County announces drainage improvements for Cottonwood neighborhood in Birch Bay

Published on Wed, Aug 29, 2012 by Jeremy Schwartz

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The residents of the Cottonwood neighborhood in Birch Bay will most likely have stormwater drainage improvements by fall 2013.

Dale Buys, an engineer with Lynden-based Reichhardt & Ebe Engineering, laid out initial designs for a new drainage pipe for the neighborhood at a Birch Bay Watershed and Aquatic Resource Management district community meeting Tuesday, August 21. The meeting showcased the proposed drainage improvements and gathered public input on other stormwater issues in the Cottonwood neighborhood. 

Under a $78,000 design contract with Whatcom County, the firm was hired to take the next step from the subwatershed planning work the county had contracted with Tetra Tech, Inc., to do earlier in the year. The Tetra Tech project determined how water flows through the individual subwatersheds in the Birch Bay area.

Tetra Tech’s work singled out the Cottonwood neighborhood as particularly affected by seasonal flooding, so Buys was called in to design a solution that would help fix the problem. Buys said he used Tetra Tech’s work to estimate flow rates in the neighborhood and figure out how best to channel stormwater to the bay.

Currently, several smaller stormwater pipes extend from Halverson Park and lead to two aging outfalls at the beach near Cedar Avenue. Some of these pipes are at least a decade old, and some have cracks that allow water to seep out and find its way above ground, Buys said.

The improvement project will install a larger, 36-inch pipe running from Halverson Park under Cedar Avenue that will be able to handle enough stormwater to accommodate future Birch Bay growth, Buys explained. The new pipe will also have several places into which smaller drainage pipes can connect in preparation for future stormwater improvements. 

“We’re planning for the future, so hopefully we don’t have to go back,” Buys said.

The pipe will include a new outfall to the beach and remove the smaller, hard-plastic outfall to the west of Cedar Avenue, Buys said. The second main outfall there, which is made of concrete, will be integrated into the new stormwater pipe. The new outfall will handle high pressure stormwater flow, while the existing outfall will handle lower pressure amounts. 

Most meeting attendees seemed satisfied with the work Buys was proposing, while some individual homeowners asked how the improved drainage system would help their property. Buys could not offer answers to everyone’s complete satisfaction, but assured concerned residents this project will set the stage for additional improvements for properties up the hill from the new proposed outfall.

“In drainage, you always work from the outfall up,” Buys said in response to questions on improving stormwater pipes up the hill from the main project area.

While a construction contractor has not yet been selected, Buys said work on the project should start by next August or September. He said Birch Bay Drive should only be affected for a few days while the new pipe is run under the road and onto the beach. 

County stormwater planner Kraig Olason said the improvement project is currently in the middle of permitting and should go out to bid by next spring. He said construction work, expected to cost approximately $300,000, is scheduled for late summer next year to avoid the major rush of tourists in June and July. 

“We’re trying to work around the peak seasons, so as not to run into too much [tourist] activity,” Olason said.

For more information on the project, visit http://www.bbwarm.whatcomcounty.org/programs/cip/cottonwood