Aug. 21, 2007 — -- Just outside Berkeley, Calif. -- the historical hotbed of resistance and revolution -- an insurrection is brewing. But this insurrection isn't about war and peace… it's about plumbing.
"We have severed pipes, we've dug trenches, we've removed concrete, we've drawn pictures," said Cleo Woelfle-Erskine.
"When I learned how this lifestyle of using water and dumping it down the drain was affecting the world, I wanted to live a different way," Laura Allen said.
One think tank estimates that Americans use two and a half times as much water as is necessary to survive comfortably.
Allen and Woelfle-Erskine are founding members of a group called the Greywater Guerrillas. What they are doing with water is simple yet subversive, a bit imaginative, and a bit illegal. And it all starts with the pipes outside their own homes.
"So, the guerilla nature of our projects happen right here, when you cut into your plumbing and you're reusing your water for a second use," said Allen, standing next to the pipes outside her home.
"It's not dirty, it's not contaminated. It's just some water with a little bit of soap in it and some dirt," said Woelfle-Erskine.
Gray water is the water that goes down the drain from your showers, sinks and washing machines. Humans would never want to drink it or wash in it, but it turns out that most lawns and most things in a garden love it. Allen and Woelfle-Erskine use theirs to feed a bed of tomatoes.
"The soaps that are in [the water] are actually plant nutrients," explained Woelfle-Erksine. "So there is phosphate in soap. There might be nitrates."
The Greywater Guerilla lair is rigged to take advantage of every last drop of gray water.
"This is one of the most basic gray water systems you can make. It takes five minutes," Allen said, pointing to her own system. "So when you're washing your hands or brushing your teeth… this is called gray water. Now you can use it to water plants or flush your toilet."
"It's about a 100 gallons a day that we're saving from the irrigation and from not flushing the toilet," she added.
And that's not just a drop in the bucket, as the Southeast and Southwest are facing major water shortages.
Allen and Woelfle-Erskine were inspired to build their first system by a very large water bill. Back in 1999, they were plumbing neophytes, so Allen decided she'd better take a plumbing class.
"My plumbing teacher was an inspector for the city of Oakland," Allen said. "At one point he told me to stop asking questions, that it was illegal, that he didn't want to hear about it."
The laws vary from state to state, but in California, building a gray water system without a permit is illegal. The guerillas build all their systems without one.
"We're forced into being guerilla-style because of economics," said Laura. "Permitted [systems] cost between $2,000 to $10,000. Nonpermitted systems can be as cheap as $100."
Claudia Cappio is the head of the plumbing inspectors for the city of Oakland. She said that "the motivation and intentions behind the Greywater Guerillas is a good one," but added that "codes are necessary to assure the safety of the family who's putting one in and of our environment."
There is concern that if not properly monitored, gray water can be a health threat and a danger to the environment. Allen said that she and Woelfle-Erskine understand the code and have designed their systems "to work and to be safe."
The guerillas have been refining and expanding their designs for years -- finding new ways to save.
"Kitchen sinks are often considered black water because of the amount of grease and organic matter that goes down the drain," said Allen.
Reusing black water is illegal, but the guerillas have designed a filtration system using a container of wood chips and a salvaged bathtub filled with cat-tail reeds. Of all the things they've built, one of Allen's favorites is a composting toilet in the bathroom, otherwise known as "the Throne." This toilet uses no water -- they remove the waste and use it later as fertilizer.
"If you're interested in water conservation and water reuse, looking at your toilet is a really key element because toilets can use up to a third of water use," explained Allen.
There are thousands of gray water systems across the United States, many of them built without permits and some with the guidance of Greywater Guerillas. "Nightline" visited the guerillas as they helped a New England woman named Rose irrigate her garden.
"What we are doing right now, may or may not be legal," said Rose, who asked that her exact location be kept private. Now every week, Rose will redirect a 150 gallons of gray water from her kitchen sink into her garden.
The guerillas at times do go public. Rose heard about the guerillas through their new book, "Dam Nation: Dispatches From the Water Underground." They've also released a pamphlet, or zine.
"I show up at some city I've never been to and there will be copies on the back of someone's toilet," said Woelfle-Erskine of the book.
Wielding power tools and a pick axe might not be for everybody, but however the work gets done, this is a movement that makes sure nothing goes down the drain in vain.
Back in California, Woelfle-Erskine is reminded of the purpose behind her cause when looking at the San Francisco Bay.
"It's something so simple that this water that has a little bit of soap in it doesn't need to go into the bay, to pollute the bay. It's so easy to redirect it slightly to create this bountiful and beautiful oasis in your backyard," she said.