The commissioning of Ranjit Sagar Dam is a part of the overall plan for optimal utilization of waters of three eastern rivers namely: the Satluj, the Beas and the Ravi. The exclusive water rights have been given to India as per Indus Water Treaty signed between India and Pakistan in 1960 under the aegis of World Bank. Ranjit Sagar Dam Project (RSDP) is one the largest multi-purpose project completed on river Ravi about 24 km upstream of Madhopur Headworks in district Gurdaspur of Punjab State. It is located near the village of Thein (approximate latitude: 32° -26'-30” N and longitude: 75°-43'-30” E). The Government headed by Sardar Prakash, the then Chief Minister of Punjab, signed inter-state agreements between Punjab and Jammu-Kashmir and between and Himachal Pradesh in 1979. Ranjit Sagar Dam comprises of 160m high earthen dam, massive concrete spillway and 600MW (4 units of 150MW each) Power Plants. This is the only Project in the country, which has been executed departmentally, in recent times, on the pattern of Bhakra and Beas Projects. All the civil works including power plant building have been executed by Punjab Irrigation Department and Punjab State Electricity Board (PSEB) has erected the mechanical/ electrical installations of Power Plant.
The site of Thein Dam came under consideration in 1912 for the first time. A committee headed by Mr. Willey in 1926-27 inspected it. Up to 1954 nothing substantial was done except site inspections by geologists. In 1957, a project report was formulated by Irrigation branch of PWD, Punjab. Another DPR envisaging a multipurpose scheme was prepared in 1964. It was eventually decided in October 1977 to start construction work on project. Finally Govt. of India approved the project in 1982 execution of this Project commenced in right earnest in November 1985 and the Project was included in the Seventh Five Year Plan with provision of Rs 500 crore.
The estimated cost of project according June 2000 price index is 3800 crore. Generation of power from Ranjit Sagar Dam Power Plant commenced in August 2000.
River Ravi is one of the five major Rivers of Indus basin and it originates from the Dhaula Dhar ranges in Himachal Pradesh. Its circuitous route of about 730 km falls in HP and Punjab. After reaching plains of Punjab, it crossed international boundary into Pakistan about 26km downstream of Amritsar district. The monsoon run-off of Ravi is flashy and could not be utilized in the absence of a storage dam on its course.
The run-off flows down to the river Ravi and goes waste besides creating havoc and damages to the land through flooding and erosion in the districts of Gurdaspur and Amritsar. Therefore an immediate necessity for construction of storage dam on river Ravi was felt to utilize Hydroelectric and irrigation potential contained in it.
Henceforth with the completion of RSDP about 2500 million cubic meters of water, which was earlier being wasted, every year to Pakistan below Madhopur headworks would now be utilized in the service of the people.
1.2 Need for tunnels
As per schematic program, construction of diversion tunnels was mandatory in order divert the flow of water and to allow the construction of main dam. 4 No. Reinforced concrete tunnels each of 12m finished dia. and about 1 km in length have been constructed. These underground works have been executed through departmental forces under difficult and fragile rock conditions. Alternative bands of sandstone and clay-silt stone belonging to the lower Shivalik formation comprise the geology of the area. Besides 9 no.deep vertical shafts for intake structures, emergency gates and hoist gates have also been constructed. Intake structure allows the ingress of stored water into the tunnels for their further regulation for power generation and irrigation purpose through the gated shafts. The excavation of 4 no.Diversion was almost completed during the year/period 1985-88.
1.3 Flood Damage
However during last week of September 1988, devastating and unprecedented floods were experienced in this area due to wide-spread and incessant rains. These floods caused heavy damage to the excavated tunnels and the loss thereof was colossal. The tunnels were filled with muck, boulders, logs, dead animals etc.; and some of the costly equipment also got rolled down in the floods and got entrapped and buried under the muck in riverbed. Conditions became so adverse that the abandoning of this project was also thought of. However, the workers and engineers of the project did not lose heart and put in concerted efforts to restore the works by de-silting of the tunnels under severe constraints and bottlenecks. Flood damage caused serious setback of 3 years to the construction schedule of the project. The flood losses / damages were assessed to be about Rs1460 million and cost for the restoration of the works at Rs.1577 million.
Earth core-cum-gravel shell dam 160m high above deepest foundation level has been constructed across river Ravi. This is the highest dam of this type in the country and its special feature is a foundation gallery that has been provided for monitoring behaviour and de-watering of seepage waters. This feature has been provided for the first time in Asia. About 256 instruments have been installed in the body of the dam its health and behaviour during construction of the dam as well as during operation of the reservoir. There has been 15.2-million cu.m fill placement in the body of the dam. The reservoir area of Ranjit Sagar Dam Lake is 87.00 sq.km and the catchment area is 6086 sq.km. The gross storage capacity of dam is 3280 million cum and live storage capacity is 2344 million cum.
A massive RCC structure has been provided on the left embankment of the dam for passing floodwaters. The spillway has multiple energy dissipation arrangement in the form of stilling basin and solid roller bucket. 7 No. Radial gates of size 15.57mX17.2m have been provided for regulating the flow of floodwaters. These gates have been designed, fabricated and erected exclusively by irrigation engineers. A quantum of 26 million cum of rock excavation and 1 million cum of concrete is involved for accomplishment of this structure.
Implementation of Infrastructure Projects
1.1 River Ravi
1.2 Need for tunnels
1.3 Flood Damages
1.5 Power Plant
2. Hydrology and Reservoir
2.1 River Ravi
2.2 Catchment Area
2.4 Flood observations
2.5 Flood Estimation
2.5.2 Methods used in present proposal
126.96.36.199The Gumbel method using frequency factors
188.8.131.52 Gumbel Method by Least Squares
184.108.40.206 Log Normal method
2.5.3 Adopted Frequency Curve
3.1 Historical background
3.2 Regional Geology
3.3 Dam site Geology
3.4 Geology of Reservoir and its competency
3.5 Spillway Geology
3.6 Power plant Geology
3.7 Tunnels and Intake Area
4. Design Seismic Coefficient for Dam Embankment
5. Dam Embankment
5.2 Type of Dam
5.3 Embankment section and Zoning
5.4.1 Peizometer installation
5.4.2 Settlement Installations
5.4.3 Surface settlement Measuring Points
6.3 Economic Design Consideration
6.4 Flood Routing Studies
6.4.1 Data and Assumptions
6.4.2 Spillway Width and Crest Elevation
6.4.3 Coefficient of Discharge
6.5 Hydraulic Design of Spillway
6.5.1 Approach Channel
6.5.2 Control Structure
6.6 Types of Energy Dissipator
6.7 Selection of Energy Dissipator
6.7.1 Stilling basin with horizontal apron
6.7.2 Stilling basin with slopping apron
6.7.3 Flip Bucket
6.7.4 Roller Bucket
220.127.116.11 Solid Roller bucket
18.104.22.168 Slotted Roller Bucket
6.8 Design parameters of slotted bucket
6.9 Hydraulic design of Slotted Bucket Roller
7. Economics and Finance
7.1 Statement of Depreciation, Operation and Maintenance
7.1.2 Operation & Maintenance Charges
22.214.171.124 Thein Dam Power Portion
126.96.36.199 Generating Equipment
188.8.131.52 Transmission Equipment
7.2 Financial Forecasts (1981-2002)
7.3 Benefit Cost Ratios
8 Statics of the Project (after completion)
8.1 Unique Features
8.2 Salient Features of the Project
8.3 Quantities of Principle Materials used
9 Comparison with other Hydel Projects in India
9.1 NHPC Projects (Public Sector)
9.1.1 North India
9.1.2 North East States
9.2 Jaypee Projects (Pvt. Sector)
Conclusion and Comments