Rediscovering Rainwater: Rain Harvesting Comes of Age — Again

By Linda Fridy

With one dry winter behind us and another forecast for this year, local water districts are asking residents to conserve water and looking at ways to increase their supplies, even to the point of building multi-million-dollar desalination plants.

Local landscape designer Bobby Markowitz says the solution lies not in water that has already reached the ground, but above our heads in the billions of gallons of rain Santa Cruz County gets even in a dry year.

“It’s not a new idea — it’s 4,000 years old,” he said with a laugh. “It’s like it’s been rediscovered.”

Rain harvesting, as it’s called, has gained popularity with increased awareness of green solutions, Markowitz said. While his interest began as a part of his landscape business Earthcraft Landscape Designs, it has become both the primary focus and a personal passion. He recently offered lectures and an extension class through Cabrillo College on the subject.

While attending the International Rainwater Harvesting and Managing Workshop held in Australia this August, Markowitz saw efforts that addressed not only garden needs, which he said represent as much as 60 percent of a household’s water use, but also uses inside the home.

He’s particularly excited about new technology that allows homeowners to switch between using rainwater and municipal supplies. It’s in place in Australia and expected to be certified for use in this country next year.

Using this approach, the storage container holding rainwater collected from the home’s runoff is connected into the pipes that fill toilets and washers. A sensor monitors the amount of water in the container, and when it gets low, automatically switches to the municipal water supply. When rain refills the storage container, the sensor switches back to using that water.

“It alleviates the pressure on municipal water supplies,” he said. A 2,000-square-foot roof generates about 30,000 gallons of water from 24 inches of rain, he said. That’s 30 percent of an average household’s annual water use.

Is Rain the Answer?

Just watch the torrents of rainwater cascading down streets and hillsides during a storm and you’ll see where Markowitz thinks we can find the answer to local water concerns.

Rather than letting the rain run to the sea, creating erosion and picking up pollutants along the way, and then going through an energy-intensive process to remove the salt and pump the water back up to homes in the hills, he advocates keeping the water as it falls.

“Think of it as money; think of it as energy. Capture it up high,” he said. “It’s distilled from the sky. It goes through the whole organic process.”

Areas such as Santa Fe in New Mexico have adopted low-impact water development ordinances, he said, in which the goal is to hold all storm water onsite and put it back into the aquifer. Closer to home, Santa Monica has implemented a water recycling program and diverts storm runoff.

He would like to see such efforts undertaken locally, noting that the Scotts Valley Water District and others offer rebates for rain harvesting.

The challenge for homes with smaller lots is where to put a storage tank, he said. They can be housed above or below ground. Interest in rain harvesting has grown exponentially, he believes.

“I was howling in the wind about four years ago,” he said. “Now my phone is ringing off the hook!”