts pay special attention to the Nooksack River. "Every fall and spring we keep an eye on her," Boyd said. And while this fall the river got everyone's attention, there are fewer worries about this spring. Because there is always a possibility of flooding, the river is constantly monitored.

"We watch the river level and have different things to do at each stage," Boyd said. When the river reaches the 12-foot stage at Deming, volunteers prepare to sandbag. Currently, the river is at approximately four feet.

Even though flooding most likely won't be a problem, other issues may occur as the Nooksack rises. Such a large snowfall does mean that the river will be high for much of the spring. Problems will be avoided because the river has been prepared. "The river will be up a lot. If the dikes weren't there, there could be flooding," Cooper said.

Dikes are present, and such a high river will inflict some excess strain on them. As the dikes become saturated they may sustain damage. "We're probably in for some flood damages," Cooper said.

One nearby river is well prepared for any flooding. The Skagit River empties into a reservoir behind Ross Lake. This reservoir was recently drained to make room for any excess runoff from the snow pack in the North Cascades. "They have dams so they can control it," Cooper said. "We have no control on the Nooksack."

Whatcom County is always prepared to deal with floods. "Once the river is over the banks and levies we do sandbagging to prevent damage," Boyd said. Search and rescue teams supervise the sandbagging, Radio Amateur Civil Emergency Services help the communication effort with short-wave radio and the Emergency Operations Center closely monitors the river.