Rajasthan’s 600 year old rainwater harvesting step wells

The monsoon used to fill the streets up to the high cement terraces of the shops and temples. They were built that high to evade the floods, but the connected buildings also create a channel for the water. There are more than 86 baoris (tanks) in Bundi (Rajasthan, India), sprinkled across the hillsides and down the valley floor. (This number according to the guard at a baori maintained by the national archaeological service; a shopkeeper estimated the number at ‘more than 50’.) When the rain comes, the baoris fill up, first one, then the next one down. The streets channeled the overflow from one tank into the next.

The baoris, or stepwells, are huge. The deepest is 46 m deep. They are also temples.

When I visited in early June, a month before the monsoon, all of the baoris were dry. But according to Bundi natives tk names, as recently as 20 years ago the baoris held water through the dry season. Twenty years ago, the government installed deep wells to provide water for agriculture and municipal supply, and the water table dropped. This change suggests that baoris tapped into groundwater aquifers, recharging them with rain (and raising the water table) during the rainy season, then providing a way for water carriers to chase the receding water during the dry. Thus each baori held much more water than the tank alone–it was, indeed, a well.

The baoris are not merely tanks, but also groundwater recharge facilities. This makes me think that their dtheirs governed by the depth to an aquifer. In addition to the baories, several wide, shallow kunds, or reservoirs, catch and infiltrate rainwater. tk name lies just above the fortification wall of the 16th century city, at the bottom of an alluvial valley. The lake is now silted in, and during the dry season serves as a grazing commons and watering hole for livestock.

Borewells and a piped-water system bring water to Bundi today (in the past, water carriers filled skins at the baoris and brought water door to door by water buffalo). The baoris, though neglected as wells, still put rain back into the aquifer.

In recent years, the government of India and various NGOs have begun repairing old rainwater harvesting structures in Rajasthan and building new ones. But these projects have so far failed to recharge enough rainwater to keep water in the baoris through the dry season.

For more information on rainwater harvesting in Rajasthan, see this paper: http://www.iwmi.cgiar.org/Publications/Working_Papers/working/WOR104.pdf

sample quote: “Bawaris [baoris]. . .are essentially sweet water aquifers getting regular heavy recharge [from rainfall and runoff]. . . .Upkeep, renovation, and minor repair of damaged structures, desiltation and detoxification of polluted water an rehabilitation of the catchments of existing structures would provide 4.4 million cubic meters of water [annually] for the benefit of a (mostly urban) population of about 336,000 during drought periods.”

see “pages” for more photos.

20110618-122832.jpg

20110618-122915.jpg

Advertisements

~ by waterunderground on June 18, 2011.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

 
%d bloggers like this: