Brief of Project and Technical and Financial Justification of Alternatives
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Brief of Project and Technical and Financial Justification of Alternatives 1. Brief of the Project & Justification of Locating the Project in Protected Area 1.1. The Bisalpur dam which is located on river Banas constructed in 1999 mainly for supply of drinking water to Jaipur and Ajmer cities along with large no villages, does not get filled up every year as such needs augmentation. 1.2. Objective of the study is to increase reliability of Bisalpur Dam used for supplying drinking water to various towns and the rural areas; by interconnecting or transferring surplus water of Chambal Basin i.e Brahamini river a tributary in Chambal river joining Chambal river just upstream of Jawahar Sagar dam to Bisalpur Dam (Banas Basin). Bisalpur Dam has been developed as a mixed drinking water and irrigation source. The dam has capacity of 939 MCM with drinking water share of 458 MCM, Irrigation Share of 226 MCM and provision of 253 MCM for losses. The dam was initially proposed to feed 6 towns of Ajmer district and Jaipur city along with the rural area of Ajmer District and en-route villages along Jaipur transmission main. It was planned for upto year 2021. The work on the dam was started in the year 1987, reliable and actually observed inflow data is available since then. The study of this data reveals that actual inflow at 75% dependability in the dam has been 177 MCM only against 939 MCM planned. The dam could be filled up to FRL only 9 times in past 27 years. The worst year inflow was 17 MCM only in the year 2002 another worst year was 2009 where inflow was 21 MCM only. On the other hand the demand of drinking water has increased with the PHED taking up projects for supply of water to additional 19 towns including the originally proposed towns and villages. The rainfall has been erratic in the past and there have been cycles of prolonged deficit inflows. There is therefore urgent need to augment the supply to Bisalpur to enable sufficiency of availability of water for upto year 2045 for all the areas already taken up for being fed from this reservoir. It is also urgent to ensure that the population of the area which at present is about 75 lacs and is projected to be about 126 lacs by 2045 is not in peril of acute shortages of water. The drinking water need would be increasing from about 900 mld (328 MCM/year) now to 1,600 mld (584 MCM/year) in 2045. It is therefore important and urgent to augment the flows to the Bisalpur Dam from the only available source in Chambal Valley where there is surplus water that overflows from the Kota Barrage and passes into the sea via Yamuna River. A study of the feasibility of tapping this surplus overflow from Kota Barrage for augmenting the Bisalpur Dam was got conducted by the PHED and it is evident that such a tapping can be done from Chambal system. The WRD has also conducted similar preliminary studies in this regard and has found diversion of Brahamini River water to Biasalpur dam as feasible 1.3. It will be worthwhile to mention here that Brahamini river is the only nearest source of water which has not been tapped as yet and is having surplus water which can be diverted to Bisalpur dam. 1.4. It is proposed to construct a dam over river Brahmani to store water during monsoon and then divert it to Bisalpur dam through a diversion system involving tunnel, Open channel and aquaducts by gravity flow. 1.5. It is also proposed to lift monsoon surplus water from Jawahar Sagar dam by constructing an intake structure in Jawahar Sagar submergence near Bhainsroadgarh town and transmitting it to diversion tunnel through 3 meter dia. Steel pipes rising mains laid almost along Bhainsroadgarh - Begun highway. Care shall be taken that minimum permissible level of 970 feet (which is the usual water level being maintained at JS dam at present) will be maintained at Jawahar Sagar dam. 1.6. Sufficient water will still be released beyond Kota barrage to maintain water level at Palghat at Chambal River as per Hon’ble Supreme court direction. 1.7. The proposed project on completion will supply water to Bisalpur dam with reliability, and the acute demand of water for Jaipur and Ajmer will be fulfilled. 2. Technical and Financial Justification of Alternatives Three proposals were studied for the proposed project. Incidentally submergence of all the three proposal lies in sanctuary area, there is no technically feasible site available for locating the dam outside sanctuary boundary, hence we are compelled to consider the location of the dam out of these three proposal only. The following table gives the comparative analysis of various components of the project for various proposals. Technical and Financial Analysis of Various proposals S. Particulars Proposal I Proposal II Proposal III No. 1 Total water transfer (from Brahamini Dam and JS Intake 446 MCM 446 MCM 446 MCM Pumping) 2 Capital Cost of the Project 6932 6875 6976 (Rs. in crores) 3 Capitalized Cost of Loss of 169.5 149.4 154.0 Power at JS (Rs. in crores) S. Particulars Proposal I Proposal II Proposal III No. 4 (a) Capitalized Cost of Pumping Operation at JS 322.34 302.97 315.68 Intake (Rs. in crores) (b) Capitalized Cost of Pumping Operation at - 13.60 - Brahamini Intake (Rs. in crores) 5 Total of Capital and Capitalized Cost (Rs. in 7424 7341 7446 crores) (2+3+4) 6 Environmental Issues 12.35 km length in 7.22 km length in 10.22 km forest area for forest area for length in forest rising main rising main area for rising main Length of tunnel is Length of tunnel is Length of maximum 54.75 km 54.5 km and muck tunnel is equally muck generation is minimum 53.75 generation is maximum i.e. 2.71 km equally maximum i.e. 2.72 lakh m 3 muck lakh m 3 generation is minimum i.e. 2.67 lakh m 3 Excavation for Excavation for Excavation for earthen dam 59.79 earthen dam is earthen dam is lakh m 3 considerably low maximum i.e. i.e. 22.66 lakh m 3 62.15 lakh m 3 then Proposal –I & II 7 Inter State Issues • Use of water down steam of RPS in Chambal basin • Issue of using Catchment Area of Madhya Pradesh • Issue of using Water Released from Machines at RPS During Monsoon through Lifting from JS Dam 8 R&R Issues (Cost included under Capital Cost) 8a Area of land under 2460 ha 2460 ha 2486 ha submergence i Area under Jawahar Sagar 345 ha 1240 Sanctuary ii Area under Bhainsroadgarh 121 ha 908 wild life sanctuary iii Area under forest 860 150 8b Houses coming under 1380 nos. 870 nos. 1113 nos. submergence 9 New Road to be constructed (Cost included under Capital 14 km 13.5 km 17 km Cost) The above table reveals that Proposal II is most economical and technically feasible. But the area under sanctuary in this proposal is 1240+908=2148 ha,( Which is about 87% of total submergence area) the area involves tiger movement corridor also, it will be very difficult to obtain diversion of sanctuary land at the time of start of construction ,therefore WRD has decided to take up construction of the dam at Proposal - I where the sanctuary land is 345+121=466 ha ( which is about 18% of total submergence) only that too on outer periphery of the sanctuary, the cost of this proposal is only 1 % higher than proposal no II but it is immaterial in view of overall huge cost of the project. Salient Features of Recommended Proposal Sl. No. Parameter Unit Proposal I 1 Coordinates Latitude 24 o 57' 52" N Longitude 75 o 27' 42" E 2 Distance from confluence point km 9.6 5 Catchment area at Brahamini dam sq km 1180.00 9 Proposed live storage MCM 184.00 10 Sediment MCM 19.00 11 Total storage proposed MCM 203.00 12 FRL M 362.00 13 MWL M 366.00 14 Free board M 2.00 15 TBL M 368.00 16 Area of submergence HA 2460.00 17 Length of Earth dam M 4115.00 18 Length of NOF M 80 19 Length of OF M 118.00 20 Total length at Top M 4255 The final proposal recommended is shown in Appendix-I 3. Survey and Investigation Proposed in Forest and other Areas The proposed feasibility study is required to carry out topographical surveys, geotechnical and other investigations in forest as well as other areas. The survey and investigation will involve the following activities 1) Dam Topographical Surveys 2) Tunnel Topographical Surveys with Total Station/DGPS and Auto Level 3) Establishing control point at every 1km 4) Geological and Geotechnical Investigations (including core drilling) 5) Soil sampling 6) Rock Sampling The survey/investigation work will require to be carried out by a team of about 10 technical and other staff in day time only for a period of approximately 180 days. The survey/investigation will not involve clearing of forest or tree cutting, blasting, use of chemical and requirement of fuel except for vehicles. No residential camp will require to be established in forest area for survey team. .