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The Rain

May 15, 2024

Photo by Chris LaRoche

Photo by Chris LaRoche

Call me a dreamer. I want to flush with rainwater. Rain barrels already anchor my downspouts. I want to hitch them to my toilet tank. It would save me money and leave the city’s drinking water for better uses.

Yet so far local plumbing rules aren’t helping me, or thousands of others in the Pacific “Northwet,” make the rain-barrel connection. It’s not so much that rules prohibit it but that even local authorities do not really understand what the rules mean. A little clarification—and publicity—would go a long way.

Already, outside my house in Seattle’s Ballard neighborhood, I’ve managed to irrigate my Victory Garden all summer from nothing but the 500 gallons of rain I collect in ten barrels. During the other three seasons, though, the garden doesn’t need extra moisture, so my barrels sit unused and, often, full to the brim.

Thanks to Hugh Geenen for supporting a sustainable Northwest.

Rain barrels for irrigation: useless 10 months of the year. Photo by Chris LaRoche.

So I’m flushing my toilet with pure, treated drinking water that’s piped scores of miles from the Cascades while I’ve got hundreds of gallons of free, naturally delivered, and naturally replenished rain stockpiled just outside my bathroom wall. Perhaps you now understand the intensity of my dream? A Rain Water Toilet Flush System (RWTF)!

I’m a perfect candidate: I live in a 1920 single-floor, 800-square-foot fisherman’s shack, so everything is down low to the ground and close together. My girlfriend and I have been doing our best to conserve water. Our consumption this past winter, for example, was half of what we used a year earlier. According to Seattle Public Utilities, we got our average daily water consumption down to 25 gallons apiece. The US average is 70 gallons per person per day according to the US Environmental Protection Agency. Vancouver, BC, estimates its citizens use an average of 90 gallons (340 liters) per day, a figure that can double in the summer with outdoor irrigation. By connecting our rain barrels to the toilets, we could reduce our water use by another 9 gallons a day (6 flushes a day x 1.6 gallons per flush). Also, we could stop being one of those stinky “if it’s yellow, let it mellow” households!

On a policy level, a toilet can account for anywhere from 27 percent (older toilets) to 8 percent (low-flow) of household water use. There are over 130,000 single-family homes in the city of Seattle; an average household size is 2.84, so 369,000 Seattleites live in such abodes. If only 10 percent of these homes used such a set-up to reduce their municipal water use by a quarter, it would save more than 645,000 gallons of water a day, or 19 million gallons a month. Extend that math across Cascadia, and the savings multiply.

On a personal level, I have a single toilet situated just a few feet above ground level. Connecting it to my rain barrels should be easy, right?



Unfortunately, it’s not as simple as drilling a hole through the wall and attaching the toilet to the barrel (aka “Experiment #1”, don’t tell the plumbing inspector, but I may have already tried that). It involves principles of hydro- and seismic engineering. For a gravity-fed system, you need height. Water weighs 8.3 pounds a gallon. A full 50 gallon barrel weighs more than 400 pounds. Hoisting it to an adequate height, in earthquake country, you need some reinforced structure. Not too complicated, but definitely not simple.

And then there’s the permitting.

Both Washington State and Seattle allow rainwater catchment systems for indoor, non-potable use, but finding out how it’s done and what the permits are sure ain’t easy. Trying to do so led me on a three-year wild goose chase that finally, I hope, is coming to a fruitful conclusion.

I found classes and examples of systems, but nearly without exception they were large buildings and off-grid suburban mega-mansions. The main take-away seemed to be that these systems can be done, but to make it worthwhile, they have to be so large (tens of thousands of gallons) and expensive (over $10,000, with a payback timeline of decades), that it makes one ask, “why bother?”

So I looked to Portland, where examples of RWTF systems are almost as common as microbrews and bicycles.

A Google search of “Portland Rainwater Toilet” led me to the Portland Bureau of Planning and Sustainability, which includes some interesting and practical examples of single family RWTF systems. A call to the office put me in touch with Valerie Garrett, who staffs the Green Hotline. After I told her of my quest, she referred me to McKenzie James, Portland’s Senior Plumbing Inspector, and Pat Lando, a local contractor. James detailed the permitting costs: $35 per fixture plus a 12 percent surcharge. When I asked if he knew people who do this, he responded with a sort of “duh.”

