CENTRAL GROUND WATER BOARD
Schemes On Conjunctive Use Of Surface And Ground Water Resources in Irrigation Commands
The Judicious use of Surface and Ground Water is conjunctive use. CGWB has taken up a total of 13 studies for establishing feasibility of conjunctive use of surface and ground water in India. The Studies have established that the isolated use of surface water ignoring optimal ground water use in irrigation command has resulted into various environmental problems. Optimal conjunctive use plan to be implemented by the State agencies in co-ordination with CADA has been recommended. The recommendations of the completed Conjunctive use studies needs to be implemented on the ground. Further, it is also felt that there is a need to adopt Ground Water Hydraulic Management Models (Management models) which incorporates a ground water simulation model as constraint in the Management model which can be efficiently used in planning the conjunctive use of water.
SCOPE AND OBJECTIVES
The scope and objectives of the conjunctive use project are as follows:-
- To evolve a suitable plan for controlling the problem of rising water levels by adopting the technique of conjunctive use of surface and ground water, and proper drainage.
- To prepare sector/ blockwise plans for development of ground water resource in conjunction with surface water based on mathematical model results.
- To test the sustainability of the present irrigation pattern with respect to conjunctive use of water resources and suggest improvement for future.
- To evaluate the economic aspect of groundwater development plan with respect to Cost benefits ratio, internal rate of return and pay back period etc.
LIST OF COMPLETED PROJECT:-
INDIRA GANDHI NAHAR PARYOJNA, STAGE - I, RAJASTHAN
SARDA SAHAYAK IRRIGATION PROJECT, U.P.
TUNGABHADRA CANAL COMMAND AREA, ANDHRA PRADESH AND KARNATAKA
GHATAPRABHA CANAL COMMAND AREA, KARNATAKA
HIRAKUD CANAL COMMAND AREA, ORISSA
MAHI- KADANA CANAL COMMAND AREA, GUJARAT.
NAGARJUNA SAGAR PROJECT, ANDHRA PRADESH.
INDIRA GANDHI NAHAR PARIYOJNA STAGE - II, RAJASTHAN
KOSI CANAL COMMAND AREA, BIHAR
GANDAK CANAL COMMAND, BIHAR,
SRIRAM SAGAR CANAL COMMAND AREA, ANDHRA PRADESH,
WESTERN YAMUNA CANAL COMMAND AREA, HARYANA,
RUSHIKULIA CANAL COMMAND AREA, ORISSA
1. INDIRA GANDHI NAHAR PARYOJNA, STAGE – I, RAJASTHAN
The study area lies in North Western Part of the Desert of Rajasthan; the Project area forms Parts of Ganganagar and Bikaner distt. of Rajasthan. The IGNP being a very large sized project, having CCA of 1.537 M.ha, it was decided to take up the construction work in two stages. The study area is divided into seven command areas, comprising six branches. It covers 189 kms of Indira Gandhi main Canal, which was completed in 1975. The area has distribution system of 2618 kms flows and 332 kms in lift command respectively. By March 1990, 3075 kms long Canal distribution in stage-I was completed and actual irrigation facilities were provided in 5.24 lakh ha area. In fact 11.5% of total water of the canal system was for drinking and Industrial purpose.
Problems In The Area.
The water logged area is estimated as 513 sq.km. , further, it is estimated that 24% of the project area is likely to be water logged, if the rise of water level is allowed at the present rate. These damages occurred due to seepage from the big manmade escape water reservoirs. In 1991, out of CCA of 5.25 lakh ha, 1.56 lakh ha area was water logged i.e. 34% of the command area. In Hanumangarh circle alone water logging affected 3014 ha, wherein no crops could be grown. Besides this, there was another 4595 ha area, which was water logged and could only support one crop of paddy. It was observed that the water table has risen at the alarming rate of 1 m per year, which was 20% higher than the Bhakra canal area.
During December 1992, a detailed study on Water logging was carried out in the total CCA of 5.25 lakh ha. of IGNP. Stage-I , the areas falling under different categories are as follows:
Class
Area ha.
% of total area
A). Potentially Sensitive area. Water level 1.5 to 6 mbgl
2,02,960
39.0
B). Critical Areas
(i) Water level 1.0 to 1.5 mbgl
22,000
4.18
(ii) Marshy land/stagnant water level 0.0 to 1.0 mbgl and total loss of crop
13,750
2.60
2,38,710
The salinity affected 3 blocks namely Eastern block, Anupgarh Shakha and Suratgarh branch. As per the Soil Survey conducted in 1990, the saline areas can be grouped blockwise as follows:
Salt affected area, ha (As per soil survey)
Anupgarh
ShakhaSuratgrahBranch
Eastern Block
Highly salt affected
73850
19930
37230
Moderately Salt affected
34580
7830
-
108430
27760
37230
Grand Total
1,73,420
Causes Of Water Logging
- In part of IGNP Stage-I especially in the Central Sector the existence of hardpan which does not allow percolation of the water below it.
- The seepage’s from the main canal, unlined water courses and return seepage of irrigation water have contributed a major proportion to the problem.
- The seepage from 18 Ghaggar depressions/reservoir meant to store flood water of Ghaggar River. The stagnant water got seeped out into the surrounding areas. As the depressions were filled with flood water between 1968 and 1977, some parts of area experienced a rise in water levels to the order of 30 m. The ground water resource remained insignificantly tapped.
Hydrogeology
The study area consists of flood plain and aeolian sands. There are two main aquifer systems in the area which comprise semi-consolidated rocks of Palana series and unconsolidated alluvial formation. The water logged areas covering 86,000 ha. were identified having depth to water level within 2 mbgl and these were found to occur as pockets around Baropal – Suratgarh –Amaipura Jatan area,. The area prone to water logging (depth range 2.5m) has been found in eastern part in Masitawali -Lakhuwali – Rawatsar belt.
Availability And Demand Of Water
The ground water resources have been computed to be around 992.16 MCM per annum and the draft has been estimated as 26.4 MCM leaving a balance of 970.7 MCM for development. The surface Water Resources based on the water released through the canal system is estimated to be around 4140 MCM per annum. Modeling studies were carried out to evolve a strategy for conjunctive use plan. Various scenarios were tested. By using only canal water with envisaged cropping intensity of 110% , the mass balance indicates that a very small amount of ground water is removed from the system and an area of 4264 sq.km will gets water logged. within a period of 15 years. Using only canal water for present cropping intensity of 94% nearly 10958MCM water is added to the ground water system and which may cause water logging conditions in an area of 3204 sq. km. in a time period of 15 years.
Conjunctive Use Planning
By developing ground water to the tune of 7% of canal releases and with a cropping intensity of 110% the area under water logging in a span of 15 years will be 1735 sq.km. But by increasing the ground water development to 18% of the canal water releases, the water logged by 15th year will be only 785 sq.km. The last strategy was found to be more suitable. Under the conjunctive use plan, 10,023 shallow tube wells has been suggested to get an optimal cropping intensity of 120%. The cost of investment for the construction of these wells is around Rs.7217 lakhs and the benefit cost ratio works out to 1.03.
2. SARDA SAHAYAK IRRIGATION PROJECT, U.P.
The study area selected is Sai Gomti Doab in the central part of the Sarda Sahayak command which exhibits elongated linear disposition in north-west-south east direction. It lies in parts of Barabanki , Jaunpur, Lucknow, Pratapgarh, Rai Bareli and Sultanpur district, covering 43 blocks and spreading over an area of 8978-km2. Sai and Gomti river bound the study area in north and south. The average annual rainfall ranges between 950 and 1050 mm. The project proposed gross command area of 40.20 lakh ha. It envisages to irrigate 19.23 lakh ha achieving 96% irrigation intensity.
Problems In The Area
The study carried out in the present project indicates that during post monsoon period of 1992 an area of 4874 km2 was found to be water logged and prone to water logging category, about 255 km2 area has been affected by usarland. The water level rising trend has been observed. The tail end of the canal command is observed to be deficient in surface water availability resulting in the reduction of yield. The percentage of reduction in crop yield is 38.75% and 84% for high yielding variety paddy and wheat respectively.
Hydrogeology
There are three aquifer zone in the area, top phreatic aquifer occur down to 50m and the first confined aquifer ranges between 50-160m bgl and the second confined aquifer between 160-250 mbgl & third beyond 250 mbgl. It has been observed that there is a difference of heads in the two-aquifer system i.e. phreatic and Confined. Thus head difference criteria would find applicability for eventual transfer of water from the phreatic zone to any or multiple deep confined aquifer system down below especially from the water logged areas.
Availability And Demand Of Water
As per the norms of GEC, 1984 the utilisable ground water resource works out to be 2603.471 MCM, the Ground Water Draft - 906.32 MCM and the Balance Ground water is found to be 1697.15 MCM. The stage of ground water development has been also worked out and it is found that 38 number of Blocks fall under White category , and only 3 Blocks fall under ‘Grey’ category.
Total surface water resource available is 2177.68 MCM (1992) out of which 1091.46 MCM during kharif and 1086.2235 MCM during rabi season.
After matching the demand and availability of water it has been observed that surface water is available for irrigation only in 37 blocks and remaining 6 blocks are devoid of surface water irrigation.
Conjunctive Use Planning
Under the conjunctive use plan, to control spreading of water logging it is proposed to reduce surface water utilisation from the present 1481.8 MCM to 1015.9 MCM and the ground water utilisation to be increased from 906.32 MCM to 1356.23 MCM. For this additional tubewells of 40 to 50 m depth has been recommended. The number of tubewells suggested is 21,375 and the estimated cost for constructing the wells comes to be around Rs.93.11 crores. This will also increase the existing cropping intensity of 153% to 200%. This will reduce the water logging from the present 33% to less than 20% and the benefit cost Ratio has been worked out to be 1.56 for the proposed plan.
3. TUNGABHADRA CANAL COMMAND AREA, ANDHRA PRADESH AND KARNATAKA
The Tungabhadra Right Bank High Level and Low Level Canal (HLC & LLC) command area selected for conjunctive use studies. The gross command area of these two canals are 6,354 sq.km and covers parts of Bellary district of Karnataka and parts of Kurnool and Anantapur district of Andhra Pradesh.
