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CHAPTER – III

HYDROLOGY AND WATER ASSESSMENT

3.0 General

As decided during the meeting of Coordination Committee of Water Resources Department Madhya Pradesh and NWDA held on November 3, 2010 at Bhopal and subsequent decisions taken in various meetings held at different levels with officials of Ministry of Water Resources, Govt. of India, Govt. of MP and NWDA, the joint visit of senior officers of NWDA and MP Water Resources Department was conducted for finalization of location of project sites in the Upper Betwa region.

NWDA has also carried out the survey of L-Section of Betwa river between Neemkheda and foreshore of Rajghat project (about 216 Km) to finalize the locations of proposed barrages, on Betwa river. The FRL of Rajghat dam is 371 m and bed level of Betwa river at Neemkheda dam site is 415 m. Therefore, only 44 m head is available for construction of barrages, two existing schemes for supply of water to Bharat-Oman Gas Refinery and J.P. Thermal Power Project near Bina. Considering the available head of 44 m, topography of Betwa basin and with the help of L-section of Betwa river, five barrages have been identified on main Betwa river to have a cumulative storage of 72.82 MCM water. The names of barrages are Neemkheda barrage, Parariya barrage, Narkheraghat barrage, Bijrotha barrage and Kotha barrage. After the joint inspection at various sites, the location of Tharr dam across Newan river (a tributary of Betwa river), Babnai dam across Babnai river (a tributary of Bina river) and Lower Orr dam across Orr river (a tributary of Betwa river) finalized and considered for the conducting Surveys & Investigations under DPR of Ken-Betwa Link Project, Phase-II. As a part of investigation of above projects, consultancy work for carrying out Hydrological studies and multi reservoir simulation studies was entrusted to National Institute of Hydrology (NIH), Roorkee. The scope of consultancy work awarded to NIH, Roorkee covered the detailed Hydrological Studies for proposed projects in Betwa Basin in the ultimate development scenario besides multi reservoir simulation studies

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of the Ken-Betwa link system. The studies were to be carried out within the ambit of the Memorandum of Understanding (MOU) between the Government of India and State Government of Madhya Pradesh and Uttar Pradesh signed on August 25, 2005 for preparation of Detailed Project Report of Ken-Betwa Link.

NIH, Roorkee has carried out hydrological and water balance studies for assessment of diversion flood and design flood, sedimentation analysis, multi reservoir simulation studies and hydrodynamic modeling and related studies for above to projects. The detailed report of NIH is enclosed at Volume-IV (Hydrology) and duly covered in present chapter and in Chapter-V Reservoir and Power.

Central Water Commission team led by Chief Engineer, Design (NW&S) visited the proposed sites for the construction of dams/barrages under Ken-Betwa Link Project, Phase-II to review the design features and proposed locations of Neemkheda Barrage, Narkheraghat Barrage, Kotha Barrage, Pararia Barrage and Tharr Barrage. The recommendations of the team are briefly described below:

Recommendations:

(a) The Kotha Barrage project is a promising project with the new pond level of El 396/397 m. The proposal for this project needs to be further supplemented with additional investigations and data.

(b) The pond levels of Tharr and Babnai need to be revised to bring their storage within the confines of the river banks as submergence for these projects lies in active agricultural land. However, prima facie it was observed that bringing pond below the banks in these barrages would result in very small storage and may not be attractive. Instead, a series of check dams can be thought of.

(c) The Bijrotha and Narkheraghat Barrage projects may be dropped as Kotha Barrage would serve their objectives.

(d) Neemkheda Barrage project also needs to be reviewed in view of the weir already constructed downstream of it and wide submergence envisaged by it.

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(e) The Parariya project can be dropped. Instead, the pond level of Barari can be raised to serve the objectives of Parariya project. However, for the present, MP state has already constructed a weir downstream of Pararia site which is taking care of the present day irrigation requirements envisaged from Pararia project. The site for Barari can be chosen depending upon the bridge requirement of local population. This would apportion part of the expenditure towards that serve making the project more attractive.

A review meeting was held under Chairman, CWC on November 26, 2013 to discuss above note in which various officers from CWC and NWDA participated. It was decided that DPR of Ken-Betwa Link Project Phase-II would be prepared with the following five components.

1. Lower Orr Dam

2. Neemkheda barrage

3. Barari barrage

4. Kesari barrage

5. Kotha barrage with increased pond level i.e. 396 m

Though NIH, Roorkee has carried out Hydrological studies considering 10 structures. Scope of present chapter has been restricted to above 5 structures only.

3.1 Brief Description of Betwa River Basin

The Betwa River originates in the Raisen district of M.P. near Barkhera village south-west of Bhopal at an elevation of 576 m above mean sea level. It flows in a north-easterly direction through M.P. and enters into U.P. near village Bangawan of Jhansi district. The total length of the river from its origin to its confluence with the Yamuna River is 590 km, out of which 232 km lies in M.P. and the rest 358 km in U.P. The river joins the Yamuna near Hamirpur in U.P. at an elevation of 106 m. The river basin lies between 22° 54' to 26° 00' N latitudes and 77° 10' to 80° 20' E longitudes. The total catchment area of the basin is 44335 Sq. km, out of which 30238 Sq. km lies in M.P. and the remaining 14097 Sq. km lies in U.P. The basin

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Figure – 3.1: Map of Betwa River basin

is saucer shaped with sandstone hills around the perimeter. A map of the Betwa basin is shown in Figure – 3.1.

During its course from the source up to the confluence with the Yamuna, the river is joined by a number of tributaries and sub-tributaries; the important among them being the Bina, Jamini, Dhasan and Birma on the right bank and Kaliasot, Halali, Bah, Saga, Narain and Kaithan on the left bank. Out of the 14 principal tributaries, 11 lie completely in M.P. and 3 lie partly in M.P. and partly in U.P. Betwa covers the areas of Bundelkhand uplands, the Malwa plateau and the Vindhyan scrap lands in the districts of Tikamgarh, Sagar, Vidisha, Raisen, Bhopal, Guna, Shivpuri and Chhatarpur of M.P. and Hamirpur, Jalaun, Jhansi and Banda districts of U.P.

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3.1.1 Topography & Geology

Upper Betwa sub-basin consists of the Vindhyan ranges running east-west in the upper reaches and the Malwa plateau in the middle and lower reaches consisting of scrap lands, barren lands and cultivated lands. The lower Betwa sub-basin consists of Shivpuri plateau. Lower reaches of the basin are mostly plain areas.

The different geological formations occurring in the basin include: Alluvium, Lateritic and Deccan traps. The lower part of the basin consists of quartzite, sandstone, conglomerate and limestone. The coarse-grained Bundelkhand gneiss overlying granite basement formations are found in the basin.

3.1.2 Climate & Rainfall

The climate of the basin is characterized by hot summer and mild winter. The temperature in the upper reach (sometimes) goes beyond 40 °C. The maximum and minimum mean monthly relative humidity are reported to be 83% (August) and 20.5% (April) respectively. The wind velocities in the upper reaches (varying between 6.6 km/h to 18.9 km/h) of the basin are generally higher than that of the lower reaches in the basin (varying between 2.9 km/h to 13 km/h). The cloud cover remains higher in upper part of the basin as compared to lower parts.

The basin receives more than 90% of its total rainfall during the south-west monsoon period (June to October). The upper part of the basin receives about 1100 mm of rainfall annually whereas in the lower part, the average annual rainfall is between 800 to 900 mm.

3.1.3 Land use & Soils

The total cropped area in the upper reach of the basin is higher (73%) compared to that in the lower reach (59%). There is a considerable portion of forest land in the upper reach of the basin. However, the culturable waste lands and area under fallow land are more in the lower reach of the basin compared to the upper reaches.

The upper part of the basin is dominated by deep black soil and medium black soil with patches of mixed red and black soil. The black soils

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are suitable for cultivation. Most of the Lower Betwa basin is covered by alluvial and plateau soils.

3.1.4 Present and Proposed Projects in the Betwa Basin

Rajghat dam, Matatila dam, Dukwan dam, Barwa Sagar, and Parichha weir are the major existing projects in the Lower Betwa basin while in the Upper Betwa basin, the existing projects are mostly of medium and small size. The only major project in the Upper Betwa sub-basin is Halali dam.

The Rajghat dam, Matatila dam, and Dukwan dam have been constructed over the main Betwa River whereas Halali dam is constructed on the Halali river and Barwa Sagar is located over the Barwa Nala near village Barwa in Jhansi district of U.P. The proposed Ken-Betwa link canal, through which surplus water of Ken River is to be diverted to Betwa basin, will terminate in this reservoir. Parichha weir, located near Jhansi city, is the last structure over the Betwa River which has been operational, primarily for irrigation, since 1906.

In the Phase-II of the Ken-Betwa Link project, it is proposed to construct a dam and 4 number of barrages in the Betwa basin viz. Lower Orr dam and Neemkheda, Barari, Kesari and Kotha barrages. A schematic diagram showing the locations of these proposed structures is shown in Figure – 3.2. The salient features of the proposed structures are presented in Table – 3.1. The line diagram of the Ken-Betwa link system is shown in Figure – 3.3.

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Figure–3.2: Location of proposed structures in Ken-Betwa Link Project Phase-II

A number of major, medium and minor projects are existing in the Betwa basin while some are under construction and some are under different stages of planning (surveyed, under-survey, pin-pointed). The details of various existing and proposed projects, with their design utilizations (in MCM), are available and the same has been used for computing net yield series at proposed project sites.

3.2 Database Development for the Betwa Basin

There are fifteen rainfall stations of IMD in/around the Upper Betwa basin whose data has been utilized in the present study. There is only one CWC, G & D site at Basoda in the Upper Betwa basin where long-term flow data are available since 1976. The data of this site has been used for

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development of rainfall – Runoff ( r – R) relationships in the study area for different monsoon months.

The average monthly meteorological data (maximum and minimum temperature, average humidity, wind speed, and cloud cover) of a few IMD stations in the region (Bhopal, Raisen, Vidisha, Sagar, Jhansi, and Guna) were available. This data has been used to compute normal monthly potential evapo-transpiration (ET0) values (by the Penman’s method) by using the CROPWAT 8.0 for Windows software. Based on the proximity of project site and the meteorological station, estimates of normal monthly evaporation depths of Raisen, Sagar, Guna, Jhansi, and Bhopal stations have been used for the simulation analysis of various proposed projects in the Betwa basin.

On the basis of above, as per studies carried out by NIH, Roorkee total storage proposed in 9 dams/barrages is 126.03 MCM and storage of 139.66 MCM comes out as suggested by CWC during their field visit and later decided in meeting convened by Chairman CWC on November 26, 2013 is considered in the study. However in respect of storage proposed by NIH, Roorkee i.e. Lower Orr dam as 371.80 MCM is considered in the study.

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Table-3.1

Salient features of proposed dams/barrages in Upper Betwa

Sl. No.

Name of Project

Name of River

Located in the district

Bed Level (m)

Full Reservoir Level FRL (m)

Catchment area sqkm.

Submergence Area (ha)

Storage Capacity (MCM)

Area to be irrigated (ha)

1 Neemkheda Betwa Raisen 415 426 1975.90 484 11.06 1659 2 Parariya * Betwa Vidisha 409 415 2694.51 335 10.04 1505 3 Barari Betwa Vidisha 400 407.7 5474.00 608 14.00 2000 4 Narkheraghat ** Betwa Vidisha 393 400 6616.82 567 19.85 2978 5 Bijrotha ** Betwa Vidisha 388 393 7830.92 502 12.55 1883 6 Kotha # Betwa Vidisha 384 388 8711.50 266 5.33 799 7 Kesari Keotan Vidisha 395 403.1 506.00 699 10.00 3000 8 Tharr * Newan Vidisha 414 424 512.89 585 9.26 1992

9 Lower Orr Orr Ashok nagar and Shivpuri 341 380 1843.00 2724 371.80 80360

10 Babnai * Babnai Sagar 421 434 497.00 1332 33.94 7144 Alternate Kotha barrage with increased pond level and dropping Bijrotha and Narkheraghat barrages as per decission taken by the team of experts of Central Water Commission, New Delhi.

Kotha (Alternate) Betwa Vidisha 384 396 8711.5 2210 104.6 21696

* Project now not considered as decided in meeting convened by Chairman, CWC on November 26, 2013. ** Narkheraghat and Bijrotha on river Betwa clubbed with enhanced pondage of Kotha barrage. # Pondage level increased from 388 m to 396 m.

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Fig-3.3: Line diagram of Ken – Betwa link scheme

3.3 Development of GIS Database for Betwa Basin

Geographic Information System (GIS) has been used to delineate the boundaries of various basins and sub-basins (of the proposed

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Figure – 3.4: Sub-catchment boundaries of project sites with drainage map

projects), extract drainage network, and compute thiessen polygons for various rainfall stations. ILWIS 3.4 GIS system (a GIS in free domain) has been used and Cartosat-II satellite digital elevation map (DEM) of the area has been used.

The drainage network, which is required to locate various project sites in the basin and to delineate sub-basin boundaries of each project site has been obtained from two sources: a) Survey of India (SOI) toposheets at 1:250,000 scale, and b) delineation from the Cartosat-II DEM using GIS analysis. The comparison of two delineations shows a very close match between the two drainage networks. Next, based on the location of 10 proposed project sites in Upper Betwa basin on drainage network, sub-basin boundaries have been delineated on the map by using GIS analysis. The sub-basin boundaries of proposed project sites (along with the derived drainage network) are shown in Figure – 3.4.

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Figure – 3.5: Location of rainfall stations in Upper Betwa basin

The areas of different sub-basins computed using GIS analysis are observed to be very close to the areas provided by NWDA. The total catchment areas at proposed project sites that have been used in the study are given in Table – 3.2.

Table – 3.2 Total catchment areas upto proposed project sites in

Upper Betwa basin as studied by NIH

Structure Name Catchment area (Sq. km) Neemkheda 1975.9 Barari 5474 Kotha # 8711.5 Kesari 506.0 Lower Orr 1843.0

# Pondage level increased from 388 m to 396 m. There are fifteen rainfall stations of IMD in and around the Upper Betwa basin whose data has been utilized in the present study. The layout of these stations is shown in Figure – 3.5.

