| Shimsha River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | India |
| Subdivision Type2: | State |
| Subdivision Name2: | Karnataka |
| Length: | 221km (137miles)approx. |
| Source1: | Devarayanadurga hills |
| Source1 Location: | Tumkur, Karnataka, India |
| Mouth: | Kaveri River |
| Mouth Location: | Chamarajanagar, India |
| Mouth Coordinates: | 12.3112°N 77.2383°W |
Shimsha is a river that flows in the state of Karnataka, India. It is one of the tributaries of the river Kaveri, which is one of the major rivers of South India. The river originates in the southern part of the Devarayanadurga hill in the Tumkur district of Karnataka and flows for about 221km (137miles). before joining the river Kaveri.[1]
Markonahalli Dam is a dam built across the river Shimsha in the Kunigal Taluk of Tumkur district. It was built by Krishnaraja Wodeyar IV, the king of Mysore under the guidance of his Diwan, Sir M Visweswaraiah.[3] It was built to irrigate 6070 hectares of land and has a masonry structure of 139 m and a pair of earth dams extending to 1470 metres on either side. The reservoir has a catchment area of 4103km² and can hold a volume of 68000000m2 of water at a full reservoir level of 731.57 m above the mean sea level.[4] 27 species of fish, including 13 species of commercial fishes have been recorded in the reservoir with Puntius being the dominant species of fish found here. Cirrhinus reba and Labeo calbasu and other transplanted carps are also found here. However, the maintenance of the dam has been poor. In 2000, a part of the dam had to be demolished to prevent floods and save 25 villages.[3] Water started overflowing the dam and only 1 crest gate could be opened. Nearly 150 feet of the dam was demolished to allow excess water to flow out.[3]
Shimsha has a waterfall at Shimshapura in Malavalli Taluk. This is also the location of the Shimsha Hydro Electric Project which has an installed capacity of 17,200 kilowatts. It was the first ever hydro electric project in Asia. Kolar Gold Fields was supplied with the electricity generated in 1902.Three years later Bangalore was electrified. The foundation stone for this project was laid by Krishnaraja Wodeyar IV, the king of Mysore.[5]
The sand found on the river bed of the Shimsha river is mined and used for construction activities, sometimes illegally. Due to the environmental issues that can be caused by sand mining, this activity is currently banned.[6]
Discharge of waste from towns and cities on the way are major contributors to pollution in the Shimsha. However, the Government is trying to clean up the river and has released funds for the same.[7]
In 1897, a railway bridge over this river collapsed during a heavy flood, killing about 150 passengers.