Rainwater harvesting for domestic use or irrigation is a sustainable practice that may be against the law in the state of Washington.
According to the Seattle Post-Intelligencer, rainwater is a “resource of the state, which regulates the use of public waters through an allocation process that can take years to navigate.”
So far Washington allows individuals and small farms to harvest modest amounts of rainwater permit-free, but the Department of Ecology’s water resource section are concerned people will collect too much if clear limits aren’t set.
City developers harvest rainwater for irrigation and to flush toilets, and use greywater diverted from sinks to conserve drinking water in urban areas.
These are practices that can prevent sewer overflows, and have inspired Seattle to legalize rainwater harvesting for most of the city.
Yet harvesting too much stormwater can affect overall groundwater levels.
According to the article, the state’s ecology department is trying to create clear regulations to govern both urban and rural areas, but attempts at consensus have been unsuccessful thus far.
“Saving rain: How much is too much?”
Seattle Post-Intelligencer, July 21, 2008