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At the Basoda G & D site of CWC in the Upper Betwa basin, the catchment area has been worked out from the GIS analysis and it comes out to be 7726.16 Sq. km. However, Bhopal Lake lies in the upstream part of the basin with a catchment area of 354.63 Sq. km which obstructs most of the flow from the catchment and water in the Lake is utilized for various purposes. Because of the very marginal spill from the Bhopal lake, the catchment of the Bhopal lake (354.63 Sq. km) has been excluded from the analysis. Therefore, the area of Bhapal lake catchment has been deducted from the catchment areas of all those project sites which lie in the downstream of the Bhopal lake.

Thiessen polygons of various rainfall stations have been prepared and overlaid with the sub-basin map of proposed project sites and Basoda catchment in GIS. Thiessen weights of different rainfall stations in sub-basins of each project site and Basoda sub-basin have been worked out as given in Table – 3.3.

Table – 3.3 Thiessen weights of rainfall stations in sub-basins of

proposed structure & Basoda site RF_Station Neemkheda Barari Kotha Kesari Lower Orr Basoda

G&D siteGoharganj 0.5436 0.1172 Sehore Bhopal 0.3883 0.2535 0.1628 Raisen 0.0681 0.0335 0.1254 Gairatganj 0.0631 0.1069 0.0568 Begumganj Vidisha 0.4212 0.0650 0.1711 Berasia 0.2227 0.2015 Basoda 0.0060 0.7389 0.8281 0.0778 Khurai 0.0491 Kurwai 0.2120 Sironj 0.0003 0.0874 Ashok Nagar 0.6136 Chanderi 0.3521 Pichore 0.0340

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Table–3.4 gives brief details of various existing and proposed medium and minor projects in the Betwa basin along with their design utilizations.

Table – 3.4 Annual planned utilizations (MCM) of medium and minor projects in

different sub-basins

Sub-basin

Medium projects Minor projects

Name Intercepted catchment (Sq. km)

Annual design

utilization (MCM)

Number

Annual design

utilization (MCM)

Neemkheda Kerwan Kaliasot

65.894 40.021

22.60 34.41

18 111.99

Barari Kurana 74.741 26.76 26 60.978 Kotha - - - 8 20.089 Babnai - - - 7 18.89 Kesari - - - 7 12.735 Lower Orr - - - 19 39.715

The utilizations from existing projects are used in the computation of virgin flows at Basoda G & D site (for development of rainfall – Runoff relations) while utilizations from all the projects is considered for deriving net availability of flows at various proposed project sites in the ultimate stage of development.

3.4 Processing of Hydrological Data

The monthly rainfall data of 15 IMD stations and daily discharge data at Basoda G & D site of CWC have been utilized in the analysis. The rainfall data for the period from June, 1901 to May, 2009 has been used. The hydrological data processing software HYMOS has been extensively used for processing of rainfall and discharge data. All hydrological database has been imported in HYMOS software for processing and analysis.

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3.4.1 Processing of rainfall data

Due to the variable year of establishment of different rainfall stations with some missing values within the period of observation, rainfall data has been gap-filled. First, the correlations have been established among various rainfall stations. Correlation coefficients among different rainfall stations have been worked out in form of a correlation matrix. In addition, a distance matrix is generated among the stations. Using the correlation coefficients, the distance matrix, and the average annual rainfall, those stations (corresponding to each rainfall reference station) have been identified which have high correlation coefficient (say, > 0.80), which lie within a specified distance (say, < 70 km) from reference rainfall station, and whose average rainfall is close to ± 10% of average annual rainfall of reference station. The correlated stations for each reference station are given in Table – 3.5.

Table – 3.5 Correlated stations considered for different rainfall stations

Station Name

Station ID Correlated stations for different rainfall stations

Ashok Nagar

1 Chanderi Kurwai Sironj Pichore

Basoda 2 Gairatganj Khurai Kurwai Vidisha Begamganj 3 Gairatganj Raisen Vidisha Basoda Berasia 4 Basoda Bhopal Sironj Vidisha Bhopal 5 Berasia Goharganj Raisen Vidisha Chanderi 6 Ashok

Nagar Pichore Kurwai Sironj

Gairatganj 7 Basoda Begamganj Raisen Vidisha Goharganj 8 Bhopal Raisen Vidisha Sehore Khurai 9 Basoda Kurwai Begamganj Sironj Kurwai 10 Ashok

Nagar Basoda Khurai Sironj

Pichore 11 Chanderi Ashok Nagar

Kurwai Sironj

Raisen 12 Begamganj Bhopal Gairatganj Goharganj Vidisha Sehore 13 Bhopal Goharganj Raisen Vidisha Sironj 14 Ashok

Nagar Berasia Kurwai

Vidisha 15 Basoda Begamganj Bhopal Gairatganj Goharganj Raisen

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Figure – 3.6: Original (dot) and revised (solid) double mass curve for Berasia

The identified correlated stations are used for gap-filling of missing data and for developing double mass curve plots. Using the data of correlated stations, rainfall data for the missing period has been gap-filled using the normal-ratio method as given below:

Px = Nx * [P1/N1 + P2/N2 + ……………Pm/Nm] / m …(3.1)

where Px is the estimated rainfall of a station ‘X’ for a particular month, Nx is the average annual rainfall of that station, P1, P2,…………Pm are the observed rainfall of nearby correlated stations in that particular month and N1, N2…………Nm are the average annual rainfall of corresponding nearby correlated stations. This way, rainfall data of all stations has been generated from the year 1901 to year 2009.

Next, double mass curve technique has been used to check the consistency of rainfall data of all stations. For each rainfall stations, the correlated stations have been considered as base stations for preparing double mass curves. No significant change of slope is observed in the double mass curves for 9 (of 15) stations. However, six stations, viz. Basoda, Begamganj, Berasia, Goharganj, Sehore, and Vidisha showed some inconsistency and corrections for the rainfall data of these stations were applied backward from the years 1967, 1982, 1938, 1971, 1989, 1965, and (1988 & 1934) respectively. The double mass curve for the Berasia and Vidisha stations are shown in Figure – 3.6 and Figure – 3.7 respectively. Computed annual average rainfall for all the rainfall stations is shown in Table – 3.6.

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Figure – 3.7: Original (dot) and revised (solid) double mass curves for Vidisha

Table – 3.6 Average annual rainfall of various IMD rainfall stations

Station name Average annual rainfall (mm) Goharganj 1329.42 Sehore 1451.41 Bhopal 1188.87 Raisen 1251.79 Gairatganj 1276.77 Begumganj 1398.53 Vidisha 1237.34 Berasia 1037.84 Basoda 1214.99 Khurai 1208.02 Kurwai 1100.27 Sironj 1007.31 Ashok Nagar 917.99 Chanderi 965.71 Pichore 884.63

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After applying necessary corrections for the rainfall data, the annual rainfall series of various stations was tested for consistency by statistical tests, such as ‘t’ test and ‘F’ test. The annual rainfall series of various stations from 1901 to 2009 was divided into 2 series: Set-I (1901 – 1954) and Set-II (1955 – 2009). The rainfall data of most of the stations was found to be statistically consistent at different levels of significance (5% and 10%) as presented in Table–3.7.

In addition, using the thiessen weights of different rainfall stations in various sub-basins of proposed projects, average rainfall in each sub-basin was worked out and ‘t’ test and ‘F’ test were carried out for the average rainfall in various sub-basins. Most of the average computed rainfall series of various sub-basins was found to be statistically consistent at different levels of significance.

3.4.2 Processing of flow data

For the water availability study at various proposed projects, observed runoff data of Betwa River at Basoda G & D site for the period 1976 to 2009 has been used. Virgin flow has been estimated at Basoda and plotted with average rainfall in the Basoda catchment as shown in Figure – 3.8.

“t” and “F” statistical tests have been carried out for the observed and virgin flow series at Basoda. The annual flow series from 1977 to 2009 has been divided into 2 sets: Set-I (1977 – 1992) and Set-II (1993 – 2009). The flow series is found to be statistically consistent at different levels of significance (5% and 10%) as presented in Table – 3.8.

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Fig.3.8: Plot of average rainfall and virgin flow (mm) in the Basoda Catchment

Table – 3.8

Results of consistency tests (“t” test & “F” test) for the observed flow & computed virgin flow (MCM) at Basoda G & D site

Test Statistics Observed flow

series Virgin flow series

Mean of Set-I 3050.61 3285.78 Mean of Set-II 2879.06 3155.66 Standard deviation of Set-I 1682.89 1704.20 Standard deviation of Set-II 1488.84 1493.00 Value of S 1582.73 1595.20 t-statistic 0.3112 0.2342 F-statistic 1.2777 1.3029 Result of “t” test at 5% significance level

Accepted Accepted

Result of “t” test at 10% significance level

Accepted Accepted

Result of “F” test at 5% significance level

Accepted Accepted

Result of “F” test at 10% significance level

Accepted Accepted

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3.4.3 Estimation of normal evapo-transpiration in Betwa basin

Normal monthly evapo-transpiration estimates have been used in the simulation analysis of all proposed projects. The average monthly meteorological data (maximum and minimum temperature, average humidity, wind speed, and cloud cover) of a few IMD station in the region (Bhopal, Raisen, Jhansi, Sagar, and Guna) were available for the period 1961 – 90 and the same has been used to compute normal monthly evapo-transpiration (ET0) values in the study area. The CROPWAT 8.0 for Windows software has been used to compute the ET0 values. The cloud cover data (in Oktas) for different stations has been converted to sunshine hours (n/N) by using the standard procedure as specified in FAO – 56 (1998).

Based on the proximity of project site and meteorological station, estimates of evapo-transpiration of Raisen station has been used for Neemkheda, Barari, Kesari, and Kotha barrages while estimates of Guna station have been used for Lower Orr reservoir. The computed ET0 values for different stations using Penman’s method are given in Table – 3.9.

Table – 3.9 Normal monthly evapo-transpiration estimates at different stations in

Betwa basin

Month Normal monthly evapo-transpiration (ET0) in

mm/month at different stations Bhopal Raisen Sagar Guna Jhansi

January 117.49 77.81 102.92 92.38 73.78 February 140.00 95.48 116.76 111.16 89.04 March 217.93 155.00 172.05 176.08 146.01 April 275.40 211.80 210.60 225.60 194.10 May 345.03 275.90 252.96 286.13 240.56 June 248.70 209.10 207.00 237.60 213.90 July 131.44 128.03 121.21 131.75 142.29 August 104.78 105.71 97.96 103.23 125.55 September 134.10 127.80 120.00 130.80 133.50 October 160.27 130.20 146.94 140.12 130.82 November 125.40 93.60 122.70 103.20 93.30 December 107.88 75.33 101.06 86.18 74.40 Annual 2108.42 1685.76 1772.16 1824.23 1657.25

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3.5 Estimation of Water Demands

Assessment of water demands in foreseeable future for various purposes including domestic, industries, irrigation, hydropower and navigation etc. is essential for planning of water resources development and management. Water needs are to be met either from surface flows or ground water resources or a combination of both. The procedure adopted for estimation of water demands for different purposes in Betwa basin is detailed below.

3.5.1 Domestic and industrial demands

To assess the domestic and industrial water demands in a sub-basin, the population is assumed to be distributed uniformly in a district and based on the percent area of a district within each sub-basin, the human and livestock population is assessed. Table–3.10 shows the percent areas of districts in sub-basins of various projects.

Table – 3.10 Percent areas of districts lying in sub-basins of proposed projects

District name Sehore BhopalRaise

n Vidish

a Sagar

Ashok Nagar

Shivpuri

District area (Sq. km)

6578 2772 8395 7371 10252 4674 10298

Project name Percent area of districts within various sub-basins Neemkheda 2.66 25.25 8.89 - - - - Barari - 33.08 3.10 14.78 - - - Kotha - - - 5.08 - - - Kesari - - - 6.86 - - - Lower Orr - - - - - 36.69 1.24

The human population has been projected for the year 2050 AD on the basis of medium variant growth rate as given in U.N. Publication ‘World Population Prospects – 2010 revision’ (given in Table - 3.11). For livestock population, annual population growth rate of 1 % has been considered uniformly. The formula used for population projection is of the form:

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Pt2 = Pt1 * (1 + r/100)(t2 – t1) …(3.2)

where Pt2 is population at time t2, Pt1 is population at time t1, and r is the population growth rate (% per annum) between time t1 and t2.

Table – 3.11 Medium variant population growth rate (%) for India

(World Population Prospects–2010 revision)

Period 2005-10 2010-15 2015-20 2020-25 2025-30 2030-35 2035-40 2040-45 2045-50Growth Rate (%

per annum)

1.40 1.27 1.10 0.92 0.73 0.58 0.48 0.37 0.25

District-wise census data for human population (in the year 2011) and livestock population (in the year 2008) and their projected population for the year 2050 AD are computed as shown in Table – 3.12.

Table – 3.12 Present and projected populations in different districts (in thousand)

District Population from census data

Projected population in 2050 AD

Human (2011)

Livestock (2008)

Human Livestock

Sehore 1311 562 1719 853 Bhopal 2368 222 3106 337 Raisen 1332 692 1746 1051 Vidisha 1458 463 1912 704 Sagar 2378 847 3119 1286 Ashok Nagar 845 503 1108 764 Shivpuri 1726 943 2263 1432

Based on the human and livestock population in different districts and their percent areas in different sub-basins, domestic and industrial demands have been worked out in different sub-basins as per the following guidelines:

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a) Urban population is considered as 55.2% and rural population is considered as 44.8% of the total projected population.

b) Per capita water demands for urban, rural and livestock population is considered as 135 lpcd (litres per capita per day), 70 lpcd, and 50 lpcd respectively.

c) All urban water demands and 50% of the rural water demands are met from surface water while 50% of the rural water demands and full livestock demands are met from ground water.

d) Industrial demand is taken equal to the sum of the urban, rural, and livestock demands and it is fully assumed to be met from surface water.

e) 20% of the surface water supply (for urban and rural population demands and industrial demands) is consumed while 80% is regenerated back to the surface flows at downstream node. No regeneration is considered for ground water supply.

Based on these guidelines, the domestic and industrial water demands and regeneration have been worked out in different sub-basins. Computed gross and net water demands for domestic and industrial purposes from surface water resources (after accounting for regeneration) are given in Table – 3.13. Monthly distribution of net water demands in each sub-basin from surface water resources is given in Table – 3.14.

