National Compilation on Dynamic Ground Water Resources of India, 2017
Total Page:16
File Type:pdf, Size:1020Kb
National Compilation on Dynamic Ground Water Resources of India, 2017 Government of India Ministry of Jal Shakti Department of Water Resources, RD & GR Central Ground Water Board Faridabad July 2019 भारत सरकार K C Naik केीय भूिम जल बोड Chairman जल श मंालय जल संसाधन , नदी िवकास और गंगा संर ण िवभाग Government of India Central Ground Water Board Ministry of Jal Shakti Department of Water Resources, River Development and Ganga Rejuvenation FOREWORD Water is crucial to life on Earth, however, its availability in space and time is not uniform. The near utilization of surface water resources has made the public and Government to look towards groundwater resources to supplement the water supply. The ever- increasing demand has resulted in the greater dependence on groundwater and consequently resulting in depletion of groundwater resources in many parts of the country. In the era of climate change, groundwater may act as a buffering resource in the time of drought and it needs to be managed more intensively to enhance its sustainability. The change in groundwater extraction and rainfall pattern necessitate periodic revision of groundwater resources assessment. The report 'National Compilation on Dynamic Groundwater Resources of India, 2017' is a compilation of State-wise assessment carried out jointly by CGWB and State Groundwater Departments at periodical intervals under the supervision of State level Committee of the respective States/UTs and under overall guidance of Central Level Expert Group. The groundwater resources of India are assessed following Groundwater Estimation Methodology, 2015, which takes care of all the relevant parameters contributing to the net annual ground water recharge and extractions for various uses. The database thus generated plays a significant role in ground water management and planning. I genuinely appreciate the work done by the officers of Central Ground Water Board and State Groundwater Departments in assessing the dynamic groundwater resources to provide inputs for the planners. I am hopeful that this report will motivate all groundwater professionals to join hands for optimal development of the groundwater resources, so as to conserve water for future generations to come. (K C Naik) Bhujal Bhawan, CGO Complex, NH-IV, Faridabad – 121 001 Tel : 0129-2477101 Fax : 0129-2477200 18/11, Jamnagar House, Mansingh Road, New Delhi Tel : 011-23383561 Fax : 011-23382051 Email : [email protected] Web : www.cgwb.gov.in जी. सी. पति कᴂ द्रीय भूमि जल बो셍 ड भारत सरकार सदय जल श啍तत िंत्रालय G. C. Pati जल संसाधन, नदी विकास और गंगा Member संरक्षण विभाग Central Ground Water Board Government of India Ministry of Jal Shakti Department of Water Resources, River Development & Ganga Rejuvenation PREFACE Water is an indispensable natural resource for life on this planet. Groundwater has emerged as the main source for agriculture, domestic and the industry. In general, groundwater is a reliable source of water for the agriculture and can be used in a flexible manner. However, it is important to realize that groundwater is not a resource that could be utilized indiscriminately. Issues such as water logging, salinity, agricultural toxins, and industrial effluents need to be looked upon. As for the environment, groundwater plays a very important role in keeping the water level and flow into rivers, lakes and wetlands. Ground water has slowly become the mainstay of India's agriculture and drinking water security as it is considered a dependable source. India being a home to more than 1.3 billion people, the increasing population, urbanization and non-uniform extraction have accelerated depletion of ground water resources. This is reflected in falling ground water levels trends and contamination of aquifers. In addition, there has not been adequate thoughtfulness to water conservation, efficiency in water use, water re-use & recycle, groundwater recharge, and ecosystem sustainability. This calls for dedicated plans and schemes to manage this scarce resource. The Dynamic Ground Water resource assessment as in March, 2017 carried out jointly by CGWB and state ground water departments provides a basic database for ground water management in the country. The exercise categorizes assessment units into ‘Safe’, ‘Semi- Critical’, ‘Critical’ and ‘Over-exploited’ blocks depending on Stage of Ground water Extraction. Over-exploited assessment units gives a red flag, demanding immediate change in extraction pattern and surface water interventions. Groundwater resources, though is replenishable, the over exploitation has resulted in mining of groundwater resources more than the annual replenishment. The efforts have always been on the supply side interventions but the continued and ever increasing water stress indicates that simultaneous demand side interventions also required to manage the groundwater resources. I appreciate the efforts of the officers of CGWB, CHQ, who were involved in the work of national compilation and the officers of CGWB and State Groundwater Agencies, who had carried out the