Banglaore Institute of technology New tank project 2010-11CONTENTS Page. 1. Synopsis 2 2. Salient features 3 3. Topography sheet 6 4. Aim and Objectives of the Project 7 5. Technical aspects of Project 8 6. Introduction to Irrigation 10 7. Survey work 18 8. Location of bund 21 9. Types of Earthen Dams 22 10. Methods of construction of earthen dams 29 11. Design criteria for earthen dams 30 12. Selecting a suitable preliminary section for earthen dams 31 13. Seepage control in earthen dams 34 14. Slope protection in earthen dams 39 15. Area of capacity contours 41 16. Estimation of materials of Bund 42 17. Channel Design 46 18. Design of Waste Weir 48 19. Conclusion 49 20. Bibliography 50 Extensive Survey Project Batch A2 1 Banglaore Institute of technology New tank project 2010-11 1. SYNOPSIS New tanks are constructed to provide water for multipurpose irrigation purpose. Tanks and reservoirs requires very careful planning, design and operation for which certain observations relating to selection of site, relative merits of different types of tanks, storage capacity, optimum yield, coordinated uses of storage for different purposes etc, are to be studied in detail. The irrigation reservoir is primarily meant to store the excess water during the period of large supply and release it gradually for irrigation as and when required. A scheme of this type of formation of new tank near Melkote, Pandavapura Taluk, Mandya District, has been taken up as mini project work as per the university regulations. The proposed site across the stream called Hebballa, and is situated nearly 2Km from Yoganarashimha swamy temple, Melkote, Pandavapura Taluk, Mandya district. The Catchment area is good, with Seasonal rainfall. The latitude and longitude of the place are 12°39' N and 76°38' E respectively. Extensive Survey Project Batch A2 2 Banglaore Institute of technology New tank project 2010-11 2. SALIENT FEATURES OF THE PROJECT DETAILS OF SITE Place of Project - Melkote, Pandavapura Taluk, Mandya District. Distance from Bangalore - 140 km. Distance from Development - 3 km from Temple Nature of the Project - New Tank Project Type of Bund - Homogeneous Earthen Bund DETAILS OF STORAGE RESERVOIR Catchment area of tank - 7.00 Sqkm. (From: Toposheet no.57D/10) Area Irrigated - 64 Hectares Proposed crop pattern - Wet crops & vegetables Average Annual Rainfall - 75 cm (assumed) Extensive Survey Project Batch A2 3 Banglaore Institute of technology New tank project 2010-11 DETAILS OF BUND Type of Bund - Homogeneous type earthen dam Length of Bund - 233.5m Maximum Height of Bund - 17.737m Top Level of Bund (TBL) - 928.000 m Maximum Water Level (MWL) - 927.000 m Full Tank Level (FTL) - 925.500 m Dead Storage Level (DSL) - 920.000 m Lowest Bed Level (LBL) - 910.736 m Sluice level - 920.000 m Top width of Bund - 3.000 m Upstream slope - 3:1 Downstream slope - 2:1 Rock toe - Provided Extensive Survey Project Batch A2 4 Banglaore Institute of technology New tank project 2010-11 U/s pitching - 50 cm thick stone revetment over 10cm thick gravel backing. DETAILS OF WASTE WEIR Type - Broad Crested Surplus Weir Crest level - 925.500 m Depth of Spillage - 1.000 m Waste Weir Length - 18.50 m Top width of Weir - 1.500 m Bottom width of Weir - 3.000 m DETAILS OF MAIN CHANNEL:- Channel off taking RL - 920.000 m Longitudinal Gradient provided - 1: 1500 Bottom width of channel - 0.500 m Depth of water - 0.300 m Side slopes - 1H:1V Free Board - 0.20 m Type of Sluice - Tank Sluice with tower head Extensive Survey Project Batch A2 5 Banglaore Institute of technology New tank project 2010-11 Canal Length Surveyed - 600.000 m 4. AIM AND OBJECTIVES OF THE PROJECT:- OBJECTIVES: In view of acquiring a sound knowledge of both theory and practical situations and also difficulties that would be encountered during field survey work, an extensive survey project camp is usually arranged for civil engineering students. With this motive survey camp was arranged with the help of our lecturers at Melkote from24/01/2011 to 07/02/2011. We were able to finish the survey works under guidance of our lecturers and the knowledge gained by us in our course of study. FOLLOWING ARE THE TECHNICAL AIMS AND ABILITIES: To impart training in the use of surveying instruments and to acquire a Comprehensive idea of the project, along with designs, drawings and Estimations. To learn handle real and difficult situation of project surveying. To develop team spirit in practical situation. To impart and develop the self-confidence in the management of project survey. AIM OF THE PROJECT: Longitudinal Section for the New Tank. Cross Section for the New Tank Extensive Survey Project Batch A2 6 Banglaore Institute of technology New tank project 2010-11 Capacity Contour Canal Alignment. 5. TECHNICAL ASPECTS OF A PROJECT Before designing and construction of a dam, road or any other project it requires a thorough investigations of the site, its stability etc., This investigation starts right from: 1. Reconnaissance work. 2. Study of Toposheet(Map). 3. Proposal of alternate sites etc. The second stages of work i.e., actual work done by us includes the survey work at site. This is done to calculate and collect the data necessary for the design of the parts of the project. In the classroom we do the drawings and the design like 1. Knowing the amount of earth work in cutting and filling 2. Profile of the land 3. Sluice and weir points 4. MWL, FTL, sill, storage levels, etc. 5. Length of canal and its alignments. BOOKING THE STAFF READING IN THE LEVEL BOOK 1. The readings should be entered in the respective columns and in order of their observation. 2. The first entry on the page is always a back sight and the last one always a foresight. Extensive Survey Project Batch A2 7 Banglaore Institute of technology New tank project 2010-11 3. In carrying forward the readings from one page to the next, if the last entry happens to be an IS, it is entered in both IS and FS columns and in the BS and IS columns as a first entry on the next page. 4. The FS and BS of the change point should be written in the same horizontal line. 5. The R.L. of P.C. should be written in the same horizontal line opposite the B.S. 6. B.M., change point and other important points should be brief, but accurately explained in the remarks column. 6. INTRODUCTION DEFINITION:- Irrigation may be defined as the science of artificial application of water to the land, in accordance with the “crop requirements” throughout the” crop period” for full fledged nourishment of the crops. NECESSITY OF IRRIGATION India is the tropical country with a vast diversity of climate, topography and vegetation. Rainfall varies considerably in its place of occurrence, as well as in its amount. Crops cannot therefore be raised successfully over the entire land, without ensuring artificial irrigation of fields. More than 70% of our population directly depends on agriculture and remaining depends indirectly on agriculture. Only 50% of total geographical is cultivable in country. In order to saw this area from the complete wishes of nature, and to ensure full growth of crops, it is necessary that adequate artificial irrigational facilities be ensured. THE NEED FOR IRRIGATION CAN BE SUMMARIZED IN THE FOLLOWING 4 POINTS. 1.LESS RAINFALL: When the total rainfall is less than that needed for the crop, artificial supply of water is necessary. In such a case, irrigation system be developed at Extensive Survey Project Batch A2 8 Banglaore Institute of technology New tank project 2010-11 the place where more water is available, and then the means to convey this water to the place where there is deficiency. 2. NON-UNIFORM RAINFALL: The rain in a particular area may not be uniform throughout the crop period. During the early periods of the crop rain may be less or the crop may wither. But the accumulated or stored water during the excess rainfall periods may be supplied to the crops during the period when there may not be rainfall, but there is a need for watering. 3. COMMERCIAL CROP WITH ADITIONAL WATER: The rainfall in a particular area may be just enough to raise the usual crops, but more water may be necessary for raising commercial or cash crops in addition to increasing the annual output by adopting multiple cropping patterns distributed throughout the year. 4. CONTROLLED WATER SUPPLY; Buy constructing proper distribution system; the yield of crops may be increased. Applications of water to the soil by modern methods of irrigation serve the following PURPOSE: It adds water to the soil to supply moisture essential for the plant growth. It washes out all diluted salts in the soil. It washes the hazards of soil piping. ADVANTAGES:- 1) Increase in food production: Irrigation helps in increasing crop yield, and hence to attain self-sufficiency of food. Extensive Survey Project Batch A2 9 Banglaore Institute of technology New tank project 2010-11 2) Optimum benefits: Optimum utilization of water is made possible by irrigation by optimum utilization, we generally mean, obtaining maximum crop yield with any amount of water. 3) Elimination of mixed cropping: By mixed cropping we mean, sowing together of 2 or more crops in the same fields. If irrigation is ensured mixed cropping may be eliminated. 4) General prosperity: Revenue returns are sometimes at high and helps in all-round development of the country and prosperity of the entire nation and community. 5) Generation of Hydroelectric power: Canal falls can be used for power generation. So, cheaper power generation can be obtained on projects, primarily designed for irrigation, available with great difficult. 6) Facilities of communication: The inspection paths of irrigation channels provide a good roadway to the villager for walking, cycling or sometimes even for motoring. 7) Inland Navigation: Sometimes, larger irrigation canals can be used and developed for navigation purposes. 8) Afforestation: Trees are generally grown along the banks of the channels, which increase the timber wealth of the country and also help in reducing soil erosion. SOURCES OF IRRIGATION:- 1) RAINFALL AND ITS DISTRIBUTION: Areas of high rainfall are a good source for a good irrigation project. 2) RUNOFF AND SURFACE RUNOFF: Extensive Survey Project Batch A2 10 Banglaore Institute of technology New tank project 2010-11 Runoff includes all the water flowing in the stream channel at any given section. Surface runoff includes only the water that reaches the stream channel without first percolating down to the water table. 3) YIELD OF DRAINAGE BASIN: It is as same as the runoff, with the only difference that it is expressed over long periods, while runoff is expressed for short periods. 4) SUB-SURFACE RUNOFF: The water that reaches stream channel without first percolating down to the water table. 5) INFILTRATION: When waterfalls on a given formation, a small part of it, is first of all, Absorbed by the top thin layer of soil so as to replenish the soil moisture deficiency. This is called Infiltration. The maximum rate at which a soil in any given condition is capable of absorbing water is called its infiltration capacity. 6) SOIL MOISTURE: The water below the water table is called ground water and that above water table is called soil moisture. BASIC PRINCIPLES OF IRRIGATION DUTY: Duty represents irrigating capacity of a volume of water. I is the relation between the area of crops irrigated and the quantity of irrigation water required during the entire period of the crop. FOR EXAMPLE: If 3 cumec of water supply is required for a crop sown in an Area of 5100 hectares, the duty of irrigation water will be 5100/3=1700 hectares/cumec, and the discharge of 3 cumec will be required throughout the base period. DELTA: Delta is the total depth of water required by a crop during the entire period from the day of sowing of seeds to the harvesting. Extensive Survey Project Batch A2 11 Banglaore Institute of technology New tank project 2010-11 FOR EXAMPLE: If a crop requires about 12 watering at an interval of 10 days and a water depth of 10cm in every watering then the delta for the crop will be 12*10= 1.2 meters. If the area under that crop is “A” hectares, the total quantity of water required will be 1.2*a=1.2A hectares – meters in a period of 120 days. CROP PERIOD: Crop period is the time, in days that a crop takes from the instant of sowing to that of its harvesting. BASE PERIOD: Base period for a crop refers to the whole period of cultivation from the time of First watering for preparation of soil for sowing the seeds to the last watering before Harvesting. THE DUTY OF WATER IS EXPRESSED IN THE FOLLOWING WAYS: 1)By the number of hectares that 1 cumec of water can irrigate during base Period i.e. 1700hectares per cumec 2) By the total depth of water i.e., 1.20 meters 3) By the number of hectares that can be irrigated by million cubic meter stored Water. This system is used for tank irrigation 4) By the numbers of hectares meters expended per hectares irrigated. This is also used in the tank irrigation. RELATION B/W DUTY (D), DELTA (Δ) AND BASE PERIOD (B) IN METRIC SYSTEM: Let there be a crop of base period “b” days. Let one cumec of water be applied to this crop on the field for B days. Now, the volume of water applied to this crop during B days (V) V=(1*60*60*24) m cube = 86400(cubic meter) Extensive Survey Project Batch A2 12 Banglaore Institute of technology New tank project 2010-11 By definition of duty (D), one cubic meter supplied for B days matures D hectares of land.Therefore this quantity of water (V) matures D hectares of land or 10 square meters of area. Total depth of water applied on this land = Volume / area = 86,400 b/10^4 meters = 8.64 B/D meters. Therefore Δ=8.64 B/D meters Or Δ=864B/D cm. Where, Δ is in cm or m, B in days and d is duty in hectares/cumec. GROSS COMMANDED AREA: This is an particular area lying under the canal system, the irrigation can be done only up to the drainage boundaries. The gross commanded area is thus the total area lying between drainage boundaries, which can be commanded or irrigated by a canal system. CULTURABLE COMMANDED AREA: The gross commanded area contains unfertile barren land, alkaline soil, local ponds village and other area as habitation. These areas are known as uncultivable areas. The remaining area on which crops can be grown satisfactorily is known as cultivable area. Cultivable commanded area can be further classified as cultivable cultivated area and cultivable uncultivated area. TYPES OF CROPS: The duty varies from crop to crop. The various types of crops can be classified as follows 1. WET CROP: A wet crop is that which requires water for irrigation. Extensive Survey Project Batch A2 13 Banglaore Institute of technology New tank project 2010-11 2. DRY CROP: A dry crop is that which does not require water for irrigation. 3. GARDEN CROP: A garden crop requires irrigation throughout the year. 4. KHARIF CROP: Kharif crop are sown by the beginning of the southwest monsoon and are Harvested in autumn i.e. from 1st October to 31st March. 5. RABI CROP: Rabi crop are sown in autumn and are harvested in spring i.e. from 1st of April to 31st of September. BASE PERIOD OF THE CROP: If the base period of the crop is more, the amount of water required will be high. Hence duty will be low and vice versa. CLIMATIC CONDITIONS OF THE AREA: The climatic conditions which affect the duty are temperature, wind humidity and rainfall. Due to high temperature and wind evaporation loses will be more, and duty will be less. A humid atmosphere reduces the losses, Rainfall during the crop period will reduce the irrigation water requirements; the duty will thus be higher. NECESSITY OF THE NEW TANK: Primarily all the irrigation structures are developed and built to cater to the needs of: 1) Irrigation 2) Water supply 3) Recharging of ground water resources 4) Flood mitigation. 5) Drought relief measures or any other such relevant needs of the community. Extensive Survey Project Batch A2 14 Banglaore Institute of technology New tank project 2010-11 A bund is usually constructed in valley keeping in mind the greatest possible ratio of height to length for a given capacity. In deep gorge, the length of the bund will be usually of less and capacity of water stored will be more, which is directly proportional to the height of the bund. In all such cases due to storage of water environmental mismanagement invariability occurs. As per basic human instinct, to develop civilization near water fonts habitations begin to develop leading to deforestation and environmental changes. Deforestation will lead to soil erosion of the green cover. Soil erosion will lead to situation in tank due to removal of the topsoil by surface runoff. This result is gradual reduction of storage capacity of tank and the rate of citations is directly proportional to rate of denigration of green cover. The erosion of green cover invariably has a disastrous effect on environment. With the present much talked about phenomenon of global warming and its resulting effect, it has generally lead to either untimely or scanty rainfall in much area. This necessitates the development of proper storage system to optimize the solution for our needs since there is a wide area of land left barrel especially on side of a gradual slope being on the left side of the stream the proposal of a new tank is ----appropriate. More over the earth and rock necessary for construction is available at the site. The labor would easily available from the local area for their people seem to be relatively in need of such jobs as there is less part of their area is not cultivated and quite a lot sell coconut along the road though there isn’t much scope of earning from the moderately dense population. BASIS FOR FORMATION OF TANKS 1.Area of the catchment basin: The catchment area for the proposed tank should be determined accurately. If the catchment is large, it could be traced from the Survey of India contour map. However, if the area is small the watershed has to be traced by a compass and the area is to be determined by running a closed traverse. Extensive Survey Project Batch A2 15 Banglaore Institute of technology New tank project 2010-11 2. Nature of the catchment: The nature of the catchment has to be examined to check whether it is good, average or bad for purpose of computing runoff. Generally, catchment with vegetation gives good yield. Those with porous soil give poor yield. If there are already some tanks with their ayacuts in the catchment of the proposed tanks, the details of storage capacities and the ayacuts they irrigate have to be gathered and noted. ACHIEVEMENT OF IRRIGATION Irrigation is achieved by means of irrigation projects such as construction of dams, channels with only 20 to 25% of our cultivated land under irrigation and definite limits to the additional area, which can be brought under irrigation. MINOR IRRIGATION PROJECTS These envisages the construction of minor irrigation projects such as earthen Dams etc., a low diversion water across a small stream, an open well, tube well, lift Irrigation from non-perennial system. Minor irrigation projects have small catchment area hence water supply may not be continuous. MAJOR IRRIGATIONAL PROJECTS A major project consists of major irrigation works like storage reservoir like a dam, a barrage, and solid diversion weirs across perennial rivers. The cost of major projects will be in terms of crores of rupees. These projects will benefit large areas of cultivated land and will have major head works, elaborate canals, masonry works. These projects take many years for construction after planning. 7. SURVEY WORK The various survey works carried out are as follows: a) Reconnaissance Extensive Survey Project Batch A2 16 Banglaore Institute of technology New tank project 2010-11 b) Fly leveling c) Longitudinal sections and cross sections d) Contour tracing e) Block leveling at sluice point and waste weir site. f) Channel alignment a) RECONNAISSANCE: It involves the determination of the most feasible site by observing the who are. It consists of the following things, 1) Location of bund 2) Area to be irrigated 3) Nature of the soil 4) Crops to be cultivated 5) Communication links like roads, bridges 6) Population 7) Availability of construction material FLY LEVELLING OBJECT: The object of fly leveling is to establish a temporary reference benchmark near the site, which is accurate, from mean sea level. INSTRUMENTS USED: 1) Auto Level, 2) Leveling staff. LONGITUDINAL SECTION AND CROSS SECTIONS: OBJECT: Longitudinal and cross section are required to be carried out in order to determine the length of bund, area of bund and in turn to calculate earthwork quantities also. The longitudinal section is required in order to complete the Extensive Survey Project Batch A2 17 Banglaore Institute of technology New tank project 2010-11 other survey works as block leveling at its sluice point and tracing of capacity contours. INSTRUMENTS USED: a)Auto Level, b)Leveling staff, c)arrows, d)Chain-Tape, e)Ranging rods, f)Cross staff. CONTOUR TRACING: OBJECT: The object of contour tracing is to