A New Project for Augmenting Drinking Water Supply to Chennai City by forming new Reservoir near Kannankottai and Thervaikandigai, Thiruvallur District, Tamilnadu � An Alternative Efficient & Cost effective proposal

Abstract

Objectives: Since the present storage capacity of drinking water by four reservoirs (Poondi, Chembarambakkam, Red Hills & Cholavaram) is only about 11 TMC, there is an urgent necessity to create additional storage facilities. A new project by taking an open canal from Krishna Water Canal, storing the same in the proposed two tank - reservoir and again pumping into Krishna Water canal, leading to the existing Poondi Reservoir is now implemented by TN Public Works Department. Methods/Statistical Analysis: By inadequacy in studying all other alternate measures available, Government of Tamilnadu officials embarked upon in creating a new reservoir of 0.5+0.5TMC (2 fillings) storage capacity-by converting 2 existing tanks, namely Kannankottai and Thervai Kandigai near Uthukkottai in Thiruvallur district at an estimated cost of Rs.330 Crores, including Rs.160 Crores towards land acquisition. Again, by a bad planning, this new reservoir water is initially taken from Krishna Water canal at +2200m and again pumped into the same canal at LS +3850m –which flows another 21.425KM to reach the Poondi Reservoir. It causes considerable quantity loss of precious drinking water by evaporation, seepage and illegal pumping en-route besides causing pollution of drinking water. Findings: This research paper analyses the deficiencies in the above Government sponsored project proposals and suggests 3 alternative efficient and cost effective proposals without involving land acquisition, no loss of water as well as no pollution for implementation in the best interest of the stakeholders, taking all the field realities into account. The proposal of Water Resources Organization, TNPWD does not actually create additional storage except an intermediate transit point. Further it does not increase the storage capacity after spending Rs.330+Rs.100Crores. Instead, the deepening the Poondi Reservoir by 1.00m depth creates an additional storage of about 1.152TMC at cost of Rs.198.85Crores only. Alternatively it is further suggested that if an off take canal from KW canal at LS + 2200m is taken – by closed RC concrete pipes directly to nearby Red Hills Reservoir it cost about Rs.280.23 Crores without land acquisition, thereby reducing the cost of transporting water from Poondi Reservoir to Red Hills tank (P2). Improvements: By these alternative proposals, time and cost over run towards implementation of the project is reduced very much besides elimination of evaporation loss and pollution of drinking water en-route. Keywords: Bulk waterdrawal by RC Concrete Pipes, Drinking Water Supply, Open Canal.