REPORT ON DYNAMIC GROUND WATER RESOURCES OF RAJASTHAN (As on 31 st March, 2013 ) Prepared by Central Ground Water Board Ground Water Department Government of India Government of Rajasthan Western Region, Jaipur Jodhpur Jaipur February 2016 Executive Summary Rajasthan is the largest state of country having an area of 3,42,326 Sq.Km. (10.4% of the country’s geographical area). In Rajasthan, 91% of the Domestic Water requirements of Rural/Urban Sector are being catered from Groundwater Sources and only 9% Water requirement is being met from surface water sources. The source of surface water is limited to canal system of only few rivers mainly IGNP, Mahi, Chambal, Bisalpur Reservoir & recently constructed Narmada Canal. In spite of poor quality and meager quantity, the groundwater resources in the state are the only most reliable and dependable source for sustenance of life. Water demand is increasing at a faster rate due to increase in population, green revolution, rapid Industrial growth, urbanization and changing living standards. About 77% of the total irrigation water demand and most of the Industrial Water requirements are being catered from Groundwater resources only. Thus, meeting the various sectors’ demands and safe water supply to human being are the challenging tasks for the planners in the State. The necessity, therefore, arises to estimate this dependable and precious resource periodically for meeting the various demands. Administration of the state is controlled by seven divisions constituted by 33 districts, 215 tehsils, 248 blocks and 44672 villages. About three fourth (76.6%) population of state resides in rural area whereas less than a quarter (23.4%) lives in urban area. The female to male ratio of the state accounts to only 921/1000 which is lower than national average ratio. The population density of the state has lower value of 165 persons/Sq.Km. because the 2/3 rd part of the state is covered by Thar Desert. The Decadal population growth is 21.4% at present, which is further increasing at a fast rate. Rajasthan has the largest livestock (18.7%) of the country. The net cultivable area of the state is 53.54% of the total area. In the western districts of Jaisalmer, Bikaner and Barmer, percentage of cultivable waste and fallow land is the highest on account of sandy soils in these areas. The gross irrigated area in the State is 8321825 ha (24.28%) whereas total forest cover is 2742705 ha (8%). The Canals irrigate approximately 19.57% of the gross irrigated area whereas remaining area is mostly irrigated through wells and tube wells. The state is characterized by the most arid and drought prone state of the country because of low and scanty rainfall. The eastern part of Aravalli hill range covered by consolidated formations, receives higher rainfall whereas western area covered with Aeolian sand and alluvium receives scanty rainfall. The normal rainfall in the State is 549.1 mm and temperature varies from 0 0 in winters to 48 0 in summers, which has resulted in higher evapotranspiration rates. Due to excessive ground water draft, lowering of water table and quality deterioration of groundwater is the common problem in the State. Physiography is the result of prolonged erosional and depositional processes. Land forms and drainage systems have been greatly influenced and determined by the geological formations and structures. About 58% area of the state is covered by sand dunes and desert. The highest elevation of state lies at Mount Abu (1722m amsl). Major part of western Rajasthan has inland drainage system whereas southern, south-eastern and the eastern parts have well developed drainage systems. Except Chambal River, other rivers are ephemeral and flow only during rainy season. The drainage in the alluvial areas is of dendritic nature. The Aravalli hill range is forming the main water divide in the State. Luni is the only major river in the west of Aravallis. Perennial rivers like Mahi and Chambal are important in southeastern and eastern part respectively. Sambhar, Didwana, Lunkaransar, Kuchaman, Pachpadra, Pokaran, Phalodi and Chhapar are Saline lakes . Desert soil is quite common in the western, northern and northwestern parts whereas black cotton soil is limited to eastern and southeaster parts along Madhya Pradesh border. In other areas, alluvium is the most common soil. Rajasthan State is divided into 15 major River Basins. There are several irrigation projects that have been accomplished in the State and many are in progress. On completion of these projects, total irrigated area will increase to many folds. Rajasthan displays a very significant part of the Indian shield with regard to both span of geological history and complexity of evolution. The region has well-preserved records of long and protected geological history varying from Archaean to Recent. Due to this, Rajasthan is also known as the Museum of Geology. Central Ground Water Board in association with Ground Water Department, Govt. of Rajasthan is carrying out estimation of Groundwater Resources on periodic basis. Last assessment was carried on 31/03/2011 and the current estimation is as on 31/03/2013. As per the current estimates, the State has Net Groundwater Availability of 11256.7695 MCM (11.256 BCM) whereas the gross groundwater draft is 15705.9976 MCM (15.706 BCM) with the Stage of groundwater development at 139.52%. The situation at block level reveals that out of total 248 blocks as on 31/03/2013, 164 blocks have become Over- Exploited, 09 are Critical, 28 are Semi-Critical and only 44 blocks fall under Safe category. Three blocks have Saline groundwater. It is obvious that in Over-Exploited areas, the groundwater is mined from the Static reserves since the dynamic reserves are not getting replenished at a similar rate to its withdrawal. So the increasing number of Over-Exploited blocks has become the most challenging issue for the planners. Dynamic Ground Water Resources of Rajasthan As on 31 st March 2013 Contents 1. Introduction.............................................................................1 2. General Features of the State ................................................2 2.1. Physiographic Features ........................................................................2 2.1.1. Topography............................................................................................................ 2 2.1.2. Aravalli Hill Ranges.............................................................................................. 2 2.1.3. The Eastern Plains ................................................................................................ 2 2.1.4. The Western Sandy Plains and Sand Dunes....................................................... 3 2.1.5. Vindhyan Scarpland and Deccan Lava Plateau ................................................. 3 2.2. Drainage.................................................................................................4 2.3. Climate ...................................................................................................4 2.3.1. Rainfall ................................................................................................................... 4 2.3.2. Temperature .......................................................................................................... 5 2.4. Geology...................................................................................................9 2.4.1. Archaeans............................................................................................................... 9 2.4.2. Proterozoics............................................................................................................ 9 2.4.3. Palaeozoics ............................................................................................................. 9 2.4.4. Mesozoics................................................................................................................ 9 2.4.5. Deccan Traps ....................................................................................................... 10 2.4.6. Tertiaries .............................................................................................................. 11 2.4.7. Recent ................................................................................................................... 11 2.5. Hydrogeology.......................................................................................11 2.5.1. Porous Formations .............................................................................................. 11 2.5.2. Fissured Formations ........................................................................................... 12 2.5.3. Ground Water Level ........................................................................................... 12 2.5.4. Ground Water Quality........................................................................................ 13 3. Ground Water Resources Estimation Methodology .........13 3.1. Ground Water Recharge....................................................................14 3.2. Ground Water Draft...........................................................................15 3.3. Stage of Ground Water Development & Categorization of Units .15 3.4. Future allocation of Ground Water Resources................................16 3.5. Poor Quality Ground Water..............................................................17 3.6. Additional Potential recharge............................................................17 4. Computation