STATUS OF SUB BASINLEVEL WATER RESOURCE & WATER AVAILABILITY
1.1 Government of Uttar Pradesh have adopted a "State WaterPolicy" and accordingly, have drawn an Action Plan for implementation of thesame. To achieve the objectives of the "State Water Policy" the Government ofUttar Pradesh has received a credit from International Development Associationequivalent to US$150 million towards the cost of "Uttar Pradesh Water SectorRestructuring Project", through the Government of India. The UPWSRP envisages acomprehensive program of reforms in management of State Water resources ingeneral and irrigation, drainage and ground water in particular.
1.2 Redesign / design for the purposes of rehabilitation andmodernization of irrigation and drainage systems of Haidergarh branch in itslength from km 0.0 to km 22.98 and the Jaunpur branch in its entire length,covering a Gross Command Area of about 6,00,000 ha and a Culturable CommandArea of about 3,00,000 ha and associated in a network within the Gomti and Saisub basin herein after described as pilot project area and piloting ofreplicable management options for sustain irrigation and drainage operations isone of the main objectives of the UPWSRP.
1.3 The contract assignment stipulates the following inrespect of sub basin level, water resource status and water availability.
(i) Sub basin level water resource status : "In order tofulfil the objectives of Integrated Water Resources Development and Management(IWRDM), the Consultant shall evaluate all competing uses at the sub-basin levels,and review the sub-basin level water resources in terms of potential, actualuse and allocation to the various sectors in order to evaluate the amounts ofwater available for irrigation in the areas under study from differentsources."
(ii) Water availability : "The irrigation systems of theselected areas receive their allocated water at the head works through adiversion structure. The Consultant will evaluate the long-term stream flows atthe diversion point and upstream in the river system. Taking into considerationthe other competitive water demands (domestic, industrial, power and demand ofother irrigation systems), the Consultant will evaluate the water available forirrigation in the systems under study in terms of long-term annual volumesduring normal, dry and wet years. The Consultant will also analyze the streamflow fluctuations during the year on a daily, ten-daily and monthly basis.Irrigation water requirements will be evaluated based on the crop waterrequirements of the proposed revised cropping pattern, effective rainfall,losses in the conveyance and distribution systems (on farm and conveyanceefficiencies) and leaching requirements to prevent soil salinization. Theeffect of improved modern technologies will be taken into consideration inevaluating the irrigation requirements. Accepted methodologies for calculatingReference Crop Evapo-transpiration and crop water requirements usingstate-of-art methods will be adapted and applied. GIS methods shall be used toproduce reliable and updated maps of agricultural land use, and incorporationof these maps in the procedure for estimating irrigation water demand.
Additional sources ofirrigation water are ground water (replenished from rainfall and seepage fromthe irrigation system) and return flows (drainage water). In order to preventwater logging and salinity problems, it will be necessary to extract (and use)ground water that is being replenished by infiltration of surplus irrigationwater and seepage in conveyance system. The Consultant will also considerlining of the canals (mains and distributaries) in light of the anticipatedinfiltration to ground water and resultant water logging on the one hand, andthe need to ensure water supply to tail end farmers on the other. The Consultantwill evaluate the technical and economic feasibility of the canal lining optionfor presentation of the Review Committee for decision with the InceptionReport."
2. Sub Basin Level WaterResource Status Evaluation
2.1 The area bounded within Gomti and Sai river sub basin isthe delineated project area. The water resource in this project area comprisesof two distinct sources (i) surface water (ii) underground water.
2.2 The surface water in the project area which providesirrigation facilities in the command through a vast network of branch,distributary and minor canals is transported from outside the sub basin throughthe main feeder canalof Sarda Sahayak Projectfrom rivers Ghaghra and Sarda. The allocation of water to the project area fromSarda Sahayak FeederCanal has been decidedunder the Sarda Sahayak Project based on the assessment of dependable flows inthe two rivers during different months of the year. The discharge in Sardariver during the monsoon season (Kharif) is sufficient to meet the design headdischarge capacity of the feeder canal. During non monsoon period (Rabiseason), the discharges in river Sarda drops considerably and the supplies ofriver Ghaghra are diverted through alink channel between the Sarda and Ghaghra barrages to meet the ProjectIrrigation demands. Haidergarh branch which is the main carrier for the projectarea is allocated a head discharge of 165.5 cumec. The branch is planned to runwith its head discharge capacity for most part of the Kharif crop season whenthe supplies at the head works of the project are sufficient for meeting thetotal design requirement of the project. The Haidergarh branch, thereafter, isproposed to run with full discharge on a time sharing basis with other branchcanal systems of the Sarda Sahayak Project during the lean period of suppliesin the river.
