Alam Santi's Water Harvesting Design

The planet's fresh water supplies are limited, climate change is adding to periods of intense rain and subsequent drought and the structure of the earth’s subsurface is easily damaged if the water table is not able to remain relatively consistent or to be replenished. The installation of deep wells contributes to the lowering of the water table, impacting on plants and animal life and contributing to the occurrence of landslides.

The Alam Santi design team have been working with the UN, governments, businesses and local communities to design rainwater harvesting systems that can be used by everyone to help replenish natural fresh-water resources.


The team have worked out a system for both calculating the size of tank needed to store water, to remove debris and to filter the water itself, ready to store and deliver with a pump by demand. They recommend the use of traditional, corrugated steel cladding and a maximum roof length for optimal drainage. Their calculator for working out the size of the system needed per household or per building is easily adapted for different environments. Their design further specifies materials needed to build and install the system.

Alam Santi’s work makes recommendations for devices to reduce water use by adapting shower and tap heads and by installing specially designed toilets that extract urine with separate flushes for faeces or urine. The latter allows for water with diluted urine to be reused in irrigation and to add additional nutrients to plants.

Combined with simple technology (like perforated bamboo pipes inserted next to trees and plants to ensure water reaches their roots directly) and landscaping and storm drains designed to capture and use any water run-off,  the planet’s limited freshwater supplies can be conserved and used most effectively.


  • Heightening public awareness of the water they use and the difference they are able to make

  • Ensuring water is more equitably shared and available for all sections of the population

  • Enabling people to reuse and recycle water in order to cultivate gardens and produce their own food


  • Prevents the desertification of land caused by lowering the water table through excessive drilling of wells

  • Limits the landslides caused when the water table is unable to be replenished

  • Provides irrigation (and urine fed irrigation) for plants and vegetables avoiding excessive use of pesticides or GM crops


How can water harvesting deepen human relationships with natural systems?

Water harvesting, at individual household, community, or state level brings