Who needs so much water downtown?
Published 1:00 pm Saturday, November 3, 2007
Will bigger water pipes open the spigot on downtown growth?
That issue seems implicit in questions over plans for a bigger water main under Winlsow Way as part of the upcoming Streetscape project. In today’s letters column, City Hall watchdog Dennis Vogt assiduously notes a rather stupid error in our midweek reportage about the downtown water system. The current 6-inch main will be replaced by a 12-inch pipe, which we reported would double the water system’s capacity. But as absolutely everyone knows, doubling the diameter of a pipe actually quadruples its capacity. It’s pi times radius squared; twice the pipe, four times the flow.
So Dennis asks: Why all that water, if not to accommodate more development around Winslow Way?
His question is heavy with implication: Should downtown water capacity not be increased? Increased, but not as much as planned? Should the capacity of water pipes and other utilities determine whether or not adjacent properties can be redeveloped?
Dennis said he’d understood city officials to justify the water pipe upgrade as necessary to meet the needs of future – presumably, taller – buildings. If not, he asked, how does it relate to the needs of current businesses – are they running dry part of the day? Do they have low pressure?
So we dutifully put the question to Bob Earl, city engineer. Whatever others at City Hall may have said, to Earl, the question has less to do with what might be built tomorrow than what’s on the ground today. He notes that as far back as 1985, the Washington Surveying and Rating Bureau identified the need for a larger water main in Winslow, for fire suppression. The current 6-inch main allows “fire flow” (loosely defined as the pressurized stream firefighters can draw from hydrants) of about 1,500 gallons per minute; yet even in 1985, the WSRB found, downtown Winslow needed fire flow of 3,000 to 4,000 gallons per minute to properly battle a blaze.
The bureau’s recommendation was incorporated into the city’s water plan in 1995, where it has languished until now. (The findings of the WSRB, it should be noted, help determine insurance rates on affected properties, so a good rating is good for the individual consumer.) Looking forward, Earl believes that advances in the fire code – particularly, requirements for sprinklers inside new commercial buildings – should make the new 12-inch main adequate for protection of future buildings of whatever size.
Our take: water availability may or may not impact growth on Bainbridge Island at some point, but distribution should be free of politics. Where it’s needed, run the pipe; that’s what public utilities do.
Doubling the diameter of a pipe does increase its capacity four times, but zoning and density have their own formulas altogether.
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Correction
• A Wednesday story on a proposed medical building on Madison Avenue contained several errors. Several comments on the lack of island health care facilities were incorrectly attributed to Todd Schneiderman; the comments were made by John Kist, who was quoted elsewhere in the story. Also, Jason Cheung was incorrectly identified as an optometrist. He is a doctor of ophthalmology.
