Rainwater Harvesting Methods

Water conservation is becoming a real priority, particularly in dry climate areas. A very simple, economical means of significantly reducing your household water consumption is rainwater harvesting, and all you need to do is connect a rain barrel to your downpipe.

Water collected from rainwater harvesting can be used for garden irrigation or cleaning. Virtually anyone who has a roof can attach a rain barrel and make a contribution to water conservation, and if you take into account the money you’ll save on your water bills, you’ll find it will cost you practically nothing.

The simplest type of rain barrel connects directly to your downpipe, and catches the water from the roof which would otherwise disappear down the drain. You then store the water, and pump it onto your garden and lawn, or use it to wash the car or the windows later when the weather is dry. The most basic systems have a spigot or a simple manual pump, or for a little extra money you can buy a labor saving electric pump.

If you want to use the water from your rain barrel as drinking water you will need a water purification system. This is also highly recommended if you plan to use the water for washing dishes or clothes.

Calculating how much water rainwater harvesting will save you

Working out how much water your roof will collect over a year requires a few measurements, and some simple arithmetic.

First, measure the length of the sides of your house, adding two feet on each side for the roof overhang.

Multiply the length of the house by the width to find the total area. You don’t need to take into account the angle of the pitch of your roof. One inch of rainfall provides around 600 gallons of water for every thousand square feet of roof catchment area.

Next you need to look up the average annual rainfall in your area, which should be fairly easy to find online. If the area of your roof is two thousand square feet, and you have fifteen inches of rainfall per year, you can potentially collect:

2 x 600 x 15 = 18, 000 gallons of water per year

This can make a substantial difference to your water bill!