Table – 3.13 Projected population and gross and net surface water demands in

different sub-basins

Sub-basins Projected population (in

thousand) (2050 AD) Gross SW demand

(m3/day)

Net SW demand after accounting for

regeneration (m3/day)

Urban Rural Livestock Domestic Industrial Domestic IndustrialNeemkheda 544 441 201 88875 114378 17775 22876 Barari 753 611 248 123039 156821 24608 31364 Kotha 54 44 36 8766 12078 1753 2416 Kesari 72 59 48 11842 16315 2368 3263 Lower Orr 240 195 298 39214 60930 7843 12186

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Table – 3.14 Monthly net water demands (MCM) in different sub-basins for

domestic/industrial purposes

Sub-basin Jan Feb Mar Apr May Jun Jul Neemkheda 1.260 1.138 1.260 1.220 1.260 1.220 1.260 Barari 1.735 1.567 1.735 1.679 1.735 1.679 1.735 Kotha 0.129 0.117 0.129 0.125 0.129 0.125 0.129 Kesari 0.175 0.158 0.175 0.169 0.175 0.169 0.175 Lower Orr 0.621 0.561 0.621 0.601 0.621 0.601 0.621 Neemkheda 1.260 1.220 1.260 1.220 1.260 14.837 Barari 1.735 1.679 1.735 1.679 1.735 20.430 Kotha 0.129 0.125 0.129 0.125 0.129 1.522 Kesari 0.175 0.169 0.175 0.169 0.175 2.055 Lower Orr 0.621 0.601 0.621 0.601 0.621 7.311

3.5.2 Irrigation water demands

The existing and proposed major, medium, and minor projects in sub-basins of proposed projects and their planned utilizations have been given by NWDA. Halali is the only major project in Barari sub-basin with intercepted virgin catchment of 655.239 Sq km and annual design utilization of 227 MCM. Details of various medium and minor projects in the sub-basins of proposed projects along with their annual design utilizations are given in Table – 3.4. Since the present analysis is carried out at monthly time step, monthly utilization pattern is required. In the study area, Kaliasot and Kerwan are the two existing medium projects whose actual monthly utilizations from 1996 – 2006 were available. Average of these monthly utilizations has been used for these projects.

For other medium projects, average monthly values have been computed from the available monthly utilization patterns of four medium projects in the area (Kerwan, Kaliasot, Naren, and Kaithan) and same has been used to convert the annual design utilizations of proposed medium projects in the Betwa basin to monthly utilizations. The monthly utilization fractions used for medium projects to convert annual utilizations to monthly values is given in Table– 3.15.

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Table – 3.15 Monthly utilization fraction of medium projects used in present study

Month Average monthly utilization fraction for medium projects

June 0.012 July 0.000 August 0.000 September 0.000 October 0.057 November 0.257 December 0.226 January 0.165 February 0.127 March 0.072 April 0.038 May 0.046

Water from various minor projects is supposed to be utilized in accordance with the average rainfall pattern in the monsoon season from June to October. The average rainfall in various sub-basins has been computed and used to find the average rainfall pattern in the monsoon months in different sub-basins. The monthly utilization pattern adopted for minor projects in different sub-basins is given in Table – 3.16.

Table – 3.16

Monthly utilization fraction for minor projects in different sub-basins Sub-basin Jun Jul Aug Sep Oct

Neemkheda 0.116 0.345 0.338 0.175 0.026 Barari 0.119 0.342 0.332 0.178 0.029 Kotha 0.113 0.345 0.347 0.167 0.028 Kesari 0.113 0.343 0.345 0.171 0.029 Lower Orr 0.105 0.353 0.336 0.178 0.029 Basoda G & D site 0.117 0.343 0.337 0.175 0.028

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Further, the planned utilizations from the proposed projects has been worked out by using climatological approach with adopted cropping pattern. As per the guidelines, 10% of the utilization from major and medium projects is regenerated back as surface flow while no regeneration is considered for minor projects. The monthly demand pattern from various projects is shown in Table– .17 (a) and 3.17 (b). For barrage projects, transmission losses have not been considered as water is assumed to be utilized in the vicinity of the pond area through local pumping.

Table – 3.17 (a) Monthly design demands (MCM) from four proposed

Upper Betwa projects

Month Monthly design demands (MCM) from four proposed

projects including transmission losses Neemkheda Barari Kotha Kesari

January 1.70 2.94 13.468 3.54 February 1.28 2.94 10.982 2.88 March 1.28 2.40 10.982 2.88 April 0.00 0.00 0.00 0.00 May 0.00 0.00 0.00 0.00 June 0.00 0.00 0.00 0.00 July 0.00 0.00 0.00 0.00 August 0.00 0.00 0.00 0.00 September 0.00 0.00 3.108 0.00 October 0.00 0.00 0.00 0.82 November 3.09 3.28 18.751 4.94 December 2.32 3.50 14.711 3.86

Total 9.68 15.07 72.001 18.91

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Table – 3.17 (b) Monthly target demands (MCM) for different purposes from

Lower Orr reservoir Month Irrigation

demands of Lower Orr

canal in Shivpuri

district (MCM)

Irrigation demands of Lower Orr

canal in Datia district (MCM)

Transmission losses

(MCM)

Domestic supply (MCM)

Total demands (MCM)

January 53.79 6.01 2.079 0.500 62.39 February 38.22 4.27 1.477 0.500 44.47 March 22.29 2.49 0.861 0.500 26.14 April 4.02 0.45 0.155 0.500 5.12 May 4.89 0.55 0.189 0.500 6.12 June 38.19 4.27 1.832 0.500 44.79 July 13.73 1.54 1.132 0.500 16.90 August 14.41 1.61 1.157 0.500 17.68 September 14.05 1.57 1.106 0.500 17.23 October 13.79 1.54 0.775 0.500 16.60 November 38.44 4.30 1.486 0.500 44.73 December 36.99 4.14 1.430 0.500 43.06

Total 292.812 32.741 13.680 6.000 345.23

3.5.3 Environmental Flows

For the different proposed projects under Ken-Betwa Link, Phase-II in the Upper Betwa basin, the environmental flows have been computed from the estimated monthly flow patterns at the project site. For the monsoon months from June to October, 75% dependable flows have been computed on monthly basis and 20% of the 75% dependable flows in each monsoon month have been reserved for environmental and ecological purposes. For the non-monsoon months, average monthly flows have been worked out and 15% of the average monthly flows in different non-monsoon months have been reserved for environmental and ecological purposes.

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3.5.4 Import and Export

There is no import or export of water to and from the sub-basins.

3.6 Water Yield Assessment

Yield assessment refers to estimation of available water at a particular point in the basin with certain degree of dependability. In this study, water yield has been assessed at the sites of five proposed projects. Yield assessment requires long-term flow series at the project site. However, only flow measurement site available in the Upper Betwa basin is at Basoda (catchment area 7371.54 Sq. km excluding the catchment of Bhopal Lake) and the daily discharge data are available at this site for the period 1976 to 2009. In addition, monthly gap-filled rainfall data have been derived at 15 raingauge stations of IMD from the year 1901 to 2009. To develop long-term flow series, monthly rainfall – Runoff relationships for the monsoon season have been developed at Basoda and these relationships have been used in the sub-basins of the proposed projects to convert average rainfall in their sub-basins to flow series.

The observed flow at Basoda is affected by the upstream developments and these developments need to be taken into account for computing the virgin flow series at Basoda. Using the average rainfall in the Basoda catchment and virgin flow data at Basoda G & D site, monthly rainfall – Runoff (r – R) relationships have been developed at Basoda for the monsoon months (June – October). These relationships have been used in the catchments of five proposed project sites to convert their monthly sub-basin rainfall to flow volumes. For the non-monsoon period, the average proportion of flow in the non-monsoon period with respect to the monsoon period have been derived from the virgin flow series at Basoda (5.118 %) and flows in non-monsoon months have been estimated on the basis of proportionate flow (with respect to non-monsoon flow) in different months. After computing the virgin flows in catchments of various sub-basins, net flows (after deducting the water demands and utilizations of various existing and proposed projects) have been estimated in respective catchments. For the net flow series, dependable yield analysis has been carried out.

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The average rainfall series has been worked out in the catchment areas of five proposed project sites and in the catchment area of Basoda G & D site by using the rainfall series of 15 raingauge stations and their thiessen weights in different sub-basins. Daily observed discharge data at Basoda (in cumec) has been converted to monthly flow volume (in MCM). However, the observed flow at Basoda is affected by:

a) Spill from the Bhopal lake

b) Water utilizations and evaporation losses from existing Halali (S.A.S.) project

c) Water utilizations from existing Kaliasot and Kerwan medium projects

d) Water utilizations from minor surface irrigation projects.

3.6.1 Computation of virgin flows at Basoda

To compute the virgin flow at Basoda, the impact of Bhopal Lake and various major, medium, and minor projects has been considered. The data related to monthly spill from Bhopal Lake are available for the period 1992 – 2008. To compute probable spills from Bhopal Lake from 1976 – 1991, average monthly rainfall data for the period 1976 – 2009 in the catchment of Bhopal Lake (354.63 Sq. km) has been worked out. Bi-variate relationships have been developed between average rainfall and spill data for different monsoon months in catchment of Bhopal Lake so that spill in the period 1976 to 1991 and for the year 2009 could be estimated. From the observed spill series, it is inferred that spill from Bhopal Lake is quite marginal. Therefore, catchment of Bhopal Lake has been excluded from the yield analysis. The observed and computed spill series from Bhopal Lake has been subtracted from the observed flow at Basoda to exclude the impact of Bhopal Lake at Basoda G & D site.

The Halali dam (Samrat Ashok Sagar dam) is a major existing project located in the catchment of the Basoda G & D site. The dam was commissioned in the year 1976. To account for the impact of Halali dam on the flows of Betwa River at Basoda G & D site, the operation analysis for the dam has been carried out for the period 1976 - 2009. The spill from the Halali dam has been subtracted from the observed flows at Basoda and

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inflow to the Halali dam has been added to the observed flows at Basoda to account for the impact of dam. In addition, 10% of the Halali diversions have been added to the observed flows at Basoda to account for the regeneration of flows.

Kaliasot and Kerwan are the two existing medium projects located in the catchment of Neemkheda project site. Actual diversions from these projects have been provided by NWDA for the period 1996 – 2006. From these utilizations, average monthly utilizations have been worked out and 90% of the same (assuming 10% regeneration) have been added to the observed flows at Basoda starting from the year of completion of these projects (1973 for Kerwan and 1980 for Kaliasot) to account for impact of these projects on flows at Basoda.

There are 31 existing minor projects located in the catchment of the Basoda G & D site. These projects have been commissioned in different years. Design annual utilizations of these existing projects have been converted to monthly utilizations and the same have been added to the observed flows at Basoda G & D site starting from the year of commissioning of respective projects to account for the impact of these projects on the flows at Basoda. Computed virgin flows at Basoda G & D site are given in Table – 3.18.

Table – 3.18 Computed virgin flows (MCM) at Basoda G & D site

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1976 26.67 327.80 879.87 815.78 41.94 19.50 42.59 1977 6.08 6.40 6.11 1.22 1.58 275.42 738.33 2820.84 2273.49 261.45 94.74 74.30 1978 16.00 18.73 13.69 7.01 6.22 195.72 1580.32 2567.89 503.95 89.81 22.50 45.28 1979 34.59 30.63 17.99 11.19 8.90 76.17 150.01 467.64 37.19 7.17 86.83 79.72 1980 9.14 6.78 6.69 1.08 0.86 194.66 229.98 1043.35 416.66 76.44 17.15 14.15 1981 22.16 12.54 12.48 10.03 14.13 68.71 208.33 798.86 95.06 39.41 19.98 20.14 1982 32.45 36.96 17.03 10.28 2.20 32.60 225.91 1479.22 492.22 268.02 116.20 118.741983 45.79 15.62 11.94 5.21 1.53 16.23 333.21 1248.11 1745.67 539.96 204.24 48.06 1984 64.92 31.49 20.20 8.81 4.78 15.72 53.86 2407.44 293.85 77.30 15.85 20.17 1985 18.50 10.50 9.51 1.65 0.86 16.78 296.42 2113.85 1323.73 1128.61 185.04 39.58 1986 34.20 38.89 33.35 8.55 2.33 131.25 3941.92 1353.81 244.15 75.81 16.50 22.291987 24.01 17.97 12.64 5.37 0.98 14.90 166.94 1492.79 446.23 89.56 29.27 17.601988 13.34 17.66 10.40 1.54 0.86 51.10 603.30 958.67 138.77 62.87 18.29 20.62 1989 18.35 12.83 6.23 2.92 0.86 32.08 188.20 1353.50 344.71 42.33 7.72 14.04 1990 8.82 3.13 1.14 0.14 0.86 309.40 785.82 1238.14 1592.30 202.54 37.78 15.12 1991 9.37 10.13 9.18 4.88 1.35 72.02 260.50 2042.90 385.78 31.72 11.02 14.58

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Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1992 23.00 12.88 7.22 1.81 1.49 15.14 253.83 1072.36 397.53 53.15 4.32 7.35 1993 1.78 0.94 1.05 0.14 0.86 34.06 278.59 719.00 1574.21 432.84 31.74 22.231994 19.50 13.29 11.69 10.56 4.34 270.04 1215.71 2255.28 892.37 83.38 15.47 20.41 1995 18.77 24.86 32.29 10.98 3.32 16.87 278.27 530.31 563.64 115.41 14.68 19.36 1996 18.83 7.72 6.66 1.10 0.98 15.89 857.26 1889.40 961.17 180.18 69.71 26.27 1997 20.33 21.59 8.03 3.04 2.74 16.65 934.09 1209.96 716.90 132.64 108.19 415.141998 40.93 25.47 25.36 11.56 2.94 79.98 853.39 1017.37 967.57 613.10 140.51 25.92 1999 13.84 317.63 105.82 4.75 0.55 54.26 855.52 1224.02 2756.57 1200.61 97.77 24.212000 19.73 25.14 2.31 0.43 1.73 45.61 1676.38 550.35 132.88 32.22 7.00 19.762001 10.64 0.55 0.00 0.33 1.35 95.52 610.03 1109.05 185.83 59.03 6.88 9.40 2002 20.95 1.10 2.17 3.90 0.73 34.44 72.06 1040.28 755.33 28.52 0.57 7.08 2003 0.00 0.00 0.00 0.00 1.91 101.72 555.49 717.87 952.18 271.11 18.24 19.40 2004 17.58 26.01 15.95 0.80 1.19 41.57 374.71 1999.34 346.32 57.05 13.70 22.66 2005 35.36 19.40 7.33 0.74 0.38 28.96 1939.19 1158.09 378.43 99.32 10.27 21.51 2006 25.14 17.40 9.95 2.92 2.36 24.95 416.20 2260.46 2534.54 247.87 11.88 25.80 2007 31.16 110.59 12.89 1.28 1.13 29.98 331.21 310.99 283.13 49.76 0.00 0.07 2008 0.00 0.94 1.05 0.14 0.86 103.99 267.96 954.68 282.68 40.05 0.00 0.07 2009 0.00 0.94 1.05 0.14 0.86 16.06 507.85 341.19 653.62 215.00 177.15 54.55

Average 20.46 27.17 13.32 4.08 2.36 75.15 657.90 1312.56 778.95 204.30 47.96 39.65 Av_Mons (Jun-Oct) 3028.86

Av_Non-monsoon 155.00

Non-mon flow as %

of Monsoon

5.118

% monthly flow in Non-

monsoon

13.201 17.530 8.590 2.630 1.526 30.942 25.581

Table – 3.18 also provides computation for average flows in different months which is used to find the average flows in monsoon and non-monsoon periods. Non-monsoon flows (November – May) come out to be 5.118% of monsoon flows. In addition, flows in different non-monsoon months, as percentage of the average non-monsoon flow, have also been computed which are used to find the flows in non-monsoon months.

3.6.2 Development of r – R relationships The average rainfall series in the catchment area of Basoda

G & D site has been worked out by using the thiessen weights of the rainfall stations in the Basoda sub-basin. The virgin flows at Basoda G & D site computed for the period 1976 – 2009 have been converted to depth terms (mm) and used to develop the r – R relationships in the Upper Betwa basin

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in different monsoon months (June – October). These relationships are further used to convert the average rainfall in the sub-basins of proposed projects to runoff depth.

For each month, plots of best fit line through the data points (rainfall and runoff) have been obtained. In addition, bi-variate analysis (for the months of July, August, September, and October) has been tried in which a correlation is established between the flow in a month to the rainfall in the previous and current month. Plot of rainfall – Runoff relationships for different monsoon months are shown in Figure – 3.9 (a – e).

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Figure – 3.9 (a): Plot of r-R data for Basoda catchment for month of June

Figure – 3.9 (b): Plot of r-R data for Basoda catchment for month of July

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Figure – 3.9 (c): Plot of r-R data for Basoda catchment for month of August

Figure – 3.9 (d): Plot of r-R data for Basoda catchment for month of September

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Figure – 3.9 (e): Plot of r-R data for Basoda catchment for month of October

While finalizing the r - R relations for different months, the nature of the relations has been considered in addition to the goodness of fit (in terms of r2 value). For example, in the linear relationships, the negative constant term represents the initial abstractions in the catchment while the multiplication factor with the rainfall represents the runoff coefficient. The runoff coefficient is less in June (due to initial dry conditions) and it increases in July and August months due to comparatively wet conditions. Bi-variate relationship is used only if its nature is truly represented (positive runoff coefficients for different months and negative constant term) and it shows appreciable improvement in the coefficient of determination (r2). For months from June to September, linear relationships are used while for October month, bi-variate relationship is expected to be more representative. Final r – R relationships adopted for the monsoon months are as follows:

r - R relationship for June

RunoffJune = 0.1239 * RainfallJune – 7.8113 r2 of the relationship comes out to be 0.688.

r - R relationship for July

RunoffJuly = 0.4397 * RainfallJuly – 67.585 r2 of the relationship comes out to be 0.826.

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r - R relationship for August

RunoffAug = 0.5285 * RainfallAug – 31.837

r2 of the relationship comes out to be 0.728.

r - R relationship for September

RunoffSept = 0.5382 * RainfallSept – 7.2324

r2 of the relationship comes out to be 0.9197.

r - R relationship for October

RunoffOct= 0.0486 * RainfallSept + 0.1579 * RainfallOct – 1.2816

r2 of the relationship comes out to be 0.833.

3.6.3 Hindcast flow series at proposed project sites from independent sub-basins

Using the developed r – R relationships for different monsoon months, the average rainfall in independent sub-basins of proposed projects has been converted to flow values (in mm). The hindcast flow series for monsoon months (June – October) have been converted to volume units (in MCM) by using the independent areas of respective sub-basins. For computation of flows in non-monsoon months, first the average flow in non-monsoon period (November – May) has been estimated (5.118 % of the total monsoon flow). Finally, using average percent flow values in different non-monsoon months with respect to the total flow in non-monsoon period, the flows in non-monsoon months have been derived.

3.6.4 Estimation of net yield series at proposed project sites

From the virgin flow series computed above, net yield series has been derived after accounting for the diversions from the existing and future major, medium, and minor projects and net domestic and industrial demands from surface water resources in the sub-basins of various proposed projects.

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For the major projects (Halali is the only major project), detailed monthly reservoir operation analysis has been carried out from June, 1901 to May, 2009 considering the virgin flows on pro-rata basis, storage characteristics, diversion demands, and normal monthly evaporation losses. For the existing and proposed medium projects in various sub-basins, contributing catchment areas have been determined in GIS and virgin inflows have been estimated on pro-rata basis depending on the virgin flows in the sub-basin in which they are located. The annual design utilizations of medium projects have been converted to monthly utilizations using the average monthly utilization pattern of medium projects. Storage capacity of medium projects has been provided by NWDA. To account for the storage effect of medium projects, detailed simulation analysis has been carried out for each medium project from June, 1901 to May, 2009 and possible diversion and spill series at monthly time step has been generated.

For the minor projects in a sub-basin, annual design demands of all existing and future projects have been disaggregated into monthly values using the monthly distribution pattern. Finally, net monthly flow series at a proposed project site is computed as follows:

a) Net virgin flows from the free sub-basin of a proposed project site below any existing or future major or medium project are computed on pro-rata basis.

b) Spills and 10% of the computed diversions from the major and medium projects (as regeneration) is added to the virgin flows from the free catchment computed at (a).

c) Diversions from minor projects are subtracted from the flows computed at (b).

d) From the upstream proposed project (if any), spill and environmental flow series and 10% of the computed diversions (as regeneration) are added to flows computed at (c).

e) Withdrawals for net domestic and industrial demands (after accounting for regeneration) are subtracted from the flows computed at (d).

Integrated operation analysis has been carried out for the entire

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system (proposed projects and various existing and proposed major and medium projects) at monthly time step for the period from June, 1901 to May, 2009. Computed flow series at monthly time step at each project site has been aggregated to annual time step to compute the dependable flows at each proposed project site. The annual runoff series is arranged in descending order and ranks for each value in the series have been assigned in ascending order. Thus, the rank of the highest value is 1 (one) and that of the lowest value is the number of data in the series (108). Probability of exceedance (Pi) is computed using Weibull’s formula as follows:

1+=

niPi …(3.3)

where ‘i’ is the rank and ‘n’ is the number of data points (108) in the series.

For all the proposed projects under Ken-Betwa Link (Phase-II) in the Betwa basin, the environmental flows have been computed from the estimated monthly flow pattern at each proposed project site. For the monsoon months from June to October, 75% dependable flows have been computed on monthly basis and 20% of the 75% dependable flows in each monsoon month have been reserved for environmental and ecological purposes. However, for the non-monsoon months, average monthly flows have been worked out and 15% of the average monthly flows in different non-monsoon months have been reserved for environmental and ecological purposes.

Monthly operation analysis has been carried out for the period from June, 1901 to May, 2009 for all proposed projects using the elevation-area-capacity table, specified upper and lower pond levels, and the design demands and environmental flow requirements from the project. The monthly evaporation estimates of nearest meteorological station have been used. In most of the projects, it was inferred that more demands (in comparison to the design demands) can be met from the projects with annual reliability of 75%. A number of iterations have been made to finalize the project demands that can be satisfied with annual reliability of 75%. The environmental flows worked out for the 10 proposed projects are given in Table – 3.19. The monthly demands which can be satisfied from proposed projects with 75% annual reliability are provided in Table – 3.20. The computed dependable flows at each project site are given in Table – 3.21.

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Table – 3.19 Monthly environmental flow requirements (MCM) at five proposed

project sites

Month

Monthly environmental flow requirements (MCM) at five proposed barrages/dam

Neemkheda Barari Kesari Kotha Lower Orr

January 0.426 1.097 0.156 0.319 0.449 February 0.621 1.176 0.218 0.396 0.635 March 0.220 0.399 0.092 0.195 0.260 April 0.003 0.020 0.012 0.013 0.026 May 0.000 0.000 0.002 0.002 0.001 June 0.000 0.000 0.000 0.000 0.000 July 5.723 25.323 2.995 35.553 6.422August 19.477 69.292 8.342 113.13 24.180 September 7.936 27.259 2.899 43.325 9.633 October 0.475 2.843 0.304 3.003 1.157 November 1.370 2.819 0.401 1.231 1.179 December 1.026 2.298 0.326 0.991 0.956

Total 37.277 132.53 15.746 198.15 44.896

Table – 3.20 Monthly final water demands (excluding env. flows) in MCM at

proposed barrages/dam

Month

Monthly final water demands (excluding env. Flows) in MCM at five proposed project sites

Neemkheda Barari Kesari Kotha Lower Orr

January 3.465 6.540 1.965 13.468 53.029February 2.613 6.540 1.598 10.982 37.800 March 2.613 5.340 1.598 10.982 22.219 April 0.000 0.000 0.000 0.000 4.352May 0.000 0.000 0.000 0.000 5.205 June 0.000 0.000 0.000 0.000 38.073 July 0.000 0.000 0.000 0.000 14.366 August 0.000 0.000 0.000 0.000 15.027 September 0.000 0.000 0.000 3.108 14.646 October 0.000 0.000 0.458 0.000 14.113 November 6.298 7.290 2.745 18.751 38.019 December 4.730 7.770 2.145 14.711 36.598

Total 19.719 33.480 10.509 72.001 293.45

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Table – 3.21 Computed dependable flows (MCM) at various project sites

Name of Project Dependable Flow (MCM)

50% 75% 90% Neemkheda barrage 440.19 328.61 257.03 Barari barrage 1363.52 1078.32 785.07 Kesari barrage 156.16 120.66 91.55 Kotha barrage 2061.06 1593.99 1184.90 Lower Orr dam 501.15 362.53 263.98

3.7 Sedimentation analysis for Lower Orr reservoir

The sediment volume at the project sites in 50 and 100 years has been computed from available sedimentation rate used for the Rajghat dam. For Rajghat reservoir, it is calculated that 312.5 MCM of sediment volume would deposit in a span of 50 years. From the sediment volume, sedimentation rate per unit area per year has been worked out to be 383.03 m3/Sq. km/year. Using this rate, sedimentation volume in the proposed reservoir (Lower Orr) in a span of 50 and 100 years has been worked out. Assessment of new-zero elevation and the revised elevation-area-capacity curves after 50 and 100 years for Lower Orr reservoir has been made by using the Empirical Area Reduction method.

With value of ‘m’ as 3.018, the Lower Orr reservoir is classified as Type-II reservoir (flood plain foot hill type). The sediment volume and the new-zero elevation after 50 years and 100 years at the reservoir are as follows:

Sediment volume in 50-years = 33.90 MCM

Sediment volume in 100-years = 67.80 MCM

New-zero elevation after 50-years = 351.80 m

New-zero elevation after 100-years = 353.53 m

Using the new-zero elevation, sediment deposition profile computation with empirical area reduction method for Lower Orr reservoir after 50 years is shown in Table – 3.22.

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Table – 3.22 Assessment of sediment deposition profile in Lower Orr Reservoir after 50–years

Elevation (m)

Original RelativeDepth

(p) Ap

SedimentArea

(Sq. km)

Cumulative Sediment Capacity (MCM)

Revised Area (Sq. km)

Capacity (MCM)

Area (Sq. km)

Capacity (MCM)

340 0.004 0.000 0.000 0.0000 0.004 0.000 0.000 0.000 341 0.007 0.005 0.025 0.3006 0.007 0.005 0.000 0.000 342 0.012 0.015 0.050 0.4415 0.012 0.015 0.000 0.000 343 0.018 0.030 0.075 0.5503 0.018 0.030 0.000 0.000 344 0.027 0.052 0.100 0.6411 0.027 0.052 0.000 0.000 345 0.080 0.103 0.125 0.7197 0.080 0.103 0.000 0.000 346 0.044 0.164 0.150 0.7891 0.044 0.164 0.000 0.000 347 0.055 0.214 0.175 0.8510 0.055 0.214 0.000 0.000 348 0.076 0.279 0.200 0.9068 0.076 0.279 0.000 0.000 349 0.203 0.413 0.225 0.9573 0.203 0.413 0.000 0.000 350 0.470 0.741 0.250 1.0029 0.470 0.741 0.000 0.000 351 0.748 1.344 0.275 1.0443 0.748 1.344 0.000 0.000

351.8 1.098 2.111 0.295 1.0746 1.098 2.111 0.000 0.000 352 1.186 2.303 0.300 1.0817 1.106 2.332 0.080 0.000 353 1.930 3.846 0.325 1.1155 1.140 3.455 0.790 0.391 354 2.876 6.233 0.350 1.1457 1.171 4.610 1.705 1.623 355 3.900 9.608 0.375 1.1727 1.199 5.795 2.701 3.813 356 4.456 13.783 0.400 1.1964 1.223 7.006 3.233 6.777 357 5.447 18.726 0.425 1.2171 1.244 8.239 4.203 10.487 358 6.302 24.596 0.450 1.2347 1.262 9.493 5.040 15.103 359 7.420 31.449 0.475 1.2493 1.277 10.762 6.143 20.687 360 8.264 39.287 0.500 1.2609 1.289 12.045 6.975 27.242 361 9.111 47.971 0.525 1.2694 1.298 13.338 7.813 34.633 362 9.877 57.463 0.550 1.2750 1.303 14.639 8.574 42.824 363 10.600 67.699 0.575 1.2774 1.306 15.943 9.294 51.756 364 11.415 78.704 0.600 1.2766 1.305 17.248 10.110 61.456 365 12.036 90.428 0.625 1.2726 1.301 18.551 10.735 71.877 366 12.974 102.930 0.650 1.2650 1.293 19.848 11.681 83.082 367 13.994 116.411 0.675 1.2539 1.282 21.136 12.712 95.275 368 14.693 130.753 0.700 1.2388 1.266 22.410 13.427 108.343 369 15.334 145.766 0.725 1.2195 1.247 23.666 14.087 122.100 370 15.879 161.371 0.750 1.1957 1.222 24.900 14.657 136.471 371 16.419 177.520 0.775 1.1667 1.193 26.108 15.226 151.412 372 17.094 194.275 0.800 1.1320 1.157 27.283 15.937 166.992 373 18.211 211.924 0.825 1.0907 1.115 28.418 17.096 183.506 374 19.463 230.758 0.850 1.0415 1.065 29.508 18.398 201.250 375 21.187 251.077 0.875 0.9825 1.004 30.542 20.183 220.535 376 22.413 272.874 0.900 0.9112 0.931 31.510 21.482 241.364 377 23.493 295.825 0.925 0.8225 0.841 32.396 22.652 263.429 378 24.721 319.929 0.950 0.7072 0.723 33.177 23.998 286.752 379 25.899 345.237 0.975 0.5402 0.552 33.812 25.347 311.425 380 27.237 371.802 1.000 0.0000 0.000 33.996 27.237 337.806

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Figure–3.10: Original (dotted) and 50-year revised (solid) Elevation-Area curve for Lower Orr reservoir

Figure–3.11: Original (dotted) and 50-year revised (solid) Elevation-Capacity curve for Lower Orr reservoir

The original and revised (after 50-year of operation) Elevation-Area curves of Lower Orr reservoir are presented in Figure – 3.10 while the original and revised Elevation-Capacity curves after 50-years are presented in Figure – 3.11.

