What’s Water Catchment? – A Brief Introduction

There are some in the world that still have the idea that people in Hawaii live in grass shacks and wear hula skirts. Well, just in case that’s you, when I tell you about water catchment, you will really think that things in Hawaii are backwards.

The Softest Water You Can Get

Where there is no municipal or private water, the source of water for residents is from the rain.

Having lived on the Big Island for many years, I have grown to love water catchment. The fact being that it is pure water from heaven with no additives, minerals, or chemicals. The water is the softest water you can get.

Your soap lasts a long time because you don’t need to use much of it; and your hair, if you have any, is always nice and shiny because there are no minerals drying up on it. There are no hard water stains in your toilet or shower, so just a little bit of cleanser and a scrubber is sufficient. Rarely do you need harsh chemicals to clean. We just let our car air dry after washing it, because rain water doesn’t leave spots.

At some of the older coffee farms and homes, you can still find the old redwood tanks made of tongue and groove redwood with metal bands to hold it together. My father had a great big one in the back of his house. When it leaked he would burn some ohia lehua wood to ashes and pour the ashes into the tank to seal up the leak. It worked. If there was a drought, the wood would shrink from being dry, and then swell up when it became full again. There would be a lot of water loss before it would swell up, though.

I went to visit someone in Kainaliu, Kona, one time. He was renting an old coffee shack with a huge old redwood water tank as the bedroom. It was round, of course, but it had a window. I don’t know how legal it was, but he paid money to live in it. Reuse, repurpose, recycle…

How is the Water Collected & Stored?

When you are on a water catchment system, your roof is usually made of corrugated iron and you have rain gutters so the water will flow into your catchment tank. The most common type of catchment tanks used today are made of bent corrugated iron, riveted together, and supported by large metal bands. It normally sits on a poured concrete ring with sand in the middle to cushion the liner. The liner should be food grade; and having a frame to hold the cover is advisable.

Just a little chlorine added to the water will discourage algae and kill bacteria. The County of Hawaii has guidelines online to let you know how much to use.

The main thing with water catchment is to keep your roof, gutters, and tank cover clean. There are businesses that specialize in cleaning catchment tanks – which should be done regularly.

The downside of catchment systems is that even if you take really good care of yours and keep it tightly covered and clean, if you neighbor doesn’t, everyone gets mosquitoes. Also, if there isn’t enough rain, then you have to pay for a water truck to deliver water to fill your tank.

When you think about it, all of our water originates from rain (or snow in some cases). It just flows down the mountain through underground streams and we get it as ground water through wells. Then it gets processed by the municipality to make it safe, but by that time, it’s full of other minerals that leave spots and crusty stuff on your fixtures.

If I could have a catchment tank here on Oahu, I would do it. The water is pure, clean, and free and I am in control over what goes in it. And my bathrooms would be so much easier to clean. There are a few places here on Oahu that is on water catchment, but most of us have to suffer with the hard county water.

More Information

If you would like more information on water catchment systems, please contact me.