be contours, to find out capacity of the tank and to fix the maximum water level and sill levels. INSTRUMENTS USED: Tachometer, leveling staff, plain table, alidade, trough compass and other plain table accessory. PROCEDURE: Here the principle of tachometry is adopted .A person holding the leveling staff stands on the center line of the bund at the required R.L. and a back sight is taken to determine the plane of collimation. Next the leveling is moved forward, in the upstream side, say: for a distance of 30 m and is moved up and down to get required staff reading. The staff reading is calculated before itself, so as to get the required R.L. on the ground, i.e. the contour to be traced .The distance is calculated using the principle of tacheometry, i.e. D=KS+C, Where d is the distance between the plane table and the point, K=100 & C=0. The procedure is repeated until the same R.L. is obtained on the centre line of the bund on the other bank. Simultaneously the points are fixed on the plane table and joined with the smooth curve to some scale and hence the required contour is obtained on the paper. CHANNEL ALIGNMENT: OBJECT: To estimate the cost of channel and cross drainage works and other canal works. Extensive Survey Project Batch A2 18 Banglaore Institute of technology New tank project 2010-11 INSTRUMENTS USED: Auto level with stand, Leveling staff, Plane table with accessories, Chain, Arrows, Ranging rods, Tape. POINTS TO BE REMEMBERED: The following points are to be kept in view for channel alignment: 1. The channel is aligned in a falling contour. 2. The depth of cut should be a minimum. 3. The straight channel is preferred wherever possible. 4. If curves are unavoidable, curves of large radius are preferred. 5. There should be few cross drainage works. PROCEDURE:- 1. Starting from a Bench Mark levels are carried until the required elevation of the starting point of the channel on the central line of the bund is obtained. 2. This is the position of sluice and this point is marked on the plane table. 3. Allow a fall of 1.0m for 2000m, trace falling contours and plot it on the plane table. 4. Bench Mark should be left at an interval of 100m. 5.Pegs are driven at 30m intervals. 6.Cross sections are taken at every 30m interval and levels along the cross section along 5m intervals, to an extent of 30m on both sides of channel alignment. 7.Plane table station should be established by using three established points. 8. The details of area through which the channel passes should be marked on the Plane table . 9.Plan of the area lying between the channel and the mother valley should be prepared to determine the extent of area that can be irrigated. 10.Block levels are to be taken at all points of crossing the natural drainage. Extensive Survey Project Batch A2 19 Banglaore Institute of technology New tank project 2010-11 11.Final alignment should then be marked on the sheet. 12.The pegs are driven at 30m intervals in the final alignment and the longitudinal and cross sections are taken if necessary for the changed position of the alignment. 8. LOCATION OF BUND In the new tank project it is proposed to have an earthen bund with core wall across the stream “HEBALLA” .The stored water is used irrigate the near by lands with the help of banks canal. The selection of bund is made considering the following factors: 1. Geology of the area, surface, sub surface rocks should be of such a nature that it should offer maximum resistance to percolation. 2. Object able mineral salts, which could affect irrigation when mixed with stored water, should not be present at site. 3. The (proposed) topography of the area should be such that there is a narrow opening to reduce the length of the dam. The rapidly widening valley above the dam is desirable to facilitate greater average volume, height and length of the dam. 4. Steep slopes are not desirable as it reduces the surface area per unit volume. 5. The land selected is such that it is unimportant, and submergence of Roadways or Railways is unobjectionable. 6. The proposed site is located at about 2.0 Kms from Ahobila mutt. 7. A V-shaped valley is capable of storing the maximum amount of water for the catchment and has good runoff at the proposed site. 8. The saddle between the hillocks is the best suited since it is suited for surplus water works with a minimum cost of construction. 9. There s a subsidiary valley, the excess water flows into the other valley. 9. TYPES OF EARTHEN DAMS:- EARTHEN BUNDS: Extensive Survey Project Batch A2 20 Banglaore Institute of technology New tank project 2010-11 Earthen bund or earthen dam is a form of embankment dam that is widely used, made predominantly of earth or soil. Earthen dams have been built since the early days of civilization, but until recently these dams were designed by empirical methods and these constructions was based mostly on experience and precedent. They were built with the natural materials with a minimum of processing and with primitive equipment, but in the ancient days the cost of carriage and dumping of the dam materials was quite high. However the modern developments in earth moving equipments have considerably reduced the cost of carriage and the laying of dam materials. They are still cheaper as they utilize the locally available materials and less skilled labour is required for them. TYPES OF EARTHEN DAMS: The earthen dams may be classified on the basis of method of construction in to the following three categories. 1.Rolled fill dams 2.Hydraulic fill dam 3.Semi hydraulic fill dam ROLLED FILL DAM: A rolled fill dam is one that is constructed in successive mechanically compacted layers. The material (sand, clay, gravel, etc.,) it is transported form the borrow pits to the dam site by truck or scrapers. It is then spread within the dam section by bulldozers to form layers of 15cm to 45cm thickness. Each layers is then thoroughly compacted and bonded with preceding layer by means of power-operated rollers, of proper design and weight. Usually sheep foot rollers and heavy pneumatic tyred rollers are used either singly or in combination for compacting the fill. Further, for proper compaction, the moisture content of the material should be near that for optimum density for which the required quantity of water is sprinkled on each layer during compaction. Extensive Survey Project Batch A2 21 Banglaore Institute of technology New tank project 2010-11 The earthen dams can be of the following three types: 1) Homogeneous embankment type 2) Zoned embankment type and 3) Diaphragm type. HOMOGENEOUS EMBANKMENT TYPE: It is the simplest type consisting of a single material and is homogenous throughout. Sometimes a blanket of relatively impervious material placed on the upstream face. HOMOGENEOUS TYPE EMBANKMENT The type of embankment is used, when only type of material is economically or locally available. Such a section is used for low to moderately high dams and for levees. Large dams are seldom designed as homogenous embankments. A purely homogenous section poses the problems of seepage, and huge sections are required to make it safe against piping, stability etc., due to this a homogenous section is generally added with an internal drainage system, such as a horizontal drainage filter, rock toe etc. The internal drainage system keeps the pheratic line (i.e., top seepage line) well within the body of the dam, Extensive Survey Project Batch A2 22 Banglaore Institute of technology New tank project 2010-11 and steeper slopes and thus, smaller sections can be used. The internal drainage is therefore always provided in almost types of embankments. ZONED EMBARKMENT TYPE: Zoned embankments are usually provided with a central impervious core, covered by a comparatively previous transition zone, which is finally surrounded by a much more pervious outer zone. ZONED TYPE EMBANKMENT The central core checks the seepage .The transition zone prevents piping through cracks, which may develop in the core .The outer zone gives stability to the central impervious fill and also distributes the load over a large of foundations. These types of embankments widely constructed and the materials of the zones are selected depending upon their availabilities. Even though clay is highly impervious, it might shrink and swell too much. Hence clay is sometimes mixed with fine core. Silt or silty clays may be used as the satisfactory central core materials. Freely draining materials, such as coarse sands and gravels, are used in outer shell. Transition filters are provided between the inner zone and outer zone. These types of transition filters are always provided, whenever there is an abrupt change of permeability from one zone to other. DIAPHRAGM TYPE EMBANKMENT: Extensive Survey Project Batch A2 23 Banglaore Institute of technology New tank project 2010-11 Diaphragm type embankments have a thin impervious core, which is surrounded by earth or rock fill. The impervious core, called diaphragm is made of impervious soils, concrete, steel, timber or any other material. It acts as a water barrier to prevent seepage through the dam. The diaphragm may be placed either at the center as a vertical core or at the upstream face as a blanket. The diaphragm must also be tied to the bedrock or to a very impervious foundation material, if excessive under seepage through the existing pervious foundations has to be avoided. DIAPHRAGM TYPE EMBANKMENT The diaphragm types of embankments are differential from zoned embankment, depending upon the thickness of the core. If the thickness of the diaphragm at any elevation is less than 10 meters or less than the height of embankment above the corresponding elevation, the dam embankment is considered to be of “Diaphragm type”. But if the thickness equals or exceeds these limits, it is considered to be of zoned embankment type. SURPLUS WEIR:- The excess surplus water is spilled from a tank, into the downstream channel, so as to avoid the rise of water in the tank above the maximum water level (MWL). In fact, the water will generally starts spilling over the crest of Extensive Survey Project Batch A2 24 Banglaore Institute of technology New tank project 2010-11 this escape weir, as and when it rises above full tank level (FTL); and the discharging capacity of this weir will be designed such as to pass the full maximum flood discharge (likely to enter the tank) with a depth over the weir equal to the difference between FTL and MWL. Although the effective storage capacity of a tank is limited by FTL, the area submerged by the tank bund and revetment is dependent on MWL. And hence, in order to restrict the dimensions of this, it is desirable to keep the difference between FTL and MWL to a smaller value. The usual difference between FTL and MWL 1 m or smaller value. LENGTH OF THE TANK WEIR: In order to determine the length of the escape weir, it is, first of all, necessary to determine the maximum flood discharge that may enter into a tank, after it is filled up to FTL. This peak discharge may come from the free catchment of a tank and can be fairly estimated by using an empirical formula applicable to the given region. The following modified formula is used for calculating peak discharge. Qр=C*A^⅔-c*a^⅔ Where C1 is the coefficient in Ryve’s Formula, A is the area of the combined catchment in sq. kilometers, c1 is the coefficient for one-fifth to one-third of C1 and a is the area in sq.kilometers of the catchment intercepted by upper tanks. In general, the discharge over a broad crested free weir and without any velocity of approach is given by Q=C*L*H^3/2 Where L is the length of the weir H is the head of water over the weir (i.e. the difference between MWL and FTL), C is a constant. TANK SLUICE This is uncontrolled storage, which is given by the volume of water stored Extensive Survey Project Batch A2 25 Banglaore Institute of technology New tank project 2010-11 between normal and maximum pool level. A tank sluice is an opening in the form of a culvert or pipe running through or under the tank bund, and supplying water from the tank, to the distributory channel below, to meet the irrigation and other water requirement, as and when needed. Suitable wing walls and other bank connections are also provided as required at the head and tail end of the culvert. The size of the culvert (i.e. its cross section depends the maximum quantity of water it is required to convey, but in no case should be less than 0.6m wide and 0.75m high, so as to allow a man to enter it for examination and repairs or removal of obstructions. The size of the barrel should also be such as to limit the velocity through the sluice barrel to a maximum of 4.5m/sec, under the condition of plughole being fully open and with the water at full tank level. The pipe sluices not adopted in tank bunds, where the depth below FTL exceeds 2.5m or so. This is because, in such cases, the earthenware pipes may get fractured, or leakage through their joints may take place, resulting in a breach, as the pipes can neither be examined nor repair easily without cutting open the bund. SELECTION OF SITE FOR A DAM The following points has to be considered for the selection of site for the dam: 1. Cost of dam is controlling factor if the site is suitable for the dam i.e. types of Dam (earthen dam, masonry dam, and gravity dam) governs. 2. Geological formation for reservoir bank walls etc should be such that there is minimum leakage. 3. Geology of catchment area or basin should be such a way so as to assume minimum absorption and percolation losses. 4. The site should be such that a deep reservoir since it has a merit of lower land cost per unit capacity, less evaporation loss, less weed growth etc. Extensive Survey Project Batch A2 26 Banglaore Institute of technology New tank project 2010-11 5. The site should have very good capacity to store water so usually a valley a profile is chosen. 6. Too much silt-laden tributaries must be avoided. 7. Reservoir basin should have deep narrow opening in the valley so that length of dam is minimum. STORAGE ZONES OF RESERVOIR: a) DEAD STORAGE: It is the volume of water stored below minimum pool level. It is not used for Reservoir operation. b) VALLEY STORAGE: It is the amount stored in the stream channel before the construction of dam . c) USEFUL STORAGE: It is the volume of water between the minimum and normal pool level. It may be divided into conservation and mitigation storage in multi purpose storage reservoir. d) SURCHARGE STORAGE: This is uncontrolled storage, which is given by volume of water stored between normal and maximum pool level. e) BANK STORAGE: It is the volume of the water collected only in the permeable reservoir bank. This can be used when the reservoir is depleted. The amount of water depends on the type of geological formation. f) MINIMUM POOL LEVEL: It is the lowest water surface for irrigation that has to be kept under normal operation. It is kept equal to elevation of lowest outlet sluice of dam or at minimum head of the turbine. g) NORMAL POOL LEVEL: It is the maximum elevation to which water surface will rise during normal water operations; it is kept at elevation of spillway crest. Extensive Survey Project Batch A2 27 Banglaore Institute of technology New tank project 2010-11 h) MAXIMUM POOL LEVEL OR FULL RESERVOIR LEVEL: It is the maximum level to which water rises during the worst design flood. i) RESERVOIR YEILD: This is the amount of water that can be drawn from reservoir in a specified time interval. j) MASS CURVE OF INFLOW: It is a plot of annual inflow to reservoir with respect to time. k) MASS CURVE OF OUTFLOW: It is a plot of annual outflow from reservoir with respect to dam. 10. METHOD OF CONSTRUCTION OF EARTH DAMS There are two methods of constructing earthen dams. 1. Hydraulic fill method 2. Rolled fill method 1. HYDRAULIC FILL METHOD: In this method, excavating and transporting soils by using waters construct the dam body. Pipes called flumes are laid across the outer edge of the embankment. The soil materials are mixed with water and pumped into these flumes. The slush is discharged through the outlets in the flumes at suitable intervals along their lengths. The slush, flowing towards the center of the bank tends to settle down. The coarser particles get deposited soon after the discharge near the outer edge, while fines get carried and settle at the center, forming a zoned embankment having a relatively impervious central core. This type of embankment is susceptible to settlement over long periods because of slow drainage from the core and high pore pressures developed due to saturation in core material. Hence this method is not usually adopted. 2. ROLLED FILL METHOD: Extensive Survey Project Batch A2 28 Banglaore Institute of technology New tank project 2010-11 This method is generally universally adopted in these modern days. The embankment is constructed by placing suitable soil materials in thin layers (15 to 30 cm) and compacting them with rollers. The moisture content of the soil fill must be properly controlled. The best compaction can be obtained at moisture content somewhere near the optimum moisture content. (The optimum moisture content is the moisture required for obtaining optimum density in the field). 11. DESIGN CRITERIA FOR EARTH DAMS 1. A fill of sufficiently low permeability should be developed out of the available materials, so as to best serve the intended purpose, with minimum cost. Burrow pits should be as close to the site as possible, so as to reduce the leads. 2. Sufficient spillway and outlets capacities should be provided so as to avoid the possibility of overtopping during the design flood. 3. Sufficient free board must be provided for wind setup, wave action, frost action and earth quake motions. 4. The seepage line (i.e., pheratic line) should remain well within the down stream face of the dam, so that no sloughing of the faces occurs. 5. There is little harm in seepage through a flood control dam, if the stability of foundations and embankments is not impaired, by piping, sloughing etc., but a conservation dam must be as water tight as possible. 6. There should be no possibility of free flow of water from the upstream face to the downstream face. 7. The upstream face should be properly protected against wave action and downstream face against rains and against waves up to tail water. Provisions of horizontal berms at suitable intervals in the downstream face may be thought of, so as to reduce the erosion due to flow of f rainwater. Ripraps should be provided on the entire upstream slope and also on the down stream Extensive Survey Project Batch A2 29 Banglaore Institute of technology New tank project 2010-11 slope, near the toe and up to slightly above the tail water so as to avoid erosion. 8. The portion of the dam, down stream of the impervious core, should be Properly drained by providing suitable horizontal filter drain, or toe drain or chimney drain etc., 9. The upstream and downstream slopes should be so designed as to be stable under worst condition of loading. These critical condition occur for the upstream slope during sudden draw down of the reservoir and for the downstream slope during steady seepage under full reservoir. 10. The upstream and downstream slopes should be flat enough, as to provide sufficient base width at the foundation level, such as the maximum shear stresses developed remains well below the corresponding maximum shear strength of the soil, so as to provide a suitable factor of safety. 11. After consolidation of soil, the embankment’s height reduces. Hence a suitable allowance in height of embankments (between 2 to 3 percent of dam height, determined by laboratory test) must be made in fine grained soils so as to account for the consolidation that may takes place up to years of construction. Dewatering the foundations may sometimes be used to accelerate the process of consolidation. 12. Since the stability of the embankment and foundation is very critical during construction or even after construction (i.e., during the period of consolidation), due to the development of excessive pore pressure and consequent reduction in shear strength of soils, the embankment slopes must remain safe under this critical condition also. All the criteria must be satisfies and accounted for in order to obtain the safe design and construction of an earthen dam. 12. SELECTING A SUITABLE PRELIMINARY SECTION OF AN EARTHEN DAM A preliminary design of an earthen dam is done on the basis of existing dams of similar characteristics and the design is finalized by checking the Extensive Survey Project Batch A2 30 Banglaore Institute of technology New tank project 2010-11 adequacy of the selected section from the worst loading condition. Empherical rules are frequently used in these designs. A few recommendations, for selecting suitable values of top width, free board, up stream and down stream slopes, drainage arrangements, etc., are given below for preliminary designs. FREEBOARD: Free board or minimum free board is the vertical distance between the maximum reservoir level and the top bund level (i.e., the crown