Groundwater Management Plan

PROJECT OVERVIEW                                                                          

Bainbridge Island residents, workers and visitors rely on groundwater for all water supply needs, from drinking water and dishwashers to toilets and garden watering. Groundwater also plays a vital role in supporting healthy streams and wetlands.

GWMP goals and objectives (002)The City is developing a Groundwater Management Plan (GWMP) that will take an islandwide approach to managing our precious groundwater resource and will serve as a document that can be adapted as our needs change. The plan will include a summary of what we know about the island’s geology; groundwater systems; streams, lakes, and wetlands; climate and climate change projections; land use; and population projections.

What is Groundwater? 
 Groundwater is water in saturated ground (bedrock or sediments) that flows from recharge areas to discharge into springs, seeps, shoreline or wells or deeper into the subsurface. If you were able to take a giant knife and slice through the water-filled layers of sediment (mixtures of clay, silt, sand, and gravel) underlying Bainbridge Island, you would see four major aquifers.

Most of the island’s residents and businesses take water from those four aquifers which can be as deep as 1,000 or more feet below the ground.

Island water sources

The U.S. Environmental Protection Agency (EPA) has designated Bainbridge Island a sole source aquifer, meaning there is no other water supply source for the island. The Washington Department of Ecology has designated the entire island a Critical Aquifer Recharge Area, which the City of Bainbridge Island requires to be protected by plans incorporated into all new development.

The vulnerabilities facing the City’s groundwater distribution are the mechanical systems and pipes that pump water from the ground and distribute it to homes and businesses. The City will be developing water conservation messaging and plans that will help relieve stress on systems during extreme weather events. The City is also planning for implementing water system resiliency projects and emergency measures.


A community information session on the GWMP is scheduled for Wednesday March 2 at 5pm to share progress on the plan and to seek your input. 

Contact Us

  1. Maureen Whalen



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