DIY Green Energy For Homes

How to Harvest Your Rainwater

Have you ever thought about harvesting your rainwater?

If you live in an area with regular rainfall, then collection and storage of this will be a relatively simple process.

You may already have roof down pipes which can be adapted to fill water butts with only gravity to assist in the harvest.

If the design of your building is appropriate, then you may look at installing a tank for storage and piping to distribute water for the various uses you desire.

Ultimately it will depend on how much investment you want to make, but systems that give water filtered for all purposes except drinking are available.

A tank set into a garden setting need not be obtrusive, and in combination with a solar powered electric pump it will supply water to all areas of the house and surrounds. This will allow you to save on reducing your water bill and give you some reserve against times of restriction during droughts.

If you settle for a simple tank attached to the down pipes from the roof, you can install a sieve to screen out any material before storage - but make sure these are regularly maintained, especially before major rainfall is due.

When choosing storage for this you may look at recycling wine barrels rather than purpose-built plastic tanks, but even these are available made from recycled plastic. For any storage you will have to employ a tight cover to reduce algal bloom and the potential for breeding mosquitos. Remember also to regularly clear any leaves and debris from the roof and check the covers on spouting for build up of material.


The best idea is to look at an intermediate system which has small pumps attached to the rain butts which can deliver water where it is needed. This could be for topping up toilet cisterns or taps for washing, but must not combine with piping used for drinking water.

The potential for contaminating drinking water comes from the different types of material used in roofing and the paints that may have been used to cover older roofs. In addition, fouling from wildlife and pollutants from the atmosphere may also be present in the runoff.

When deciding what you will do with the water for inside the house, ensure that if it is to enter a dishwasher or other household appliance that appropriate extra filtering is added. Fine grit and soil may damage these machines over time.

You may also look at rainwater harvesting in conjunction with a grey water diversion system using shower and washing machine outflow. If all you are trying to achieve is extra water for garden or lawn watering and the occasional guilt free car wash, then mixing of the water is not a problem.

Remember that this water may contain contaminants from the type of shampoos and detergents you use so look for eco-friendly alternatives for these as well. When you water, do so in the evening to conserve usage and reduce the effects of evaporation during the heat of day. No point in collecting this precious resource only to waste it!

One way in which to harvest your rainwater is to construct a green roof garden that will utilize the water directly. This may not be an option for an existing structure but if you are replacing a roof or starting a new home then this is well worth considering as it has other benefits in the insulation of the house. The feasibility of collecting rainfall will depend on your local climate and the cost of any structural changes you need to make.

As a way of future proofing your home against rising costs from your utility company and the effects of droughts, even a simple system seems a good investment to make today.

What about the sun? You can power your house with energy from the sun, and make savings for your pocket and the planet at the same time: