Water Resources Day - 2008
Theme Paper
Integrated Water Resources
Development and Management
Central Water Commission
New Delhi FOREWORD
Year 2007 was observed as “Water Year” with activities focused on developing consensus on appropriate measures including legislation for better management of the water sector, timely completion of irrigation projects, maintenance of existing projects to ensure optimum water availability to farmers and awareness programmes for the masses. Conferences/workshops on important water development and management issues were also organised. It is important to maintain the pace of activities in the year 2008 as well. Water Resources day and World Water Day gives us opportunity to formulate strategy on the important aspects of water resources development and management. Accordingly Integrated Water Resources Development and Management have been chosen as the theme for discussion on the occasion of the Water Resources Day-2008.
The problems of water resources management are multidimensional and need an integrated approach for effective development of water resources to address issues in different sub-sectors such as hydropower, water supply, sanitation, irrigation, drainage and environment. An integrated water resources perspective with full involvement of all the stakeholders ensures that social, economic, environmental and technical dimensions are taken into account in the management and development of water resources.
This theme paper has attempted to cover several related aspects like assessment of water resources availability; multi-sectoral water use scenario and demand assessment, integrated approach through decision support system (Planning), etc. I hope this paper would meet the twin objectives of highlighting the critical issues in the water sector together with management aspects and making people aware of concerted, co-ordinated and well-targeted efforts to be launched in an atmosphere of cooperative participation.
I gratefully acknowledge the efforts, dedication and hard work put in by several directorates of Central Water Commission and particularly the officers and staff of Basin Planning and Management Organisation, CWC in preparing the theme paper.
(B S Ahuja)
Chairman,
Central Water Commission
CONTENTS
Chapter No. /Chapter Title
/ Page No.I
/ Introduction / 1II / Assessment Of Water Resources Availability / 3
III / Multi-Sectoral Water Use Scenario And Demand Assessment / 6
IV / Development and Management / 13
V / Integrated Approach Through Decision Support System (Planning) / 16
VI / Conclusion / 19
CHAPTER – I
INTRODUCTION
Water is prime requirement for all aspects of life. It is imperative to make certain that adequate supplies of water of good quality are maintained for all the needs of entire population of this planet, while preserving the hydrological, biological and chemical functions of ecosystems, adapting human activities within the capacity limits of nature and combating vectors of water-related diseases. Innovative technologies, including the improvements in the indigenous technologies, are needed to fully utilize limited water resources and to safeguard these resources against pollution.
Fast growing population, rapid urbanization, industrialization coupled with spatial & temporal variations in water availability, water quality problems, etc. demand integrated water resources planning and management. Such integration must consider all types of interrelated freshwater bodies, including both surface water and groundwater, and duly consider water quantity and quality aspects. The multisectoral nature of water resources development in the context of socio-economic development must be recognized, as well as the multi-interest utilization of water resources for water supply and sanitation, agriculture, industry, urban development, hydropower generation, inland fisheries, transportation, recreation, and other activities. Rational water utilization schemes for the development of surface and ground water-supply sources and other potential sources have to be supported by concurrent water conservation and wastage minimization measures. Priority, also needs to be accorded to flood prevention and control measures, as well as soil conservation and sedimentation control, where required.
All social and economic activities rely heavily on the ensured supply and quality of freshwater and as population and economic activities grow, many countries are rapidly reaching conditions of water shortage / scarcity and are facing limits to their economic development. Water demands are increasing rapidly, with around 80 per cent required for irrigation, and the balance for industrial, domestic, energy and other uses. The holistic management of freshwater as a finite and vulnerable resource, and the integration of sectoral water plans and programmes within the framework of national policy, are of paramount importance for action. Therefore, effective implementation and coordination mechanisms are required to remove impediments for promoting integrated water management.
Integrated water resources management is based on the perception of water as an integral part of the ecosystem, a natural resource and a pivot for socio-economic development, whose quantity and quality determine the nature of its utilization. To this end, water resources have to be protected, taking into account the functioning of aquatic ecosystems and the perenniality of the resource, in order to satisfy and reconcile needs for water in human activities. In developing and using water resources, priority has to be given to the satisfaction of basic needs and the safeguarding of ecosystems.
Integrated water resources management, including the integration of land- and water-related aspects, should be carried out at the level of the basin or sub-basin. Four principal objectives to be pursued are as follows:
(a) To promote a dynamic, interactive, and multisectoral approach to water resources management, including the identification and protection of potential sources of freshwater supply, that integrates technological, socio-economic, environmental, ecological and human health considerations;
(b) To plan for the sustainable development and rational utilization, protection, conservation and management of water resources based on community needs and priorities within the framework of national water policy;
(c) To design, implement and evaluate projects and programmes that are socially appropriate and economically efficient within clearly defined strategies based on a participatory approach
(d) To strengthen or develop, as required, the appropriate institutional, legal and financial mechanisms to ensure that water policy and its implementation are a catalyst for sustainable social progress and economic growth.
In a nutshell, the centrality of sustainable management of water resources encompassing ecological, economic and ethical sustainability therefore hinges on a holistic and integrated approach involving engineering, socio-economic and environmental aspects. All the problems need to be looked at in their totality. Development of hydropower, lowering of ground water table and devastations faced by people due to floods have to be examined in an integrated manner. Similarly, traditional system of water management through ponds and small tanks should be integrated with canal and pumped ground water irrigation. An integrated approach would minimize the conflicts among the multiplicity of agencies working in the water sector, each having different goals, motivation and dynamics.
The rationale of the future strategy is to meet the challenges in such a manner that development is sustained and the growth process does not disturb the delicately balanced environmental and ecological equilibrium, which are predominantly water centric. Therefore, project-centric development that was aggressively pursued during the early-plan periods for catering specific need should be replaced by integrated water resources management (IWRM) that is better suited under the present circumstances for optimizing the water resources allocation among competing multi-sectoral water demand/uses. It is evident that suitably prioritizing the water demand from the socio-economic-environmental point of view and simultaneously maintaining harmony among the different users, be it sectors or regions, should form the core of any long term vision that is being formulated for the water resources development & management.
CHAPTER – II
ASSESSMENT OF WATER RESOURCES AVAILABILITY
2.1 Assessment of average annual water resources potential of the country
Proper assessment of the availability of water from surface and sub-surface sources is the cornerstone for proper planning, development and management. The National Water Policy (2002) has stated that the planning, development and management of the water resources should be done on a hydrological unit basis, along with a multi-sectoral, multi-disciplinary and participatory approach as well as integrating quality, quantity and the environmental aspects. Accordingly the water resources assessment is being done river-basin wise.
The precipitation, in the form of rain and snowfall, is a crucial component of the hydrological cycle that makes fresh water available on a renewable basis. The geographical area of India is 329 million hectares (Mha). The mean annual rainfall, taking the country as a whole, is 1170 mm. This gives an annual precipitation of about 4,000 Km3. A significant part of this precipitation seeps into the ground and the balance flows through streams and rivers and collects in water bodies adding to the surface flow. A part of the water that seeps into the ground remains as soil moisture in the upper layers and the rest adds to the ground water resources. Subsequently, a major part of the water from surface flows, soil moisture and ground water sources, when put to various uses, returns to the atmosphere through evapo-transpiration.
Natural (virgin) flow in the river basin is reckoned as water resources of a basin. The mean flow of a basin is normally obtained on pro-rata basis from the average annual flow at the terminal site. However, at any point of time, the water resources in a river basin have already been developed and utilized to some extent through construction of major or medium storage dams and development of hydropower, irrigation and other water supply systems. A large number of diversion schemes and pumped storage schemes may also have been in operation. Assessment of natural flow has, therefore, become complex in view of the upstream utilizations, reservoir storages, re-generated flows and return flows. The natural flow at the location of any site is obtained by summing up the observed flow, upstream utilization for irrigation, domestic and industrial uses both from surface and ground water sources, increase in storage of reservoirs (surface and sub-surface) and evaporation losses in reservoirs, and deducting return flows from different uses from surface and ground water sources.
Based on the above methodology, CWC assessed the average annual water resources potential of the country as 1869 billion cubic metre (BCM) in the year 1993 and was given in the report ‘Reassessment of Water Resources Potential of India’ (March,1993). The estimation made by the National Commission for Integrated Water Resources Development Plan (NCIWRD, 1999) differed slightly owing to the reasons that in the case of Brahmaputra sub-basin the additional contribution of flow of 9 tributaries joining Brahmaputra downstream of Joghighopa site was included and secondly in case of Krishna basin the estimation was based on the mean flow of the yield series accepted by KWDT award.
The Standing Sub-Committee for ‘Assessment of Availability and Requirement of Water for Diverse Uses in the Country’ constituted by the MoWR in its Report (August, 2000) observed that the latest assessment made by CWC in the year 1993 that is, 1869 BCM is considered as reliable.