2.3 The irrigation intensity in the Sarda Sahayak Projectwhich is uniform across the board for all the sub systems has been worked outon the basis of available supplies during the two crop seasons and water demandfor various crops planned. The proposed irrigation intensity in the project is115% (Kharif 67%, Ravi 48%). The 75%dependable flows as assessed at the time of formulating the project and thoseassessed now on the basis of analysis of actual data from 1981-2006 are givenin Annexure VII
2.4 The surface water flows are allocated only for irrigationand no other competitive demand is assigned to this resource. However, if anydemand for industrial and power development arises in course of time, the sameshall be met in consideration of the provisions of G.O. no. 1056/Sa.Kha and1192/98-27-Si-4 dated 16.4.1985 and 16.5.1998 respectively. As a generalprovision, when demands for these sectors are met from existing canal systems,the water delivered, is compensated through alternate sources by way ofarrangements and at costs as provided in the above Government Orders.
2.5 The replenishable ground water potential in the projectarea has been estimated as 1892.05 MCM and is a major source of water resourceand is suggested to be exploited not only for intensification anddiversification of agriculture but also to control ground water levels withinsafe zones to mitigate the problems of water logging. Water logging in theproject area is causing not only land degradation but also adversely affectsthe agricultural yields. In deciding the exploitable ground water resource, aminimum of 15% of the replenishable ground water resource has to be earmarkedfor drinking and domestic use of the local community.
3.1 SardaSahayak Project
Sarda Canal System wascommissioned in 1928 to provide protective irrigation in 18 districts ofcentral and eastern parts of the State lying within the Ghaghra-Ganga Sub-basin.The Sarda Main Canalwhich was originally designed for a head discharge capacity of 270 cumecs hasbeen remodelled for its present head discharge capacity of 326 Cumecs. It takesoff from right side of the Banbasa Barrage, constructed across river Sarda indistrict Nainital of Uttaranchal State. The original culturable command areaunder this project was 25.4 lakh ha. with proposed intensities of irrigationfor the Rabi and Kharif crops as 17.4% and 15.3% respectively. The Sarda MainCanal is 44.3 km long and it bifurcates into Hardoiand Khiri branches having head discharge capacity of 153 cumec and 79.3 cumecrespectively. Bisalpur and Nigohi branches having head discharge capacity of 10cumec and 14.2 cumec also take-off at km 26.5 and 38.5 of the main Sarda canal.
3.2 With the development ofirrigated Agriculture in the command area of Sarda canal and higher consumptiveuse of water for maturity of crops due to changes in variety of seeds, theactual gross irrigation intensity in the lower parts of the Sarda canal commandcame down to 19 percent only.
3.3 In order to Augment thesupplies and extend irrigation facilities in the lower commands of Sarda canalsystem, Sarda Sahayak Project was envisaged. The main feature of the projectwas to utilize Sarda river flows, for Kharif season and Ghaghra river flows forRabi season by constructing barrages across river Sarda and Ghaghra and linkingthe two by a link channel. The project was commissioned for partial benefits in1974 and the main carrier along with distribution system developed in stagesupto 2000. Districts benefited by this project are Sitapur, Barabanki, Lucknow, Raibareli, Sultanpur, Faizabad, Amebedkar Nagar,Pratapgarh, Allahabad, Jaunpur, Azamgarh, Mau,Ghazipur, Varanasiand Ballia. The main features of Sarda Sahayak Project are:
· 716 M long Girija barrage across river Ghaghra nearKatarnia ghat in district Bahraich.
· Link channel 28.7 km long and 480 cumec dischargecapacity connecting Girija Barrage and Sarda Barrage.
· 408 M long Sarda Barrage across river Sarda in districtLakhimpur Kheri.
· Feeder Channel 258.8 km long and 650 cumec dischargecapacity, crossing rivers Gomti and Sai in the Ghaghra-Ganga sub-basin.
· 1378.0 km main canal and branches and 14684.0 kmdistributaries and minors.
· 17752 km of drains with masonry works.
