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Beaver Lake (79 acres) is located Sammamish, Washington. The lake consists of three interconnected bodies of water known as Beaver Lake 1, 2, and 3. Current lake water quality is good. The Beaver Lake watershed (1,100 acres) has many streams, wetlands, and lakes which remain intact, including three number-1-rated, unique and outstanding wetlands.

1993 Management Plan

In 1993, the Beaver Lake Management Plan was developed as a pollution prevention plan for the lake. At the time, the plan represented a comprehensive approach for mitigating surface water impacts of future land development on lake water quality since over 660 acres of the watershed remained forested. The plan's recommendations focus primarily on: (1) modification of existing King County stormwater treatment policy to provided more protective requirements; (2) long-term monitoring and watershed inventories; and (3) community education and involvement programs. Additional recommendations for updating the management plan and providing contingency actions were also included.

In 1994, the Beaver Lake Management Plan was adopted by the Metropolitan King County Council. In 1995, King County completed modification of its stormwater treatment policy for the watershed and established an 80 percent total phosphorus removal goal for new development.

Lake Management District

During 1995, the Beaver Lake Management District was formed to implement several recommendations from the management plan. The District's work program included lake, stream, and wetland monitoring and community involvement and education. The monitoring program was established to evaluate the effectiveness of stormwater treatment requirements.

A citizen advisory board met monthly to oversee the work program beginning in September, 1996 and continued through December, 2000 when the districts work program was completed. The district's work program concluded with an update to the Beaver Lake management plan which was published in December 2000.

Plan update

In this plan update, Beaver Lake water quality from 1996-2000 is documented. Base on the data collected, inflow and lake water quality continues to be good. However, additional land development is still slated for over 200 acres of the 1100 acre watershed which could threaten existing water quality.

To continue protecting lake water quality from degradation, the plan recommended five areas for action. These areas included: (1) wetland and resource land preservation; (2) guidelines for future land development; (3) ongoing stormwater management; (4) local shoreline and watershed actions, and (5) ongoing monitoring.

For more information about the Beaver Lake Management Plan Update, please contact Rachael Gravon or Chris Knutson.

For questions about lakes in King County, please contact or call the Water and Land Resources Division front desk at 206-477-4800.