assessment for the respective States and UTs. I strongly believe that the national compilation will be beneficial in planning and management of ground water for various upcoming projects in the country. I hope this report will spread awareness and result in conscientious usage of water for overall development of the country. G.C.Pati Member (HQ) Bhujal Bhawan, NH-IV, Faridabad – 121001 Tele : 0129-2477128 Email : [email protected] DYNAMIC GROUND WATER RESOURCES OF INDIA, 2017 AT A GLANCE 1. Total Annual Ground Water Recharge 431.86 bcm 2. Annual Extractable Ground Water Resources 392.70 bcm 3. Annual Ground Water Extraction 248.69 bcm 4. Stage of Ground Water Extraction 63.33 % Categorization of Assessment Units (Blocks/ Mandals/ Firkas/Taluks) Total No. of Assessed Units 6881 1. Safe 4310 2. Semi Critical 972 3. Critical 313 4. Over-Exploited 1186 5. Saline 100 iii EXCUTIVE SUMMARY Ground Water Resources Assessment is carried out at periodical intervals jointly by State Ground Water Departments and Central Ground Water Board under the guidance of the respective State Level Committee on Ground Water Assessment at State Levels and under the overall supervision of the Central Level Expert Group. Previous such joint exercises were carried out in 1980, 1995, 2004, 2009, 2011 and 2013. The assessment involves estimation of dynamic ground water resources or Annual Extractable Ground Water Resource, Total Current Annual Ground Water Extraction (utilization) and the percentage of utilization with respect to recharge (stage of Ground Water Extraction). The assessment units (blocks/watersheds/mandals/talukas/firkas) are categorized based on Stage of Ground Water Extraction, which are then validated with long-term water level trends. The previous assessment was carried out using GEC 97 Methodology, whereas the present assessment is done based on norms and guidelines of the latest GEC 2015 Methodology. The main source of replenishable ground water resources is recharge through rainfall, which contributes to nearly 67% of the total annual ground water recharge. India receives about 119cm of rain in a year but it has great spatial variations. Most part of India receives rainfall mainly during SW Monsoon season. However, main rainfall season in Tamil Nadu is October– December. Jammu and Kashmir, Himachal Pradesh and Uttarakhand receive significant rainfall in all four seasons. Major part of country including Northern, Central and Eastern India receives annual normal rainfall between 75 and 150cm. Highest rainfall of more than 250cm are recorded in the North Eastern States and along West Coast in the Konkan region whereas western part of Rajasthan receives about 30cm of rainfall in an year. The areas on the Western Ghats and the Sub- Himalayan areas in North East and Meghalaya Hills receive heavy rainfall of over 250cm annually, whereas the Areas of Northern parts of Kashmir and Western Rajasthan receive rainfall less than 40cm. The two significant features of India's rainfall are that, in the north India, rainfall decreases westwards and in the Peninsular India, it decreases eastwards and then increases in the coastal region. In 2016, the country received annual rainfall of 91% of its normal rainfall i.e. 118.7cm. During SW monsoon season, it received 97% of normal rainfall i.e. 89cm. The country experienced deficiency in rainfall as compared to its normal rainfall during the months of June (10%), August (8%) and September (3%). However, in July, it was 7% more than its normal rainfall. The rock formations and their properties have a significant influence in ground water recharge. Porous formations like alluvial formations in the Indo-Ganga-Brahmaputra basin having high specific yield values are the most important repository of ground water resources. Ground water occurrences in the fissured formations, on the other hand, are limited to weathered, jointed and fractured portions of the rocks, which occupy almost two-third part of the country including peninsular India. In the present assessment, the total annual ground water recharge has been estimated as 432bcm. Keeping an allocation for natural discharge, the annual extractable ground water resource is 393bcm. The total current annual ground water extraction (as in March, 2017) is 249bcm. The average stage of ground water extraction for the country as a whole works out to be about 63 %. The extraction of ground water for various uses in different parts of the country is not uniform. Out of the total 6881 assessment units (Blocks/ Mandals/ Talukas/Firkas) in the country, 1186 units in various States (17%) have been categorized as ‘Over-Exploited’ indicating ground water extraction exceeding the annually replenishable ground water recharge. In these areas the percentage of ground water extraction is more than 100 percent. In addition, 313 units (5%) are ‘Critical’, where the stage of ground water extraction is between 90-100 %. There are 972 semi-critical units (14%), where the stage of ground water extraction is between 70% and 90% and 4310 assessment units (63%) have been categorized as ‘Safe‘ where the iv stage of Ground water extraction is less than 70 %.