Category Archives: Rainwater Catchment

Rainwater Catchment, Residential Rainwater Collection

Truths and Myths About King County Rainwater Harvesting


Close-up of a worn, metallic fountain pen nib on a black surface.I have been designing and installing rainwaterharvesting 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 wheninquiring 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 statementclarifying that a water right is not required for rooftop rainwaterharvesting.Asdescribed 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: Rainwaterharvesting 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 forregulations and permitting.

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

As Washington State counties arerecognizing thebenefits of rainwater collection and the fact that rainwater can provide a viable source of water for potable usage, other counties willadopt 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 RegionalRepresentative for The American Rainwater Catchment Systems Association (ARCSA). RainBank is committed to helpingcustomers andcounties understand thebenefits, standards, and policies of rainwaterharvesting in order to provide a clean, safe, viable source ofquality water.

Seattle waterfront park photo is courtesy of Nicola under Creative Commons

Rainwater Catchment, Rainwater Harvesting Education

Standards for Rainwater Collection


Close-up of a worn, metallic fountain pen nib on a black surface.The Rainwater collection industry is rapidly becoming more accepted, consumers are becoming more aware of water shortages, quality of water, and increasing costs of operations of a centralized water system are being passed onto the customer. Many are turning to a supplementary source of water, whether from a simple rain barrel, for small irrigation needs or a large-scale sustainable system for whole-house demands. The industry itself is changing and becoming more complex. States and counties throughout the US are witnessing such a rapid growth in interest of rainwater collection, many are struggling with regulations and standards to ensure public safety. In addition, increased demand is beginning to outpace the supply of available, qualified RWC system designers and installers. Without proper regulations standards, improper designs and installations by unqualified persons can lead to underperforming or even dangerous systems.

Without quality information and education, governmental intervention can lead to laws that do nothing to protect the consumer and the industry itself. Therefore the American Rainwater Catchment Systems Association (ARCSA) is the leader in education and information about RWC. The American Society of Plumbing Engineers, (ASPE) develops plumbing and design standards through a consensus of a standards development process in accordance with the American National Standards Institute, (ANSI). The Plumbing Engineering Standards are designed to provide accurate and authoritative information for design and specification of plumbing systems.

ARCSA/ASPE/ANSI63-2013: Rainwater Catchment Systems Standard was approved by the American National Standards Institute on Nov. 14, 2013 and was developed by a joint effort and sponsorship support from the International Association of Plumbing and Mechanical Officials (IAPMO) and the National Science Foundation (NSF) International. The purpose of this standard is to assist engineers, designers, plumbers, builders/developers, local government, and end users in safely implementing a rainwater collection system. This standard is intended for application to new rainwater catchment installations, as well as alterations, maintenance, and repairs to existing systems.

ARCSA and RainBank Rainwater Systems are committed to education and the advancement of rainwater collection. RainBank’s president Ken Blair is ARCSA’s North West Regional Representative.

Rainwater Catchment, Sustainability

Is Rain Collection a Trend?


Close-up of a worn, metallic fountain pen nib on a black surface.The rise of the rain collectors may sound like a scaryHalloween prank, but it’s a trend not to be ignored.

According to a recentarticle published on Earth911, more and more folks, from millennials to baby boomers, are learning how, and then capturing the rain, to mitigatehigher water bills and help in conservation efforts, largely due to drought, but also associated to aging infrastructure.

Do you know that by capturing one inch of rainfall from the roof of a 1,000 square foot home, it means you could save up to 312 gallons of water (or what amounts to almost eight, 40-gallon baths).

If you want to know how much rainwater you might collect from your roof runoff, browse totheUnited States Geological Survey (USGS) rainfall calculator, which can estimate rainfall in areas from a couple square feet to several square miles.

Rainwater collection isn’t only for the home gardener.

Businesses are using collected rainwater for washing vehicles and toilet flushing facilities. Schools are collecting rainwater for community gardens and new multi-family construction could collect rainwater for potable use for tenants or homeowners.

Asrain collection trends, it can create a confusing frontierof information and solicitations.

If you decide to have a system professionally installed, we encourage you to know whether or not your chosen contractor has the accreditation and experience needed for a properly installed, potable or non-potable system. Visit ARCSA (The American Rainwater Catchment Systems Association) tosearch for a designer and installerwith the knowledge and experiencetomeet your needs.