(A) Sardar Sarovar Reservoir
The Full Reservoir Level (FRL) of the Sardar Sarovar Dam is fixed at RL 138.68 meters (455 feet). The Maximum Water Level is 140.21 meters (460 feet.) while minimum draw down level is 110.64 metres (363 feet.). The normal tail water level is 25.91 meters (85 feet.).
The gross storage capacity of the reservoir is 0.95 M. ha.m. (7.7 MAF) while live storage capacity is 0.58 M.ha.m. (4.75 MAF). The dead storage capacity below minimum draw down level is 0.37 M. ha. m. (2.97 MAF). The reservoir would occupy an area of 37,000 ha. and would have a linear stretch of 214 kilometer of water and an average width of 1.77 kilometer.
The submergence at Full Reservoir Level (FRL) is 37,533 ha. (86,088 acres), which comprises 11,279 ha. agricultural land, 13385 ha. forest land and112869 ha. river bed and waste land. In all 230 villages of the three states viz. 178 Villages of Madhya Pradesh, 33 villages of Maharashtra and 19 villages of Gujarat are affected. Only 3 villages of Gujarat are fully affected, while the remaining 16 villages are partly affected. As on 31.03.2018, 4763 PAFs from Gujarat, 5549 PAFs from Madhya Pradesh and 750 PAFs from Maharashtra has been resettled in 236 R&R colonies in Gujarat.
(B) Sardar Sarovar Dam
A concrete gravity dam, 1210 meters (3970 feet) in length and with a maximum height of 163 meters above the deepest foundation level, is completed and it has been dedicated to Nation at the worthy hands of Hon’be Prime Minister on 17.09.2017.
The dam is the third highest concrete dam (163 meters) in India, the first two being Bhakra (226 metres) in Himachal Pradesh and Lakhwar (192 meters) in Uttar Pradesh. In terms of the volume of concrete involved for gravity dams, this dam is ranking as the second largest in the world with an aggregate volume of 6.82 million cu.m. The first is Grand Coule Dam in USA with a total volume of 8.0 million cu.m. This dam with its spillway discharging capacity of 85,000 cumecs (30.00 lac cusecs), is the third in the world, Gazenba (1.13 lac cumecs) in China and Tucurri (1.0 lac cumecs) in Brazil being the first two.
For chute spillway Radial gates, 7 in number and size 60' x 60' and for service spillway, 23 Radial gates of size 60' x 55' are provided to negotiate the design flood. 10 number of temporary construction sluices, each of size 2.15 m x 2.75 m. are provided in the boby of the spillway at RL 18 m. Another set of 4 permanent river sluices are provided at RL 53.0 m. The lower sluices were closed in February, 1994.
The design of the dam allows for a horizontal seismic coefficient of 0.125g and it also covers an additional risk due to reservoir induced seism city. Most sophisticated seismological instruments for monitoring and evaluation of the stresses in the body of the dam as well as the effect on the periphery of the reservoir are under installation.
There are two power houses for the Sardar Sarovar Project (SSP). Power benefits are shared among Madhya Pradesh, Maharashtra and Gujarat in the ratio of 57:27:16 respectively.
(i) River Bed Power House
The RBPH is an under ground power house stationed on the right bank of the river located about 165 meters downstream of the dam. It has six number of Francis type reversible turbine generators each of 200 MW installed capacity. The T.G. Sets are supplied by M/S Sumitomo Corporation, Japan and M/S BHEL. These units can operate at minimum reservoir water level of 110.64 meters. These six units have been commissioned in a phase manner during Feb-05 to June-06. The generation of energy depends upon inflow of water from upstream projects and need of water for irrigation in Gujarat.
(ii) Canal Head Power House
The CHPH is a surface power station in a saddle dam on right bank of the reservoir having total installed capacity of 250 MW (5 x 50 MW). These five units have been commissioned in a phased manner during Aug-04 to Dec-04. These units can be operated with minimum reservoir water level of 110.18 meters.
The CHPH is being operated in consultation and as per advice of NCA/WREB based on irrigation requirement of Gujarat/Rajasthan and availability of water in reservoir and release from upstream project of Madhya Pradesh.
The energy generated from both the power houses is to be evacuated through 400 KV level through interconnecting transformers at GIS, situated in RBPH switch yard. The 400 KV Switchyard is indoor type having Gas Insulated Switch Gear and Bus bars. The energy is transmitted to party states i.e. Gujarat, Maharashtra and Madhya Pradesh in the proportion of 16:27:57 respectively through 400 KV double circuit transmission lines, namely SSP-Kasor, SSP-Asoj, SSP-Dhule and SSP-Nagda respectively. All the transmission lines are commissioned and charged.
The operation and maintenance of SSP power complex is being done by Gujarat State Electricity Company Limited (GSECL), for which O&M agreement between SSNNL and GSECL has been signed.
(iii) Small Hydro Power Projects on Narmada Branch Canals
Development of Small Hydro Power Projects at Canal falls at various Branch Canals is in progress under EPC mode of implementation for the captive use of power at pumping stations of SSNNL. Brief detail of these Small Hydro Power Projects is as link provided below:
DETAILS OF SMALL HYDRO POWER PROJECTS_SSNNL
(iv) Solar Power Projects on Narmada Branch Canals
SSNNL has successfully commissioned 10 MW Canal Top Solar Photovoltaic Grid Connected Power Plant on Vadodara Branch Canal in November-2014. It was dedicated to the Nation by H.E. Mr. Ban Ki-moon, United Nations Secretary-General on 11th January, 2015.
Also, 10MW Solar Power Projects on Canal Top & 15MW Canal Bank Power Projects at Vadodara Branch Canal have been successfully commissioned in September-2017 for the captive use of power at pumping stations of SSNNL. Brief detail of these Solar Power Projects is as link provided below:
DETAILS OF SOLAR POWER PROJECTS_SSNNL
(v) Pumping Station Projects on Narmada Branch Canals
In order to provide water in the regions of Saurashtra & Kachchh of Gujarat, SSNNL has constructed the Pumping Stations on Saurashtra Branch Canal & Kachchh Branch Canal for lifting of Narmada Canal water.
The details of Pumping Station Projects on Kachchh Branch Canal (KBC) & Saurashtra Branch Canal (SBC) of SSNNL is described as below link:
DETAILS OF PUMPING STATION PROJECTS_SSNNL
(D) Main Canal
Narmada Main Canal is a contour canal. It is the biggest lined irrigation canal in the world. It is about 458.318 km. long up to Gujarat -Rajasthan border. The canal extends further in the state of Rajasthan to irrigate areas in Barmer and Jhalore districts of Rajasthan. The Main Canal is lined with plain cement concrete to minimise seepage losses to attain higher velocity and to control the water logging in future. The lining work is carried out with the mechanized pavers. Such a large scale paving of concrete lining is done for the first time in India.
The Main Canal in its journey has to negotiate several water streams, rivers, roads, railways etc. This is possible by constructing appropriate structure on the canal. In all, there are 638 structures on the Narmada Main Canal. Narmada Main Canal as on today is completed up to 458 Km. and water has been flowing throught it right upto the state of Rajasthan.
Features of Narmada Main Canal:
- Full supply level (F.S.L.) at H.R. 91.44 m (300 ft)
- Length up to Gujarat - Rajasthan border 458.318 Km
- Base width in head reach 73.10 m
- Full supply depth (F.S.D.) in head reach 7.60 m
- Design discharge capacity
- In head reach 1133 cusecs
- At Gujarat Rajasthan border 74.55 cusecs
Statement showing total number of structures on Narmada Main Canal
|Statement showing Reach wise & Type wise Total no of structures on Narmada Main Canal from 0.0 to 458.318 km
|Reach in Km
||Total no of Structures
||DSY+ Syphon Aqudeuct
||Canal Crossing+ SP+BC Rly Crossing
|0 to 144.50
|144.50 to 263.265
|263.265 to 356.422
|356.422 to 388.164
|388.164 to 458.318
(E) Canal Distribution System and Irrigation Water Operations
- According to the Narmada Water Disputes Tribunal (NWDT) Award (year -1979), 75% dependability is considered while assessing the availability of 28 (Million Acre Feet) utilizable water in Narmada basin. 75% dependability means the probability of getting 28 MAF of water, is for the period of 3 years out of average 4 years. While in the remaining distressed year, less quantity of utilizable water will be available.
- Out of the total assessed quantity of utilizable Narmada water, (a) Madhya Pradesh is entitled to a share of 18.25 MAF (65.18%), (b) Gujarat is entitled to a share of 9 MAF (32.14%) (c) Rajasthan is entitled to a share of 0.5 MAF (1.79%) and (d) Mahrashtra is entitled to a share of 0.25 MAF (0.89%). In case of availability of utilizable in excess of the water 28 MAF in a good year or falling short of the 28 MAF is a lean year, the allocation of water among the four states shall be proportionately increased /decreased.
- The total estimated length of Canal network is 71,748 km which includes the Main Canal, Branch-Canals, Sub-branch Canals, Distributaries, Minors & Sub-minors. In the entire command it is planned to distribute the irrigation water in farmers’ fields by conveying irrigation water up to 5 to 8 Ha Sub-Chak area through the Canal network.
- Out of total 38 branch canals off taking from the Main Canal, Miyagam, Vadodara, Saurashtra and Kachchh branch canals are the major branches having their discharge carrying capacity more than 75 cumecs (2650 cusecs). About 18.55 lac Ha command area Spread over 3177 village of 77 Taluka of 17 Districts will be getting benefit of irrigation water through a Canal network of 71,748 km.
- The Canal network of the entire Project is divided in to two systems as under:
(A) Conveyance system:
It consists of Main Canal, Branch canals and Distributaries that eventually deliver water in to smaller canals.
(B) Distribution System:
It consists of Minors, Sub-minor and Field Channels, which carries water up to the farmers’ fields.
Based on the availability of water, it shall be used economically and optimally so that the protective irrigation can be provided during Kharif Season and as per the demands of the beneficiary farmers during the Rabi Season in the command area.
- The management distribution of irrigation water in the Canal network consisting of Main Canal, Branch-Canals, Sub-branch Canals and their Distributaries shall be done by the SSNNL or the Government. Whereas, management of distribution of Irrigation water below a minor and its sub minors shall be carried out in each Village Service Area by the concern Water User Association (WUA) under the provision of Participation Irrigation Management (PIM) system. Therefore the Village Service Area of @ 300 to 500 Ha area each to be served by a minor the complete distribution of irrigation management shall be managed by the concerned beneficiary farmers of their water user Association. Water shall be provided at the head of the minor to the concerned WUA on the basis of type of crop, crop water requirement & availability of water in the reservoir. WUA shall be vested with every power for the distribution of irrigation water within their Village Service Area according to allocated quantity of water at their minor head before the starting of Kharif/Rabi Season. WUA shall plan their demand for the entire season well in advance and distribute the irrigation water adopting Rotational Water System (Warabandhi) among the beneficiaries of VSA under the Participatory Irrigation Management (PIM) provisions.
- As per original planning of the project, out of annual irrigation of 17.92 lakh ha, water is planned to be allocated for irrigation to Kharif is 24%, Rabi 29%, Summer 1.8%, Two Seasonal 22%, Perennial 1.7% and other crops 5.9%. During the summer season, irrigation water is allocated only in about 38000 ha. area which is near to Sardar Sarovar Dam. Thus, there is almost no provision to provide Water for irrigation to the summer crops. Only in Rabi & Kharif irrigation season the command area of project will be getting the benefit of irrigation.
(F) Command Area Development
Sardar Sarovar (Narmada) Project covers Culturable Command Area (CCA) of 18.45 lac ha in 78 Talukas of 17 Districts within Gujarat. With extensive studies on the subject, detailed elaborate and micro level plan has been evolved to deal with the development of SSP command. Entire command area is divided into 13 Agro Climatic Regions and each Region is further subdivided in to irrigation and drainage blocks ranging from 4000 to 10,000 ha.
As per policy of Nigam in 2014, the subminors are consructed by UGPL instead of open channel. With participatory approach,
the contribution of beneficiary farmers is taken as a 2.5% (or labor contribution) in the implementation of Subminor by "underground pipeline”.
- Involvement of farmers in the construction activities and there after for irrigation management is aimed at to ensure efficient user friendly uses. The system below the VSA outlets will be managed by the Water Users' Associations (WUAs) based on Participatory Irrigation Management (PIM). As per the, “Gujarat Water Users’Association Participatory Irrigation Management Act, 2007” and “Gujarat Water Users’Association Participatory Irrigation Management Rules, 2012”;
- One of the unique feature is that the Irrigation Water in the command area of SSP would be delivered to farmer's groups (Water Users Association (WUA) and not to individual farmers. It would be for the farmers’ groups to manage distribution within their block called village service Area (VSA). The corollary to this management is that the minors, subminors and field channels will be owned and looked after by these WUAs.
- Involvement of farmers/NGOs in the construction of micro level canal network system would ensure 'owners' amongst the beneficiary farmers.
- A suitable system called Rotational Water Supply (RWS) - Varabandhi would be implemented to ensure timely, and assured and equitable supplies.
- The another important feature is the volumetric supply of water instead of conventional area approach. The subminor systems with appropriate structures are being designed and constructed to ensure timely and equitable distribution of water. This would guard against the most commonly observed problem of overuse of water by initial command blocks, leaving less supplies to the tail enders.
- To ensure efficient water uses, irrigation would be based on limited delta, i.e., 53 cm basis. Extra irrigation water for water intense crops would be arranged by farmers themeselves.
- Further, the “Gujarat Irrigation and Drainage Act, 2013” and “Gujarat Irrigation and Drainage Rules, 2014” are implemented for irrigation and drainage by state government.
- An interesting as well as innovative feature of the SSP's irrigation plan is to supplement canal water supply by conjunctive use of ground water. This would augment total water availability and stretch the irrigation benefit to more area. It will also prevent water logging by regarding excess ground water and thereby protecting command against water logging and soil salinity.