18-04-2014, 04:09 PM
Every Drop Counts
Every Drop.pptx (Size: 674.98 KB / Downloads: 14)
Water Harvesting Structures
Urban/rural water harvesting structures:
Tankas, Nadis, Talabs, Bavdis, Tanks, Rapats, Kuis, Virdas
Rural water harvesting structures:
Kunds, khadins
Nadis, Talabs, Lakes
Nadis
Natural surface depression which receives rain water from different directions
They receive their water supply from erratic, torrential rainfall.
Can lead to heavy sedimentation and siltation
Trees can prevent some of this
Dredging out the sediment before monsoon can also help
Can lose water by evaporation
Talabs, lakes are similar
Jhalara
Human-made tanks, found in Rajasthan and Gujarat
Essentially meant for community use and for religious rites.
Often rectangular in design, jhalaras have steps on three or four sides. The steps are built on a series of levels .
The jhalaras collect subterranean seepage of a talab or a lake located upstream .
Tanka
Tankas (small tank) are underground tanks, found traditionally in most Bikaner houses.
Built in the main house or in the courtyard.
Circular holes made in the ground, lined with fine polished lime, in which rainwater was collected.
Tankas were often beautifully decorated with tiles, which helped to keep the water cool. The water was used only for drinking.
Kunds
Covered underground tank, developed primarily for tackling drinking water problems.
Usually constructed with local materials or cement, kunds were more prevalent in regions where groundwater is saline.
Before the onset of rains every year, meticulous care was taken to clean up the catchment of the kunds.
Cattle grazing and entry with shoes into the catchment area of the kunds was strictly prohibited.
The proximity of a kund to the house or village saved time and effort in searching for drinking water.
Importance of Water Harvesting
Traditional water harvesting systems have withstood the test of time
The city of Jodhpur, even though several hundred years old and right in the middle of a desert, has never been evacuated for lack of water.
The traditional water harvesting systems worked even in droughts when piped water supply failed
Om Thanvi, a Rajasthan journalist found over a 45-day survey that
In villages where traditional water systems were maintained and used, there was no scarcity of drinking water even during times of drought
In villages which relied purely on piped supply, the drying up of the Rajasthan canal meant an acute water crisis
Motivations for water harvesting
India too diverse for dams
Working examples
Modern technology potentially lead to regression
Water crucial in India (50% people will suffer from lack of drinking water)