The information below is from the City of Port Townsend website at:
http://www.cityofpt.us/PublicWorks/WaterQualityHistory.asp
Big Quilcene Diversion
The City of Port Townsend’s municipal water is supplied by gravity from the Big and Little Quilcene Rivers. The existing surface water system has been in operation since 1928, making it one of the oldest water systems in Washington State. In addition to serving the residents of the City of Port Townsend, water is provided to the Port Townsend Paper Company, Glen Cove, unincorporated area west of the City, and the City wholesales water to Public Utility District No. 1 of Jefferson County (PUD) for the South Hastings Loop.
From the late 1800s until 1904 the Spring Valley Water Company (SVWC) supplied water to the City of Port Townsend from springs near the pond at F Street and San Juan Avenue. The SVWC began development of a diversion on Snow Creek as additional water was needed for growth. In 1904 the City acquired the SVWC and completed construction of the Snow Creek diversion and wood stave pipeline. Snow Creek served as the City’s water supply from 1906 until 1928 when construction of the Crown-Zellerbach kraft paper mill (now Port Townsend Paper Company) created water demands that exceeded the capacity of the watershed.
Port Townsend applied for and received water rights to the Big Quilcene and Little Quilcene Rivers in 1927. The City and Crown-Zellerbach cooperatively constructed the Big Quilcene timber crib diversion and 28.5 miles of 30 inch wood stave transmission pipe between the Big Quilcene River and Port Townsend. In the 1950s, the wood stave pipe was replaced with steel pipe. All water flows through City Lake, which serves as an equalizing reservoir. The diversion, pipeline and reservoirs are known as the Olympic Gravity Water System (OGWS).
The Little Quilcene River diversion was developed in 1956 as a supplemental supply to the Big Quilcene River. A timber crib diversion dam constructed on the Little Quilcene River conveys water via a pipeline to Lords Lake Reservoir. The Little Quilcene River timber crib diversion was replaced in 1995 with a concrete diversion structure.
Other than Lords Lake and City Lake, which are owned by the City, 95 percent of the municipal watershed is in the Olympic National Forest with the remainder in the Olympic National Park. Cooperation between the City and Forest Service for protection of the watershed dates back to the construction of the surface water diversions and transmission pipelines.
The City’s water system is one of the few unfiltered surface water systems permitted by the State Department of Health (DOH). When storms cause high river turbidity, the City uses water stored in Lords Lake and City Lake. The lakes also provide water during periods of low river flow. Water from City Lake is screened for larger debris then disinfected with chlorine gas. Within town the distribution system includes a 1-million gallon standpipe and 5-million gallon storage reservoir, a booster pump station, approximately 100 miles of distribution system pipeline and 4400 service connections.