Frequently Asked Questions About Rainwater Harvesting

Why is rainwater harvesting becoming more popular?

Every year, the world’s population grows, and several areas are enduring droughts. Together, these issues have placed a great deal of stress on reservoirs, treatment facilities, lakes and rivers. With the threat of collapse looming, people, businesses and governments are implementing precipitation reclamation methods, improving the efficiency of municipal infrastructure and reducing waste.

Why is Texas considered to be at the forefront of rainwater harvesting?

Many experts consider Texas to be at the front of the pack when it comes to precipitation reclamation. This is primarily due to Texas House Bill 3391, a piece of legislation that outlines proper forms of precipitation recycling and makes it more attractive to people considering a system. Among its provisions include:

  • Giving lenders the power to loan funds to development projectors that will use reclaimed precipitation.
  • Mandates the installation of precipitation reclamation systems in any state building with a roof size of at least 50,000 square feet, if they are in an area that receives at least 20 inches of annual precipitation.
  • Outlines the requirements for any system that will be used to reclaim precipitation for consumption.
  • Encourages local governments and municipalities in the creation of precipitation reclamation systems. HB 3391 enacted several incentives to fuel this effort.


HB 3391 is just one piece of Texas legislation that addresses precipitation reclamation
. The state has passed other initiatives that make it easier to acquire a system and offer protection from homeowner associations and other organizations that might take issue with an outdoor reclamation system.

What does a rainwater harvesting system look like?


During a downpour, precipitation reclamation starts on the roof. The building’s gutters are responsible for funneling the precipitation into the system, which collects in a series of barrels or a more sophisticated filtration system. If using barrels, the precipitation is only appropriate for watering the yard as it is not safe for consumption or personal use.

If a home or business plans on using the precipitation extensively, a filtration system will be needed to clear the precipitation of impurities. This normally includes mosquitoes, chemical runoff from the roof and any residue picked up in the air while falling. Filtration systems usually employ gravity filtration via charcoal, sand or gravel, but may also use fiber or other synthetic materials. Some systems use what is known as a first flush device to better improve the quality of anything reclaimed. If a lot of time passes between downpours, pollutants and other chemicals will build up on the roof until precipitation takes them away. Installing a first flush system ensures this contaminated precipitation does not reach the building’s supply.

Once filtered, the precipitation can be stored in an above ground or underground tank and channeled into the home when needed.

How is reclaimed precipitation used?


In most areas, reclaimed precipitation is used for outdoor irrigation, supplying toilets and, occasionally, bathing or washing clothes. Some areas are starting to use these systems to generate potable water, including Texas.

Reclaimed precipitation can channel into features like fountains, coupling conservation with beauty.

This article was published on Wednesday 01 October, 2014.


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