Pat Lando clarified everything: he’s been designing and installing rainwater systems for 10 years. He too was stymied by the high costs of household rainwater systems, so he developed his own kit. He hesitated to give estimates, but when pressed, he suggested $2,600 for an installed, effective system. The main costs are the cisterns and installation, so if you’re handy it could be much cheaper.

Not only that, to maximize savings and return in investment, I learned that I could go beyond a RWTF system, to a “Rainwater for Non-potable Household Use (RNHU)” system. That little three-letter switch in acronyms would allow me to use rainwater not only for the largest consumer of indoor water (the john) but also for the second largest: the washing machine! Doing so would cut household water use not by 27 percent, but by half!

My experience talking to Portlanders made me think the wall I’d been slamming into in Washington was about the codes. Does Oregon use a different plumbing code that allows the installation of RNHU systems, while Washington follows another that does not? No. Both states use the International Built Plumbing Code.

Knowing what to look for now, thanks to Oregon’s guidance, I searched on and, sure enough, finally found someone who installs affordable RNHU systems in Washington. Michael Durland of PurRain has been designing and installing them for more than 25 years in northwest Washington. Much of his business is in the San Juan Islands, where rain is abundant but ground water is not. ”[Rain-water plumbing] does not need to be complicated but some contractors I know make it so,” he told me.

Durland defines “affordable”: the main costs are rainwater storage tanks, which run $1,200 to $1,400; the pump, costing $300 to $800; and various other parts, which add less than $200. He has installed systems in Jefferson and Whatcom Counties. He also designed a system for installation in King County but local plumbing inspectors “said I had to pass the rainwater collection course put out by ARCSA [American Rainwater Catchment Systems Association],” said Durland. “I was putting systems together before they started and am hesitant to pay money to be ‘approved’ to do it.”

Durland also pinpointed a practical, rather than legal, difference between Oregon and Washington’s plumbing rules: the Oregon health department publishes detailed instructions on how to do—and how to inspect—RNHU systems. The Washington State Health Department does not. There is no detailed statewide reference document on how to use rain water safely indoors, so counties have to make up their own. Guess what? Most haven’t.

Larry Fay of King County Department of Public Health explained that Washington is behind Oregon partly because of timing: only in 2009 did the Washington Department of Ecology allow rainwater catchment systems at all; before that, capturing and storing rainwater violated water resource law (a common occurrence in Western states). So far, only Jefferson, King, San Juan, and Whatcom Counties have begun approving systems.

The owner of this Rainwise house in Seattle dreams of using his system for potable water. He may be able to late in 2012. Photo by Chris LaRoche.

Finally, for $210, King County residents like me can get a permit for a standard plumbing fixture and three outlets to use rain water. (I would only use two outlets: toilet and washing machine.) The price includes review. Once my plan passes review, I can legally start tapping my rain barrels for indoor use. Or I can get a bigger storage unit, a cistern (currently eligible for a rebate for Seattle residents from the Rainwise program, which is currently expanding from Ballard to other neighborhoods) for indoor use. Plumbing authorities’ main concern is that your rainwater system doesn’t cross-connect with the municipal lines, allowing contamination of city drinking water.

(What’s more, King County’s new approach will even allow rainwater catchment systems to provide household potable water. That’s right. You’ll be able to put the stuff in your dishwasher or sink. You’ll just need to pay for a review of your plumber’s plans, at an hourly rate of $201. (Standard houses, I’ve been told, will rarely take more than an hour.)

No word if Idaho or BC has adopted these policies. (If you know, drop us a line!) Nor if Washington will make life easier for its county health departments by adopting a state-wide policy like in Oregon. But in King County, at least, the “someday” when we’ll make the rain-barrel connection is drawing closer all the time, for the regulations, the dreamers, and me.

Chris LaRoche focused his MPA studies on developing innovative, community solutions to grand, global challenges like climate change and water resource management. A rainwater capture system is an integral part of his zombie apocalypse plan.

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This sounds like a project that will make you feel green and eco-groovy, but let’s not labor under the illusion that this super-fun project will save anyone money.

Let’s do some math: I pay $4 per 1000 gallons for drinking water. I assume that you pay about the same. If you save 9 gallons a day, that’s, let’s see, 3300 gallons, or $13 per year. So we start with paying a plumber $200 for a plan review. That’s a 15-year straight line payback right there.

And if we take the estimate of $2600(!) for a full system, we’re looking at a 200-year payback. How many of our houses will still be standing in 200 years?

