rainwater harvesting

Caminos de Agua works with a 12,000 liter ferrocement cistern with a first-flush system (to clean off collection surface in every rain event). 

Caminos de Agua, in partnership with El Maíz Más Pequeño A.C. and Fundación Gonzalo Río Arronte, ran a workshop to construct a ferro-cement rainwater harvesting cistern at Bachillerato SABES Cerritos school in Guanajuato, over 5 days in February 2017.

Why Rainwater Harvesting

View our Rainwater Harvesting Manual 

Rainwater harvesting is a simple, inexpensive, and sustainable way to secure water for rural and urban communities. Rainwater harvesting eases stress on underground aquifers, which are often overexploited and being quickly depleted throughout México and around the globe. As more communities begin to use rainwater for their daily consumption, our aquifers will begin to recharge — a process that will, in some parts of the world, take thousands of years. Since we can continue to use rainwater harvesting systems for the indefinite future without compromising our or the planet’s health, rainwater is considered a sustainable water source.

Rainwater is also considered a healthy water source because it is free of contaminants that lead to long-term health problems. Groundwater can contain heavy metals and minerals, some of which cause developmental disorders, cancers, and acute poisoning. Due to industrial dumping and inadequate corporate regulation, surface and shallow well waters including rivers, canals, lakes, and reservoirs are often contaminated with agrochemicals and other toxins known to cause organ failure, neural degradation, and reproductive disorders. Harvesting and consuming rainwater supports ecologically sustainable and healthy lives across generations.

Components of a rainwater harvesting system

  1.  Roof: the roof surface 'catches' the rain. 
  2.  Gutters & Piping: gutters are the horizontal pipes along your roof which catch the water from your roof.  The piping transports harvested rainwater throughout the system.
  3.  Leaf Filters:  all entrances and exists should be covered by a leaf filter, which keeps larger debris from entering the first flush system and the main storage cistern.  Additionally, leaf filters inhibit small animals or insects from entering the system. 
  4.  First Flush System: A first flush system separates the first harvested rain from each rainfall to: 1) clean your roof, and 2) ensure the rainwater that enters your main water storage is as clean as possible. It will keep dust, leaves, mud, debris, animal droppings, and potential biological organisms from entering the cistern.  Water collected in a first flush system is not meant for drinking and cooking but is great for watering your garden, for instance. There are different types of first flush systems, which can be constructed with barrels, PVC piping, or other containers. 
  5.  Cistern: the cistern is the main storage for your harvested rainwater. 
  6.  Biological Treatment:  Rainwater is free of chemicals, heavy metals, and minerals (like arsenic and fluoride), but it is still at risk for pathogens, bacteria and other biological contaminants.  ALWAYS treat your harvested rainwater for these biological contaminants before consuming.  Our ceramic water filter eliminates more than 99.9999% of bacteria and pathogens. Other options include boiling, solar/UV disinfection, chlorine, and other biological filters.

Rainwater harvesting in combination with biological treatment is a safe, healthy, and sustainable water solution.



During our rainwater harvesting projects we use our own educational materials. You can review these materials below: