Bharathapuzha
The Bharathapuzha river is the second longest West Flowing River that drains into the Arabian Sea in Kerala State. This basin is bounded in the East by the Cauvery basin, in the West by the Arabian Sea. The basin lies approximately between 100 26' and 110 13' North latitudes and 750 53' to 770 13' East longitudes. Its drainage area is 6,186 sq.km spread over the two states namely Tamil Nadu and Kerala. The basin is elongated in shape and finds its outlet into the Arabian Sea. There are five Hydrological Observation Stations on this river maintained by CWC i.e at Kumbidi, Pulamanthole, Mankara, Pudur & Amabarampalayam.
The Total drainage area of the basin is 6,186 sq. km out of which nearly 71% lies in the Kerala State. The State wise distribution of the drainage area is given below:
1. Tamil Nadu - 1,786 sq km (29%)
2. Kerala - 4,400 sq km (71%)
The Bharathapuzha or Ponnani river as it is called in the lower reaches, rises in the Eastern slopes of Anamalai hills of the Western Ghats at an elevation of 2,250 m above MSL and flows in the North-Westerly direction in Pollachi taluk of Coimbatore district in Tamil Nadu State. On its 45th km. run from its origin, it is joined by a tributary namely, the Palar on its right bank. Traversing another 15 km Westward, it enters the Palghat district of Kerala State through the Palghat gap. At its 100th km run, it is jointed by the Kalpathipuzha on the right bank. Traversing another 109 km. in the Westward direction through Palghat and Malapuram districts, it finally discharges into the Arabian Sea near Ponnani town. The total length of the river from its origin to out fall is about 209 km and drains a total area of 6,186 sq km. The upper reaches of the river is called as the Aliyar. When it enters Kerala, it is called as the Kannadipuzha till it meets the Kalpathipuzha. After confluence with the Kalpathipuzha, it is known as Bharathapuzha or Ponnani river. It is joined by the Gayathripuzha on the left bank and the Pulanthode on the right bank as it flows down to the Arabian Sea. It also receives a large number of small streams and rivulets.
The Gayathripuzha, the Kalpathipuzha and the Pulanthode, are the three important tributaries. All the three tributaries rise in the Western slopes of the different ranges of the Western Ghats and drains a major parts of the Palghat, Trichur and Malapuram districts.
The Bharathapuzha basin receives copious rainfall during the South West monsoon and it lies in the rain shed region of the Western Ghats. The rainfall varies from 2,000 to 2,800mm in the hilly region to 3,000mm in the coastal region. Since, the basin is located in tropical region, the temperature varies with the season.
At present there are 13 completed structures either reservoirs or weirs in the Bharathapuzha catchment out of which there are three important structures namely the Aliyar reservoir, Tirumurthi reservoir and Malampuzha reservoir.
