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2024 | Buch

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India's Water Future in a Changing Climate

verfasst von: Kuppannan Palanisami, Udaya Sekhar Nagothu

Verlag: Springer Nature Singapore

Buchreihe : Advances in Geographical and Environmental Sciences

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

This book comprehensively addresses the most challenging water issues in India in a changing climate for the first time and suggests potential solutions. It has been observed that over the past two decades, water usage has significantly increased in India due to population growth, economic development and an increase in multiple uses of water, including irrigation, hydropower, industries, domestic consumption, fisheries, eco-system needs and the environment. India’s water future is mainly influenced by rising food demand to feed the increasing population, emerging climate change impacts on agriculture and the water sector, the increasing cost of interventions, poor cost recovery, the low level of technology adoption and weak water policy.

Artificial recharge of the groundwater aquifers, improved water use efficiency and the groundwater–energy–agriculture nexus are important for the future of India’s water planning and are well addressed in this book. Also covered are climate-smart practices, wastewater reuse methods, and digital water and agriculture tools. The book further analyses improved irrigation modernization plans and explores the potential for micro-irrigation expansion including canal and tank irrigation systems in the country.

Overall, this book is one of the first of its kind to present India’s future water and irrigation issues with field-based solutions, providing lessons learnt from successful national and international case studies. The volume is a useful resource for a wide range of readers including policy makers, planners, donors, implementing agencies and researchers in the water sector.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Agriculture and Irrigation in India—Trends and Turning Points

Abstract

India’s ultimate irrigation potential is about 139.9 million hectares (m·ha) and the irrigation potential created (up to the Eleventh Plan period) is about 113.53 m·ha (81.16%). The total annual replenishable water supply is about 1122 billion cubic metres (bcm) and the annual reliable supply will be only 744 bcm. The future water demand is projected as 910 bcm in 2025 and 1072 bcm in 2050. Major problems in Indian water sector include low irrigation project efficiency (36%), overexploitation of groundwater (up to 30% including critical and semi-critical areas), declining tank irrigation (about 50%), less coverage under micro irrigation (17.4%), poor technology adoption (8–10%), low wastewater treatments and reuse (26%), reduction in water supplies and increasing crop demand due to climate change, less focus on water management in hill ecosystems, use of old crop water requirement data for water planning, poor cost recovery, inappropriate subsidy calculations, weak institutional and governance structure. Appropriate interventions to sustain the irrigation sector are discussed in this chapter.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 2. Water Future—Drivers of Changing Climate and Impacts

Abstract

The key drivers of change in water demand are climate change, population growth, and growing water scarcity. Other drivers include changing diets and food demand, competition between sectors, deteriorating water quality, and falling groundwater levels. The gross irrigated area in India will increase from 76 to 117 M ha in 2050. The gross groundwater irrigated area will increase to 60 M ha by 2025 and to 70 M ha by 2050. The total food requirement will be between 382 and 449 million tonnes by 2050. Annual irrigation requirement will increase from 4.63 to 20.46% in 2050 and climate change will reduce major crop yields by 4.5 to 9%. The net irrigation requirements are expected to increase by another 5% and gross irrigation requirements by 10%. It is expected that the efficiency of groundwater irrigation would increase to 75% by 2050 and surface irrigation projects would also increase to about 60%. Efficient and integrated water management and implementation strategies are expected to bridge the future water supply–demand gap.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 3. Stabilizing the Canal Irrigation

Abstract

Irrigation sector in India is known for its Build–Neglect–Rebuild approach. Overall, the major and medium irrigation (MMI) projects account for about 73% of the irrigation potential already created and about 82% of the ultimate irrigation potential (UIP). The gap between the created and utilized potential is increasing over the years, which is about 25.6 M ha (27.15%) at the end of the Eleventh Plan. The average water use efficiency of the canal irrigation projects in the country is only about 36%. The measures to improve the performance of irrigation schemes include improving the overall water use efficiency, investment in command area development including more pressurized (micro) irrigation systems and participatory irrigation management, modernization of the existing schemes, inter-basin transfers in feasible locations, etc. A recent development in the area of canal irrigation modernization in India is the establishment of Support for Irrigation Modernization Program (SIMP) which is a natural progression by the ADB and the GoI and will support the states in preparing future irrigation modernization programmes for MMI schemes.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 4. Sustaining Groundwater Irrigation