3.4 The main discharge parametersof the Feeder Channel and major canals off-taking there from are as detailedbelow:
Nameof Canal Location / chainage Discharge
1. Feeder Channel head regulator Km 0.00 780.0 Cumec
2. Silt ejector (design discharge) Km 0.30 130.0 Cumec
3. Feeder Channel Km26.3 650.0 Cumec
4. Dariyabad Branch Km104.0 242.0 Cumec
5. Barabanki Branch Km119.7 36.0 Cumec
6. Gomti aqueduct Km153.0 357.0 Cumec
7. Haidergarh Branch Km171.5 165.5 Cumec
(i) Jaunpur Branch Km22.98 123.2 Cumec
8. Allahabad Branch Km 258.8 149.0 Cumec
9. Pratapgarh Branch Km258.8 32.76 Cumec
3.5 The project will ultimatelyprovide irrigation facilities in a culturable command area of 2.0 million ha ata proposed intensity of 115%. However, at present the culturable command areacovered is 1.67 million ha and accordingly the proposed crop-wise irrigation is0.804 million ha for Rabi and 1.121 million ha for Kharif. An index map ofSarda Sahayak Project is enclosed (Figure-1).
4.1 Discharge Data
The project authoritiesestablished gauge sites on each river near the proposed sites of constructionof barrages on rivers Ghaghra and Sarda. Observed daily discharge data at thesites of Sarda Barrage & Ghaghra Barrage collected. The observation ofgauge discharge started since June 1969. A perusal of the data reveals thefollowing :
4.1.1 Data from June 1969 toMay 1981
(i) At Sarda Barrage site, Pondlevel has been indicated although there was no ponding till June 1979. D/Sgauge is shown from 12thSeptember, 1979 to September, 1980 after completion of barrage.Discharge data is shown irregularly & no correlation is available betweengauge and discharge. No data is available from 18th September to endof May 1981. Thus entire data from June 1969 to May 1981 can not be used foranalysis.
(ii) At Ghaghra Barrage, no gaugedischarge data is available upto December 1975. From January 1976 to December1978, discharges are indicated but there are many missing data in between. Inthe absence of any gauge data, it is difficult to estimate the missing links.Since January 1979, gauge as well as discharge data is available upto 10th January 1981and thereafter no data is available. Thus, this data would also not provideuseful information.
4.1.2 Data from June 1981 toMarch 2006
Since June 1981, Continuous data for both the rivers at the two Barragesites is available. This data from June 1981 to March 2006, for about 25 years,has been considered for long term analysis.
4.2 Water Availability years
4.2.1 Evaluation of long term annualvolumes during Normal, Dry and Wetyears are the basic requirement for evaluation of longlearn steam flows. Also FLOW fluctuations on a daily, ten daily and monthly bases need to beanalyzed. Keeping this in mind, evaluation of water availability has been donewith following considerations:
Normal year : Run offassessed on the basis of 50% dependability, 50%
dependable flows of the years.
Dry year : Yearswhere the runoff is less than 90% of the years, 90%
dependable flows of the years.
Wet year : Yearswhen the total runoff is more then the 25%
Further, since existing canal capacities and agricultural planning isbased on the run off which is available in 75% of the years, the wateravailability in 75% of the years has also been analyzed to make a comparisonwith the original design.
4.3.1 Following methodology has beenadopted for the analysis :
(i) Recording of observed dailydischarge data for years from June 1969 to May 1981 (AnnexureI) & and from June 1981 to March 2006 (Annexure II).
(ii) Finding out Yearly volumes offlows and arranging them in descending order to find out Normal, Dry and Wet years (Annexure IIIA & IIIB).
(iii) Finding out Monthly averages and arranging them in descending order to find out Normal, Dry and Wetyears (Annexure IVA & IVB).
(iv) Arranging month wise 10 day averages for the years from June 1981 to March 2006 in descending order forGhaghra and Sarda rivers to find out Normal, Dry and Wet years. (Annexure V).
(v) Sarda Sahayak Project isplanned on the basis of 75% dependable flows in the two rivers. Saryu Canal Project, whichis under construction, has been planned to utilize the monsoon flows of riverGhaghra. During non-monsoon period, Ghaghra river discharges can be diverted toSaryu canal only after meeting the Sarda Sahayak commitment. Net wateravailability on 75 % dependability which has been considered in the twoProjects has been worked out on 10 days average, monthly average and yearlybasis by keeping in view the above considerations and are shown in Annexure VI.
