Rainwater Catchment System


When planning out your homestead make sure that you don’t forget to make room for a simple rainwater catchment system. They are great for watering the gardens and to have as an emergency backup if needed. Rainwater harvesting can provide a water supply during restrictions and can help supplement your monthly usage.

Although rainwater is potable I would still properly filter and process the water coming out of a catchment system to make it 100% safe for drinking. Metal is preferred for a roofing material to collect the water but one thing that is often overlooked is the gutter system. If you plan on using the water for drinking or cooking it is imperative that you clean your gutters regularly and install a diverter system for the initial rainfall. With a properly installed system you can theoretically capture .6 gallons of water per inch of rainfall. So for a 20×40 roof like ours; we have the potential of collecting 480 gallons between our two totes with one inch of rain. You can see how we built ours below.

1. Check Craigslist for 275 gallon totes, we paid $75 apiece for ours.

2. Set the totes side by side and check for level.


3. Excavate as needed.

4.Use a threaded disconnect to connect the totes and add a spigot.


5. Run a 4 inch pipe from the gutter to the totes.


6. The system is basically complete.


7. Add  a hose reel to make watering the garden easier.

ImageWith our system the tote on the right fills first which then fills the second tote through the piping on the bottom. This allows us to flush the system of any debris that may have collected. We simply fill the first tote fully and then open the valve on the second one which cause the water to rush through the system and forces a majority of the debris into suspension. We then remove the disconnect valve and drain both containers; it’s not perfect but it works for our needs.

Below are a couple thoughts after having the system for several years now:

  1. Check local laws about capturing rainwater, it is illegal in some states.
  2. Add some bleach and let it set overnight before draining for the season to control any algae blooms.
  3. You need to protect the totes from UV light; it will cause them to degrade.
  4. Make sure whatever container you use that it was previously used for food grade materials.
  5. Make sure the totes are higher than your garden to increase water pressure.

For further information the Texas Water Development Board put together an excellent rainwater collection manual as seen below. Good luck with your planning.


  1. i am starting a project like this. I am also considering how i will filter the water for drinking should we need to. Do you have another storage for drinkable water? If not what is your plan? thanks

  2. Hey allchokedup, there are several things to do, the biggest thing is pre-filter, there are diversion systems that will divert the initial run off, basket systems to capture solids, and vortex filters. Here is a good site that explains each system. http://www.conservationtechnology.com/rainwater_prefiltration.html One thing that is hard to see in the pics is my initial tank sits higher than the second tank, so as that tank fills up it flows into the second and then overflows out of the top of that so that the water is moving and not sitting stagnant. We also have several methods of post filtering from the tanks, I am currently working on a slow sand filter design, once I complete it and test it, I will share it with you guys

  3. i have looked at a few designs of slow sand filters. I may go that route as well.Not sure yet as i am just trying to get a catchhment system in place first. There is the promlem of filtering the water fast enough to keep up with the rain. otherwise you will need a few extra tanks which I dont have room for. I plan on starting a garden in spring so Im trying to get this going. I plan on using a wire mesh in the gutter to keep out large debris. Just to water plants and my chickens. Future plans on filtering for drinking water if/when needed.
    like your site its great. Everyone seems helpful and no B/S
    is there a place to start you own threads or are we only to comment on yours? thank you