Envis Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Friday, April 19, 2024

Karamana

  

Basin area, km2

:

702

Basin area in Kerala State, km2

:

702

District of Kerala in which basin are located

:

Thiruvananthapuram

Origin of River

:

Nedumangad Hills Elevation.m : 1860

Length of main stream, km

:

68

Main tributaries

:

Kaviar, Attaiar,Vaiyapadiar, Todiyar

Average annual rainfall, mm

:

2600

Average annual streamflow, Mm3

:

836

Important rainguage stations marked on the map (with code numbers)

:

1.     Kovalam (1)

2.     Nedumangad (2)

3.     Thiruvananthapuram OBS (3)

4.     Thiruvananthapuram Aerodrome(4)

5.     Thumba (5)

6.     Vellayani (6)

Important discharge stations marked on the map (with code numbers)

:

1.     Aryanad (1)

2.     Karamana (2)

Water requirement for wetland for three crops, Mm3

:

343

Water requirement for gardenland , Mm3

:

123

Water requirement for domestic use (2021 AD), Mm3

:

106.8

Water requirement for industrial use  (2021 AD), Mm3 

:

45

 

(Note: The river flows 68 km westward and merges into the Arabian Sea at Thiruvallom-Karumam area near Kovalam. The river gets its name from Karamana, a suburb of Trivandrum city, through which it flows. The Karamana river has the distinction of having two dams on it despite its relatively short length. These are the Peppara Dam meant for irrigation on the upper reach of the river, and the Aruvikkara Dam, meant for irrigation as well as drinking water supply to the city of Trivandrum. The Karamana river has several bridges across it. The largest is at Karamana itself, where the NH-47 crosses it. Other important bridges are at Thrikkunnapuram, Mangattu Kadavu, Kundamon Kadavu, Vellaikadavu, Aruvikkara (on the dam), Maruthoor kadavu, Aryanad and a low bridge near Malamukal. The latter makes the river unusable for navigation. Some of the bridges provide spectacular views of the river. It is reported that, in 1820, the Karamana river was diverted from its original location at Karamana to the present location in order to facilitate the construction of a bridge at the current location.)