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 and El Maíz Más Pequeño ran a workshop to construct a ferro-cement rainwater harvesting cistern at Bachillerato SABES Cerritos school in Guanajuato, over 5 days in February 2017. The project was an initiative of a group of eight female students, who proposed the project as an alternative solution for access to water at the school.

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: