Roger’s Slough on Birch Point should be filled in if it keeps on clogging and causing neighboring properties to flood.
That was the message the community sent to Whatcom County Public Works representatives at a public meeting last week held to gather input on how to deal with the flooding and drainage issues near the Birch Bay Village housing development. County storm water engineer Kraig Olason said the meeting marks the beginning of a process to deal with flooding in the area, which the Birch Bay Watershed and Aquatic Resources Management (BBWARM) district is working to alleviate.
“It is not a simple problem,” Olason cautioned.
The county contracted with Everson-based engineering firm Osborn Consulting to study three alternatives to solve Roger’s Slough drainage problems. Engineer Tarelle Osborn said the study results are preliminary and would need further work should the county decide to move forward with one of them.
“We’re still in the discovery stages,” Osborn said.
Osborn said the firm took a comprehensive approach and considered all the factors involved, including local habitat and future maintenance of alternatives. The problem is quite complex and it will take time to come up with a solution that all parties can support, she added.
“There is no silver bullet, that’s for sure,” Osborn said.
The firm’s analysis showed Roger’s Slough receives drainage water from about 430 acres of land which is then diverted to Birch Bay through a pipe. Currently, there is a 36-inch pipe leading from the slough to the bay that has enough capacity to fit all that water, Osborn said.
However, the pipe often gets clogged with logs and other debris washed in from Birch Bay, and the pipe’s tide gate does not allow the debris to return back to the bay. A number of Birch Bay Village residents said when blocked, the pipe acts as a dam as opposed to a drainage system. Up to now, it has always been Birch Bay Village Community Club crews who clear the pipe when it gets clogged.
One aspect of the study was to suggest alternative routes for the drainage system, and Osborn determined not many options exist. An earlier effort in 2006 to address the problem collapsed after the county and the community club were unable to come to an agreement.
Osborn’s study determined that the easiest and cheapest option would remove the tide gate completely so drainage backups are less likely to occur. This would cost the county next to nothing, but might result in flooding during high tide events, Osborn said.
A second option would re-route water from Birch Bay Village ponds to the slough to increase flow volume which could potentially clear debris due to the force of the flow, Osborn explained. This would also involve replacing the 36-inch pipe with a fish culvert, which would mean less maintenance. This alternative would build a flow passage on the north side of Birch Bay Drive, diverting flow from the slough and allowing it be filled in.
This option would cost about $500,000, Osborn said. The Washington state Department of Fish and Wildlife made clear to the county that if the bay tends to naturally fill in the slough, then that can be allowed to happen, Osborn explained.
A third alternative would be to collect the drainage water and bypass the slough by running pipe underground directly into Birch Bay. However, this would require a relatively long length of pipe in order to flow the water via gravity, Osborn explained. This option would be the most costly at an estimated $730,000.
Another option was to divert water through the Village’s two lakes to ease the pressure on the slough, but club members felt it would lead to more work to clear the lakes. In addition, any toxic substances coming from the uplands would introduce liability for the club. The community club currently spends around $50,000 a year treating the lake water, and representatives from the club estimated it would cost more than $100,000 extra each year if significantly more amounts of water were routed through the lakes.
For more information on the progress of Roger’s Slough drainage improvements, visit BBWARM’s website.