Home Page
Link to Seattle Department of Neighborhoods home page

Seattle Historical Sites

New Search

Summary for 4th AVE / Parcel ID 3124049028 / Inv # SPU021

Historic Name: SW Trenton Street Gate House Common Name:
Style: Other - Industrial Neighborhood: South Park
Built By: Year Built: 1932
The Seattle Water Department completed this small gate house in 1932 to serve the twin 1,1930,000-gallon standpipes built in conjunction with the 68,000,000-gallon West Seattle Reservoir located up the hillside to the west. A hydraulic pump station was also constructed on the site in 1934. As early as 1916, the Water Department had recognized the need for two reservoirs in West Seattle and had acquired a large tract of land in the vicinity of SW Cloverdale Street and 8th Avenue SW for the purpose of constructing one of them. At the time, six wooden tanks at 40th Avenue SW and SW Charleston Street served the entire West Seattle area with a combined capacity of 300,000 gallons. Within a few years, the construction of three more wooden tanks at SW Charleston Street and a new steel tank at 36th Avenue SW and SW Myrtle Street increased West Seattle’s capacity to almost a 1,000,000 gallons. By the early 1920s, it was apparent that West Seattle had the poorest and most unreliable water supply of any portion of the city more than ten years after its 1907 annexation. The Water Department began a program of improvement in order to give West Seattle an adequate and reliable supply of Cedar River water. This included a tunnel under the West Waterway near Michigan Street, new steel water mains, two new standpipes for low and intermediate service, and a new pump station at 6th Avenue SW and SW Kenyon Street. After the completion of the above improvements, the Water Department decided to proceed with the construction of its long-planned West Seattle reservoir. In 1929, plans were prepared for an 80,000,000-gallon reservoir at 8th Avenue SW and SW Trenton Street and a large pipeline to connect it to the city’s main supply pipelines in the vicinity of 51st Avenue South and South Leo Street. With the new reservoir, most of West Seattle would be supplied by gravity service as opposed to the previous system, which relied on the pumping of water to the few tanks and standpipes scattered through the large area. By the time of construction, the Water Department had decided to reduce the size of the planned reservoir and construct two standpipes on an adjoining parcel down the hill to the east, each with more than a million gallons of capacity. The reservoir was largely completed by 1931 and put into service the following year. As proposed, the standpipes were to have a capacity of 1,400,000 gallons each in order to increase the storage capacity for the low service system but were completed in 1932 with slightly less capacity than originally planned. After 1934, water used to power the hydraulic equipment at the newly constructed SW Trenton Street Pump Station emptied into the standpipes for subsequent distribution to the low service gravity fed district. This modest utilitarian structure is somewhat unusual in that it contains equipment controlling two standpipes. The SW Trenton Street Gate House is significant for its association with the growth and development of the Seattle water system.
Completed in 1932, this small one-story reinforced concrete building is located between the twin 1,1930,000-gallon standpipes, which share its equipment. This complex is situated at the western end of a large grassy terrace on the hillside below an upper terrace occupied by a 1934 pump station and a later chlorine station. A long set of stairs provides access to the lower level. The entire site is surrounded by a chain link fence and served by a restricted access road off of 3rd Avenue SW, which make it impossible to view the structures from the public right of way. The square plan building measures 13 feet by 13 feet and rests on a concrete plinth. The simple cornice of the original flat roof is somewhat obscured by the front gable roof, which was added later. While the original metal door remains intact on the west elevation, the window openings on the south, north and east elevations have been filled with concrete. The sills remain, as do the outlines of the openings. Although altered, this building is well maintained.

Detail for 4th AVE / Parcel ID 3124049028 / Inv # SPU021

Status: Yes - Inventory
Classication: Building District Status:
Cladding(s): Stucco, Wood Foundation(s): Concrete - Poured
Roof Type(s): Gable Roof Material(s): Asphalt/Composition
Building Type: Industry/Processing/Extraction - Waterworks Plan: Rectangular
Structural System: Concrete - Poured No. of Stories: one
Unit Theme(s): Architecture/Landscape Architecture, Science & Engineering
Changes to Windows: Extensive
Changes to Plan: Intact
Other: Extensive
Changes to Original Cladding: Intact
Major Bibliographic References
King County Property Record Card (c. 1938-1972), Washington State Archives.
McWilliams, Mary. Seattle Water Department History, 1854-1954: Operational Data and Memoranda. Seattle, WA: Water Department, City of Seattle, c1955.
Seattle Water Department. Annual report / City of Seattle, Water Department. Seattle, WA: 1908-1965.

Photo collection for 4th AVE / Parcel ID 3124049028 / Inv # SPU021

Photo taken Nov 17, 2000
App v2.0.1.0