Tag Archives: King County

How-to, Rainwater Catchment

Is Sole Source Use of Rainwater Collection Legal in King County?

lake-176942_640There has been a great deal of inquiry about sole source use of rainwater collection in King County, causing confusion for the public – as well as for King County public officials. RainBank is currently consulting on four different projects, assisting clients with navigating the system.

A change in Department of Public Health Policy, which is the authority on single source rainwater collection, has been transferred back to the Onsite Sewage System Authority (OSS) of King County Public Health.

There is a section of Title 13 that refers to rainwater collection for single source usage. This authority has jurisdiction over sole source use; any other permitting approval for supplementary source is to be approved by King County Public Health Department’s senior plumbing inspectors. There are plumbing codes that must be met with regard to installation and permitting from KCH plumbing division for any RWC system that is potable or non potable, that is connected to household plumbing.

Below is the section of Title 13 dated November 20, 2013, which refers to sole source usage

D. A rainwater catchment system that serves as the only source of drinking water for a single family residence and that complies with each of the following conditions:

1. The health officer finds that requiring connection of the plumbing system to an approved public water source or to an approved private well would cause undue hardship.

2. Application for a rainwater catchment system source approval shall be submitted for review on forms provided by the health officer. The applicant shall pay to the health officer the rainwater catchment system review fee as specified in the fee schedule, payable after completion of the application review.

3. Application for a rainwater catchment system source approval shall be prepared by any one or more of the following:

a. A professional engineer authorized under a current, valid license to practice in Washington state;

b. An environmental health professional holding a current, valid registration from either the Washington State Environmental Health Association or the National Environmental Health Association;

c. A King County licensed water system designer holding a current, valid license to design water systems in King County; and


d. A rainwater system designer holding a current, valid accreditation from the American Rainwater Catchment System Association.


4. Rainwater catchment system source design shall conform to Part III of Chapter 16 of the Uniform Plumbing Code, 2009 edition, as amended, and shall include, at a minimum, the following information:

a. Estimated daily and weekly and annual demand;


b. Available catchment area and estimated annual rainwater capture;


c. Roofing materials used;

d. Storage capacity of and materials used in the construction of the rainwater catchment system; e. treatment specifications including filtrations and disinfection system specifications; and


f. Operation and maintenance requirements.

5. Composite or shake shingles or other materials determined by the health officer to present a risk of contamination may not be approved or used as roofing materials for a rainwater catchment system source.


6. Before using a rainwater catchment system source, the property owner shall file in the county recorder’s office a notice on title advising that the property is served by a rainwater catchment system and including the following information:

a. The estimated daily, weekly and annual water supply furnished by the rainwater catchment system;

b. That the water supply from the rainwater catchment system may be limited due to variations in rainfall or usage; and

c. That regular maintenance of the treatment system and components is required in order to minimize the risk of consuming contaminated water.

As rainwater collection becomes less of a niche and more mainstream for residential and commercial applications, and with 15 years of design and installation experience, RainBank is the go-to source and your advocate for rainwater collection systems in the Pacific Northwest. Using the form below, contact us today to learn how we can help you with proper system design, installation and consultation through the sometimes confusing permitting requirements for potable, non-potable, sole source and supplementary systems in and around Seattle, Washington state and beyond.

Rainwater Catchment, Residential Rainwater Collection

Truths and Myths About King County Rainwater Harvesting

Seattle Waterfront ParkI have been designing and installing rainwater harvesting systems in King County and throughout Washington State for 15 years and am still amazed and dismayed at the misinformation that is presented to the pubic when inquiring about the legality, procedures, and permitting for rainwater harvesting.

TRUTH: Rainwater collection is legal throughout Washington State

Washington State Department of Ecology issued an interpretive policy statement clarifying that a water right is not required for rooftop rainwater harvesting. As described by Washington State Department Ecology, Clarifications of Washington State Rainwater Law Pol 1017 in reference to RCW980.03 & RCW90.54 and the Environmental Protection Agency’s paper on Rainwater Harvesting Conservation, Credit, Codes, and Cost Literature Review and Case Studies

False: Rainwater harvesting is not allowed for drinking water in Washington State.

It is up to each county and city in Washington State to allow for potable usage of rainwater. King, Jefferson, Whatcom, San Juan, Skagit, and Island are counties that currently allow potable use of rainwater for a single-family residence. It is the health department of those counties that are the typical authorities for regulations and permitting.

Here are some resources for gathering information about rainwater collection guidelines in Washington:

As Washington State counties are recognizing the benefits of rainwater collection and the fact that rainwater can provide a viable source of water for potable usage, other counties will adopt RWC as an alternative water source.

RainBank Rainwater Systems is the leader in rainwater collection system designs and installations in Washington State and president Ken Blair is the NW Regional Representative for The American Rainwater Catchment Systems Association (ARCSA). RainBank is committed to helping customers and counties understand the benefits, standards, and policies of rainwater harvesting in order to provide a clean, safe, viable source of quality water.

Seattle waterfront park photo is courtesy of Nicola under Creative Commons

Rainwater Catchment, Rainwater Harvesting Education

When Will Your County Adopt Rainwater Collection for Potable Use? 

LowWaterPuyallupRiver potableSnohomish County has over 1,000 water districts that are close to drying up, which ramps up the need to purchase potable water from the city of Everett.  Spada Lake is dangerously low, which jeopardizes water availability for fighting fires

Pierce County faces a similar issue – small water districts are running out of supply, forcing the potential for needing to purchase water from the city of Tacoma. The Center for Urban Waters, led by the University of Washington Tacoma, promotes rainwater collection, while some of the districts are not fully supportive of the concept.

Is it time for both of these counties to adopt RWC for potable use?

Snohomish County is surrounded by other counties that have expanded RWC to include potable usage. These counties recognize that potable use of rainwater for single-family dwellings is not a threat to public safety or to the revenue of their water districts. King, Skagit, Whatcom, San Juan, Jefferson, and Island counties all accept the benefits of potable RWC for single-family dwellings.

RainBank Rainwater Systems along with support from the American Rainwater Catchment Systems Association (ARCSA) will continue to educate these two counties as well as others by offering seminars, workshops, and general discussion on the benefits of RWC to motivate them to allow potable usage of rainwater.

Please watch the recently aired KIRO News report about small water districts that are running out of water.

Photo courtesy of King.