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Figure – 3.12: Original (dotted) and 100-year revised (solid) Elevation-Area curve for Lower Orr reservoir

Figure – 3.13: Original (dotted) and 100-year revised (solid) Elevation-Capacity curve for Lower Orr reservoir

Using the new-zero elevations for 100-year deposition, the sediment deposition profile computation with the empirical area reduction method for Lower Orr reservoir after 100 years has also been made. The original and revised (after 100-year of operation) Elevation-Area curves of Lower Orr reservoir are presented in Figure – 3.12 while the original and revised Elevation-Capacity curves after 100-years are presented in Figure – 3.13.

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For the Lower Orr reservoir, the dead storage level has been specified as 360.50 m by NWDA which is above the new-zero elevation of 353.53 m as computed for the 100-year time span. Therefore, MDDL of 360.50 m can be adopted for the Lower Orr reservoir. 50-year revised elevation-area-capacity table is considered for simulation analysis.

3.8 Simulation analysis for Lower Orr Reservoir

The simulation analysis has been carried out for the Lower Orr reservoirs to estimate the level of demands that can be satisfied from the available live storage capacity of reservoirs with the specified reliability. The reservoir operation package developed at NIH has been used. This is a simulation program in which the operation of a multi-reservoir system is simulated. The data requirement of the simulation approach includes the Elevation–Area–Capacity (EAC) table, monthly target demands for various purposes (domestic supply, irrigation, environmental flow etc.), normal monthly evaporation depths, and the net inflow series in the reservoir at monthly time step. In addition, the reservoir details such as the FRL, MDDL, storage capacities at FRL and MDDL, and the rule curve levels for various purposes (critical levels below which full supply for that demand and other lesser priority demands cannot be assured up to the end of water year) also need to be specified. The simulation analysis is carried out at monthly time step for the period from June, 1901 to May, 2009 (a total of 1296 months or 108 years).

Monthly target demands from the Lower Orr reservoir have been specified by NWDA. The revised EAC table for the reservoir after 50 years of sediment deposition has been used in the analysis. The normal monthly evaporation depths of Guna meteorological station have been used. Lower Orr reservoir has its independent catchment. The net inflows to the Lower Orr reservoir have been computed and used.

Depending on the target demands, the operation of the reservoir has been simulated as per rule curve based policy at monthly time step for the period from June, 1901 to May, 2009. The upper rule levels have been taken at FRL (380.00 m) while the middle and lower rule curves have been kept at MDDL (360.5 m). With the generated reservoir working table (RWT), annual reliability for meeting target irrigation demands has been

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assessed. A year is considered as a successful year if the supply in all the months of a year equals or exceeds full design demands (including environmental flow demands). If water supply in any month falls below the target demands in that month, that year is considered as a failure year.

With the FRL at 380.00 m and MDDL at 360.50 m, the reservoir is not able to meet full target demands with 75% annual reliability. A number of iterations have been taken with different levels of demands and 75% annual reliability is achieved with target irrigation and domestic supply demands as 85% of the design demands.

3.8.1 Estimation of evaporation losses from proposed reservoir

In the simulation analysis, the evaporation loss from the reservoir surface is estimated by using the initial and final water spread areas during the month and multiplying the average area with the normal monthly evaporation depth in the month. It is computed separately in the reservoir working table generated for a reservoir. For the proposed reservoir considered in this analysis, the monthly evaporation loss series has been arranged to compute average evaporation loss in each month. Average Monthly evaporation loss for the Lower Orr reservoir is presented in Table – 3.23.

Table – 3.23 Average monthly evaporation losses (MCM) for Lower Orr project

Month Average monthly evaporation loss (MCM)

January 2.962 February 1.886 March 2.105 April 3.235 May 3.56 June 2.49 July 1.906 August 1.804September 1.849 October 2.594 November 3.136 December 3.864 Total 31.39

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3.9 Supplementary simulation analysis at increased pond level of kotha barrage

Due to increase in the height of Kotha barrage, the earlier proposed Narkhedaghat and Bijrotha barrages became abandoned. Thus, earlier proposed Narkhedaghat and Bijrotha barrages have been dropped from the Ken Betwa link phase-II. Accordingly, Revised simulation analysis has been carried out for the Kotha barrage assuming that the upstream Narkhedaghat and Bijrotha projects do not exist. The EAC table of the Kotha barrage has been revised and new demand pattern has been considered. The database utilized for the project is described below.

3.9.1 Estimation of Inflow Series

If the upstream Narkhedaghat and Bijrotha projects are dropped from the planned configuration of projects in the Upper Betwa basin, the inflow series at Kotha project will get modified. The revised inflow series at Kotha project is computed as follows:

a) The outflow from the Barari project is computed as the sum of the environmental flow release, spill and 10% of the irrigation release (as return flow).

b) To the outflow from Barari project, virgin flow from Narkhedaghat sub-basin is added and the demands for domestic and industrial purpose in this sub-basin are subtracted.

c) To the net flow series computed at step (b), the virgin flow from Bijrotha sub-basin is added and the demands for domestic and industrial purpose in this sub-basin are subtracted.

d) To the net flow series computed at step (c), the virgin flow from Kotha sub-basin is added and the demands for domestic and industrial purpose in this sub-basin are subtracted.

e) To the net flow series computed at step (d), the outflow from the Kesari project [computed as the sum of the environmental flow release, spill, and 10% of the irrigation release (as return flow)] is added.

The net inflow series at the Kotha project are given in Table–3.24.

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Table – 3.24 Computed monthly net flow (MCM) series at Kotha project site

Year Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May1901-02 0.000 167.724 1679.591 154.449 5.250 19.984 15.970 7.037 7.913 3.356 0.307 0.1201902-03 0.000 564.051 394.535 752.562 135.434 20.367 14.908 6.494 7.193 3.003 0.224 0.0721903-04 0.000 210.993 793.707 1372.644 139.279 24.493 18.318 7.516 8.708 3.495 0.316 0.1251904-05 0.000 428.988 411.737 319.238 13.347 15.735 10.854 5.927 6.439 2.319 0.165 0.0371905-06 0.000 34.427 480.889 717.569 48.383 16.258 11.509 5.546 5.934 2.385 0.077 0.0001906-07 0.566 611.696 112.681 887.563 61.289 19.913 14.531 6.851 7.667 3.235 0.295 0.1131907-08 0.000 67.517 1498.430 42.389 2.134 14.007 11.622 6.323 6.920 2.653 0.183 0.0471908-09 0.000 786.631 1017.212 150.364 6.952 15.648 15.406 7.011 7.879 3.339 0.306 0.1191909-10 6.828 195.422 1212.434 89.489 2.146 16.415 12.924 5.858 6.340 2.405 0.096 0.0031910-11 3.193 23.902 684.360 1137.273 102.274 20.641 15.133 6.882 7.707 3.255 0.246 0.0851911-12 0.000 83.472 647.099 996.024 79.939 20.960 15.396 6.554 7.272 3.041 0.199 0.0571912-13 0.000 290.549 967.786 433.169 20.927 18.442 13.315 6.206 6.810 2.815 0.180 0.0461913-14 38.457 39.967 814.539 64.508 2.820 10.363 8.610 4.769 4.662 0.803 0.000 0.0001914-15 3.827 744.536 590.021 356.583 17.474 19.962 14.571 6.115 6.690 2.756 0.144 0.0251915-16 49.735 83.283 921.965 250.090 117.974 16.269 11.518 5.494 5.865 2.352 0.071 0.0001916-17 52.671 224.797 2197.354 498.586 139.789 29.593 22.870 9.651 11.542 4.584 0.535 0.2521917-18 53.649 494.444 1824.833 1034.825 111.845 33.704 26.626 10.340 12.480 4.665 0.558 0.2661918-19 16.947 25.890 687.953 205.907 7.151 13.506 9.494 5.225 5.493 1.206 0.039 0.0001919-20 0.000 389.222 2769.541 535.576 92.273 36.736 29.319 11.247 14.616 4.619 0.503 0.2341920-21 8.103 469.931 172.678 108.486 1.973 12.160 8.747 4.625 4.617 0.829 0.000 0.0001921-22 11.713 23.620 1336.311 969.510 64.015 23.124 18.066 6.867 7.688 3.245 0.263 0.0941922-23 1.948 563.385 265.378 863.918 56.626 20.288 14.841 6.848 7.662 3.233 0.251 0.0871923-24 0.000 1532.269 1344.459 981.604 54.733 38.807 31.031 11.076 17.008 4.446 0.520 0.2431924-25 0.000 212.001 891.594 849.987 92.427 21.474 15.822 6.661 7.415 3.111 0.209 0.0631925-26 21.097 264.230 454.736 162.010 5.154 12.777 9.139 5.042 5.121 1.276 0.032 0.0001926-27 0.000 454.488 1618.620 856.227 101.815 29.906 23.652 8.528 10.527 3.730 0.334 0.1351927-28 2.688 620.880 667.349 187.448 46.245 18.580 13.430 6.203 6.806 2.767 0.135 0.0251928-29 0.000 943.421 348.679 50.846 19.710 15.503 10.886 5.419 5.765 2.267 0.047 0.0001929-30 1.211 440.791 962.177 282.210 10.573 20.164 14.739 6.745 7.526 3.166 0.253 0.0891930-31 0.210 893.218 424.151 352.102 39.281 18.602 13.448 6.051 6.604 2.714 0.149 0.0281931-32 0.000 282.559 1072.031 1232.975 238.937 27.889 21.950 7.699 9.350 3.408 0.270 0.0981932-33 0.000 1655.926 146.307 1627.480 127.987 34.455 27.343 10.394 13.168 4.231 0.452 0.2041933-34 44.822 333.461 1038.803 1224.532 97.787 26.220 20.289 7.599 8.817 3.523 0.297 0.1141934-35 23.459 325.403 1241.790 2552.587 188.705 43.934 35.402 12.283 19.440 5.243 0.733 0.3671935-36 11.532 555.442 331.993 985.745 95.900 20.744 15.219 6.563 7.285 3.048 0.201 0.0591936-37 19.259 250.511 949.474 1086.805 69.348 23.166 17.221 6.950 7.956 3.005 0.172 0.0421937-38 20.126 1019.118 522.705 621.668 55.391 23.346 17.370 7.027 8.058 3.329 0.250 0.0871938-39 124.872 731.832 876.345 162.482 125.193 20.760 15.231 6.162 6.752 2.787 0.157 0.0331939-40 0.000 744.961 1038.932 825.458 43.208 25.339 19.561 7.585 8.800 3.304 0.255 0.0901940-41 26.128 1115.600 1288.925 326.533 34.457 26.012 19.575 8.165 9.569 3.852 0.376 0.1601941-42 0.000 26.897 1200.313 352.607 14.022 18.528 13.386 6.056 6.611 2.717 0.141 0.0241942-43 26.868 1495.021 860.772 569.389 26.706 28.974 22.644 8.919 10.571 4.092 0.475 0.217

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Year Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May1943-44 0.358 729.403 458.158 497.860 106.180 19.818 14.453 6.744 7.524 3.165 0.256 0.0901944-45 0.000 1463.933 1551.359 399.162 56.822 35.281 28.116 9.384 15.361 3.406 0.223 0.0711945-46 221.215 1028.968 343.938 650.893 36.693 22.783 16.905 6.945 7.792 3.296 0.208 0.0631946-47 135.886 680.435 1641.033 220.537 11.786 25.546 19.189 8.061 9.274 4.022 0.453 0.2041947-48 0.000 647.144 1635.588 1503.929 133.716 38.437 30.726 11.229 16.308 4.638 0.530 0.2491948-49 21.736 984.584 1461.947 1321.875 104.690 37.646 30.035 11.373 14.769 4.874 0.604 0.2921949-50 15.294 347.035 328.011 2005.727 249.319 28.667 21.901 8.949 10.610 4.276 0.498 0.2311950-51 0.000 452.228 452.290 531.717 32.575 14.998 10.468 5.141 5.396 2.122 0.040 0.0001951-52 0.000 195.409 668.872 78.778 4.055 11.929 9.604 5.282 5.500 1.238 0.014 0.0001952-53 27.146 516.396 822.708 49.191 1.783 13.760 11.417 6.218 6.826 2.534 0.204 0.0601953-54 0.000 506.800 935.312 366.638 32.289 19.071 13.836 6.379 7.040 2.928 0.236 0.0791954-55 0.000 497.777 292.646 1750.704 153.977 25.599 19.835 7.741 9.007 3.355 0.234 0.0781955-56 27.223 25.890 1872.130 1822.093 264.251 38.410 30.925 10.590 17.073 4.551 0.498 0.2311956-57 4.566 1356.877 1044.192 609.088 66.073 30.042 23.038 9.478 11.314 4.734 0.591 0.2851957-58 0.000 139.237 850.826 317.907 29.561 16.345 11.582 5.900 6.404 2.514 0.107 0.0091958-59 0.000 520.214 792.101 896.433 138.319 23.776 17.725 7.210 8.301 3.366 0.276 0.1021959-60 1.190 834.094 1303.327 978.576 161.395 31.653 24.957 9.697 11.604 4.343 0.498 0.2311960-61 4.725 230.633 1481.005 90.857 78.938 20.521 15.034 6.408 7.078 2.947 0.173 0.0421961-62 0.000 604.354 1248.953 2554.318 360.442 48.113 39.021 14.386 21.888 5.363 0.670 0.3301962-63 0.000 260.953 565.142 1225.375 85.265 21.950 16.216 7.049 7.930 3.364 0.255 0.0901963-64 0.000 64.116 1431.790 547.677 37.736 20.657 15.147 6.588 7.317 3.064 0.215 0.0671964-65 1.355 600.294 1304.520 844.613 44.257 26.398 20.317 7.969 9.310 3.512 0.277 0.1021965-66 0.000 861.188 172.866 488.665 33.003 17.234 12.318 5.847 6.333 2.581 0.105 0.0031966-67 0.428 368.228 450.967 138.131 3.800 13.272 9.529 5.243 5.221 1.100 0.046 0.0001967-68 7.397 268.781 835.636 1087.704 78.094 23.115 17.179 7.155 8.070 3.432 0.264 0.0951968-69 0.000 551.941 1008.650 284.588 11.003 20.154 14.731 6.320 6.962 2.889 0.142 0.0241969-70 0.000 1450.179 1967.839 564.629 27.529 38.278 30.831 11.494 15.719 4.883 0.581 0.2791970-71 47.813 636.110 1921.594 1294.987 93.465 39.012 31.333 10.976 17.347 4.541 0.473 0.2161971-72 74.599 1049.368 379.694 906.645 137.953 25.754 19.361 8.276 9.559 4.162 0.464 0.2111972-73 0.000 20.541 1461.761 146.863 4.406 17.156 12.252 5.716 6.159 2.426 0.080 0.0001973-74 0.000 1410.443 2360.400 794.272 55.174 45.945 37.171 13.924 21.245 5.226 0.640 0.3131974-75 0.000 341.683 1959.555 79.185 47.545 22.763 16.888 7.146 8.058 3.427 0.303 0.1181975-76 45.989 437.765 1318.171 1093.212 144.548 28.930 22.598 9.188 10.928 4.523 0.564 0.2691976-77 11.648 67.072 729.327 660.338 52.686 16.823 11.977 5.373 5.704 2.206 0.022 0.0001977-78 56.404 656.224 1742.341 914.704 76.668 32.840 26.011 9.925 11.959 4.299 0.431 0.1921978-79 54.012 661.175 1610.733 218.525 7.219 24.305 18.483 7.623 8.793 3.737 0.344 0.1411979-80 0.000 16.704 237.768 53.082 1.895 8.835 5.395 2.480 0.686 0.051 0.000 0.0001980-81 55.518 25.891 1289.162 221.670 8.551 18.173 13.093 6.054 6.608 2.716 0.135 0.0201981-82 0.000 126.056 984.361 282.939 23.669 17.563 12.589 6.136 6.717 2.759 0.145 0.0311982-83 0.000 111.727 2280.703 452.049 48.614 27.222 20.990 8.599 10.147 4.312 0.519 0.2431983-84 0.000 232.566 1577.772 2047.378 210.930 40.421 32.366 11.591 18.273 4.827 0.632 0.3091984-85 0.000 20.818 1769.373 101.271 2.696 15.434 12.119 5.471 5.834 2.280 0.037 0.0001985-86 0.000 356.285 1467.188 1105.492 298.445 30.859 24.185 9.266 11.031 4.350 0.497 0.2301986-87 22.425 1740.403 567.593 126.381 3.655 23.800 18.762 6.322 6.885 2.737 0.094 0.0011987-88 0.000 121.584 1550.410 449.732 118.543 24.155 18.039 8.109 9.337 4.053 0.536 0.253

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Year Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May1988-89 28.296 515.952 725.798 209.329 23.332 18.609 13.453 6.193 6.793 2.751 0.157 0.0381989-90 11.563 19.371 870.834 506.263 26.839 16.595 11.789 6.041 6.592 2.592 0.148 0.0281990-91 64.890 396.731 1170.734 643.818 60.151 22.319 16.975 6.500 7.360 2.905 0.101 0.0001991-92 35.887 271.173 1331.090 32.384 1.783 14.300 12.860 5.845 6.331 2.580 0.097 0.0001992-93 0.000 336.067 1194.781 350.071 25.668 19.613 14.284 6.233 6.846 2.832 0.167 0.0391993-94 0.117 327.511 1028.945 1798.661 163.648 31.288 24.463 9.933 11.917 4.776 0.618 0.3001994-95 159.231 731.193 1757.504 406.608 18.549 28.994 22.598 8.932 10.588 3.964 0.390 0.1681995-96 0.000 535.294 809.415 518.171 63.785 20.910 15.356 6.694 7.459 3.133 0.256 0.0901996-97 0.000 1105.405 1834.973 558.318 106.475 34.224 26.981 10.285 13.032 4.374 0.487 0.2241997-98 0.235 717.998 958.154 401.256 111.049 21.419 15.776 6.484 7.180 2.996 0.182 0.0471998-99 20.435 585.315 586.556 839.344 78.296 20.562 15.068 6.222 6.832 2.826 0.134 0.0191999-00 3.587 704.949 820.310 2540.315 360.816 44.922 36.381 12.914 20.093 4.606 0.553 0.2632000-01 6.418 1250.983 330.589 40.056 1.783 14.946 12.399 6.724 7.498 3.152 0.294 0.1132001-02 52.971 424.712 745.592 81.522 42.434 16.893 12.035 6.063 6.620 2.671 0.164 0.0372002-03 0.000 0.528 1668.836 221.927 9.136 19.219 13.958 6.681 7.441 3.124 0.254 0.0892003-04 0.000 418.681 870.864 936.295 62.228 23.572 17.557 7.747 8.856 3.818 0.357 0.1492004-05 13.318 196.419 1350.656 135.455 52.376 19.049 13.817 6.471 7.161 2.987 0.160 0.0352005-06 0.811 1215.624 308.647 537.787 32.415 21.434 15.789 6.907 7.741 3.271 0.260 0.0932006-07 0.000 523.372 2094.245 1241.390 89.834 39.069 31.248 11.220 17.364 4.869 0.464 0.2022007-08 4.942 331.543 319.327 511.914 27.698 15.448 10.777 5.756 6.212 2.237 0.074 0.0002008-09 79.236 79.172 414.298 325.367 25.460 13.649 9.855 5.411 5.586 1.325 0.091 0.000

3.9.2 Supplementary Demand Pattern from the Kotha Project

The revised demand pattern from the Kotha barrage is given in Table-3.25. Based on the revised inflow series, the environmental flow requirement in each month has been modified as given in Table – 3.25.

Table – 3.25 Revised demand pattern for Kotha project

Month Design irrigation demand (MCM)

Environmental flow demands (MCM)

January 13.468 1.129 February 10.982 1.358 March 10.982 0.490 April 0.000 0.042 May 0.000 0.016 June 0.000 0.000 July 0.000 39.284 August 0.000 113.519 September 3.108 44.107 October 0.000 3.710 November 18.751 3.548 December 14.711 2.714

Total 72.001 209.915

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3.9.3 Revised Elevation-Area-Capacity Table

The revised EAC table of the Kotha barrage is given in Table–3.26.

Table – 3.26 Revised Elevation-Area-Capacity table for Kotha project

Elevation (m) Area (Sq. km) Capacity (MCM) 384.00 0.00 0.00 385.00 1.50 0.50 386.00 2.80 2.60 387.00 4.00 6.00 388.00 4.70 10.30 389.00 5.30 15.30390.00 6.90 21.40 391.00 8.30 29.00 392.00 10.00 38.20 393.00 13.80 50.00 394.00 16.80 65.30 395.00 19.90 83.60 396.00 22.10 104.60 397.00 23.90 127.60

3.9.4 Simulation analysis for the Kotha project

Simulation analysis for the Kotha project has been carried out assuming the revised inflow series, revised demand pattern and revised EAC Table. A number of scenarios have been analyzed with different levels of demands and FRLs so as to achieve a minimum annual reliability of 75% for meeting various demands from the project. The results of simulation analysis are summarized in Table – 3.27 while the detailed simulation tables for various scenarios are presented in the Volume-III (Hydrology).

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Table – 3.27 Results of simulation analysis under different scenarios for Kotha

barrage

Description of Scenarios and Variables Values

Scenario – 1 (Demands as 72 MCM and FRL as 396.00 m) Annual reliability for meeting full demands (%) 100 Monthly reliability for meeting full demands (%) 100 Volume reliability (%) 100

Scenario – 2 (Demands as 136.803 MCM and FRL as 396.00 m) Annual reliability for meeting full demands (%) 75.93 Monthly reliability for meeting full demands (%) 94.91 Volume reliability (%) 99.37

Scenario – 3 (Demands as 72 MCM and FRL as 392.00 m) Annual reliability for meeting full demands (%) 75.00 Monthly reliability for meeting full demands (%) 93.67 Volume reliability (%) 99.19

3.10 Estimation of Design Flood for Proposed Projects

Two approaches are generally practiced for design flood calculations: (i) unit hydrograph (UH) approach and (ii) statistical approach. In case the UH approach is followed, it is necessary to determine the design storm for the project area. After the unit hydrograph for the catchment is derived, the required flood hydrograph, i.e. the probable maximum flood (PMF) is obtained by appropriate convolution of excess PMP rainfall after accounting for the infiltration losses and base flow additions. In the case of large basins, it becomes necessary to sub-divide the catchment and mark out the flood hydrographs of its sub-areas and route them through the river channel to the desired site by following suitable flood routing method and synthesizing them to obtain the design flood hydrograph. When there are existing reservoirs in the basin upstream of the site, it will also be necessary to route the flood through such reservoirs to account for the moderation provided by the storage. Wherever sufficient data are not available for UH computation, synthetic methods are used to derive the UH. In case, the

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statistical models are used for design flood estimation, at-site flood frequency analysis shall be applied using annual maximum series of gauge site records for deriving a design flood for a specific return period. The return period shall be selected as per the guidelines of the Ministry of Irrigation (1980) report. For this study, design flood is derived as follows:

(i) Synthetic unit hydrographs (SUH) are developed for the sub-catchment up to Neemkheda, Barari, Kesari, and Lower Orr projects because historic data is not available for these sites. Furthermore, sub-catchments of Kotha and Barari are divided into two sub-basins and SUH are developed for each sub-basin.

(ii) UH at step (ii) is convoluted with a critical design (critical sequencing of PMP) to produce the corresponding PMF hydrograph of the sub-catchments. Network models have been developed for Kotha sub-catchments for the computation of PMF.

(iii) Statistical approach

3.10.1 Synthetic unit hydrograph derivation

In practice, a synthetic unit hydrograph is derived from few salient points of the UH by manually fitting a smooth curve, especially for catchments with limited or no data. For the present case, sub-catchments of Neemkheda, Barari, Kesari, Lower Orr and Kotha projects have no observed hourly rainfall-runoff data. Therefore, SUH’s were developed for these sub-catchments using the physiographic parameters. This is achieved by using Regional formulae of CWC (1989) for 1(c) sub-zone. The two parameters, viz. the time to peak tp, and peak discharge qp, that were used to describe the unit hydrograph, are expressed by CWC (1989) as:

( ) 492.0/331.1 −= SLqp … (3.4)

( ) 944.0195.2 −= pp qt … (3.5)

where L is the length of the main stream from the outlet to the catchment boundary in km; S is the average channel slope of the catchment in m/km; and tp, and qp, are expressed in units of hours and m3/s/Sqkm, respectively. The shape of the hydrograph is determined using the

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parameters W50, W75, WR50, WR75, and TB (CWC, 1989). These parameters have been determined by using the following equations:

( ) 0265.150 04.2 −= pqW … (3.6)

( ) 864.075 25.1 −= pqW … (3.7)

( ) 968.050 739.0 −= pR qW … (3.8)

( ) 813.075 500.0 −= pR qW … (3.9)

( ) 99.0917.3 pB tT = … (3.10)

A unit hydrograph was plotted through these salient points and the hourly ordinates were adjusted so that the total area enclosed under the hydrograph equals 1 cm (10 mm). The hourly ordinates of unit hydrograph in m3/s for 1 mm of rainfall were then estimated.

3.10.1.1 Synthetic unit hydrograph derivation for sub-catchments

Using the geomorphologic parameters for the catchments as shown in Table – 3.28, qp and tp for the sub-catchments are computed as shown in Table – 3.29.

Table – 3.28

Geomorphologic characteristics of sub-catchments used for SUH derivation

Name of sub-basin

Area “A” (sq. km)

Length of mainstream “L” (km)

Slope (m/km)

Lower Orr 1843 105.50 1.6332 Neemkheda 1976 111.63 0.9464 Kesari 506 47.01 1.0690 Barari (U) 2329 114.53 0.7570 Barari (D) 3145 109.86 0.6749 Kotha (U) 3837.7 153.34 0.5934 Kotha (D) 4873.8 147.33 0.5565

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Figure – 3.14: Synthetic Unit Hydrograph for Lower Orr sub catchment (ER = 1 cm)

Table – 3.29 Salient points of sub-catchments for SUH derivation

Project Catchment

Qp qp

tp

W50 W75 WR50 WR75 TB

Lower Orr 315.47 0.171 11.62 12.48 5.74 4.08 2.10 44.40Neemkheda 251.58 0.127 15.36 16.90 7.42 5.43 2.67 58.54Kesari 104.68 0.207 9.71 10.27 4.88 3.40 1.80 37.19Barari (U) 262.35 0.113 17.24 19.17 8.25 6.12 2.95 65.65Barari (D) 341.74 0.109 17.84 19.89 8.51 6.33 3.04 67.89Kotha (U) 332.21 0.087 22.11 25.11 10.35 7.89 3.66 83.96Kotha (D) 416.97 0.086 22.36 25.42 10.46 7.99 3.69 84.90

For small catchments (< 5000 sq. km) of projects such as Lower Orr, Neemkheda and Kesari the SUH are derived by using equations 3.4 to 3.10 and Table – 3.28 and Table – 3.29. These SUH are shown in Figure – 3.14 to 3.16. Large catchments (>5000 sq. km) of projects such as Kotha and Barari are divided into two sub-catchments having catchment areas less than 5000 Sqkm. Catchment of Kotha is divided into Kotha (Upstream) and Kotha (Downstream) sub-catchments. Kotha (Upstream) catchments is having catchment area of 3837.7 sq. km. Similarly, Barari catchment is also divided into Barari (Upstream) and Barari (Downstream). SUH for the sub-catchments of these large catchments are given in Figure – 3.17 to 3.20.