Problems In The Area
The problem of salinity and alkalinity has become very severe in many parts of the study area and has reached a critical stage. According to one study the canal-wise, year wise area affected by salinity is as follows.
Canal-wise, Year-wise area affected by salinity, in the project Area
YearRight bank
Left bank
Total
1975-76
6975
9483
16458
1977-78
14472
10003
24475
1984-85
20870
14230
35000
According to Smedema, L.K. (1990), the waterlogged area is spread over 1300 ha and salt infested land occupies 6700 ha. These confirm that vast area is going out of production and land became infertile.
Hydrogeology
The area is underlain by oldest rock of Archean, which include Peninsular gneissic complex, Dharwar super group. Few patches of alluvium also occur in river courses. All the exploratory wells drilled down to depth of 200 mbgl, the yield varies from 1.50 lps to 4.30 lps. The maximum yield of 4.30 lps encountered was at Kautlam and minimum of 1.50 lps at Ratsamarri. In general depth to water level during pre-monsoon period was observed to vary from 2.75 to 17.80 mbgl, whereas during post monsoon period the depth to water level varied from 1.90 m to 14.01 mbgl. Based on the data, depth to water table maps were prepared and water logged areas demarcated, which varied from 98.75 sq.km in pre-monsoon to 229.00 sq.km area in post -monsoon period.
Availability And Demand Of Water
The utilisable ground water recharge was worked out to be 650 MCM and stage of groundwater development varied from 2 to 33%. The dynamic groundwater resources calculated thus to be 499 MCM, present ground water draft is 71 MCM leaving a balance of 428 MCM. Based on the canal water releases, the surface water availability have been worked out, the total annual surface water available in the area is
827 MCM in low level canal command and 784 MCM in high level command. The total water demand for all sectors. viz. Irrigation, domestic and industrial uses envisaged in the project proposals have been worked out to be 1074.036 MCM.Conjunctive Use Planning
The conjunctive use study indicates two possible scenarios or development plans. By implementing an integrated ground water development by these two plans 85.8% of the canal water shortage areas can be irrigated. The remaining 14.2% of the water shortage areas can be brought under irrigation adopting water saving methods. Also by implementing the conjunctive use projects, cropping intensity can be increased from the present 61.43 % to 116%. Modeling studies has indicated that an additional amount of 600 MCM water can be utilised under conjunctive use plan without undesirable effects. The financial analysis shows that under the ground water development plans with annual investment of Rs. 235 crore, the benefits will be Rs.280 crores, with B.C. ratio up to 3.45 and the IRR of 48.12%.
4. GHATAPRABHA CANAL COMMAND AREA, KARNATAKA
The river Ghataprabha is one of the important tributaries of Krishna River. The study area is bounded by the river Krishna in the north, Maharashtra state in the West, the confluence of Krishna river and Malaparabha river in the east and the South. The total area taken up for study is 10370 sq.km. The existing canal command area is served by Ghataprabha Left Bank Canal (GLBC) and six branch canals. There are 90 distributories, (majors and minors). The canal system was completed in 1974-75. The net irrigated area is 161871 ha. The canal system provides irrigation to parts of four taluks in Belgaum and three talukas of Bijapur district. The proposed Right Bank Canal will irrigate 1,55,559 ha. covering part of six taluks in Belgaum and four taluks in Bijapur district.
Problems In The Area
In the project area, canal water is generally released in June/July and water logging condition sets in by August which increase progressively over the area by Nov. The water logged area (<2m,bgl) observed during the month of July, Aug and Nov. 1993 are 143 sq.km, 344 sq.km and 580 sq.km respectively. The long term water levels (1981-92) studied in the area indicates a general rise in water level within 2m.
Hydrogeology
Geologically, the area is underlain by rocks of Archaean crystallines to recent alluvium. Two distinct aquifer system is present in the area, the first layer is made-up of top weathered zone extending down to a depth of 30 m and forms the shallow or phreatic aquifer tapped mostly by dug wells, dug cum borewell, shallow bore well etc. The fractured aquifer which is below the shallow zone and extend down to 80 m and beyond. The yield of shallow aquifer varies from less than 1.0 lps to 5.0 lps and the permeability varies from less than 1m/day to 5m/day. The deeper fractured aquifer behaves as confined to semi-confined aquifer, the transmissivity of the zone varies from 5 m2/day to more than 100 m2/day. The yield varies from less than 1.0 lps to 7.6 lps. In the canal command area, the depth to water level varied between 2 to 8 m.bgl. during post -monsoon period. The entire area indicates a rise in water level during the period of canal operation. The water logging conditions, have already been discussed in the problem of the area.
Availability And Demand Of Water
The talukwise net ground water recharge has been estimated based on GEC 1984 norms, the ground water recharge computed for three year varied from 1406 MCM during 1988-89 to 1034 MCM during 1990-91. The net draft for the same period varied from 333 MCM in 1988-89 to 361 MCM in 1992-93 and ground water balance varied from 862 MCM during 1988-89 to 599 MCM during 1992-93. The stage of groundwater development in most of the taluks are below 50% and fall under WHITE category.
Surface water availability in space and time, taluk wise, ranges from more than 400 MCM in a year for Raibog taluk to about 5 MCM for Athani taluk. The present canal withdrawal through the left bank main canal on an average is 1410 MCM. The present cropping intensity is 84% utilizing 881 MCM and leaving a balance of nearly 529 MCM unutilized.
The net sown area available is 2873061 ha during 1992-93. However considering only the command area coming under irrigation was 3,17400 ha., which will be about 31% of the project area. As per the original project document the desired cropping intensity for both the command was 100% i.e. for the left and right bank canal command is 40% Kharif, 40% Rabi and 20% biseasonal.Conjunctive Use Planning
Considering the terrain, depth to water below ground level and yields of dug wells/bore wells, construction of additional dug wells in the command area is not recommended as most of them go dry or have very little water when the canals are closed for irrigation. Even in areas where the water levels are within 2 m.bgl during kharif and rabi seasons, and fall below 4 m. bgl during the summer season, necessitating deepening of wells if they have to be used during no canal flow periods. In such a situation, construction of borewells in the area has been proposed as a better alternative. To make effective the proposed conjunctive use plan a total of 8880 number of borewells in the Left Bank Canal command and 11739 in the right Bank Canal Command will need to be constructed, involving investments of Rupees 175 million for the Left Bank command and Rupees 231 million for the Right Bank Command totaling to Rs. 406 million. The cost benefit analysis of the development plan carried out indicates that B.C. ratio varies from 1.25 to 5.34 for irrigated dry crops and oil seeds. The studies also indicated that present cropping intensity in the left bank is only 84% and there is a scope for increasing cropping intensity to 200% by utilising 84% of surface water and 16% of ground water. In the right bank there is a scope of having cropping intensity of 140% by using 69% surface water and 31% ground water.
5. HIRAKUD CANAL COMMAND AREA, ORISSA
The Hirakud dam is a multipurpose Project built across Mahanadi river about 14 km upstream of Sambalpur town in Orissa state.. The CCA of Hirakud command is 157018 ha and present irrigation intensity is 170% (100% in Kharif and 70% in Rabi. The area has been divided into four sectors with ridge canals and major rivers, viz. Mahanadi and Ong as boundaries of the sectors in order to determine and represent the different components of the study into smaller unit. The average annual rainfall in the area is 1169.2 mm.
Problems In The Area
It has been found that water logging conditions (DTW <2m) exist in an area of 174 sq.km during Pre-monsoon (May'94) and it was 1494 sq.km during Post-monsoon period (Nov’94). Topographic set up, unlined canals, over irrigation and predominant paddy cultivation during kharif and rabi are mainly responsible for water logging conditions in the command area.
Hydrogeology
The weathered residuum (average thickness 15m) and fracture zones form the principal repository of ground water which occur under phreatic condition in weathered residuum and under semi confined to confined conditions in the fracture zones. Aquifer parameters of the phreatic aquifer reveals that specific yield varies from 0.7 to 11 lps average being 5 lps. The specific capacity value ranges from 2.317 lpm per meter of drawn down to 142.9 lpm per mt of draw down. The discharge of deeper borewells tapping the fractured aquifer varies from 2.7 to 10 lps for drawdown varying from 3.89 to 21 mt. The transmissivity values (T) ranges from 5.8 m2/d to 125 m2/d similarly the storage coefficient (S) ranges from 1.96 x 10-4 to 6.9 x 10-4.
Depth to water level varied from 0.8 to 9.7 m bgl during pre-monsoon period and 0.3 to 4.03 m bgl during post-monsoon period. During the month of August major part of the command area remains within a depth to water level range of 0 to 2 mbgl. The ground water flow direction in general is towards southeast .Hydraulic gradients varied from 1/300 to 1/500.
Availability And Demand Of Water
As per GEC norms, 1984, the utilisable ground water resources during Kharif season have been estimated as 508.04 MCM and net draft through existing structure worked out to be 2.35 MCM leaving a balance of 506.09 MCM for further development. Similarly utilisable G W resources during Rabi season have been estimated on 764.44 MCM with a net draft of 4.35 MCM leaving a balance of 760.09 MCM for future development.
Availability of surface water during the Kharif season have been estimated as 1360.8 MCM and during the Rabi season it is 1494.8 MCM.
The Projected annual domestic water demand for the year 2025 was computed as 49.89 MCM similarly the projected water demand for industrial purposes have been computed as 261 MCM. A linear programming model has been formulated to optimise and allocate the surface and ground water as per the cropping pattern for meeting the irrigation demand.Conjunctive Use Planning
During the Kharif season paddy coverage is 98% and sugarcane is 2%. During Rabi season, five major crops like paddy, pulses, oil seeds, vegetable and sugarcane have been considered. Demand of water for 200% irrigation intensity can be met from surface water (90%) and ground water (10%) for both the seasons. The surface water irrigation being cheaper an attempt has been made to determine optimal cropping pattern for the maximum use of available surface water in conjunction with groundwater to get maximum return. Various possible conjunctive use strategies have been tested with the ground water simulation model and it has been found that ,the above scenario of 90% surface water and 10% ground water use appears to be the most viable one. In Hirakud command area development of groundwater is feasible through dug wells and borewells. Dugwells are the most suitable ground water structure in the area. For meeting the additional demand of water a total of 17,526 dug wells are required which should be installed in the identified area within a period of two years. The simulation studies also indicates that water logging reduces with increase in the use of ground water. The financial analysis of the development plan show that with an additional investment of Rs.953.99 million the B.C. ratio worked out to 1.66 and the internal rate of return (IRR) of 55%.
6. MAHI – KADANA CANAL COMMAND AREA, GUJARAT
The Command area covers parts of Thasra, Nadiad, Cambay, Motar, Bursad Anand and Petland talukas of Kheda districts. According to IMD records, the normal annual rainfall varies from 727 to 947 mm. The area is mostly occupied by sand soils of varying grades. Prior to introduction of the irrigation, Bajra was principal crop covering about 40%, paddy and wheat were other major crops. During 1959-60, gross cropped area was 3.81 lakh ha utilising water from rainfall and wells. The crop yields have increased from 8.96 to 17.39 quintal per ha for paddy and from 5.79 to 15 quintals per ha for wheat during the period 1959-60 to 1980-81.
Problems In The Area
In order to study effect of continued irrigation on the ground water regime since inception of the project a comparative study of depth to water level for the period 1956 and 1991 was made which reveals that maximum rise of water level has taken place in the central part around Valsan and Nes and is more than 20m. Water level rise of 15 to 20m. has taken place south of Anand. The rise in water level gradually reduces towards western and south eastern parts. The minimum rise of less than 2m was observed in the Bhal region and around Mahi river in north eastern part. During pre-monsoon 1991 the water logged area ( < 1.5 mbgl) was 3370 ha and has increased to 16080 ha during post-monsoon period.
Hydrogeology
The phreatic aquifer made up of alluvium is extensive throughout the area. Thickness varies from 18m in the west to 50m in the central parts. The aquifer material consists of sand salt and gravel. However, coarser material like pebble and boulders are not uncommon, occasionally kankar and clay lenses are also present in the aquifer. Within the explored depth of 300m., three distinct aquifers, separated by persistent clay layers forming aquitards have been identified. Of the three aquifer the first two are continuos throughout the area but the continuity of the deeper aquifer could not be established throughout the area. Generally the first phreatic aquifer extend up to a depth of 45 m, below which the first confined aquifer is present and continues up to depth of nearly 200m, and below which the discontinuous deeper confined aquifer is present. The wells located close to the canals are capable of yielding up to 98 m3/hrs. The shallow tube wells tapping phreatic aquifer are capable of yielding 40 to 50 m3/hr for draw down ranging between 4.5 to 7.8 m. The specific yield varied from 0.01 to 0.08 and transmissivity from 164 to 2732 m2/day. The deep tube wells in the semi-confined and confined aquifer have discharges from 52 to 63 m3/hr with draw down varying from 0.48 to 3.70 m. The transmissivity value ranges from 702 to 2363 m2/day. The depth to water level has been studied for several years, the pre monsoon water level for the year 1993 varied between 15 and more than 25m bgl.
In the central part,the water level rests between 5 to 15 mbgl, in western part it was less than 5 mbgl. The deepest water level of 25.26 m bgl was noticed at Nawapur and the shallowest 1.63m bgl at Padra. The long term behavior of water level indicates a rising trend till mid 70s to 80s, after which downward trend has been observed. During 1991 the water logged area, with water level within 1.5 m bgl was 3370 ha during pre-monsoon and has increased to 16080 ha. during post-monsoon..
Availability And Demand Of WaterThe total annual ground water resource has been computed as 921 MCM based on the GEC norms 1984. Further the dynamic ground water resource has been computed separately for kharif, Rabi and summer season. The overall status of ground water development was determined as 85%. The highest being 141% in zone Tetlad-Petlad tract and lowest 36.15%in Petlad-Tarapur tract.The surface water availability was computed on the basis of releases of canal water to different commands during 1989-90, the total canal water released was 2258.91 MCM feeding a gross irrigated area of 151372 ha in three crop seasons of Kharif, Rabi and summer. The gross irrigated area has increased from 4085 ha. in 1959-60 to 151,372 ha in 1989-90.
The agriculture sector consumes 95% of the total water demand. During 1990-91, the irrigation intensity was 179% covering 3,78,658 ha. utilising 2955 MCM of water resources. The surface water and ground water contributions were 2212.65 MCM and 734.64 MCM respectively. The domestic and industrial sectors consumption’s were 55 and 5 MCM. The total water demand was computed as 3016 MCM.
Conjunctive Use Planning
From the study it has been observed that out of 12 zones, in five zones already maximum possible irrigation intensity is achieved, in one zone, because of existing shallow water condition and saline groundwater, no further increases in irrigation has been considered. In the rest six zones spreading over are area of 33000 ha, only the irrigation intensity have to be maximized. It is proposed for an irrigation intensity of 185 % till 2015 with the water requirement of 2221 MCM from surface water and 792 MCM from ground water. The results of ground water simulation studies indicate that the present utilization of surface water and ground water in the proportion of 65:35 is optimal situation of conjunctive use , without creating any adverse effect. The conjunctive use studies in the IGNP Stage -II covers an area of about 7000 sq.km in parts of Jaisalmer, Jodhpur, Bikaner districts of Rajasthan. The conjunctive use study commenced from October 1995.
7. NAGARJUNA SAGAR PROJECT, ANDHRA PRADESH
Conjunctive Use studies in the Nagarjuna Sagar Project comprise of about 6350 sq.km area covering parts of Nalgonda, Krishna, Khammam and Guntur districts of Andhra Pradesh. The study area is located between N lat 16o 15' to 17 o 15' and E Long 79 o 10' to 80 o 20' falling in survey of India toposheet No. 56P, 56O, 65C and 65D. The study area is served by two major canal systems, left bank main canal and right bank main canal with nearly 91 distributaries. The studies were taken up from October, 1995 onwards.
A total of 110 number of key wells established in the month of Dec 1995, monitoring and analysis of water level data completed. Collection and analysis of all other data related to hydrogeology, hydrology, hydrometeorology, and canals have been collected and analysed.
Detailed hydrogeological surveys completed along with study of satellite imageries, the data analysed have been utilised for demarcating the areas irrigated by different sources, as well as demarcate areas under different crops. Availability and demand of ground water and surface water computed separately in space and time and matching of demand and supply positions in different blocks of the command have been refined as per the additional data. Ground water simulation study and generation of various alternative scenarios for conjunctive utilisation of ground water and surface water resources has been completed and also economic analysis has been carried out to arrive at optimal conjunctive use plan.
8. INDIRA GANDHI NAHAR PARIYOJNA STAGE - II, RAJASTHAN
The conjunctive use studies in the IGNP Stage -II covers an area of about 7000 sq.km in parts of Jaisalmer, Jodhpur, Bikaner districts of Rajasthan. The conjunctive use study commenced from October 1995. Monitoring of key wells established for the purpose, and analysis of all data related to hydrogeology, hydrology, hydrometeorology, and canals have been completed.
Changing water level situations after introduction of canal irrigation and status water logging, along with various causes of water logging have been studied in detail. Depth to water level zones for the year 1985 and 1996 have been compared to see the ground water regime changes. Availability and demand of ground water and surface water computed separately in space and time and matching of demand and supply positions in six zones of the command have also been completed. As the data available for in zone VI was not adequate for any meaningful interpretations the other five zones have been considered for changes in ground water regime. Remote sensing studies carried out to demarcate areas covered by various crops. Irrigation development has taken in zone I, II, and III only. The data for mathematical modeling has been collected for these zones. The area has been discritized in space, necessary maps required to carry out modeling have been prepared and grid wise tabulation of data entered into the computer, initial runs made for calibration of the model. Depending upon the demand and availability of water in space and time, various alternative scenarios have been generated and tested with the ground water model. Economic analysis has been done to arrive at optimal conjunctive use plan.
9. KOSI CANAL COMMAND AREA, BIHAR
The Kosi command canal taken up for conjunctive use studies covers an area of 4500 sq.km. falling in parts of Saharsa, Supaul, Madhepura, Purnea, and Ararea districts of Bihar. The command area is served by the eastern Kosi main canal. The studies have been taken up since October 1995.
Various state and central government departments have been contacted for relevant hydrological, hydrometeorological, agricultural, irrigation, canal flows data. Relevant data have been collected and analysed, further refinement for some of the data are under progress. Availability and demand of ground water and surface water computed separately in space and time and matching of demand and supply positions in different blocks of the command have been completed, refined of data for few blocks are under progress, as per the additional data.
Ground water simulation study in the Kosi command area for steady and unsteady state has been completed using the software PM3, (MODFLOW), developed by USGS. Various conjunctive use scenarios generated depending upon the availability and demand of water, for arriving at the optimal conjunctive use strategy.
10. GANDAK CANAL COMMAND, BIHAR
Gandak canal command area taken up for conjunctive use studies covers an area of nearly 6000 sq.km. It covers parts of east Champaran, West Champaran, Muzaffrapur and Vaishali dis tricts falling between Gandak and Burhi gandak rivers of Bihar. The entire area has been incised by Tirhut main canal (TMC). The study has been taken up since October 1996. Monitoring of 144 numbers of key wells on monthly basis is under progress. Data related to hydrogeology, hydrology, hydrometeorology and canals have been collected from various sources and being analysed. The software CROPWAT, developed by FAO has been utilised for computation of crop water demand. Detailed hydrogeological surveys and remote sensing studies completed in the area. Computation of availability and demand of water in space and time have been completed on prorata basis. The ground water simulation study has been carried out to generate plan for optimal Conjunctive use of surface and ground water.
11. SRIRAM SAGAR CANAL COMMAND AREA, ANDHRA PRADESH
The study area lies between north latitudes 18°00' to 18°24' and east longitudes 79°09' to 79°47' and falls in Survey of India Topographic maps 56 N/3, 7, 8, 11 and 12. The gross command area is 1680 sq.km and covers parts of Karimnagar and Warangal districts in Andhra Pradesh.
The project area is within the drainage basin of the river Godavari. The major source of irrigation is from Sriramsagar project canal network mainly on Kakatiya canal, which runs for 284 km. The study area is confined to 146 to 234 km with a designed discharge of 14,158 cu.m/sec.for irrigating the localized area of 84,962 ha.
Availability & Demand of water
The surface water availability has been estimated mainly on the basis of canal water releases in the study area and has been worked out 568 MCM. Actual areas irrigated and their demands were worked out based on the crop water requirements.
The ground water potential in the area is computed following the GEC 1997 norms and is estimated as 483 MCM which includes recharge to ground water due to rainfall infiltration, canal irrigation and return seepage. The present draft which includes draft due to irrigation and domestic and industrial draft up to year 2025 is around 227 MCM leaving a balance of 256 MCM for future use. The total water resources available in the study area is 1051 MCM from both surface and ground water sources.Conjunctive Use Planning
Based on the irrigation water requirements, the demands for the entire localized area has been estimated as 742 MCM. This can be met with the available surface water resources of 568 MCM plus 174 MCM of ground water leaving a balance of 309 MCM of ground water for creating additional irrigation potential.
At present 40% of the localized area is being irrigated for which the irrigation water demand is calculated as 343 MCM. The actual utilis.ation is 795 MCM which shows that 452 MCM of the resource is being wasted due to crop pattern violation and poor management practices.
By utilizing the balance ground water resource of 309 MCM an additional irrigation potential of 31,000 ha can be created for which 20,600 borewells needs to be constructed. For implementing this plan the investment cost will be around Rs. 80 crores and the benefits that are expected will be around Rs. 240 crores. The Benefit - Cost ratio works out to be 3.07.Recommendations
To solve the water shortage problems in the canal command area, implementation of the proposed ground water development plans is recommended in conjunction with surface water. If implemented judiciously 90% of the water starving areas can be brought under ground water irrigation. The remaining 10% per cent of the area also can be brought under irrigation by modern water saving methods like sprinkler/drip irrigation.
Farmers should be educated regarding excess utilization of water in the head reaches and violation of cropping pattern. Canal water supply management needs improvement to avoid wastage of water in the head reaches and for equitable distribution of available water as per the designed discharge for the entire canal system by strictly adopting canal roastering techniques.
Modernization of canals and distribution system is recommended by lining the canals and replacement / repairs of canal regulators to minimize the conveyance losses and proper management of water distribution. The water allocations at the field head should be restricted to the crop water requirement after duly considering the percolation losses.
Since huge investments are required to implement the plan proposed Farmers Co-operative Societies Programme is recommended so that loans from the financial institutions like NABARD can be sought through the formation of such societies. This will facilitate better management of agricultural activities and efficient irrigation practices and to obtain ambititious farm benefits.
Finally it is recommended that for implementing the plan experienced ground water scientists are to be employed while selecting and pinpointing the exploratory sites. All the well sites are to be located strictly within the ground water potential zones and follow the well spacing norms meticulously on scientific basis.
12. WESTERN YAMUNA CANAL COMMAND AREA, HARYANA
The Western Yamuna Canal (WYC) command area is located between the north latitudes 28°20' & 30 29' and east longitudes 75°48' 77°35' and forms eastern central and southern part of the Haryana State. It has a geographical area of about 13,543 sq.km. About 45 sq.km area of Chhacharauli block of Yamuna Nagar district lie within the Kandi Zone i.e. the piedmont deposits forming 2-3 km wide fringe zone along the outer margin of Siwaliks. The command is identified in blocks falling fully in the districts of Karnal, Panipat, Sonepat, Rohtak and Jhajjar and partly in the districts of Hisar, Bhiwani, Jind, Yamunnagar, Gurgaon and Rewari. A total of 49 blocks falls in the command area.
Problems in the area
The WYC command area forms a part of Upper Yamuna Basin and Inland Alluvial Basin. The command are has a state boundary with Uttar Pradesh on the eastern side and National Capital Territory Delhi on South-eastern side. It is served by the Western Yamuna Canal System, which takes off from river Yamuna at 'HATHNI KUND BARRAGE', constructed across river Yamuna, 3 km U/sof Tajewala Head Works.
The area is facing both the problem of declining water level in central, north and all along the river Yamuna covering approximately 8060 Sq.Km. and rising water level covering an area of approximately 5480 Sq.Km. Long-term behavior of water table (May'1985- May'2004) reveals that in central, north and all along river Yamuna in an area of 8060 sq km, water level has gone down by 10 to 16m. Also, in the south and southwestern part an area of 5480 sq.km. water level has risen by 5 to 10m.Causes of water logging
Due to intense canal irrigation water table in certain area of Rohtak. Jhajjar, Hisar Sonepat and Panipat districts has risen to shallow depth creating water logging conditions. The water logged area has increased from 17 sq.km. in pre monsoon 1985 to 176 sq.km. in pre monsoon 2004. In post monsoon it was 851 sq.km. in 1985 and increased to 2830 sq.km. in 1995 and then decreased to 816 sq.km in 2003 post monsoon.
