Collaborative Drainage System Repair on Birch Point

Construction on this project was completed in September 2016.

Project Goals

• Replace a failing stormwater outfall pipe subject to overflow.
• Significantly reduce the risk of flooding and erosion on a steep bluff.
• Address a priority safety problem

Project Description

This project replaced a stormwater system that carries flows from central Birch Point under Semiahmoo Drive and across Washington State Department of Natural Resources (DNR) property to Semiahmoo Bay. This area is subject to high flows during winter storms. The previous outfall pipe was undersized and became overwhelmed during storm events, causing flooding and erosion on the beach bluff and threatening homes on DNR leased land. this was collaborative project funded by BBWARM and other Whatcom County Public Works funds.

The new drainage system includes:

• A larger cross culvert under Semiahmoo Drive.
• A new outfall pipe anchored above the fragile beach bluff.
• A new energy dissipater at the end of end of the outfall pipe.