Water – a scarce resource

On Monday morning I took the plane back to Mexico City to follow up on my other duties as running our solar water heater company kessel-solar.com.

Now that we are building the walls of the HackShack we must fit in the water piping and detail our water treatment system.

The dessertic climate of Baja California Sur provides very little rainfall (average of 25 mm / year) and water is very salty and scarce. So water management becomes here the biggest challenge in building an autonomous house for 4 persons. This is how we approached the challenge:

For housing normally you count 100 ldp (liters per day per person) and they split approx. into:

  • 40 l for flushing the toilet
  • 40 l for showering
  • 10 l for laundry*
  • 5 l for dish washing
  • 3 l for cooking
  • 2 l for drinking water

– To eliminate the 40 liters required for flushing, we decided to implement a dry toilet (more details in a future blog entry)

– To reduce the 40 liters required to shower and the 10 liters for the laundry, we implement a grey water recycling system with slow sand filter. This means that all soapy water from the shower, the bathroom sink and the laundry machine will be filtered and re-injected into the water circuit. So in other words you will shower several time with the same water. Of course each timer filtered and processed!

With this measures we estimate to reduce the daily water consumption from 100 liters to 15-20 liters per day person.

Now these are all theoretically estimated numbers. I am excited to build this system and test how far off we will be in reality. Challenge accepted! 🙂

The water recycling is an adapted copy of the SELF container developed at EMPA in Switzerland. The Ecocapsule concept also inspired the work for autonomous housing.

*(daily average, assuming 1 laundry per person per week)

by the way: the title picture is Reschensee… 😉

3 thoughts on “Water – a scarce resource

  1. Pingback: Hack Shack Toilet – Sam's Hack Shack

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