Availability & Demand of water
The total ground water resources have been worked out to be 5966.19 MCMI for the year 2002 based on GEC-1997 norms, out of which 5077.23 MCM/yr is considered as reserved for irrigation. The gross draft is calculated to be 4793.93 MCM. Out of 49 blocks falling in WYC area 25 blocks fall in White category, 09 blocks in Grey category and 15 blocks in Dark category. The blocks of white category generally fall in the area where ground water quality is brackish. Some blocks of Yamuna nagar, Panipat, Sonepat, Rohtak, Jhajjar, Bhiwani, Hisar, Jind Karnal Gurgaon and Rewari districts have surplus ground water to the tune of 1804.90 MCM for future ground water development.
The total surface water resource available in the are has been calculated as 2954.76 MCM, out of which 1742.55 MCM is supplied during non monsoon and 1212.21 MCM is during monsoon periods. The total water demand for various sectors namely domestic, livestock, irrigation and industrial have been computed to be 10,148.75 MCM, out of which 9220.24 MCM (90.85%) is pertains to agriculture sector i.e. irrigation, showing that the largest consumer of water is this sector and only a negligible part is used by domestic livestocks, and industrial sectors.Conjunctive Use Planning
The total area identified for artificial recharge is 4330.35 sq.km. This area has the potential to store 2561.97 MCM of water. However, 144.65 MCM of non-committed monsoon runoff is available for artificial recharge. To recharge this water 3364 No of structures will be required. The recharge structures feasible for the Western Yamuna Canal Command area are recharge well, injection well deep trenches, gabion structures at the Yamuna river bed, skimming well etc.
The Jagadhari, Radaur blocks and parts of Chhachrauli block of the Yamuna nagar district, Ladwa block of Kurukshetra district, Indri and Nissang blocks and parts of Karnal Gharaunda, Assandh blocks of Karnal district, Samkalkha, Madlauda, Panipat, Bapoli blocks and part of Israna block of the Panipat district, Ganaur, Mundlana blocks and parts of Sonepat, Rai, Kharkhauda, Kathura, Gohana blocks of Sonepet district, Parts of Rohtak, Lakhan Majra, Sampla blocks of Rohtak district, Parts of Bhadurgarh and Jhajjar blocks of Jhajjar district, Farukknagar of Gurgaon district, Jatusna block of Rewari district, Safidon, Pillukhera blocks and parts of Alewa and Jind blocks of Jind district, Parts of Narnaud, Hansi, Hisar blocks of Hisar district are feasible for artificial recharge.
13. RUSHIKULIA CANAL COMMAND AREA, ORISSA
Conjunctive use of surface water and ground water studies was taken up by CGWB, South Eastern Region, in the Rushikulya Canal Command Area, Ganjam district. The major irrigation canal of the system is the Rushikulya Main canal, which off takes on the right of Janivilli Anicut and covers a total length of 87.417 Km. The canal has 16 numbers of distributaries off taking from it. The total length of distributaries with their minors and sub minors is 152 Kms. The Rushikulya Main Canal integrates 88 numbers of tanks and 11 numbers of channels through its canal system and was originally designed to command an area of 33,525 Ha.
Major part of the area is underlain by the hard crystalline rocks of Archaean age. Sediments of recent to sub-recent age occur along the coastal tract and as discontinuous patches along the Rushikulya river. Laterite also occurs in the area as capping over the older formations.
Problems in the area
Water logged condition is mainly confined near to the head reaches of Rushikulya Main Canal near its origin between Janivilly Anicut and the Rushikulya River. Small water logged patches could also be found near the bottom reaches of the command area extent near Gopalpur and near Ganjam. The shallow aquifers comprising the weathered residuum, vary in thickness from 5 to 15 m and offers vast scope for ground water development through open wells. The exploration carried out by the CGWB indicated that in general, the saturated fractures are within the depth range of 125 mbgl in the hard rock areas which recorded a discharge varying from 3 to 16 Ips with draw down of 34 to 36 m.
Conjunctive Use Planning
The study area has shown a positive recharge trend in the post-monsoon season. There is no sign of any fall in the area. The fluctuation range varies from 0.43m to 10.63 m. Thus the ranges described below refers to the rise in post monsoon water level over that of pre monsoon water level.
Chemical quality of ground water from the Rushikulya command area have been studied in detail from the water samples collected from the command area and its environs from the established monitoring wells, exploratory wells and surface water body as well. Most comprehensive dataset exist for the phreatic aquifer with samples being collected from all the monitoring stations both during pre and post monsoon period.
104 nos. of key wells was established in the pre-monsoon season in the blocks of Rangeilunda, Chatrapur, Ganjam, Purushottampur, Hinjlicut, Dighapahandi, Sanakhemundi, Sheragada, Aska, Dharakote, Sorada, Belaguntha and Chikiti blocks and the relevant well details have been collected. Apart from the established key wells, 63 nos. of existing NHS have also been earmarked for monitoring in the canal command area.
Mathematical Modeling Studies
Preliminary studies like data collection, baseline information gathering etc for carrying out mathematical modeling were partly done. The water level of observation well related data has been entered into the database. However, it is needed to critically identify the gaps for proceeding for the mathematical modeling.