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Summary for 4th AVE / Parcel ID 3124049028 / Inv # SPU023

Historic Name: SW Trenton Street Pump Station Common Name:
Style: Other Neighborhood: South Park
Built By: Year Built: 1934
The Seattle Water Department completed this reinforced concrete pump station in 1934, two years after the construction of the twin 1,1930,000-gallon standpipes and their shared gate house located on the level just below. This complex was built in conjunction with the 68,000,000-gallon West Seattle Reservoir located up the hillside to the west. 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. The entire complex was completed two years later with the construction of this pump station, which is one of the few within the Seattle water system with hydraulic equipment. Water flowing downhill from the West Seattle Reservoir into the pump station powers the equipment, which pumps water to the SW Myrtle and SW Charleston Street Standpipes. Once the water flows through the hydraulic pumps, it empties into the adjacent standpipes where it is then distributed to the low service gravity fed district. After this pump station was put into service in June of 1934, it resulted in significant savings for the Water Department in electric power formerly used by the SW Kenyon and SW Spokane Street Pump Stations. The SW Kenyon Street Pump Station was eventually retired while the SW Spokane Street Pump Station was used for partial capacity operation during the summer. Unlike the earlier pump stations constructed by the Water Department, this reinforced concrete structure has little exterior ornamentation or embellishment. However, it exhibits some Neo-Classical Revival stylistic features and maintains the composition and massing of Beaux Arts-inspired buildings. The pump station is similar in design and materials to the 1932 West Seattle Reservoir Gate House located up the hillside to the west. The SW Trenton Street Pump Station is significant for its design and for its association with the growth and development of the Seattle water system.
Completed in 1934, this one-story reinforced concrete building is located near the eastern edge of a large grassy terrace, which is also occupied by a chlorine station. A long set of stairs down the hillside to the east provides access to a lower terrace where twin 1,1930,000-gallon standpipes and a shared gate house are situated. 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. Measuring 33 feet by 22 feet, the rectangular plan building rests on a concrete plinth and exhibits some Neo-Classical Revival stylistic features in terms of its symmetrical composition and massing. The simple cornice of the original flat roof is somewhat obscured by the front gable roof, which was added later. When initially constructed, the building was half its present size. After the completion of the West Seattle Reservoir and the twin standpipes in 1932, an addition was made to the pump station by November of 1934, which doubled the size of the existing building. At the center of the principal south elevation, a single large opening contains modern double entrance doors. The window openings on either side have been have been filled with concrete although the sills remain, as so the outlines of the openings. This is also the case with the two windows on the identical east and west elevations and the single window on the north elevation. The opening for the double entrance doors remains at the western end of the north elevation but contains modern replacements. Although altered, this building is well maintained.

Detail for 4th AVE / Parcel ID 3124049028 / Inv # SPU023

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
Other: Extensive
Changes to Original Cladding: Intact
Changes to Windows: Extensive
Changes to Plan: 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 # SPU023

Photo taken Nov 17, 2000
App v2.0.1.0