What am I missing?

Chris LaRoche

Jonesey- thanks for the question. I hope that some contractors can chime in on the topic, but initially let me adjust some of your assumptions:

1- Cost of water will rise and considerably, especially outside of Cascadia.

2- The $200 plan review is not for a plan that saves 9g/day with toilet, but a toilet/washing machine system that will save half of your water use, or about 35-50gpd, or 13,000-18,000 gallons, or $52-72, making the payback only a couple years.

3- My initial research showed me very large, extensive systems involving tens of thousands of gallons, costing well over $10k(I have no idea how much the system in Seattle City Hall cost, but I doubt they got it for that cheap). These systems were for complete, potable indoor household use, and the designer/installer admitted that the payback timeline was “20 years or more”.

4- I started researching the topic under a simple premise: a simple rainwater catchment system to flush toilets shouldn’t be that expensive, I don’t need (nor can afford) a 10,000g system costing $10k. Sure enough, I found designers/installers who can do it for a price that an intern can afford! I wanted to get the ball rolling, hopefully it has.

5- Some more thoughts on Point #1: there needs to be a massive cultural shift in North America regarding water usage. Cascadia is less in trouble than California, Arizona or Texas, but we can be part of that shift by more efficiently using the water that falls on our homes and better using Grade A municipal drinking water rather than flushing it down our toilets.

Ms. Molly

It’s not convenient, and they’re somewhat awkward, but we use 3-5 gallon buckets of rainwater and greywater to flush. The rainwater is collected from the roof, the greywater from the shower (yes, we shower with a bucket!) We feel that even if buckets aren’t very pretty, it’s the least we can do to reduce that piece of our footprint. Since we’re on a septic system, this practice also reduces input there. I’m a 49 year old lady (previously pampered urban chick) and have gotten used to the buckets. If I can do it, ‘most anyone can!

Bob Simmons

Ms. Molly’s got the right idea, and it’s the same one my grandfather used on the farm in Southern Iowa. (He was born at the end of the Civil War and died in 1957). I remember his flushing system clearly: a large bucket in each of the two bathrooms, one upstairs, one down. Alternate sets of buckets caught the runoff from two corners of the house. I expect we’re mostly too handsome and too spoiled to tolerate such a primitive setup, but it works.

Herb Butterfield

Great article Chris, honestly, I feel most of the problems getting these kinds of things adopted is the fear of liability. King County doesn’t want to approve of a system they didn’t design and don’t understand so they pass it off onto some other organization: “you have to have accreditation from ARCSA [American Rainwater Catchment Systems Association]”, this kind of lets them wash their hands of the issue, figuring that most people wouldn’t want to go through the effort and expense of getting that certification, and guess what? they don’t! Rainwater harvesting is one of the many things that interest me and I would love to learn more about it. Thanks again for the informative article.


Herb Butterfield


Seems if you could catch one of your rain barrels when it’s empty, and place it on something sturdy about 3 ft. off the ground, you could run a line from the bottom of the barrel to the bottom of your toilet tank… as long as there’s water in your elevated barrel, it’ll fill the tank. THAT you could refill with a 5-gallon bucket, or for those empty days, you could unhook the barrel from the toilet and reconnect the city water . Seismically, if you’re deeply concerned that tank could hurt someone if it fell off its pedestal, you might put an eye-bolt in the side of your house and run a rope around your barrel. Done, yes?

Chris LaRoche

No, not quite. See my response below to Eric’s similar comment.


Wow, thanks for this article! I’ve been becoming increasingly uncomfortable with the way my standard house uses water, and have started fantasizing/plotting building a modified “living building” inside my little city’s limits.

But, short of full earthship plans, I didn’t know where to look for a normal-ish rainwater catchment system design. So I am downright thrilled to learn that we not only have code that accommodates them, we even have experienced system designers and builders!

An Australian friend of mine, who’s used to living off stored rainwater, was shocked at our near-universal use of composite roof shingles — because they add heavy metals to the rainwater that runs off them. It’s a very strong argument for metal roofs.

Eric Clark

I agree with Charlie’s post above. I’m currently building three-foot high platforms for my backyard rainbarrels so that we can get better hose pressure for watering the veggies. I’m using PT 4×4’s lag-bolted into a three foot high x three foot wide x six foot long platform. This should spread the 800 lb of two full barrels out enough to not be a problem. The mention of earthquake above has me thinking that I should consider strapping each barrel to the houses’ framing. With the heighth, it should not be too difficult to plumb to your toilets’ in-valve.

