Total Water Requirement of India:
Verma and Phalsankar (1999), Summarized the water demand of India. Taken into account the availability and variations, the utilizable water resources of the India add up to 1,086 BCM, of which 690 BCM is the utilizable surface water resources and 396 BCM is the utilizable ground water potential. Taking into account the water requirement the projection for the year 2010, 2025 and 2050 of the various sectors are given in the following Table No.1.1
Table: 1.1: Total Water Requirement 2010, 2025 and 2050 (BCM)
|Use of water||1997-1998||Scenario||2010||2025||2050||%SW*||Projection of 2025 of SW (BCM) at low level in %**|
|Irrigation||524||High||557||611||807||57-61 (59 )||360.49
|Domestic and Municipal||30||High||43||62||111||53-59 (56 )||34.72
|Grand Total||629||High||710||843||1,180||63-65 (64)||539.52|
(* Proportion of requirement proposed to be meet from surface water sources
** To meet the challenge of water scarcity at 2025 clear indicate the emphasis must be on watershed development and management.)
Verma and Phalsankar (2007) reported that, main sources of irrigation in the country are canals, tanks and wells including tube wells. Analyzing the provisional data on net area irrigated by source for the year 2007-08, it is observed that wells provided 60.7% irrigation followed by canals with 26.5% at all India level. Among the States Mizoram and Meghalaya are the only states getting 100% of their irrigation through canals followed by Jammu and Kashmir, Chhattisgarh and Haryana with 92.9%, 68.5% and 45.6%. The present and projected water requirement of the various sectors is discussed in above Table. No.1.1. The agriculture is of fundamental importance in India’s economy contributing about 20 – 21% of gross domestic product (GDP) and generates two third of the employment. The assured irrigation water supply is of utmost importance for food security. The total ultimate irrigation potential of the country is estimated at 140.0 M. Ha (Major and Medium Irrigation projects-58.5 Million hector and Minor Irrigation projects-81.5 M. Ha) with UP, Bihar, MP and AP accounting for 52%. (Water Resources and Related Statistics, 2010)
Considering growing population and food demand the water requirement is spread for the 543 BCM by the year 2010 which will increase by 561 BCM by the year 2025 with low growth scenario. Almost the dependency on the ground water resources for irrigation is also growing at an alarming rate. Ground water is dynamic natural resource with both ecological and economic value and is of vital importance for sustaining life, health and integrity of ecosystems. The ground water resources increasingly threatened by over abstraction which has insidious long term effects. Scarcity and misuse of ground water pose a serious and growing threat to sustainable development and livelihood. (GSDA Report, 2007-08).
As per UN projections the demand of the fresh water in all sectors will pressurize the available water resources in case of India. On this background the efforts in improving the irrigation potential in Drought Prone Area (DPR) was undertaken by adopting the various types of the water harvesting technology interventions is essential. Government of India, (2007) reported that, as regards to use, the extent of extraction has increased significantly over the years due to steep increase in the number of wells (tube and open wells). The average rate of increase in number of wells per year in India was 2.3%. The number of tube and open wells increased at the rate of 6.3% and 2.4% per year, respectively. It is estimated that currently there are 19 million wells in the country, out of which 16 million wells are in use and drawing about 213 BCM of water
Besides irrigation, the water demand is blooming in other sectors. The domestic water requirement of the Indians will be shifted from 135 liters (As per UN standards) to 220 liters per capita per day (LPCPD) for urban population and 150 LPCPD for rural population by the year 2050. On the other hand the contribution of the surface water to meet the demand is 55 to 60 %. To harvest the rainwater the rooftop rain water harvesting scheme is implemented by the government of Maharashtra with the great deal of enthusiasm, but not much significant achievement have been achieved. These technologies have high potential to tap the good quality water and these practices had traditionally implemented in various parts such as Rajasthan in India. The demand of domestic and municipal water will spread for 62 BCM for the year 2025 and 111 BCM for the year 2050. The industrial belts are also blooming in India and on behalf of the industrial revolution ultimate demand for the water resources is spread for the 67 BCM for the year 2025 and 81 -103 BCM for the year 2050.
The water use efficiency is increased in the sectors of power generation. Energy resources are backbone of economy of any country. Water resources have crucial role in energy sector i.e. generation, cleaning, cooling, evaporation etc. Verma and Phalsankar (2007) reported that, the data on Hydro Electric Power Potential Development for the country revealed that about 32.08 thousand-mega watt (MW) i.e. about 21.6% generated from dams. It is noted that about 148.7 thousand MW is identified capacity of hydropower as per reassessment study has been developed as on 31.03.2010, about 14.3 thousand MW (i.e. about 9.6%) was under development. Water requirement in all other power sector such as thermal, hydropower, nuclear, solar/wind, and gasification will grow from 18.10 BCM in 2010 to 31.10 BCM by the year 2025 with low growth, considering norm of water requirement 0.001 BCM per 100 MW. The water requirement for inland navigation will be shifted from 7 BCM to 10 BCM by the year 2025 considering low growth scenario. The water requirement for functioning of the various ecosystems and environment means will also be increased from 5 BCM to 10 BCM by the year 2025. Challenging task for sectors of inland navigation and environment is managing its sole demand from surface water resources.
Blog Submited By:
Dr. Chandrashekhar Pawar
Asst. Professor ICCS, Pune