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Figure – 3.17: Synthetic Unit Hydrograph for Barari (D) sub-catchment (ER = 1 cm)

Figure – 3.18: Synthetic Unit Hydrograph for Barari (U) sub-catchment (ER = 1 cm)

Figure – 3.20: Synthetic Unit Hydrograph for Kotha (D) sub-catchment (ER = 1 cm)

Figure – 3.19: Synthetic Unit Hydrograph for Kotha (U) sub-catchment (ER = 1 cm)

Figure – 3.15: Synthetic Unit Hydrograph for Neemkheda sub-catchment (ER = 1 cm)

Figure – 3.16: Synthetic Unit Hydrograph for Kesari sub-catchment (ER = 1 cm)

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3.10.2 Probable Maximum Precipitation (PMP)

PMP is used to derive the design flood. For a given duration, it is theoretically the greatest depth of precipitation that is physically possible over a given area at a certain time of the year. Both PMP and SPF for the study area are supplied by IMD and the data is given in Table – 3.30.

Table – 3.30 PMP and SPS values for the study area

Duration in days

SPS Values (mm) PMP Values (mm)

Kesari1-day 431 586

Neemkheda1-day 355 483 2-day 593 806

Barari1-day 306 4162-day 567 771

Lower Orr1-day - 589 2-day - 758

3.10.2.1 Design storm

As per the IMD guidelines, no clock hour corrections are applied for 2-day PMP (Table – 3.30). The time distribution of 24-hour and 48-hour storm rainfall is supplied by IMD and is given at Table – 3.31. These values have been taken as the design storm depths for estimating the design flood.

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Table – 3.31 Time distribution of PMP for Lower Orr project

Duration

(Hours)

Temporal distribution of percentage of design storm 24-hour storm 48-hour storm

3 33 24 6 47 339 59 41 12 69 47 15 78 5318 86 58 21 94 63 24 100 68 27 73 30 77 33 81 36 85 39 8942 93 45 97 48 100

Time distribution of Design Storm for Kesari, Neemkheda & Barari Barrage

Duration (Hours)

Temporal distribution of percentage of design storm 24-hour storm 48-hour storm

3 35 24 6 50 32 9 62 3912 72 46 15 80 52 18 87 58 21 94 63 24 100 68 27 73 30 78 33 82 36 86 39 90 42 9445 98 48 100

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3.10.2.2 Duration of design storm

The duration of design rainfall is determined considering the size of the drainage basin, duration of the flood, and the type of hydraulic structures. It is necessary that the selected duration be at least as long as the supply duration. As per the CWC (2001) guidelines, the design duration of PMP is adopted as follows:

“UG base governs the duration of the storm depth. For UH having a base of 24 hours or less the design storm of one day is considered appropriate and sufficient. In case the UG base is more than 24 hours but less than 48 hours, 2-day design storm should be considered. For basins having UG base of more than 48 hours, a design storm of 3-day should in general be adopted. Storms of period exceeding more than 72 hours are not generally required to be considered in the design flood estimation.”

3.10.2.3 Critical sequencing of PMP

The critical sequencing of PMP hyetograph is carried as per the recommended guidelines given in “Manual on Estimation of Design Flood, CWC (2001)”. Two-day SPS values of Neemkheda have been used for the computation of design storms for Neemkheda project. Two-day SPS values of Barari have been used for the computation of design storms for Barari project. In case of Kesari, only one day SPS was available therefore two-day SPS value of Kesari is considered similar to same as Two-day SPS of Barari project. However, one day SPS of Kesari project is considered as obtained from IMD. SPS values of Neemkheda have been used for computation of design storms for the upstream catchment of Kotha. Similarly, for the computation of design storms for the downstream catchment of Kotha, SPS values of Barari has been used. For calculating the excess rainfall hyetograph of the PMP/SPS, loss rate of 2.3 mm/hr as recommended for subzone 1(c) (CWC, 1989) is adopted.

3.10.3 Flood hydrographs using the PMP and SPS

The derived excess rainfall PMP for Lower Orr project and SPS hyetograph for various other project sites are convoluted using the respective derived SUH to get the direct flood hydrographs. The base flow at the rate of 0.018 m3/s/sq.km (CWC, 1989) is added to the direct flood

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hydrograph to get the design flood hydrograph. The design flood hydrograph for Lower Orr, Kesari and Neemkheda projects are given in Table - 3.32 to Table – 3.34. Similarly, the flood hydrographs for the excess rainfall derived from the SPS hyetograph for Kotha (U), Kotha (D), Barari (U) and Barari (D) are convoluted using the respective derived SUH and adding the base flow and these are presented in Table-3.35 to Table-3.36. Further, for Kotha and Barari projects, the flood hydrograph from upper basins are routed to the outlet and the downstream flood hydrographs are added to the routed hydrograph in order to derive the SPF at the respective project sites.

The Muskingum-Cunge routing technique available in HEC-1 has been used to route the upstream hydrograph through a main channel. The channel routing technique is a non-linear coefficient method that accounts for hydrograph diffusion based on physical channel properties and the inflowing hydrograph. The advantages of this method over other hydrologic techniques are: (1) the parameters of the model are physically based; (2) the method has been shown to compare well against the full unsteady flow equations over a wide range of flow situations (Ponce, 1983 and Brunner, 1989); and (3) the solution is independent of the user specified computation interval. The major limitations of the Muskingum-Cunge application in HEC-1 are that: (1) it cannot account for backwater effects; and (2) the method begins to diverge from the full unsteady flow solution when very rapidly rising hydrographs are routed through very flat slopes (i.e. channel slopes less than 1 ft./mile). The basic formulation of the equations is derived from the continuity equation and the diffusion form of the momentum equation. Various physical properties of the channel such as channel length, channel slope, channel roughness (Manning's n), channel shape channel bottom width and channel side slopes have been used to route flood hydrograph using HEC-1. Channel length, channel slope have been derived from the topographical data. Further, Manning’s roughness coefficient is considered as 0.04, channel width as 100 m and channel side slop as 1 m/m. The PMF and SPF values for different proposed projects are given in Table–3.37.

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Table–3.32 Flood hydrograph (PMF) for Lower Orr sub-catchment using SUH

Time (hrs)

Flood (m3/s)

Time

(hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

0 33.174 25 8507.716 50 4596.411 75 225.814 1 42.555 26 9092.098 51 4210.665 76 190.264 2 66.802 27 9617.779 52 3853.043 77 164.704 3 106.415 28 10162.25 53 3554.989 78 144.434 4 164.102 29 10727.55 54 3300.324 79 127.494 5 241.197 30 11387.8 55 3058.888 80 112.274 6 338.149 31 11870.51 56 2800.02 81 99.394 7 455.013 32 12067.67 57 2530.975 82 87.074 8 623.815 33 11865.42 58 2253.343 83 76.144 9 857.985 34 11425.65 59 1994.621 84 65.864

10 1157.493 35 10846.53 60 1748.254 85 57.604 11 1504.388 36 10249.04 61 1532.629 86 49.444 12 1875.96 37 9699.519 62 1321.127 87 41.774

13 2261.756 38 9168.835 63 1124.617 88 36.194 14 2665.418 39 8662.943 64 954.395 89 33.594 15 3079.326 40 8218.138 65 826.416 90 33.254

16 3536.731 41 7856.063 66 727.396 91 33.174

17 4038.762 42 7592.274 67 645.688

18 4618.976 43 7326.076 68 573.784 19 5162.377 44 7022.818 69 512.114 20 5684.432 45 6652.19 70 454.894

21 6167.833 46 6244.495 71 404.034 22 6686.678 47 5824.249 72 354.654

23 7262.161 48 5399.391 73 310.934 24 7887.366 49 4999.861 74 266.474

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Table – 3.33 Flood hydrograph (SPF) for Kesari sub-catchment using SUH

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

0 9.11 22 1421.34 44 1302.2

4 66 74.18

1 11.15 23 1593.35 45 1176.3

3 67 61.15

2 15.25 24 1760.11 46 1058.8

9 68 51.21 3 22.62 25 1920.14 47 951.41 69 43.93 4 33.29 26 2069.37 48 849.47 70 39.17 5 47.25 27 2261.11 49 757.72 71 35.61 6 65.76 28 2460.31 50 674.98 72 32.51 7 88.82 29 2635.59 51 609.21 73 29.52 8 129.89 30 2690.14 52 552.82 74 26.39 9 186.79 31 2630.93 53 501.72 75 23.22 10 259.81 32 2483.27 54 444.98 76 20.05 11 334.75 33 2316.87 55 383.74 77 16.85 12 407.81 34 2162.60 56 326.85 78 14.06 13 484.95 35 2029.88 57 280.07 79 11.72 14 564.70 36 1909.51 58 244.69 80 10.20 15 670.02 37 1809.10 59 215.48 81 9.35 16 789.51 38 1724.04 60 188.76 82 9.09 17 911.22 39 1674.37 61 164.92 83 9.10 18 1000.57 40 1636.84 62 143.20 84 9.11 19 1060.12 41 1601.17 63 124.19 20 1139.90 42 1530.55 64 106.32 21 1257.78 43 1427.46 65 89.27

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Table – 3.34 Flood hydrograph (SPF) for Neemkheda sub-catchment using SUH

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

0 35.57 27 4138.34 54 4946.82 81 714.08 1 37.89 28 4455.81 55 4809.18 82 643.77 2 44.27 29 4804.93 56 4675.12 83 575.09 3 54.69 30 5183.00 57 4527.58 84 509.07 4 69.16 31 5587.53 58 4366.57 85 446.11 5 89.43 32 5979.19 59 4168.92 86 385.92 6 115.49 33 6322.30 60 3952.66 87 332.47 7 158.94 34 6569.42 61 3726.46 88 282.76 8 219.77 35 6654.60 62 3507.06 89 241.58 9 297.89 36 6633.31 63 3296.86 90 207.20 10 381.81 37 6554.57 64 3092.79 91 182.47 11 473.25 38 6482.71 65 2898.71 92 162.46 12 573.16 39 6427.86 66 2710.65 93 144.64 13 687.77 40 6390.89 67 2531.51 94 129.16 14 820.90 41 6400.50 68 2359.13 95 114.25 15 974.01 42 6439.65 69 2190.70 96 99.88 16 1141.80 43 6505.35 70 2027.36 97 86.18 17 1338.00 44 6566.85 71 1867.31 98 73.02 18 1562.41 45 6592.29 72 1714.65 99 61.93 19 1835.16 46 6564.78 73 1567.62 100 51.73 20 2141.13 47 6429.37 74 1425.29 101 44.30 21 2466.81 48 6226.60 75 1293.72 102 38.95 22 2770.94 49 5981.38 76 1168.16 103 36.80 23 3039.89 50 5736.66 77 1055.79 104 35.94 24 3296.39 51 5505.12 78 954.11 105 35.61 25 3550.29 52 5289.00 79 867.25 106 35.57 26 3829.96 53 5099.97 80 788.49

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Table – 3.35 Flood hydrograph (SPF) for Kotha sub-catchment using SUH

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

1 157 46 21107 91 7755 136 372 2 159 47 21359 92 7407 137 352 3 164 48 21631 93 7065 138 333 4 174 49 21892 94 6728 139 314 5 186 50 22120 95 6402 140 294 6 205 51 22291 96 6081 141 275 7 228 52 22422 97 5759 142 256 8 270 53 22486 98 5445 143 239 9 328 54 22405 99 5134 144 223

10 404 55 22226 100 4830 145 210 11 485 56 21904 101 4538 146 198 12 570 57 21490 102 4255 147 189 13 658 58 21034 103 3981 148 181 14 757 59 20578 104 3710 149 175 15 871 60 20161 105 3457 150 170 16 1003 61 19776 106 3222 151 167 17 1154 62 19417 107 3007 152 164 18 1329 63 19067 108 2803 153 162 19 1529 64 18724 109 2609 154 161 20 1786 65 18375 110 2420 155 160 21 2104 66 17993 111 2240 156 159 22 2502 67 17565 112 2068 157 158 23 2969 68 17092 113 1907 158 158 24 3508 69 16595 114 1756 159 158 25 4112 70 16091 115 1613 160 157 26 4779 71 15598 116 1475 161 157 27 5507 72 15128 117 1354 162 157 28 6299 73 14681 118 1248 163 157 29 7135 74 14250 119 1158 164 157

152

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

30 7986 75 13828 120 1076 165 157 31 8825 76 13414 121 1002 166 157 32 9683 77 13008 122 932 167 157 33 10574 78 12605 123 866 168 157 34 11547 79 12209 124 804 169 157 35 12577 80 11813 125 746 170 157 36 13655 81 11421 126 692 171 157 37 14732 82 11030 127 641 172 157 38 15796 83 10647 128 593 173 157 39 16823 84 10270 129 551 174 157 40 17820 85 9900 130 516 175 157 41 18742 86 9533 131 486 176 157 42 19525 87 9169 132 460 177 157 43 20114 88 8808 133 436 178 157 44 20534 89 8454 134 413 179 157 45 20841 90 8103 135 392 180 157

Table – 3.36

Flood hydrograph (SPF) for Barari sub-catchment using SUH

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

1 99 46 15900 91 2058 136 99 2 100 47 16120 92 1886 137 99 3 104 48 16304 93 1723 138 99 4 111 49 16449 94 1571 139 99 5 122 50 16449 95 1427 140 99 6 138 51 16300 96 1289 141 99 7 159 52 15989 97 1158 142 99 8 197 53 15602 98 1040 143 99 9 253 54 15169 99 935 144 99

