Taanka

Rainwater or surface run-off from rooftops, courtyards, or artificially prepared catchments (locally called agor) flow into the tank through filtered inlets in the wall of the pit.

This shift is mainly due to dominant groups monopolizing or taking disproportionate shares of communal water, marginalizing the needs of poor and lower caste.

Such water harvesting structures have also been reported being built in other arid developing countries such as Botswana, Ghana, Kenya, Yemen, Sri Lanka, Thailand, and Indonesia.

The choice of Bikaner as an urban center seems to have been strongly influence by the availability of tracts of mudiya kanker, also known as murrum (मूरड़), a particular set of gravel and dirt which compacts easily when mike with water and possesses excellent run off characteristics.

This includes desilting the taanka cistern, sweeping the micro-catchment, and painting inlets and the outlet to keep the system in good working condition.

Periodic dosing with oxidizing agents, such as potassium permanganate, helps prevent the growth of microscopic organisms and the consequent development of bad taste, odor and color in the water.

At least a few centimetres of water should always be maintained in the taanka to ensure that the cistern walls remain moist, avoiding the development of cracks and other physical defects.

The water needs of the town were met by the innumerable tanks in and around Bikaner, together with the wells and taankas that each house traditionally built for harvesting rainwater from the roof tops.