Declares that RCW 90.03.250 and 90.03.370 do not apply to rain barrels, cisterns, and other similar facilities for capturing runoff from roofs, paved areas, and other hard surfaces on a single residential, commercial, or industrial property or public facility when the: (1) Total amount of water storage does not exceed five thousand gallons; and

(2) Water is intended to be put to beneficial use on the property where the rainwater is collected.

Directs the department to consult with local building permit agencies to monitor the installation of very large capacity rainwater collection systems for any cumulative effect that the systems have on ground water recharge rates and potential impacts upon other well users from the same ground water source.