Integrated Water Management Scheme — A Case Study of North Karanpura Super Thermal Power Project

NTPC LTD., Noida, India

Abstract: North Karanpura Super Thermal Power Project (NKSTPP) with capacity of 3x660 MW is located in the Chatra District of Jharkhand, India. Water for North Karanpura STPP would require a sustained/continuous water supply from nearby available sources. Only available source in vicinity is river Garhi, which is rain fed and remains dry in non-monsoon periods. However, sufficient volume of Garhi river discharge, meeting the annual Plant demand of make-up water is available during the monsoon period. Initially, without Air Cooled Condensers (ACCs) total water required was about 55 MCM and to fulfill this huge water requirements of plant, dam of height 22.5 m and 1830 m length was envisaged. This required land acquisition to the tune of 5000 acres, including submergence of forest/fertile land and rehabilitation of some villages. To avoid the resettlement of villages and acquisition of forest/fertile land, an alternative scheme was worked out. In the present scheme, arrangement for lifting of water by pumping from river Garhi during monsoon period with storage facilities (raw water reservoir) in the plant area is envisaged. To reduce water requirement of power plant, power plant is now proposed with ACCs, thereby reducing water requirement to about 20 MCM. The present integrated scheme involves construction of a 6 m high and 121 m long barrage across river Garhi, with associated make up water pump house & pipeline of about 2.0 kms. length and raw water reservoir spread over 800 acres. The raw water reservoir inside the plant boundary has been designed to cater to the water requirements of non-monsoon period of nine months. During monsoon period of three months reservoir will store and also function as buffer & online supply to power plant. The low height barrage has been planned within the river regime and without acquiring any land. To avoid submergence of nearby Tandwa village and private fertile land on both sides of river even during flood peaks, the embankment as well as abutment wall of length of about 1.0 km. on both sides of banks has been provided. The Intake pump house has been provided at 100 m u/s of barrage for pumping the monsoon water from the river into raw water reservoir. The barrage control room building is planned to be constructed above the piers of the barrage. To avoid the seepage from the raw water reservoir 1 mm thick HDPE liner, geo-textile and 75 mm thick PCC at the bed and inside slopes of reservoir has been provided. The maximum height of reservoir embankment is 12.0 m and side slopes are 1V:2.5H. In this paper, integrated water management studies have been carried out for fulfilling the water requirement of North Karanpura STPP, thereby saving the resettlement of ten villages & about 220 nos. of families displaced and acquisition of about 5000 acres of fertile/forest land. This is a true example of sustainable development without using existing resources and using untapped monsoon flows.