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Resources and Links

Goal  The goal of the Comal Trinity Groundwater Conservation District is to develop rules to provide protection to existing wells, prevent waste, promote conservation, provide a framework that will allow availability and accessibility of Trinity groundwater for future generations, protect the quality of the groundwater in the recharge zone of the aquifer, insure that residents of Comal County maintain local control over their Trinity groundwater, and operate the Comal Trinity Groundwater Conservation District in a fair and equitable manner.


Rain harvesting materials and equipment are sales tax free--complete this form


What is a water footprint?  A water footprint is a measurement that totals the amount of water that is consumed by a process, individual, community, company, or country.  Your water footprint includes your direct and indirect sources of water consumption.  Direct includes the water that is used to brush your teeth or wash your face whereas indirect is the water consumed by your clothes manufacturing or the production of the burger you eat.  To determine an individual’s water footprint, we need to add together all their water consumed--ALL water.  It includes  everything from the amount of water used in your shower to the water used to produce the cheese on your breakfast sandwich.

Where did it come from?  In the early 2000s, a Dutch professor named Arjen Hoekstra opened people’s eyes to how we manage this vital resource.  In fact, his water footprint concept created a whole new scientific discipline—one that promises to shape solutions for the challenges we face. 

A water footprint shines a light on what you don’t see: water use that occurs in each step of the production process of the goods you buy.  It accounts for surface water and groundwater (referred to as “blue water”) as well as rainwater (“green water”).  It also captures water used to make wastewater generated in manufacturing safe for reuse (“grey water”).

A water footprint can reveal water-use patterns that can help us understand how we can use less water.  Our decisions affect water resources not just in the home or the country in which we live, but wherever products we consume are grown or made.

Calculate your water footprint.  By understanding our individual water footprint, we can appreciate the role water plays in everyone’s lives.  So what’s yours?  Click Here

Rainwater Harvesting Resources


1. Presentations (pdf)

2. Video

  • Brad Lancaster lists rainwater videos here.

3. Photos

  • We could have some "albums" for folks to view various rainwater harvesting images.  We could link to photo pages such as: rainwater tank images, rain barrel images, rain garden images

4. Brochures and Handouts

5. Studies

6. Publications

Roof water collection and irrigation

Rain gardens


  • Rainwater Harvesting for Drylands and Beyond, Volumes 1 and 2 (2nd and 3rd reprints). By Brad Lancaster, Rainsource Press, 2013. Must read books by world-wide rainwater harvesting expert Brad Lancaster.

  • Water Storage: Tanks, Cisterns, Aquifers, and Ponds for Domestic Supply, Fire, and Emergency Use. By Art Ludwig, Oasis Design, 2013. Info on tanks design details for rainwater harvesting, making ferrocement tanks, storage in in the root zone, and pond storage.

  • Rainwater Collection for the Mechanically Challenged, 2nd ed. Banks, Suzy, and Richard Heinichen, Tank Town Publishing, 2004. Good info on whole house rainwater systems.

  • Water from the Sky. Earthship Biotecture. By Michael Reynolds,  2005. Book about Earthships, with details on their greywater and rainwater harvesting systems.

  • Rainwater Catchment Systems for Domestic Supply: Design, Construction, and Implementation. By John Gould and Erik Nissen-Petersen. Practical Action Publishing, 1999.An excellent review of rainwater harvesting practices around the world.

  • Creating Rain Gardens: Capturing the Rain for Your Own Water-Efficient Garden. By Cleo Woelfle-Erksine and Apryl Uncapher.  Timber Press, 2012. Excellent book for anyone wanting to build a rain garden.

7. Suppliers and Educational Organizations

On-line vendors of rainwater components

  • Blue Barrel Systems  Sells kits for converting closed-top barrels with resources for local suppliers of barrel.

  • Rain Harvest Systems Sells all types of rainwater components including first-flush diverter kits, leaf eater downspout screens, pumps, and tanks. They also offer great technical support.

  • Aqua Barrel Sells kits for closed- and open-top barrels, and IBC tote rainwater tanks

Educational websites

  • Harvesting Rainwater for Drylands and Beyond. Brad Lancaster’s website full of information on rainwater harvesting.

  • Harvest H20– educational website with resources about system design, codes, incentives, and products.

  • This is a great website documenting Ole Ersson’s permitted potable rainwater harvesting system in Portland, Oregon. Includes diagram of the system and components used. The system cost $1,500 and harvests 27,000 gallons per year.

  • Oasis Design’s Water Information Central has info on natural water purification, rainwater harvesting, and water storage.

Classes and trainings


Metal Tanks

Plastic & Fiberglass Tanks


Stores & Suppliers

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