|Sharavathi is a river which originates and flows entirely within the state of Karnataka in India. It is one of the few westward flowing rivers of India and a major part of the river basin lies in the Western Ghats. The famous Jog Falls are formed by this river. The river itself and the region around it are rich in biodiversity and are home to many rare species of flora and fauna. |
The river Sharavathi originates at a place called Ambutheertha in the Thirthahalli taluk of Shimoga district. According to a legend of the times of Ramayana, this is the place where the Hindu God Rama broke a bow to win the hand of Sita The total length of the river is around 128 km and it joins the Arabian Sea at Honnavar near Uttara Kannada district.  On its way, the Sharavathi forms the Jog Falls where the river falls from a height of 253 mts. The river is dammed at Linganamakki and the portion of the river above the dam is upstream and the remaining is downstream. The major tributaries of the river are Nandihole, Haridravathi, Mavinahole, Hilkunji, Yennehole, Hurlihole, and Nagodihole. Sharavathi river basin falls into two districts of Karnataka namely Uttara Kannada and Shimoga. The upstream river basin is extended to two taluks in Shimoga viz. Hosanagara and Sagara. The entire basin has an area of 2985.66 km². with upstream being 1988.99 km². and the downstream being 996.67 km².
The river basin mainly consists of Pre-Cambrian rocks. The two major groups of rocks found in the Sharavathi river basin are the Dharwar system and the peninsular gneiss.
* The Dharwar system: This system contains metamorphic rocks that are considered to be among the oldest in India. These rocks are derived from ancient sediments like conglomerates, ferruginous quartzites, greywackes, schists and limestones. They are rich in iron and manganese.
* Peninsular gneiss: These are crystalline rocks and are made up of granite, granodiorite, granito-gneiss, migmatite etc.
Soils in the Sharavathi basin are mainly lateritic in origin and tend to be acidic and reddish to brownish in colour. The various type of soil found here are clay loamy, clayey, clayey-skeletal, and loamy.  Four soil orders are found in the upstream river basin viz. ultisols, alfisols, inceptisols and entisols.
Jog Falls:- Jog Falls is the 11th highest waterfall in India. The Sharavathi river plunges 253 metres into a deep gorge here in four different segments called as Raja, Roarer, Rocket and Rani. The volume of water that reaches Jog Falls is controlled upstream by the Linganamakki dam and the falls are at their mightiest when water is released from the dam.
Flora and fauna:- The Sharavathi river basin is rich in biodiversity. In a survey conducted in the basin, 23 amphibians belonging to the families of Bufonidae, Ichthyophiidae, Microhylidae, Ranidae and Rhacophoridae were recorded. Out of these 23 amphibians, 15 species are endemic to the Western Ghats. The river lends its name to the following species of fish that have been discovered in its waters:
* Batasio sharavatiensis: A bagrid catfish discovered near Jog Falls, Uttara Kannada district.
* Schistura sharavathiensis: A fish species discovered in Sharavathi river near Algod, Shimoga district.
Sharavathi Valley Wildlife Sanctuary:- A part of the Sharavathi river basin was declared as a wildlife sanctuary on 20 April 1972. Spread over an area of 431.23 km²., it has dense evergreen and semi-evergreen forests. Linganamakki reservoir spread over an area of 128.7 km². is a part of this sanctuary. The remaining area has been divided into core zone (74.33 km².), buffer zone (170.67 km²) and tourism zone (57.53 km².). The altitude in the sanctuary varies from 94 to 1102 mts, the highest point being Devarakonda on the southern edge of the sanctuary. Temperatures range from 15° to 38 °C and mean annual rainfall is 4500 mm.
Flora:- The sanctuary has mainly evergreen, semi-green and some moist deciduous forests. Trees in the evergreen forest include species such as Dipterocarpus indicus, Calophyllum tomentosum, Machilus macrantha, Caryota urens and Aporosa lindleyana.  In the semi-evergreen and moist deciduous forests, common species include Lagerstroemia lanceolata, Hopea parviflora, Dalbergia latifolia, Dillenia pentagyna, Careya arborea, Emblica officinalis, Randia sp., Terminalia sp. and Vitex altissima.
Fauna:- The sanctuary is a refuge of the endangered Lion-tailed macaque. Other mammals include tiger, leopard (black panther), wild dog, jackal, sloth bear, spotted deer, sambar, barking deer, mouse deer, wild pig, common langur, bonnet macaque, Malabar giant squirrel, giant flying squirrel, porcupine, otter and pangolin. Reptiles include king cobra, python, rat snake, crocodile and monitor lizard. Some of the avian species found in the sanctuary include three species of hornbill, paradise flycatcher, racket-tailed drongo, blue-throated barbet and Indian lories and lorikeets.