New regulation will allow Island households to capture rain
Published 3:39 pm Tuesday, August 2, 2011
In a move some say could open the door to more development on Vashon, King County will allow homeowners to install systems that harvest a new source for residential drinking water — the stuff that falls from the sky.
The King County Board of Health unanimously approved a regulation on July 21 allowing rainwater catchment as a household’s sole source of water. The decision means King County will join the ranks of San Juan County, Jefferson County and other parts of the country where groundwater is limited in allowing rainwater catchment systems as a source for potable water.
“We’re certainly not frontrunners,” said Larry Fay, a section manager at Seattle-King County Public Health. But, he added, “As far as I know, we’re the most urban county to do it.”
The rule is limited to those who wish to develop a home on a lot where they face what Fay called an “undue hardship” in obtaining water. It also applies only to homes that use septic systems.
As such, those who follow water policy in the area say, the rule will largely apply only to rural or semi-rural parts of unincorporated King County, such as Vashon or the far reaches of eastern King County, where access to water has proven difficult and has limited growth.
Vashon’s largest water purveyor, Water District 19, currently has a moratorium on new water shares; and under state rules, one can install a well only on a parcel at least five acres in size. As a result, Fay said, the owner of a smaller-sized lot within District 19’s boundaries would likely qualify as facing an undue hardship in obtaining water.
“There is a possibility that people could build on a lot on Vashon next year that they can’t today because they have a new way for getting water,” Fay said.
Doug Dolstad, owner of Island Water Management and an Islander active in civic affairs, agreed. “It sounds like it would make lots that were heretofore unbuildable buildable,” he said. “My guess is that a creative builder will find a way to move ahead.”
Indeed, the systems are becoming more widely used on San Juan Island, where access to water has long been a limit to growth. According to Fay, such systems have become “quite common” on San Juan, where as many as 200 catchment systems are in place. “This is not coming completely out of left field,” he said.
But Fay and others said there are significant limits to the use of rainwater catchment. It can be expensive: Under King County’s new rule, only certain kinds of roof materials can be used, and the water would have to be disinfected and filtered. What’s more, rainwater catchment — even in a place as rainy as the Puget Sound region — doesn’t provide nearly as much water as the average family on Vashon uses.
Most households on Vashon use about 200 gallons a day or 75,000 gallons a year, according to Steve Haworth, chair of District 19’s three-member board of commissioners. Depending on the size of the roof, a catchment system would provide far less water — between 20,000 and 40,000 gallons a year, Fay estimated.
Michael Laurie, a water conservation specialist and an advocate of rainwater catchment systems, said such systems would only work for a household extremely committed to water conservation.
“To collect all your water from rainwater means that you have to be really ultra-conservative in your water use,” he said.
The issue of rainwater catchment has been stirring discussion and debate on Vashon for the last few years — ever since Islanders Dick Sontgerath and Truman O’Brien suggested they’d used a catchment system to provide potable water to their proposed development, K2 Commons. Some objected to the idea at the time, contending that if there were a drought, District 19 would be on the hook as a backup provider of potable water.
In recent months, the 15 or so Islanders drafting an update to Vashon’s outdated town plan have also tackled the issue. In language to be voted on later this month, the Town Plan Committee has called for rules that would allow rainwater catchment as a source for irrigation but not residential drinking water.
Marty Liebowitz, an architect and a member of the Town Plan Committee, said the group voted overwhelmingly for language limiting rainwater catchment to irrigation because members worried that District 19 would be forced to provide water in the event of a drought that affected homeowners dependent on rainwater for all their needs. King County’s new rule doesn’t require a water purveyor such as District 19 to provide that backup. But if there were a serious drought, Liebowitz said, “It would become a political thing. … The state could force District 19 to step in.”
The group also noted the impact such a rule could have on development.
“You can’t use the current moment of time as a barometer, because we’re in the deepest recession (since 1930). No one’s building,” he said.
Should the economy change, Vashon could once again feel development pressure, he said. “The cost of doing water catchment is expensive,” he added. “It won’t be affordable housing.”
But others applaud the Health Board’s decision, noting that rainwater catchment is an ecologically sound way to develop water sources and provides an important step towards greater sustainability.
“It’s a huge bonus for the environment, because the less that we pull out of the ground, … the more there is for the environment and the less pressure there is on the aquifer,” said Islander Jenny Bell, a water consultant who owns Watersmart.
Conventional water systems require a considerable amount of energy, Bell and others noted. What’s more, some said, a heavy rain often leads to rainwater surges — mini-flash floods that overwhelm treatment plants or run quickly into Puget Sound. A rainwater catchment system would store that rainfall in a cistern, releasing water slowly through a septic system as the household uses it.
Laurie compares the approach to that of an old-growth forest. “It absorbs those peak storm events like a forest and slowly release the water into the ground.”
Others take issue with those who use Vashon’s water supply as a way to limit growth and have voiced frustration with the direction of the Town Plan Committee. Bob Powell, a District 19 commissioner who attended several Town Plan Committee meetings early on, said he has long argued that Vashon’s growth should be limited by zoning and land-use laws, not water-use policies.
Indeed, Powell calls the Town Plan Committee’s desire to limit rainwater catchment to irrigation and non-potable uses bad policy.
The issue has triggered debate and concern, he said, “because of a vehement argument that allowing potable rainwater use would lead to dozens and dozens of new homes that are allowed under present land-use policy but are disallowed because they don’t have access to water.”
But, he added, disallowing a new approach such as rainwater catchment “unnecessarily restricts the Island’s options to deal with our uncertain future. I’d rather see the water district and individual property owners have more options available for water supply and determine growth policy directly.”
Meanwhile, Fay, with the public health department, hopes the new rule will enable homeowners along Vashon’s waterfront — some of whom are discharging untreated or poorly treated sewage directly into Puget Sound — to upgrade their septic systems.
Many of Vashon’s waterfront houses are second homes on small lots, where there’s not enough room for both a septic system and a well, he noted. By giving those homeowners — many of whom have have reduced water needs — the option to develop a new source for drinking water, they could decommission their wells and install septic systems that would protect the Sound, he said.
“It creates one more tool for people to work with,” Fay said.
Frank Jackson, a former District 19 commissioner, however, suggested that providing waterfront homeowners with a new tool “is a double-edged sword.”
“Does it make a whole bunch of waterfront lots that are now unbuildable suddenly buildable?” he asked. “If so, it could create another set of problems.”