or crest of dam). The dam vertical distance between normal pool level or spillway crest and the top of the dam is termed as normal free board .The minimum height of the free board for wave action is generally taken to be equal to 1.5Hw where, Hw = 0.032(V.F) 1/2 +0.763-0.271(F) 3/4 for F<32kms Hw= 0.032(V.F) 1/2 for F>32kms. Hw = height of water from top of crest to bottom of trough in meters. V = wind velocity in km/hr. F = fetch or straight length of water expense in km. Most of the hydraulic failures of the earthen dams have occurred due to overtopping of dams. Hence, the free board must be sufficient enough as to avoid any such possibility of overtopping. Values of free board, for various heights, recommended by U.S.B.R are given in the following table. Spillway type Height of dam Minimum free board over MWL Uncontrolled (i.e., free) Any height Between 2 m to 3m spillway Controlled spillway Height less than 60 2.5 m above top of gates meters Controlled spillway Height more than 60 3m above top of gates meters Extensive Survey Project Batch A2 31 Banglaore Institute of technology New tank project 2010-11 An additional free board up to 1.5m should be provided for dams suited in areas of low temperatures for frost action. WIDTH: The top width of large earthen dams should be sufficient to keep the seepage line well within the dam, when the reservoir is full. It should also be sufficient to withstand earthquake shocks and wave action. For small dams, this top width is generally governed by minimum roadway width requirements. The top width (A) of the earth dam can be selected as per the following recommendations: A=H/5+3 for very low dams A= 0.55H1/2+0.2H for dams lower than 30meters A=1.65(H+1.5) 1/3 for dams higher than 30meter, Where H is the height of the dam. UPSTREAM AND DOWN STREAM SLOPES: The side slopes depend upon various factors such as the type and nature of dam and foundation materials, height of the dam etc., the recommended values of side slopes as given by Terzaghi are tabulated in the following table, TYPE OF MATERIAL UPSTREAM SLOPE DOWNSTREAM (H:V) SLOPE (H: V) Homogenous well graded 2.5:1 2:1 Homogenous coarse silt 3:1 2.5:1 Homogenous silty clay 2.5:1 2:1 1.height less than 15 meter 2.height more than 15 meter 3:1 2.5:1 Sand or sand and gravel 3:1 2.5:1 with a central clay core Extensive Survey Project Batch A2 32 Banglaore Institute of technology New tank project 2010-11 Sand or sand and gravel 2.5:1 2:1 with R.C diaphragm The various dimensions of low earth dams for their preliminary section, may sometimes be selected from the recommendations of strange, as given in the following table: Height of Maximum Top width Upstream Down stream dam freeboard in (A) slope in meters meters (H: V) slope (H: V) in meters Up to 4.5 1.2 to 1.5 1.85 2:1 1.5:1 4.5 to 7.5 1.5 to 1.8 1.85 1.5:1 1.75:1 15 to 22.5 2.1 3.0 3:1 2:1 14. SEEPAGE CONTORL IN EARTHEN DAMS:- The following are the seepage control in earthen dams, 1. Seepage controls through embankments 2. Seepage control through foundations SEEPAGE CONTORLS THROUGH EMBANKMENTS: a) Rock toe or toe filter b) Horizontal blanket or horizontal filter c) Chimney drain ROCK TOE OR TOE FILTER: The ‘rock toe’ consists of stones of size usually varying from 15 to 20 cms. A toe Filter (graded in layers) is provided as a transition zone, between the homogenous Embankment fill and rock toe. Extensive Survey Project Batch A2 33 Banglaore Institute of technology New tank project 2010-11 Toe filter generally consists of three layers of fine sand, coarse sand and gravel, as per the filter criteria requirements. The height of rock toe is generally kept between 25 to 35% of reservoir head. The top of the rock toe must be sufficiently higher than the tail water depth, so as to prevent the action of tail water. HORIZONTAL BLANKET OR HORIZONTAL FILTER: The horizontal filter extends from the toe (downstream end) of the dam, inwards, up to a distance varying from 25 to 100% of the distance of the toe from the central line of the dam. Generally, a length equal to three times the height of the dam is sufficient. The blanket should be properly designed as per the filter criteria, and should be sufficiently pervious to drain off effectively. Extensive Survey Project Batch A2 34 Banglaore Institute of technology New tank project 2010-11 CHIMNEY DRAIN: The horizontal filter not only helps in bringing the pheratic line down in the body of the dam but also provides drainage of foundation and helps in rapid consolidation. The horizontal filter tries to make the soil more pervious in the horizontal direction and thus causes stratification. When large scale stratification occurs, such filter becomes inefficient as shown in figure. In such a possible case, a vertical filter (are inclined upstream or down stream) is placed along with horizontal filter, so as to intercept the seeping water effectively, as shown in figure. Such an arrangement is termed as chimney drain. Some times a horizontal filter is combined and placed along with a rock toe, as shown in figure Extensive Survey Project Batch A2 35 Banglaore Institute of technology New tank project 2010-11 SEEPAGE CONTRL THROUGH FOUNDATION: a) Impervious cutoff b) Relief wells and drain trenches IMPERVIOUS CUTOFF: Vertical impervious cutoff made of concrete or sheet piles may be provided at the upstream end (i.e., at heel) of the earthen dam. These cutoffs should generally, extend through the entire depth of the pervious foundation strata is very large cutoff, up to a lesser depth, called a partial cutoff may be provided. Such a cutoff reduces the seepage discharge by smaller amount. So much so, that a 50% depth reduces the discharge by 25% and 90% depth reduces the discharge by 65% or so. Extensive Survey Project Batch A2 36 Banglaore Institute of technology New tank project 2010-11 RELIEF WELLS AND DRAIN TRENCHES: When large scale seepage takes place through the pervious foundation, overlain by a thin less pervious layer, there is a possibility that the water may boil up near the toe of the dam, as shown in the figure. Such a possibility can be controlled by constructing relief wells or drain trenches, through the upper impervious layer, as shown in the figure, so as to permit escape of seeping water. Providing may also control the possibility of sand boiling downstream berms behind the toe of the dam as shown in the figure. The weight of the overlaying material, in such a case, is sufficient to resist the upward pressure and thus preventing the possibility of sand boiling. The provision of such berms also protects the downstream toe, from possible sloughing due to seepage. Extensive Survey Project Batch A2 37 Banglaore Institute of technology New tank project 2010-11 Extensive Survey Project Batch A2 38 Banglaore Institute of technology New tank project 2010-11 15. SLOPE PROTECTION PROTECTION OF UPSTREAM SLOPE: The upstream of earth dam is protected against the erosive action of waves, by stone pitching or by stone dumping as shown in the figure. The thickness of the dumped