Making Lemonade

No, the lemon tree is not yet producing lemons. I'm talking about taking a bad situation and turning it into something really useful and valuable. And in this case, that bad situation is our little water supply in the basement.

Yesterday I measured it at 1 gal/minute. That's a decent amount of water (1440 gallons per day). I don't have to tell the Californians in the group how precious that much water is. Get super-conservative on the numbers, and we can count on 360 gallons a day, which is actually more than we currently consume for the whole house (keep in mind that we're not really irrigating much right now because it's winter and the sky is handling it for us). It seems a shame to remove good, clean water from the aquifer and dump it into the San Francisco Bay (which is where our storm drains go; actually, I think they go into the estuary first, but same diff).

So why not use it for irrigation?

For the last several months I have been somewhat half-assedly designing a cistern/pump/irrigation system for the yard, and I figure that with a 5,000 gallon tank, we can float out (heh) even the lowest-water years without ever once having to irrigate with tap water. On heavy years, we could flush our toilets in addition to irrigating with the free water all year round. This makes me incredibly happy, because it means saving a resource I care a lot about (water) and also doing all kinds of funky eco-weenie things with the house.

I'm not 100 percent keen on digging up the yard again, understandably, but the best place to locate the water tank would be right behind the house in the spot where we plan to build a deck (which could conceal the tank). I considered a water tower (traditional for Alameda), but to get the pressure we'd need we'd need a variance. Also, it would be a real earthquake danger. A pressure booster tank is actually a saner idea and not too expensive to run.

So what kind of permission do you need to do such things? You need a health department approval, for one thing, and planning permission and a plumbing inspection and special purple piping for the non-potable water lines if we do bring water in to flush the toilets. But, all things considered, it's not that much. You need to do more to be allowed to dump greywater in your yard, which in general Alameda seems to be averse to allowing, but we're proposing to sort of do the opposite: introduce besoiled rainwater into the sewage system. As much as I'd love to drink and wash and everything with local water, then dump it in the yard for a cycle around again, that's not really appropriate on a lot the size of ours with soils like ours (very thin and sandy).

But first, I need to find a testing lab that will tell us whether the water under the house is clean or not.

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posted by ayse on 03/23/06


I've been quietly obsessed with water cisterns for years. My wife thinks I'm a little nuts.

For now, even with all the droughts we've had over the last 10 years, Arkansas has a lot of water. However, I'm not convinced that it will always be so. With climate change, population growth, and wasteful water practices (the rice farmers are ruining our aquifers) I'm thinking the future isn't looking too good.

Archeologists working in the Middle East and the old Roman Empire have found thousands of cisterns buried throughout the region. Most are silted up, but, according to these archeologists, if you cleaned them out and make a few simple repairs, they still work. Ironically, some of these cisterns were still in use about a 100 years ago, but they were abandoned in favor of modern wells and municiple water systems.

Supposedly, if you fixed them all up, they would capture about 2% of the rainfall in the region (most of which is arid or semi-arid) and fully provide for everyone's water needs. I find this utterly amazing.

If I ever have a chance to, I'd love to install a cistern at the Queen (or where ever we end up). Please keep us posted on your cistern project. I'd love to know how it turns out.

I live in seattle, and the only person in the city to have a cistern permitted has a web site about his house here Its also an interesting read if you are interested in environmental building.

Thanks, Ed, that is an interesting site. One of the things I've been really enjoying in architecture school is the focus on sustainable design and alternative energy and water systems. Of course, with the volume of sump water we're talking about, drought-tolerant landscaping is not much of a concern.

At some point we're likely to put PV panels on the roof here and go off the grid. We get enough sunlight year round. My major concern is the toxicity of the PV manufacturing process.

I do find it amazing that in a city the size and age of Seattle, there is only one permitted rainwater cistern. We don't have many around here, but they do exist.

Note: We're getting pummeled with spam comments, so I've turned off the ability to use any HTML or include any links for the time being. Email with any issues.

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