Stormwater Management Program


The City of Bainbridge Island’s Stormwater Management Program seeks to minimize the negative effects of development and pollution, while maximizing environmental protection and conservation.

Current Documents:


The Challenge

Impervious surface area (roads, parking lots, roofs) has increased regionally by more than 10% over a 10-year span. This percentage has a direct correlation to increased runoff volume, reduced groundwater recharge, and greater stream volumes. This altering of the existing stream hydrology results in eroding stream banks, wider stream channels, excessive sediment transport, and damaging fish and wildlife habitat.

Rainfall hits these hardened surfaces, picks up pollutants, known as non-point source pollution, and travels across the land’s surface eventually discharging into Puget Sound through outfalls along shorelines. Pollutants of concern include lead, copper, pesticides, and petroleum byproducts.

The Solution

The Stormwater Management Program focuses on National Pollutant Discharge Elimination System (NPDES) permit compliance, stormwater violation response, regulation development, and day-to-day stormwater operations management.


The Department of Ecology’s NPDES permit regulates stormwater discharges from the city’s Municipal Separate Storm Sewer System (MS4) ( streets, ditches, culverts, sidewalks, etc.) for the following requirements:

  • Controlling runoff from development and construction sites
  • Illicit discharge detection and elimination program
  • Monitoring
  • Pollution prevention and operation and maintenance for municipal operations
  • Public education and outreach
  • Public involvement and participation
  • Reporting
  • Total maximum daily load allocations (TMDL)

Rain Garden Handbook for Western Washington

The Rain Garden Handbook for Western Washington (June 2013 edition) is a guide to plan, design, and build rain gardens to assist in controlling stormwater runoff. This guide can be used by homeowners, landscapers, landscape architects, engineers, and others to implement rain gardens for regulatory as well as non-regulatory requirements.

Best Management Practices

The handbook is also a guide on how to meet Best Management Practices (BMP) as well as the minimum requirements for the 2012 Stormwater Management Manual for Western Washington.

Request a Copy

Request a copy (free of charge) at the City of Bainbridge Island City Hall Public Works Engineering and Planning counters located at:
280 Madison Ave. N
Bainbridge Island, WA 98110

      * Western Washington Phase II Municipal Stormwater - Permit S5.C.2.b Pg. 19 - Each Permittee shall post on their website their SWMP Plan and the annual report required under S9.A no later than May 31 each year.