One of the first steps to harvest rainwater for off-grid living is to choose a suitable location and method for collecting rainwater. This will depend on several factors, such as the type of catchment you want, the amount of rainfall in your area, the size and type of your roof, the space and budget you have, and the legal regulations in your state/province/country. Find the Canadian Rainwater harvesting regulations here.
The most common and effective way to collect rainwater is by using your own gutters, which then collect the rainwater in rainwater barrels or plastic tanks. This method allows you to capture large volumes of water from your roof, which is usually the largest catchment area in your property and store it for later use.
You can also store water in an underground cistern. We also make use of a first flush system to divert the first dirty water that comes from off the roof. This helps to significantly improve the quality of the water you collect.
If you do not have the option to collect rainwater from the roof, or if you want to increase your water supply, you can use other methods, such as using a large tarp placed on the ground, which then channels all the water into a barrel or cistern. This method is simple and cheap, but it requires a lot of space and maintenance. You can also use other catchment areas, such as patios, driveways, or green roofs, to collect rainwater.
Another important factor to consider is the total storage capacity of your rainwater collection system. You’ll need a large enough tank/barrel or multiple tanks/barrels to store the collected rainwater for later use during extended dry spells and during cold weather events (winter). We also have a 300 liter (80 gallon) secondary water container in our loft that stays at cabin temperature all year long. We can easily fill this horizontal water tank with a small portable electric pump or even a small cordless drill pump. The size of your tank or barrel will depend on how much water you wish to have on hand, how often it rains in your area, and how much space you have to store your rain water.
We use a small electric pump to transfer potable drinking water from a couple of 5-gallon water jugs up to the water storage tank in the loft using a drinking water safe Flexilla garden hose reserved just for this evolution.