The Why, Where and How To of Rainwater Catchment Systems

Listen To The Podcast

On today’s podcast, I will discuss everything you need to know about building your very own DIY rainwater catchment system. From why you should build one, where it should be, to the details of how to build a rainwater capturing setup.


I discuss:

  • Why you should consider putting in a rainwater catchment system.
  • Laws pertaining to rainwater catchment.
  • Where to install a rainwater catchment system.
  • Options for capturing water.
  • Specific pieces to a catchment system.
  • How to care for and maintain a catchment system.
  • Using the water from your rainwater catchment system.

Why Install a Rainwater Catchment system?


Conserves Water

Having stored rainwater can save a lot on the use of water from a municipal water supply or even your well during dry parts of the year, even more, if you set up your system for greywater use.


Possibly Conserves Energy

If your water comes from a well then every time you use a gravity-fed rainwater storage system for your water needs you are saving on the use of your well pump which can have significant energy savings.


Water Security

Everything needs water to survive and having hundreds of gallons of stored water on hand for emergencies is never a bad thing.


Where to install a rainwater catchment system.


Rainfall Amount Considerations.

The average roof collects over 600 gallons of water for every inch of rainfall.


Water Needs.

What are you going to be using the collected rainfall for? This will have a direct impact on the location of your system.


Roofing Material.

This can make a difference depending on the purpose of the water. Metal roofs are best but asphalt shingles are fine depending on the water use.


Options for capturing water.


Barrel Collection

Food-grade plastic barrels or IBC tanks.



Rooftop cisterns, attic cisterns, ground-level, and below-ground-level water storage cisterns.


Using Berms and Swales

This is called passive water harvesting and it’s the practice of slowing water down and encouraging it to soak into the ground. With simple land contouring that catches and directs stormwater runoff, rainwater can be used beneficially, encouraging plant growth in landscapes and natural areas, healing erosion cuts, and can even replace the need to irrigate with tap water. 



I will defer you to a page with information and a video explaining more about using ponds and water features for rainwater storage. –



Specific pieces to a catchment system.


Downspout Diverter

This flushes away leaves and large debris before entering the catchment system. 


Downpipe First Flush Water Diverter

This diverts the first few gallons of rainwater away from the storage tank until the roof is washed clean of dust and fine particles.



This captures what’s left of any fine debris that was missed by the diverters maintaining cleaner water in your storage tank.


Collection Tank

This will be the final storage place for your clean rainwater. This can be a large cistern, plastic barrels, or IBC tanks.


Overflow Valve

Your collection tank will eventually fill up so it will need to be fitted with an overflow valve which will allow the rainwater to be diverted to the ground once that happens.


How to care for and maintain a catchment system.




Using the water from your rainwater catchment system.

  • Garden and Landscape Usage.
  • Grey Water Usage
  • Using Rainwater For Drinking and Cooking – Must be filtered

Resources and Product Links:



Other Links


It is now legal to collect rainwater in Colorado. HB 16-1005 is the bill that was signed May 12, 2016.


This Post Has 2 Comments

  1. Hanna Rice

    I appreciate your creativity and the effort you put into every post. Keep up the great work!

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