Save rain now for a sunny day

Question: I just had a big veggie garden for the first time last year. My water bills were through the roof. I've heard about using rainwater storage as an alternative to using city water and want to learn about it.? Is rainwater harvesting legal? Is it safe? Do you know of any good local references I can use to learn more about this?

Answer: Water is publicly owned in Oregon, but state law allows residents to collect runoff from rooftops, driveways, parking lots or other artificial, impervious surfaces and store it in reservoirs, rain barrels or other containers. This process is called "rainwater harvest."

Rainwater harvesting is the capture, diversion and storage of rainwater for use in the yard. Harvesting and storing rainwater can cut both city and/or well-water consumption as it can serve as an alternative source for irrigating landscapes, vegetables or small fruit gardens.

If your property is an acre or smaller, it can make a real difference in water consumption. If you have more acreage than that, stored rain most likely won't likely meet of all your needs for irrigation. Rain gardens are not suitable on top a septic field or in a riparian area or floodplain.

For rainwater harvesting and storage, there's the initial cost of installing a catchment — tank(s) and pumping-and-delivery system. But the rainwater is free. And rainwater is unchlorinated, soft (fewer salts than city or well water) and near neutral pH (not acidic or basic).

I harvest rainwater, albeit at a tiny scale. My well water is really hard, and in the summer, I've noticed that when I'm summer irrigating with well water, my soils get crusty with mineral deposits. So, I have placed a couple of clean garbage cans out in the yard. I let rain fill these over the winter and spring. My spring garden seedlings, transplants and indoor houseplants love this nice soft rainwater.

Oregon State University Extension Service has just published (online) "Harvesting Rainwater for Use in the Garden" (EM 9101). This 10-page illustrated guide goes over how to design a catchment system, small or large, how to calculate how much water you'd get, roofing materials, filtering and the like so you can get an idea of what building a system might entail.

As our world becomes ever more paved and developed, more rain falls upon hard surfaces, flowing over land into ditches and storm drains, instead of infiltrating into the ground. Too much water flows too fast into our streams and rivers from storm drains during rainstorms. Rainwater capture helps moderate the intensity and flow of storm waters.

If you don't have the room or the funds for infrastructure such as a large storage tank, you might design and develop a rain garden instead.

Rain gardens are specially designed gardens in low spots that collect storm water from hard surfaces such as roof tops, driveways, parking lots and streets. They work like a native forest, meadow or prairie to help filter out pollutants before they enter streams and lakes. And, they can actually recharge aquifers by encouraging water to soak into the ground. To learn more about rain gardening, see http://extension.oregonstate.edu/stormwater/node/69/print.