rock should be about one meter, and should be placed over the gravel filter of about 0.3-meter thickness. The filter prevents the washing of fines, from the dam into the riprap. The provision of such a dumped riprap has been found to be most effective and has been found to fail only in 5% cases. The stone pitching, i.e. the hand picked riprap requires a lesser thickness and may prove more economical if suitable rock is available only in limited quantity. However, when provided in smaller thickness (i.e. single layer), it is more susceptible to damage and has been found to fall in about 30% cases. Concrete slabs may also be laid over the upstream slope of the earth dam. Then such slabs are constructed, they must be laid over a filter and weep holes should be provided so as to permit escape of water, when the reservoir is drawn down. If the filter is not provided, the fines from the embankment may get washed away from the joints, creating hollows beneath the slab and causing the consequent cracking and failure of the slab under its own weight. Extensive Survey Project Batch A2 39 Banglaore Institute of technology New tank project 2010-11 Concrete slab protection have been found to fail in about 36% cases mainly because of not providing filter below them. PROTECTION OF DOWNSTREAM SLOPE: The downstream slope of the earthen dam is protected against the erosive action of wave up to a slightly above the water depth, in a similar manner as is explained above for upstream slope. More over, the downstream slope should be protected against erosive action of rain and its runoff by providing horizontal berms at suitable intervals, say about 15 meter or so has to intercept the rainwater and discharge it safely. Attempts should also be made so as to grow grass and plants at the downstream slope, soon after their construction. 16. AREA OF CAPACITY CONTOUR AREA OF CONTOUR VOLUME OF Sl no RL OF CONTOUR m m2 WATER IN m^3 1 912.650 14100.00 0 2 918.500 36400.00 146950 3 919.500 40800.00 185500 4 920.000 42550.00 206300 5 921.500 47800.00 274060 6 922.000 50420.00 298615 7 923.500 55490.00 378045 8 924.000 71680.00 409835 9 924.500 83705.00 451688 10 925.000 95730.00 493540 11 925.500 100060.00 542480 Area under submergence = 100060.00 m2 VOLUME BY TRAPEZOIDAL RULE V1=((A1+A2)/2)*DIFFERENCE OF CONTOUR Extensive Survey Project Batch A2 40 Banglaore Institute of technology New tank project 2010-11 17. ESTIMATION Caluclation : Mean Area = BD + SD2 Where B = Bredth of top bund D = Mean Depth =( d1 + d2)/2 =D S = (3+2)/2 =2.5 L = Length between chainage Volume = (BD+SD2)*L EARTH WORK CALCULATIONS FOR EARTHEN BUND SL NO. CHAINAGES DISTANCE AREA MEAN VOLUME (m) (m) AREA (m3) (m2) 1 0 0 0 0 0 2 42.87 42.87 265.6252 132.8126 5693.676 3 75.27 32.4 316.5957 291.110 9431.978 4 110.47 35.2 189.2092 102.902 535.0904 5 142.01 31.54 99.7486 144.4789 4556.8645 6 196.01 54 0 49.8743 2693.2122 7 233.51 37.5 0 0 0 Total = 22910.821m3 Net Earthwork = 22910.821m3 CALCULATIONS FOR STONE PITCHING Calculation : Sloping breadth = D*√(S2 + 1) D = difference b/w RL = (d1+d2) S = side slope =3 Mean area of side slope = (D*√(S2 + 1))*L Volume of pitching = (D*√(S2 + 1))*L)*d d = thickness of pitching (m) QUANTITY CALCULATIONS FOR STONE PITCHING Extensive Survey Project Batch A2 41 Banglaore Institute of technology New tank project 2010-11 DEPTH OF AREA(m^2) MEAN VOLUME SL CHAINAGE DISTANCE PITCHING AREA PITCHING NO (m) (m) (m) (m²) (m³) 0 0 1 0 0 0 0 2 42.87 42.87 0.6 17.0479 8.5239 365.4217 3 75.27 32.4 0.6 19.9560 18.5019 599.463 4 110.47 35.2 0.6 13.6927 16.824 592.217 5 142.01 31.54 0.6 7.9640 10.828 341.526 6 196.01 54.00 0.6 0 3.982 215.028 7 0.6 0 233.51 37.5 0 0 TOTAL = 2113.6557m3 NET STONE PITCHING=2113.6557m3 18. CHANNEL DESIGN From Topo sheet: Assuming, CCA= 40 hectares PROPOSED CROPPING PATTERN CROP TYPE INTENSITY DELTA cm Kharif crop 60 % 100.00 (Rice) Rabi crop 30 % 45.00 (Vegetables) 30% 45.00 (Ground nut) Duty for certain crops For Rice : 775hectares/ cumec For Robi : 2000 hectares/ cumec Area to be irrigated in Kharif season = 0.60*64 = 24.00hectares. Extensive Survey Project Batch A2 42 Banglaore Institute of technology New tank project 2010-11 Area to be irrigated in Rabi season = 0.3*64 = 12.00hectares. The water required at the discharge tributary to irrigate Kharif area = (24/775)= 0.0309 cumecs. The water required at the discharge tributary to irrigate Robi area = (12/2000) = 0.006 cumecs. Allowing 7% losses in canal = (1.07*0.0309) = 0.03306cumec Q = 0.03306cumec DESIGN OF CANAL: LACEY’S THEORY:- DATA: Q = 0.03306cumec F = 1 silt factor D=0.5m Side slopes=05H:1V 1)silt factor F=1 B=0.5m F =1.76√mr 1=1.76√mr mr=0.32mm 2)Velocity of flow V=(Q.F2/140)ˆ(1/6) V=(0.03306*1²/140) ˆ(1/6) V=0.25 m/sec 3)To find area of channel A=Q/V =(0.03306/0.25) A=0.1322 m² 4)Wetted perimeter P=4.75√Q Extensive Survey Project Batch A2 43 Banglaore Institute of technology New tank project 2010-11 =4.74√0.03306 P=0.86 m² ≈ 0.9 m² 5)Depth of channel D=(P-√(P²-6.944*A))/3.47)= (0.9 -√(0.9²-6.944*0.1322))/3.472 D=0.27 m 6)Base width of channel B = P-2.236*D = 0.9-2.236*0.27 B = 0.29m ≈ 0.3m 7)Now Rt = (BD+(D²/2))/(B+2.236D) = (0.3*0.27+(0.27²/2))/(0.3+2.236*0.27) Rt = 0.13 m Hydraulic mean depth Ra = 2.5(V²/f) = 2.5*(0.25²/1) Ra=0.156 Ra>Rt hence checked 8)Bed slope(S) S =1/(3340*Qˆ(1/6)) S =1/(3340*(0.03306) ˆ(1/6)) S =1/1892 m .’. B=0.5mt, D=0.3+0.2=0.5m 19. DESIGN OF WASTE WEIR The catchment area = 7.00 km2 C =10.0 Q= C*A^ (2/3) Q= 10.0*(7.00)^(2/3) Q= 36.593 cumecs LENGTH OF THE WASTE WEIR Extensive Survey Project Batch A2 44 Banglaore Institute of technology New tank project 2010-11 We have discharge equation over a rectangular weir Q =2/3*Cd*L*√ (2*g)*(H)^(3/2) 36.593= 2/3*0.67*L*√ (2*9.81)*(1)(3/2) L= 18.5 m BODY WALL OF WASTE WEIR Top width = 2.0m Bottom width = 3.0m Sloping towards down stream side(1H:8V) CONCLUSION 1. The Survey carried out at Melkote was effective as the site is suitable for the construction of dam and reservoir. 2. Carrying out the survey work with the help of necessary instruments, the dam and Reservoir can be effectively and successfully designed. 3. The project carried out involving various surveys is helpful in estimating and Calculating various data like runoff, total reservoir capacity, ground feature etc, for the dam or reservoir to be economical and effective. 4. A new communication road over the dam is proposed to connect right bank and left bank. Extensive Survey Project Batch A2 45 Banglaore Institute of technology New tank project 2010-11 BIBLIOGRAPHY 1.Irrigation and Water Power Engineering -By Dr. B.C. Punmia and Dr. Pande B.B. Lal. 2.Irrigation Engineering and Hydraulic Structures -By Santosh Kumar Garg 3.Surveying -By Dr. B.C. Punmia Extensive Survey Project Batch A2 46 Banglaore Institute of technology New tank project 2010-11 4.Surveying -By Kanitkar 5.Soil Mechanics & Foundation Engineering -By Dr. B.C. Punmia 6.Soil Mechanics & Foundation Engineering -By Prof. V.N.S. Murthy 7.Engineering Hydrology -By K. Subramanya Extensive Survey Project Batch A2 47