Then, it became a sort of religious duty for wealthy and powerful people
to excavate "tanks" --reservoirs-- and erect stone dams. The resulting lakes
grew to very large sizes.They were generally named after the person who funded
them.
Generally the heavy downpour simply flows away in innumerable small rivulets. Prehistoric man (megalithic culture) in these parts discovered that by blocking the little streams, small reservoirs of water could be made, which retained water for a few months beyond the rainy season.
This dam making continued for ages, and in the medieval times this hydraulic activity increased with the plentiful supply of iron tools .
Then, it became a sort of religious duty for wealthy and powerful people
to excavate "tanks" --reservoirs-- and erect stone dams. The resulting lakes
grew to very large sizes.They were generally named after the person who funded
them.
Thus in the 11th century a.d. a feudal baron called Rudra Reddi gave a major part of his plunder towards the construction of a long stone dam and a canal system. The resulting very large lake was called Rudra Sagar or sea of Rudra.
In a place where summer could be arid, this was naturally a boon to all animals. The large Pakhal lake in Warangal district was formed in this way and is a nature reserve.
When the sluices are opened to let the water out in dry times, farmers appreciate and still remember the good ideas of Rudra Reddi... eight hundred years after.
There are many such lakes formed by this manner, some very large. The lake called Husain Sagar in the middle of the city of Hyderabad too is an example.These artificial reservoirs are seen along the course of almost every rivulet, and in satellite photographs a characteristic pattern can be seen. By keeping the land moist long after the rainy season, lush crops can be raised in an otherwise rather dry and arid land. Lately, hardy species of fish like tilapia have been successfully bred in these reservoirs.
Telangana is aptly called the "land of the innumerable tanks" .