Collecting rainwater

Decide whether you want to collect rainwater for outdoor use only, or to plumb it to the house to use as non-drinking water. This will determine the size of your tank.

• For outdoor use, you may only need a barrel or a small tank, which is easy to install. You can learn how to do it from workshops organised by environment trusts. Simple barrels start at 200 litres.

• For indoor use, you will need a bigger tank. Think ahead about the plumbing, backflow prevention and applying for consents. This is more effort than for a barrel, but your reward will be in higher water savings. Most domestic-use tanks are 3000 to 5000 litres

• If you’re aiming for self-sufficiency, your tank should be at least 20,000 to 25,000 litres.

• Type of tank. Several companies sell rainwater tanks in Auckland and can advise you on the best tank for your needs. The Eco Design Advisor team at Auckland Council is a great source of information on sustainability when building and renovating. Go to www.aucklandcouncil.govt.nz/ecodesign

• Decide how you will connect it to your electricity supply and what the additional energy use will be.

• Location: Choose a place that is next to the downpipe and where you can collect water from the largest possible roof area. Make sure the tank won’t restrict access to the garden or block views.

• Weight when full. For example, you should not place a tank on top of a retaining wall.

• Maintenance. You need to regularly clean gutters, roof, tank inlets and filters. You should also check the pipework and inside the tank.

Depending on the size and the use of your tank, you may need to apply for consents. Click here to find out if you need consent.