Chiapas Rainwater

(This is part of a five project series on HSU Chiapas 2010 started here)

Part of rainwater team building a system in a community near Acteal.

Rain.  Coming back from a summer in Mexico, everyone expects me to be tanner. Like other assumptions about a country as big and diverse as Mexico, not necessary so…  San Cristobal de las Casas was gorgeous.  San Cristobal was interesting.  San Cristobal had great coffee, chocolate, people, languages, music and fun.  San Cristobal was not that sunny… in fact, it rained about an inch per week during the five weeks of Appropriate Technology classes. There is a dry season, we just weren’t there for it.  The rain is enjoyable, but the waterborne and foodborne illnesses that affect many (including me and the students) are not. It was in that context that we were so excited to have one of the five projects for the Humboldt State University – Chiapas 2010, full immersion in Spanish and Appropriate Technology, summer abroad program be rainwater catchment systems.
Rainwater Catchment At A Glance
Description: Catching rainwater (often before it hits the ground), filtering and storing it for future use.
Inputs: rain
Outputs: Usable, potable if filtered, water
Improvements: reduced run-off and erosion, increased access to clean water, reduced time spent collecting and transporting water, reduced mosquito breeding areas near home

The whole rainwater catchment team building in Chiapas.

A team of four students collaborated with local designers and community members to build three systems: one with the appropriate technology demonstration home of Juan Hidalgo in San Cristobal and two with a community near Acteal. The student designers went through a few iterations at the demo house, testing and finding leaks, until they got it right. They then used that information to design and build the systems with the more rural community.  They also worked with Otros Mundos to start the construction of two 20,000 liter ferrocement tanks for storage.  Here is their rainwater system documentation in English and Spanish.  Here is some of the needed math for design.
Their innovations:
  • Using a first flush in Chiapas (I haven’t seen it other places here)
  • Using a PVC cap with one hole drilled high (for drainage and a cord for removing it) as the drain of the first flush. Having this hole high on the end-cap of a 90 degree elbow will keep it from plugging soon and keep the spray away from the house and into a bucket for reuse.
  • Using used vegetable oil to protect the wood supports.
  • Using costales (earth bags) for the base of one system.
  • Using tamped sand, instead of concrete, for the supports of one system.
  • Using wire to keep bent roofing metal in a channel shape.
Next steps:
  • Finish the ferrocement tanks in the community.
  • Revisit the systems in one year to see what went wrong.
  • Innovate!
  • Build a database of local rainwater systems (see image) and feedbacks.
  • Re-Innovate!
  • Workshops and community meetings on rainwater collection and water in general.
different (and probably better) way to use PVC with Rainwater Catchment
*This image is not our rainwater system, but it is the coolest way I have seen PVC used as a gutter (which is usually a big pain and doesn’t work all that well). We are going to try out this system at Otros Mundos.  In this image, Tania and Claudia are assessing its construction.  Now take that system and get a first flush on it and you’d probably have one great system!

Chiapas Rainwater

(This is part of a five project series on HSU Chiapas 2010 started here)

Part of rainwater team building a system in a community near Acteal.

Rain.  Coming back from a summer in Mexico, everyone expects me to be tanner. Like other assumptions about a country as big and diverse as Mexico, not necessary so…  San Cristobal de las Casas was gorgeous.  San Cristobal was interesting.  San Cristobal had great coffee, chocolate, people, languages, music and fun.  San Cristobal was not that sunny… in fact, it rained about an inch per week during the five weeks of Appropriate Technology classes. There is a dry season, we just weren’t there for it.  The rain is enjoyable, but the waterborne and foodborne illnesses that affect many (including me and the students) are not. It was in that context that we were so excited to have one of the five projects for the Humboldt State University – Chiapas 2010, full immersion in Spanish and Appropriate Technology, summer abroad program be rainwater catchment systems.
Rainwater Catchment At A Glance
Description: Catching rainwater (often before it hits the ground), filtering and storing it for future use.
Inputs: rain
Outputs: Usable, potable if filtered, water
Improvements: reduced run-off and erosion, increased access to clean water, reduced time spent collecting and transporting water, reduced mosquito breeding areas near home

The whole rainwater catchment team building in Chiapas.

A team of four students collaborated with local designers and community members to build three systems: one with the appropriate technology demonstration home of Juan Hidalgo in San Cristobal and two with a community near Acteal. The student designers went through a few iterations at the demo house, testing and finding leaks, until they got it right. They then used that information to design and build the systems with the more rural community.  They also worked with Otros Mundos to start the construction of two 20,000 liter ferrocement tanks for storage.  Here is their rainwater system documentation in English and Spanish.  Here is some of the needed math for design.
Their innovations:
  • Using a first flush in Chiapas (I haven’t seen it other places here)
  • Using a PVC cap with one hole drilled high (for drainage and a cord for removing it) as the drain of the first flush. Having this hole high on the end-cap of a 90 degree elbow will keep it from plugging soon and keep the spray away from the house and into a bucket for reuse.
  • Using used vegetable oil to protect the wood supports.
  • Using costales (earth bags) for the base of one system.
  • Using tamped sand, instead of concrete, for the supports of one system.
  • Using wire to keep bent roofing metal in a channel shape.
Next steps:
  • Finish the ferrocement tanks in the community.
  • Revisit the systems in one year to see what went wrong.
  • Innovate!
  • Build a database of local rainwater systems (see image) and feedbacks.
  • Re-Innovate!
  • Workshops and community meetings on rainwater collection and water in general.
different (and probably better) way to use PVC with Rainwater Catchment
*This image is not our rainwater system, but it is the coolest way I have seen PVC used as a gutter (which is usually a big pain and doesn’t work all that well). We are going to try out this system at Otros Mundos.  In this image, Tania and Claudia are assessing its construction.  Now take that system and get a first flush on it and you’d probably have one great system!

HSU Chiapas 2010 Follow-up


A monument to the December 22, 1997 Masacre in Acteal

After the Zapatista armed uprising in Chiapas during the 1990’s, you may find it surprising that the Humboldt State University, Spanish and Appropriate Technology, summer abroad program had to move from Coahuila in Northern Mexico to Chiapas in Southern Mexico for safety reasons.  Yet, that is where we found ourselves this year… with the drug war ravaging much of Northern Mexico we were unable to return to our friends, colleagues and projects in the beautiful oasis town of Parras de la Fuente, Coahuila, Mexico.

For those same safety reasons, after four consecutive years, we had cancelled the 2009 program completely. This year we moved it to the ethereal San Cristobal de las Casas and surrounding villages in Chiapas, Mexico. This summer’s projects were very exciting. Thanks, in large part, to the great organizations we worked with, especially our incredible project and community liaison – Otros Mundos.
Over the next two weeks, I will share the inputs, outputs, improvements, innovations and learnings from each of the following HSU Chiapas 2010 projects:
  • Improved cookstoves
  • Microhydro feasibility study
  • Windbelts
  • A biodigester
  • Rainwater catchment systems

some of the HSU Chiapas 2010 students studying microhydro