(vi) The net availability from Ghaghra and Sarda rivers is the water availablefor irrigation use in the Sarda Sahayak Project. The combined 75% dependable discharge,as assessed on the basis of present analysis and its comparison with theoriginal project provisions are shown inAnnexure VII.
5.1.1 10 days Average Data
Month wise 10 daily averagedischarge data arranged in descending order are shown in Annexure V. Theaverage discharges during wet, normal and dry periods for Ghaghra and Sarda rivers 75% dependability have been worked outand are given in the Table-1 below :
Table 1 : Average Water Availability in Ghaghra / Sarda Rivers on 75% Dependability in cumecs
The pattern of flows in wet,normal and dry years as well as on 75% dependability in rivers Ghaghra andSarda is shown in Figures 2 and 3 respectively.
Figure 2 : Ghaghra RiverFlows on 75 % Availability (10 days average basis)
Figure 3 : SardaRiver Flows on 75 %Availability (10 days average basis)
The results indicate :
(i) During monsoon period, full design headdischarge of 780 cumecs can be had from Sarda river during 21st Julyto 20th of September even in dry Years. Adequate discharge isavailable for the remaining monsoon period from Ghaghra river for running of Feeder Canalat its full designed capacity.
(ii) During Non-monsoon period, averagedischarge from river Ghaghra & Sarda reduces to 335.8 and 41.8 cumecsrespectively during February in normal years and are in accordance with theoriginal provisions. Additional requirements has to be met from ground water resource.
5.1.2 Monthly Average Data
Average discharges during each month in the two rivers have beentabulated in Annexure IIIA & IIIB. The average discharges available during wet, normal and dry years havealso been worked out. The result show better availability of discharges. Duringnon-monsoon period, minimum average discharge available from Sarda &Ghaghra rivers in normal years are 59.96 and 357.15 cumecs respectively duringthe month of February and are slightly higher than the original provisions.
5.1.3 Yearly Data
On yearly basis, following are the results as shown in Annexure IIIA& IIIB.
(i) Wet year 1985 Total availability 0.462 Lac MCM
(ii) Normal year 2001 " 0.311 "
(iii) Dry year 1997 " 0.260 "
(i) Wet year 1992 Total availability 0.360 Lac MCM
(ii) Normal year 1983 " 0.276 "
(iii) Dry year 2002 " 0.139 "
The 10 days average discharges during the aforesaid years would determinewet, normal and dry year water availability. On yearly basis, it may be seen :
§ Wet year discharges in riverGhaghra, before monsoon from January to June, are lowest.
§ Wet year discharges in riverSarda, during January to March, are lower as compared to normal year.
As per Project report of Sarda Sahayak, water availability has beenassessed corresponding to the 75 % dependability year. On this basis, dischargedata of 10 day average, monthly average and yearly basis has been analyzed andresults are presented in Annexure IIIA, IIIB,IVA, IVB and V. After implementation of Sarda SahayakProject, another project, Saryu Canal Project, off taking from left bank ofGhaghra river, has been envisaged and is under construction. The Saryu projectwill utilize monsoon discharges of Ghaghra river to its full designed capacitywhich is not required for Sarda Sahayak during this period. Certain provisionsfor Rabi irrigation during the month of October, November and first 10 days ofDecember has been made in Survey but these can be made available only aftermeeting the requirements of Sarda Sahayak Project. Keeping this in view, netdischarges available from Ghaghra river on 10 days average, monthly average andyearly basis have been found out and are appended in Annexure VI. The month wise combined availability fromSarda and Ghaghra rivers has been indicated in AnnexureVII and compared with original project provisions.
The correct assessment of water availability as per standard practices isto analyze 10 days average data. The monthly average data can be relied to anextent. But finding out water availability on the basis of total yearly flowswould be erroneous. The analysis of 10days and monthly average data reveals that water availability in Sarda Sahayakfeeder canal is more or less according to original project provisions whereason yearly basis, river flows are Slightly higher from January to May but almostdouble in October and 10-20 % higher during November & December. Thevariation of flow assessed on yearly, monthly and daily with those as assessedin original Sarda Sahayak Project is shown in Figure4.
Figure 4 : Variation of Combined available flowson 75 % Availability
Forintensification & diversification of agriculture in the command area, thecropping intensity is to be increased substantially to 175 – 200 % from theproposed intensity of 115 %. This will require additional water which has to bemet from ground water. Since certain areas in the entire Project area is waterlogged, it will help in lowering the ground water and would increaseproductivity of the land as well.