Chris LaRoche

First, I really have to stress the weight of water and the potential calamities of perching 800 pounds a few feet off the ground. A solid and well-designed porch or balcony? No problem. A perch… yikes! (I actually met someone who had a simple gravity fed system for his basement toilet. Barrels sat on the ground.)

More importantly, a gravity fed system with hand-made, jerry-rigged platform isn’t for everyone, isn’t scaleable (sp?) and won’t translate into significant large-scale impact. This article hopes to promote a practice and policy that can be widely adopted and change people’s habits!


One thing not obvious when this occurs on a large scale is that treated, piped water use will go down. However, in Seattle, sewage costs are based on the amount of city provided water. So the interesting corollary is that our sewage treatment rates will go up because the percentage of city provide water in the sewage will go down. Seems counter-intuitive, but it is real.

The other point I’ll make is that conservation provides the biggest bang for the buck for you and me as individual householders. Molly’s grey water reuse system is remarkably efficient. My friend in Ballard just had installed a $4200 rainwater catchment system to irrigate his garden alone. The city’s program paid for the lion’s share of that. Our payback as taxpayers (who paid for his system) on that comes on the combined sewage overflow side, not on the water delivery/consumption side.

Chris Webb

You mentioned that rainwater harvesting may not be as simple as piping a cistern directly to a toilet but that is in fact exactly what I did for a client near the arboretum in Seattle. I designed a gravity only system that avoided running a water line out to this structure and saved them money.

And as far as the economics of these systems overall, the comments about saving money based on the water meter rate of water misses much of the economic value of these systems. The Combined Sewer Overflow (CSO) mitigation value alone of cisterns can be much more economically favorable than large central facilities because you can build a rainwater cistern for about $0.50/gallon and the City of Seattle spends $8/gallon for central storage. Then there is the value of resiliency of having multiple sources of water available for a building owner. We are in a region where a large earthquake is going to occur some day and relying on the central water grid as your only supply of water is risky. I don’t like to have all my eggs in one basket.

There is a lot more to the value of rainwater harvesting than saving $13 worth of water, i consider the water conservation benefit as gravy on top of the real benefit of resiliency and stormwater/CSO mitigation.

Sea Wolf

EXCELLENT piece. Thanks very much. Wonderful comments and responses as well.


Love the article but do not think all systems need be “Scalable and adaptive to old habits” Thinking in terms of creative diversity and decentralized systems adapted to site will teach us how to be flexible “free range thinkers” I love that you are being so conscientious though. I have been thinking solar water heating systems that could heat radiatiors in old homes. Found out we have a tank in attic. 1911 house. That attic tank thing might be useful for flush intentions. It is really pathetic that so many ideas are not funded due to limitations of an antiquated profit, win/lose construct rooted in the banking system. Any interest in community funding for real projects? This seems the way to jump start a whole lot of experimental sites that can be testing and development, design projects. The new school of habitational designs!

andy peters

Chris, good story. You didn’t mention the conversion rate that will help readers know how much rainwater they can collect, which I think is 7.48. Multiply square feet of roof you have X 7.48 X the number of feet of rain and the total you get is the amount of rainwater you can collect in gallons. For instance, we have 2500 square feet of roof X 7.48 X 3feet of rain year = 56,100 gallons.I like the brown color rain collection system you show in the photo. Can you tell me where I could find a little more information on this product?


Fabulous article and comments.I live in West Seattle and was fed up with the base rate I was paying for water so I had my water shut off.I flush with a bucket and sponge bath with the one gallon..yes I said one gallon of distilled water I purchase each day.This means I use approximately one fiftieth 1/50th of the average persons use.I feel great about it.I also don’t drive.My footprint is the size of a mouse’s.I am doing it because my planet is sacred to me.She is the only one I know of that is so beautiful so far.Keep up the good work and thoughts everyone.

Rick Clark

I truly wish I had discovered this site before I decided to hook up a toilet to my rain barrel. I live in a “temperate rain forest”. We get 80 to 120 inches a year. Perfect for rain barrel use. I hooked up a rain barrel with the bottom of the barrel the same height as the top of the toilet in question. With the barrel full it will not even start to fill the tank. Any suggestions? It is a 55 gallon barrel. The top level is over 3 feet above the tank. Thanks in advance for your help.

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