Nano Dams: An introduction
A nanodam is a type of dam which is specifically built as a barrier to store water on the given river bed. Term 'nano' is used to signify smaller size of dam and smaller cost(fractional cost) to build and use compared to large dams. A 'nano gate' (water release gate) may be provided for complete water removal from nanodam. Water is stored to height of dam and excess water is allowed to overflow over the dam structure, avoiding flooding of surrounding area. Unlike regular dams, nanodams will not submerge adjacent lands. Water is stored to a height that will not overflow to adjacent lands and hence water encroachment of lands is avoided. Electricity generation is not explored as it economically unviable due to smaller quantity of water stored compared to a larger dam.
The idea of nanodams is to store as much water on ribver bed as possible using a blockade. This blockade is usually made of concrete material (other materials studied) along with a water discharge gate(nanogate). Overflow of water over the nanodam is allowed and considered normal in operation but overflow of water into adjacent area is not allowed by design. The height of the dam is kept lower than the adjacent surface area by around 15% to 30% depending on waterflow velocity characteristics and geographical area on zone of influence from the present nanodam.
Height of the dam starts from 10 feet and maximum height depends on the geographical surroundings and water storage that can be ahieved(financial investment needed vs water storage possible)..