Do It Yourself - START HERE
This site has hundreds of articles on rainwater harvesting. But where to start? This is the right page for those that want to design and install a system on your own.
There are hundreds of parts in a typical-sized rainwater harvesting system and with time and research most aspects of a rain water harvesting system can be figured out. The tools on this page help you get started.
Articles and books available on this website can also help. Below are the steps I recommend you follow. This is by no means a complete list but it will provide you a great starting place.
- Deterimne how much you can capture - This tool helps you assess what you can capture (i.e. supply).
- Now you know how much you can capture in theory, this needs to be reduced by the efficiency of your roof.
- Knowing how much water you need (i.e. demand) should always be part of the equation. Here is a simple rule of thumb on how much you may need.
- Sizing a system is typically a balance involving 3 variables: how much you can capture, how much you need and finally cost. Since tanks are the major component cost in building a system, this article on tank options supplies an estimate on what your system might cost. Plus the article can help you select the tank that is right for you.
- By now you should have an idea on the size of your system and type of tank which would be best your needs. The next step is starting to piece it all together. The first step is getting the rain off your roof. This typically involves gutters or rainchains.
- Once you have started to harvest the rain off the roof you will need to convey it from the roof to tank.
- An important step in the conveyance process is keeping the water clean prior to it entering the tank. This can be done with gutter screens, downspout debris eliminators, or inground filters. Pick one of these methods or you will be constantly cleaning your tank and that is not a fun process I assure you.
- Now you have clean water, it is time for the big step - the tank. You should know the approximate size of tank and type of tank. If not, please review the storage tank article and make this decision. Another tool you can use is this interactive tool - System Sizing Tool.
- You have now figured out the tank and how to get the water cleanly to it, the next step is getting the water out of the tank. A majority of times this will involve a pump and potentially a floating extractor.
- Many of the prior decisions should have been greatly influenced by how you are going to use the water. Is it a simple irrigation system or is a drinking water system where you will need disinfection? Even for a irrigation system is time to clean the water again prior to use.
- Congratulations you now are the proud designer of a rainwater catchment system, but it will need maintenance. This step is one of the last to be considered, but is one of the most critical. You need to document every one of the decisions made above and decide how to make it fit your lifestyle. It is possible to add options throughout the process to make maintenance easier or add them later after you have run the system for a while and fully understand the type of maintenance your system will require. My recommended approach is to plan for it now and make some minor adjustments to your plan before proceeding.
You now have all the major pieces of a system in place: supply, demand, roof, conveyance, pre-filtering, storage, distribution system (i.e. pump) and the secondary cleaning system. These are the steps in designing a system as well as the major components of every rainwater system.
The above is simplified decision-making process. There are literally hundreds of parts that need to be put together to make a system work, but the above provides you a good foundation for the decisions you will need to make regardless of who is installing the system. Below are a few more items you may want to consider in designing your system.
If you would like to have all or part of your system designed for you, please contact me. Or if you are looking for a good installer in your area, please contact me.