Using rain barrel or other containers to collect rain was illegal in Washington State until October 12 , 2009 . That was when the state ’s Department of Ecology overrule a long - standing insurance that made it illegal to harvest rain teem from roofs . For many days , it was legal to buy but not to habituate rain barrels in Washington . The job flowed from sure-enough - time water laws in semi - arid westerly DoS .

Semi-Arid Lands

Western Washington , include Seattle , is renowned for its rainy weather from fall through spring , averaging 30 to 60 inch annually in the lowland and forked that figure in the Cascade foothill and the Olympic Peninsula . But the area east of the Cascade Mountains , which includes Spokane , gets one - third that amount and is semi - waterless , standardized to western states such as Colorado and Utah . The Washington Department of Ecology says it might seem hard to opine a motivation for rain barrels in Seattle , but there is picayune rainfall along the sea-coast during the sentence of greatest want — summer .

Western Water Law

Western water laws are complicated and date back to pioneer days in the mid-19th one C . Many are based on what Colorado State University refer to as a " first in meter , first in right " doctrine that countenance farmers and other settlers to obtain courtroom orders let them to earmark certain quantity of stream flow annually and forever . In time , western water became over - appropriated , and there was n’t enough to reconcile all who held rights to it .

Old Policy

Although Washington did n’t actively enforce its sometime , no - rain - cask normal for homeowners , the policy created problems for developer of eco - friendly buildings who wanted to pull in rainwater for intention such as even can , according to Sightline Institute , a northwestern organization concenter on environmental sustainability . Because of Washington ’s backlog of applicants for water right , the Institute enjoin , the old policy made it easy for anyone oppose to construction of a green projects to slow down it down by contend water rights .

Reasons for Reversal

The Modern insurance allows property owners to use rain cask and surreptitious reposition arrangement to collect rooftop overflow for use on the property where it is harvested . However , the state can step in if the practice negatively affects exist water right or harms the weewee supply . The Washington Department of Ecology notes that rainwater assembling aids storm urine management and is an ecologically friendly way to provide for home irrigation demand . One major panorama of this ecological friendliness that proponents of rainwater harvest home cite is that it minimize the amount of municipally treated body of water demand for watering railyard .

Laws in Other States

Colorado revised its stringent law against rainwater harvest in July 2009 . Now landowners who have well and do n’t have access to municipal water supply may harvest rain . Utah rescinded its law against the practice in May 2010 . The new Utah practice of law allows anyone to collect rainwater for habit on the place where it is pull in . But the size and number of collecting containers are limited .

References

…