The construction of regulator and head sluices for North Rajan Channel across the Coleroon in Athanur–Kumaramangalam villages in Nagapattinam district has come as a boon to farmers and alleviates water scarcity in the district.
Nearly 100 cusecs from lower anaicut is passing through this river during the storage period of minimum four months. Taking into account this factor, 1,037 mcft is lost as the water passes through the river for four months.
If this water could be stored to a height of 3.05 m by installing a regulator, there is a wide scope that this water could be utilised for the stabilisation of existing ayacuts of South Rajan channel. Further, there is a possibility to increase the groundwater potential between lower and the proposed regulator for a stretch of 11.25 ms. The stored water in this regulator may be useful for the infiltration wells of TWAD Board above the lower anaicut indirectly.
Collector T. Munusamy told The Hindu that the Coleroon carries surplus water discharged from Mettur dam and carries the surplus water from the tributaries of Cauvery.
The right bank of the proposed regulator is situated in Kuaramangalam hamlet of Thiruchitrambalam village in Myladuthurai taluk in Nagapattinam district.
The proposed regulator has to be designed to discharge the original designed capacity of lower anaicut is 4,50,000 cusecs against 3,35,015 cusecs for 15 years. This year during August 2013 the observed flood discharge in the lower anaicut was 2,15,414 cusecs, said the Collector.
In connection with South Rajan Channel in Nagapattinam a storage level of proposed regulator is plus 13.050 m. A quantity of 400 mcft of water had been proposed to be discharged from this regulator into this channel towards stabilisation of the existing ayacuts. For this, a head sluice had been designed at the right flank of the regulator at the right bank of the Coleroon.
The sill level of the head sluices is proposed as plus 11.700 m. The existing bed level of the North Rajan channel (Cuddalore) is plus 11.090 at the proposed site.
A quantity of 200 cusecs has been designed to be discharged to the existing channel for a period of 23 days. For this head sluice, two vents have been designed for a size of 2.1x0.90 m. This will ensure irrigation of the existing ayacut of 10,000 acres of South Rajan channel. Further, there is an advantage of increased groundwater potential because of this storage spring water, according to PWD sources (Planning and Design Division).
The discharge of water from lower anaicut has been unused and goes to the sea as waste. The stored water of 900 mcft could be used for the stabilisation of existing ayacuts on South Rajan and for the benefit of 26,089 acres.
However, farmers had expressed their skepticism over the implementation of the project as the Chief Minister had announced the dredging and the renovation of A class channels at the cost of Rs. 1,536 crore. But the scheme was still in paper but yet to take off.
Hence, the Government would now implement the Rs. 400 crore project (Coleroon) for the benefit of farmers and for other multi-purposes, said district secretary of All India Kisan Sabha V. Subramanian.
However, the ultimate aim was to the quantum of water stored in Lower anaicut could effectively be taken into Veeranam tank through Vadavar from Lower anaicut thereby this scheme becomes an advantage for the new Veeranam scheme which was a resource for Chennai drinking water supply, said the Public Works Department official sources in Nagapattinam.
