2. The concept of rainwater catchment
systems technology is as old as the mountains - The history of rainwater
Rainwater harvesting has been a popular technique in many parts of the
world, especially in arid and semiarid regions (almost 30 % of the earth's
1). Rainwater harvesting was invented independently
in various parts of the world and on different continents thousands of
years ago. It was especially used and spread in semiarid areas where rainfall
occurs only during some months and at different locations.
I would like to illustrate this with some examples:
In the loess plateau of China (Ganzu Province), rainwater wells and jars
existed already two thousand years ago.
In India, a research project called the Dying Wisdom lists many traditional
experiences in rainwater harvesting from the different 15 environmental
zones of that country.
In Iran we find the Abanbars (Fig.
3), the traditional rainwater catchment systems for
2000 years ago an integrated rainwater management and runoff agriculture
existed in the Negev desert of Israel and Jordan.
As a representative of the Americas, I will say some words about the Pre-Columbian
practices of the Maya people in the Yucatan, Mexico. Mexico as a whole
is rich in ancient and traditional rainwater harvesting technologies (dating
back to the Aztecs and Mayas).
South of the city Oxkutzcab on the foot of the Puuc Mountain we can still
see the achievements of the Mayas. In the 10th century AD an integrated
agriculture based on rainwater harvesting existed in this region. The
people lived on the hillsides and their drinking water was provided by
20 to 45 thousand liters cisterns called Chultuns (Fig.2).
These cisterns had a diameter of more or less 5 m and
were excavated in the lime subsoil with a waterproof plaster. Above them
there was a ground catchment area of 100 to 200 m². In the valleys
other types of rainwater catchment systems were used such as Aguadas (artificially
dug rainwater reservoirs from 10 to 150 million liters) and Aquaditas
(small artificial reservoirs from 100 to 50 000 liters).
It is interesting to see that the aguadas and aguaditas were used to irrigate
fruit trees and/or forests and to provide water for the plantation of
vegetables and corn on small areas. Lots of water was stored, guaranteeing
water supply even during unexpected droughts. This is one example of integrated
water management and we can find many similar ones all over the world.