2.2 Assessment of utilizable water resources potential of the country
Utilization of water resources can be considered in two different ways. Utilization can be taken as the quantum of withdrawal of water from its place of natural occurrence such as river or ground water. Withdrawability of water depends on the possibility of storage and diversion structures. Alternatively, it can be considered as the additional evaporation / evapotranspiration caused by man, of the natural water through its diversion and use. The former approach has been used more commonly and is used for estimating the utilizable flow. Within the limitations of physiographic conditions, environmental consideration, problem of resettlement & rehabilitation, legal & constitutional constraints and the technological development available at a given point of time, utilizable quantities of water have been assessed from time to time by different authorities.
Irrigation Commission 1972 placed the country’s utilizable quantity at 666 BCM from surface structures or 35% of the surface water resources of the country and indicated that utilization possible from ground water could be of the order of 204 BCM. Dr. K.L Rao put the utilizable quantity much more and has suggested that the quantum should be about 50% of the country’s available annual surface water resources. The National Commission on Agriculture, 1976 have estimated the utilizable quantity as 1050 BCM. This includes 350 BCM from ground water resources. This amount constitutes about 56% of the annual average flow of the river. Central Water Commission estimated the utilizable water in each river basin considering the suitable sites / locations for diversion and storage structures to meet the needs of irrigation and demands of domestic, industrial and other sectors. Central Water Commission has estimated the utilizable water from surface structures at about 690 BCM. The National Commission for Integrated Water Resources Development Plan (NCIWRD, 1999) as well as the Standing Sub-Committee for ‘Assessment of Availability and Requirement of Water for Diverse Uses in the Country’ constituted by the MoWR (August, 2000) have adopted utilizable surface flows in various basins as assessed by CWC that is 690 BCM.
The dynamic ground water resource in the active recharge zone in the country has been assessed by the Central Ground Water Board in association with the concerned State Government authorities and the National Bank for Agriculture and Rural Development (NABARD). The assessment was carried out with Block/Mandal/Taluka/Watershed as the assessment unit and as per norms recommended by the Ground Water Estimation Committee (GEC) – 1997. As per the latest estimates of 2004, the annual replenishable ground water resource in this zone has been estimated as 433 BCM, out of which 399 BCM is considered to be available for development for various uses. The remainder of 34 BCM is set aside for natural discharge during non-monsoon period for maintaining flows in springs, rivers and streams.
Therefore based on the above, the total utilizable water resources of the country have been assessed as 1123 BCM. A table showing the river basins of the country catchment area, average water resources potential and the utilisable surface water resources is given below.
Water Resources Potential of River Basins of India
S.No. / River Basin / Catchment area (sq.km) / Average Water Resources Potential (BCM) / Utilisable surface water resources
1 / 2 / 3 / 4 / 5
1 / Indus / 321289 / 73.3 / 46
2 / Ganga-Brahmaputra-Meghna
(a) Ganga / 861452 / 525 / 250
(b) Brahmaputra / 194413 / 537.2 / 24
(c) Barak & others / 41723 / 48.4
3 / Godavari / 312812 / 110.5 / 76.3
4 / Krishna / 258948 / 78.1 / 58
5 / Cauvery / 81155 / 21.4 / 19
6 / Subernarekha / 29196 / 12.4 / 6.8
7 / Brahmani-Baitarni / 51822 / 28.5 / 18.3
8 / Mahanadi / 141589 / 66.9 / 50
9 / Pennar / 55213 / 6.3 / 6.9
10 / Mahi / 34842 / 11 / 3.1
11 / Sabarmati / 21674 / 3.8 / 1.9
12 / Narmada / 98796 / 45.6 / 34.5
13 / Tapi / 65145 / 14.9 / 14.5
14 / West Flowing Rivers from Tapi to Tadri / 55940 / 87.4 / 11.9
15 / West Flowing Rivers from Tadri to Kanyakumari / 56177 / 113.5 / 24.3
16 / East Flowing Rivers between Mahanadi and Pennar / 86643 / 22.5 / 13.1
17 / East Flowing Rivers between Pennar & Kanyakumari / 100139 / 16.5 / 16.5
18 / West Flowing Rivers of Kutch and Saurashtra including Luni / 321851 / 15.1 / 15
19 / Area of Inland Drainage in Rajasthan / --- / Negl. / --
20 / Minor Rivers draining into Myanmar (Burma) and Bangladesh / 36202 / 31 / --
Total / 1,869.4 / 690
CHAPTER – III