Editing Seattle Public Utilities (section)

==Water supply==

SPU owns two water collection facilities in the [[Cascade Mountains]] that supply drinking water used by 1.6&nbsp;million people in Seattle and surrounding suburbs in 2023.<ref>{{cite web|title=Drinking water quality report|year=2023|publisher=Seattle Public Utilities|url=https://www.seattle.gov/documents/Departments/SPU/Services/Water/Reports/Water%20Quality/2023WaterQualityAnnualReport.pdf|access-date=August 10, 2024}}</ref> The [[Cedar River (Washington)|Cedar River]] watershed comprises 60 percent of the normal supply, and the [[Tolt River]] watershed supplies the remaining 40 percent (primarily north of [[Green Lake (Seattle)|Green Lake]]). The Cedar River supply is unfiltered, while the Tolt River is filtered and relied upon more heavily during dry years.<ref>{{cite news |last=Swanson |first=Conrad |date=February 5, 2024 |title=Seattle's water comes from 2 river systems. Which one do you drink from? |url=https://www.seattletimes.com/seattle-news/climate-lab/seattles-water-comes-from-two-river-systems-which-one-do-you-drink-from/ |work=[[The Seattle Times]] |accessdate=July 25, 2024}}</ref>

From the city's founding through the 1880s, Seattle's water was [[Utilities of Seattle#Early water supply|provided by several private companies]]. In a July 8, 1889, election,<ref name=Stein>Alan J. Stein, [http://www.historylink.org/essays/output.cfm?file_id=2123 Seattle voters authorize Cedar River Water Supply system on July 8, 1889.], HistoryLink, January 1, 2000. Accessed online 6 December 2007.</ref> barely a month after the [[Great Seattle Fire]] (June 6, 1889) gave a dramatic illustration of the limitations of the city's water supply, Seattle's citizens voted 1,875 to 51 to acquire and operate their own water system. In accordance with this vote, the city Water Department acquired the Lake Union and Spring Hill plants for $400,000.<ref>{{Harvnb|Fleming|1919|pp=20–21}}</ref>

This was understood from the first to be only a temporary expedient, inadequate to the expected growth of the city. Attention soon focused on the [[Cedar River (Washington)|Cedar River]],<ref name="Stein" /> an idea first proposed in the 1870s;<ref name=Peterson-117>{{Harvnb|Peterson|Davenport|1950|p=117}}</ref> the question was how to bring that water to the city. From 1892, the responsibility for doing so fell to newly hired City Engineer [[Reginald H. Thomson]] and his assistant [[George F. Cotterill]]. Besides the technical challenges, they and a series of Seattle mayors had to keep the citizenry on board to move forward with this expensive project through the [[Panic of 1893]].<ref name="Stein" />

The [[Klondike Gold Rush]] put Seattle on a sound economic footing.<ref name="Stein" /> The 1901 completion of Cedar River Supply System No. 1 (active from February 21, 1901<ref name=Peterson-117 />) gave the city a steady supply of clean water with an intake {{convert|28|miles}} from the city itself; this was supplemented by Cedar River Supply System No. 2 in 1909. Together, these systems gave the city a supply of more than {{convert|60000000|USgal|kl|0}} of water a day.<ref name=Fleming-21>{{Harvnb|Fleming|1919|p=21}}</ref>

The original Cedar River pipeline was made of reinforced wooden pipe "big enough so a small boy could stand upright in it" and carried {{convert|22500000|USgal|kl|0}} of water a day. By 1950, three big mains carried up to {{convert|162000000|USgal|kl|0}} of water a day.<ref name=Peterson-117 />

To guard against contamination at the source, the city purchased or otherwise gained control of {{convert|142|sqmi|km2}} of land and placed it under the jurisdiction of the Department of Health and Sanitation. The city also established an extensive system of [[reservoir]]s within city limits. By 1919, six reservoirs had a combined capacity of {{convert|270000000|USgal|kl|0}}.<ref>{{Harvnb|Fleming|1919|p=21}} says that Seattle "owns or controls" the entire drainage of the Cedar River</ref> In 1950, the city owned "about two-thirds" of the [[drainage basin|watershed]], the federal government "about one-fourth"; the remainder, "around eleven square miles," was owned by private lumber companies.<ref name=Peterson-118>{{Harvnb|Peterson|Davenport|1950|p=118}}</ref>

Seattle has at times contracted to provide water for entities outside of city limits.<ref name=Peterson-123>{{Harvnb|Peterson|Davenport|1950|p=123}}</ref> By 2007, it provided water to 19 municipalities and water districts in King County.<ref>{{cite news |last=Holt |first=Gordy |date=August 22, 2007 |title=Short Trips: Feast your eyes on Seattle's water supply |url=https://www.seattlepi.com/news/article/short-trips-feast-your-eyes-on-seattle-s-water-1247226.php |work=Seattle Post-Intelligencer |accessdate=August 9, 2024}}</ref>

In recent decades, the Seattle Regional Water System has significantly improved conservation. 2008 usage was roughly equal to usage in 1960, despite roughly a 35% increase in population over that period.<ref>[http://www.seattle.gov/util/stellent/groups/public/@spu/@ssw/documents/webcontent/spu01_005056.pdf Drinking Water Quality Report 2008], Seattle Public Utilities. Accessed online 2009-06-05.</ref> From 1990 to 2012 total water usage declined 29%, despite a population increase of 17%.<ref>"More than 100 Years of Water Stewardship: Seattle 2012 Drinking Water Quality Report", p. 3.</ref>