10 327 55 14750 100 844 145 99

153

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

11 407 56 14342 101 764 146 99 12 493 57 13960 102 695 147 99 13 586 58 13601 103 633 148 99 14 693 59 13253 104 575 149 99 15 816 60 12898 105 522 150 99 16 960 61 12543 106 473 151 99 17 1126 62 12152 107 425 152 99 18 1322 63 11724 108 377 153 99 19 1552 64 11260 109 329 154 99 20 1866 65 10787 110 286 155 99 21 2271 66 10322 111 248 156 99 22 2766 67 9868 112 216 157 99 23 3315 68 9420 113 189 158 99 24 3910 69 8986 114 168 159 99 25 4546 70 8560 115 151 160 99 26 5188 71 8143 116 137 161 99 27 5814 72 7727 117 126 162 99 28 6416 73 7322 118 118 163 99 29 7022 74 6925 119 112 164 99 30 7651 75 6541 120 108 165 99 31 8312 76 6170 121 105 166 99 32 9049 77 5812 122 103 167 99 33 9862 78 5469 123 101 168 99 34 10740 79 5134 124 100 169 99 35 11629 80 4808 125 100 170 99 36 12495 81 4493 126 99 171 99 37 13324 82 4192 127 99 172 99 38 14009 83 3901 128 99 173 99 39 14515 84 3619 129 99 174 99 40 14830 85 3347 130 99 175 99 41 15042 86 3092 131 99 176 99

154

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

Time (hrs)

Flood (m3/s)

42 15198 87 2855 132 99 177 99 43 15328 88 2635 133 99 178 99 44 15482 89 2430 134 99 179 99 45 15675 90 2240 135 99 180 99

Table – 3.37 PMF values for different proposed projects

S. No. Project PMF (cumec) 1 Lower Orr 12067.67

S. No. Project SPF (cumec)

2 Kesari 2690.14 3 Neemkheda 6654.60 4 Kotha 22486 5 Barari 16449

3.10.4 Annual Maximum Series Model

At-site flood frequency analysis using annual maximum series (AMS) of gauge site records is used as a check to the derived PMF value. The AMS model is used to arrive at a return period flood growth curve that is eventually used for deriving a design flood q (T) for a specific return period (T). The return period should be selected as per the guidelines of IS codes as detailed in Table – 3.38.

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Table – 3.38 Frequency of return period advocated by IS code

S. No.

Structure Return Period of design flood (Yrs)

1. Major dams with storage more than 6000 ha.m. (50,000 ac. ft.)

1000

2. Minor dams with storage less than 6000 ha.m. 100*

3. Barrages and pick up weirs (a) Free board (b) Items other than free board

500+

50-100 4. River Training Works (Calculation of Scour) 50-100@ 5. Water way of bridges 50

Note: * IS 5477 - Method of fixing capacities of reservoirs-Part IV.

+ IS 6966 - Criteria for hydraulic design of barrages and weirs.

@ IS 3408 - Criteria for river training works for barrages and weirs in alluvium.

Two basic assumptions in statistical flood frequency are the independence and stationarity of the data series. In addition, the assumption that the data come from the same distribution (homogeneity) is made. The tests which are commonly used to test for stationarity, homogeneity and independence of data have been discussed and applied to the AMS data of Basoda.

3.10.4.1 Test for independence and stationarity

Given a sample of size N, the Wald-Wolfowitz (1943) (W-W) test is used to test for the independence of a dataset and to test for the existence of trends in it. For a data set x1, x2,…xN the statistic R is calculated from Eq. – 3.11.

∑−

=+ +=

1

111

N

iNii xxxxR …(3.11)

When the elements of the sample are independent, R follows a normal distribution with mean and variance given by Eqs. 3.12 and 3.13:

156

( )1

22

1

−−

=N

ssR

…(3.12)

( )

( )( )21244

1)var( 4312

21

4124

22

−−−+−

+−−−

=NN

ssssssRN

ssR

…(3.13)

where sr = N 'rm and '

rm is the rth moment of the sample about the origin and var(R) denotes the variance of R. The statistic

( ) 5.0)][var( RRRu −= is approximately normally distributed with mean zero and variance unity and is used to test the hypothesis of independence at significance level α, by comparing the statistic u with the standard normal variate uα/2 corresponding to a probability of exceedance α/2. This test to check for independence and stationarity of the data has been recommended by Rao and Hamed (2000).

For the Basoda data, statistic R = 5.45E+08, R = 4.45E+08, and var(R) = 7.07E+15. Hence, test static u = 1.18. This value is less than the critical value at 5 % significance level u0.025 = 1.96. Thus the hypothesis of independence and stationarity can be accepted and the data of Basoda are concluded to be independent and stationary at 5% significance level.

3.10.4.2 Test for outliers

An outlier is an observation that deviates significantly from the bulk of the data, which may be due to errors in data collection, or recording, or due to natural causes. The presence of outliers in the data causes difficulties when fitting distribution to the data. Low and high outliers are both possible and have different effects on the analysis. The Gurbbs and Beck (1972) test (G-B) may be used to detect outliers. In this test, the quantities xH and xL are calculated by using Eqs. 3.14 and 3.15,

XH = SKX N+ …(3.14)

XL = SKX N− …(3.15)

where X and S are the mean and standard deviation of the natural logarithms of the sample, respectively, and is the G-B statistic tabulated for various sample sizes and significant levels by Gurbbs and

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Beck (1972). Sample values greater than xH are considered to be high outliers, while those less than xL are considered to be low outliers.

Step-1 Compute the relevant statistics. Log transformed annual peak discharges have the following statistics:

Mean Logarithm 8.03

Standard Deviation of logs 0.668

Skew Coefficient of logs -0.138

Years 34

Step-2 Check for Outliers

The station skew is between 4.0± ; therefore, the tests for both high outliers and low outliers are based on the systematic record statistics before any adjustments are made. From the relevant table of the KN for a sample size of 30 is 2.563.

The high outlier threshold XH is computed by:

XH = SKX N+

= 8.03 + 2.563 ×0.668 = 9.58

QH = antilog (9.58) = 14554 cumec

The low outlier threshold XL is computed by:

XL = SKX N−

= 8.03 - 2.563 ×0.668 = 6.199

QL= antilog [6.199] = 492

There are no value above QH and no value below QL. Hence all the data were used in frequency analysis.

In this study, peak flows for various return periods were computed by fitting the following distributions: Normal, Extreme value Type 1 (Gumbel distribution) and Log Pearson Type 3. The method of moments was followed to determine distribution parameters. The peak flood QT for the return period T is expressed by the following relation:

QT = Qmean + sQ * KT …(3.16)

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where Qmean is the mean flow, sQ is the standard deviation of flows, and KT is the frequency factor. For different distributions KT is computed for different values of T and then QT are determined.

The available AMS data for Basoda gauging site as used in the study along with the basic statistics of the data are given in Table – 3.38. Since the instantaneous maximum flows were not available, the AMS values of Table - 3.38 were obtained by multiplying the daily maximum flows by 1.17 (this is the ratio of instantaneous maximum flow/ daily maximum for Daudhan dam). For the Neemkheda, Barari, Kotha, Kesari and Lower Orr project sites, peak flows were estimated from the Basoda data adjusted in proportion to the ratio of (Catchment areas)0.75.

Table - 3.38 AMS data of Basoda site as used in the study

Year AMS (m3/s) Year AMS (m3/s)1976 1551 1993 2913 1977 5043 1994 4212 1978 3276 1995 3101 1979 823 1996 5875 1980 2253 1997 2367 1981 810 1998 1530 1982 1234 1999 4410 1983 2439 2000 7862 1984 5725 2001 1860 1985 6277 2002 1966 1986 10868 2003 1397 1987 5795 2004 6084 1988 3278 2005 5265 1989 3389 2006 9144 1990 2309 2007 2086 1991 6154 2008 2081 1992 3945 2009 1439

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Statistical properties of the data are:

Mean = 3787 m3/s SD = 2447.18 m3/s Coeff. of skewness = 1.081

It is noted here that the AMS models are generally used for a series of length 30 years or more. In the present case, data for a period of 34 years was available and used. Design floods for different return periods computed using the Gumbel distribution (method of PWM) are shown in Table – 3.39.

Table – 3.39 Return period flood (QT in m3/s) using Gumbel (EV-1) Distribution

Return Period (Year)

Basoda Neemkheda Barari Kotha Kesari Lower Orr

2 3230.0 1168.2 2508.5 3554.4 420.5 1108.8

10 7008.2 2534.6 5442.8 7711.9 912.4 2405.7

20 8662.5 3133.0 6727.6 9532.3 1127.8 2973.5

50 10999.5 3978.2 8542.6 12104.1 1432.1 3775.8

100 12908.0 4668.4 10024.8 14204.2 1680.6 4430.9

200 14955.0 5408.8 11614.6 16456.7 1947.1 5133.6

500 17896.4 6472.6 13899.0 19693.6 2330.1 6143.3

1000 20316.7 7347.9 15778.7 22356.9 2645.2 6974.1

3.11 Estimation of Diversion Flood

The guidelines laid down for arriving at the diversion design flood according to criteria of risk and damage for different types of dams and barrages are as follows (“Guidelines for preparation of Detailed Project Reports of Irrigation and multipurpose Projects – Working Group Report, Ministry of Irrigation (1980/2010”) :

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(i) Diversion capacity for concrete dams and barrages

The capacity of the diversion flood for concrete dams and barrages may be less because flood higher than the designed one could be passed safely over the partly constructed dam. The following criteria would help in deciding the capacity:

a) Maximum non-monsoon flow observed at the dam site.

OR

b) 25-year return period flow, calculated on the basis of non-monsoon yearly peaks.

The higher of the two should be taken as the design flood for diversion.

(ii) For large dams

For large dams, it is desirable that 100-year flood should be adopted for diversion works. For the present study, the peak of daily flow for non-monsoon months (November to May) was available for 33 years at Basoda as given in Table – 3.40. This data was used to estimate the values for Lower Orr, Neemkheda, Barari, Kotha and Kesari in proportion to the ratio of (Catchment area)0.75. On basis of this data, 25-year return period flow using GEV (PWM) model is calculated for project sites. Table – 3.41 gives maximum observed flow as well as flow for 25- year return periods computed using the GEV (PWM).

As per clause I (a), the maximum of non-monsoon flow for Lower Orr, Neemkheda, Kesari, Barari and Kotha are 288.34 m3/s, 303.81cm3/s, 109.37 m3/s, 652.37 m3/s and 924.35 m3/s respectively. As per clause (II), using the AMS, the 100-year return period flood for Neemkheda, Barari, Kotha, Kesari and Lower Orr are 4668.4 m3/s, 10024.8 m3/s, 14204.2 m3/s, 1680.6 m3/s, and 4430.9 m3/s respectively. Keeping in view the guidelines, the recommended diversion floods are given in the last column of the Table – 3.41.

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Table – 3.40 Non-monsoon maximum flow (m3/s) at various project sites

Site Basoda Lower Orr Neemkheda Kesari Barari Kotha Area (km2)

7668 1843.04 1963.68 519.71 5474 8711.5

Year Basoda Lower

Orr Neemkheda Kesari Barari Kotha

1976-1977 31.1 10.68 11.25 4.05 24.15 34.22 1977-1978 63.72 21.87 23.05 8.30 49.49 70.12 1978-1979 58 19.91 20.98 7.55 45.04 63.82 1979-1980 530.85 182.22 192.00 69.12 412.28 584.16 1980-1981 9.61 3.30 3.48 1.25 7.46 10.58 1981-1982 48.12 16.52 17.40 6.27 37.37 52.95 1982-1983 96.5 33.13 34.90 12.56 74.95 106.19 1983-1984 158.29 54.34 57.25 20.61 122.93 174.19 1984-1985 10.05 3.45 3.63 1.31 7.81 11.06 1985-1986 118.64 40.73 42.91 15.45 92.14 130.55 1986-1987 15.43 5.30 5.58 2.01 11.98 16.98 1987-1988 26.12 8.97 9.45 3.40 20.29 28.74 1988-1989 10 3.43 3.62 1.30 7.77 11.00 1989-1990 7.65 2.63 2.77 1.00 5.94 8.42 1990-1991 41.13 14.12 14.88 5.36 31.94 45.26 1991-1992 11.86 4.07 4.29 1.54 9.21 13.05 1992-1993 4.72 1.62 1.71 0.61 3.67 5.19 1993-1994 25.11 8.62 9.08 3.27 19.50 27.63 1994-1995 13.85 4.75 5.01 1.80 10.76 15.24 1995-1996 11.33 3.89 4.10 1.48 8.80 12.47 1996-1997 53.73 18.44 19.43 7.00 41.73 59.13 1997-1998 840 288.34 303.81 109.37 652.37 924.35 1998-1999 250.37 85.94 90.55 32.60 194.45 275.51 1999-2000 73.88 25.36 26.72 9.62 57.38 81.30

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2000-2001 17.13 5.88 6.20 2.23 13.30 18.85 2001-2002 16.86 5.79 6.10 2.20 13.09 18.55 2002-2003 8.7 2.99 3.15 1.13 6.76 9.57 2003-2004 17.28 5.93 6.25 2.25 13.42 19.02 2004-2005 18.5 6.35 6.69 2.41 14.37 20.36 2005-2006 11.21 3.85 4.05 1.46 8.71 12.34 2006-2007 13.412 4.60 4.85 1.75 10.42 14.76 2007-2008 0 0.00 0.00 0.00 0.00 0.00 2008-2009 0 0.00 0.00 0.00 0.00 0.00 2009-2010 520 178.50 188.08 67.70 403.85 572.22 2010-2011 51 17.51 18.45 6.64 39.61 56.12 Maximum 840.00 288.34 303.81 109.37 652.37 924.35

Table – 3.41 Diversion flood for various project sites in the study area

Project Site

Flow (m3/s) Maximum observed

(non-monsoon)

25-year return period

(non-monsoon)

100-year flood

Recommended diversion

flood

Lower Orr

288.34 116 4430.9 4430.9

Project Site Flow (m3/s)

Maximum observed (non-monsoon)

25-year return period (non-monsoon)

Recommended diversion flood

Neemkheda 303.81 122 304

Kesari 109.37 45 110

Barari 652.37 263 653

Kotha 924.35 373 924