Abstract

India’s annual groundwater extraction is 239.16 bcm compared to the total annual groundwater recharge of 437.60 bcm. Stage of groundwater extraction (as on 2022) is 60%. Out of the total 7089 groundwater assessment units in the country, about 14% are “Over-exploited”, 4% are “Critical”, and 12% are “Semi-critical” units. Irrigated agriculture accounts for about 87% of total annual groundwater extracted. As on 2020–21, the average failure rate (drying up) of open dugwells is about 56% and borewells is 65% in critical and over-exploited areas indicating the negative externalities in irrigated agriculture. It is predicted that the demand of energy may rise between 3.2 and 4.9% by 2030. At national level, groundwater pumping by electric and diesel pumpsets with an average pumping of 1600 h/year accounts for about 14.38 million tonnes of carbon emissions. Groundwater recharge is affected by widespread impact of climate change. Managed Aquifer Recharge (MAR) is a promising adaptation measure. Water conservation through watershed development programme, adoption of micro irrigation, crop diversification towards less water intensive crops, addressing water–energy nexus and use of solar and wind energy for pumping, regulatory measures, and groundwater governance are suggested in sustaining the groundwater irrigation in the country.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 5. Reviving Tank Irrigation

Abstract

There are about 0.25 million tanks in India and the tank irrigated area has declined from 3.3 m·ha in 1953 to 1.67 m·ha in 2018. Encroachment of the tank catchment, weak tank-based institutions, erratic rainfall and poor tank filling, inadequate budget for maintenance, improper land use in the upstream, and siltation of the tank water spread over years had resulted in poor performance of the tanks. Tank rehabilitation programmes by various agencies have started around four decades ago and the performance was not satisfactory due to poor implementation protocols followed. Looking at the past rehabilitation performance and need of the future, six time-tested options for tank modernization are suggested: Option 1: Desilting only in selected locations in the tank water spread area. Option 2: Desilting the entire tank water spread area to a given depth. Option 3: Converting the tanks into percolation ponds. Option 4: Providing 1–2 fillings to the tanks during the tank season. Option 5: Full (optimum) groundwater development in the command area. Option 6: Adopting sluice rotation (opening and closing the sluices in alternate weeks) so that groundwater and tank water will be simultaneously (conjunctively) used throughout the crop season. At national level, a tank authority can be established mainly to coordinate and mobilize funds for tank investment and management by closely working with the states.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 6. Maximizing Wastewater Reuse

Abstract

The core drivers to increase the reuse of wastewater include frequent shortage of water sources, and technology and cost viability/efficiency of treating wastewater resources. The current installed sewage treatment capacity is 31,841 MLD, but the operational capacity is 26,869 MLD (26%). The amount of water needed by the manufacturing sector will increase by 2.2 times between 2010 and 2050 and the energy sector will increase by 3.7 times. Wastewater reuse decreases the demand for freshwater by 20–50% depending on the extent of the treatment and reuse possibilities. Cost of freshwater per m³ is less under recharge borewell followed by percolation ponds and if treated wastewater is considered, it will be much cheaper. Using Life Cycle Cost Assessment (LCCA) analyses four wastewater treatment technologies were compared for cost efficiency. Challenges encountered in reclaimed water reuse include technical challenges, institutional challenges, economic challenges, and social challenges. Investments in wastewater treatment projects are also a social investment like investment in major and medium irrigation projects and hence future government priorities in water sector investment should also include wastewater treatment projects. Policies to augment and efficient wastewater reuse are discussed.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 7. Enhancing Water Productivity and Climate-Smart Technologies

Abstract

The India water vision on enhancing water productivity aims for a technology-based improved water use by providing affordable, appropriate, and accessible water management technologies at all levels. About 22% of the available technologies/practices are currently adopted and based on the financial viability, only 8–10% of the adopted technologies are successful. Among the regions, southern and western regions account for comparatively a higher percentage of adoption (23–26%) and north-east region for a lower percentage (11%). The region-wise technology gap in water saving is comparatively lower (32%) in the southern region whereas the per cent gap in yield is lower in the northern region (48%). Two possible ways to increase the productivity per unit of water include bridging the technology gaps (i) by adopting the appropriate technologies/practices for different crops in those areas where traditional practices are followed (technology gap1), and (ii) by effectively adopting the technologies for different crops and soils in farmers’ fields as per research station guidelines (technology gap2). Measures like digital agriculture, climate-smart agriculture (CSA), and transformative investment in CSA are also discussed. Refocusing water management research, strengthening the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) implementation, initiating capacity building programmes for farmers, and developing public–private partnership are suggested to improve technology up-scaling.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 8. Re-Estimating the Crop Water Requirement (CWR)

Abstract

Crop water requirements (CWR) are changing over a period due to climate change. The CWR derived with limited field data in the past using broad assumptions couldn’t represent the actual CWR to plan the water allocation in the present era of climate change. Reworking the crop water requirements (CWR), net irrigation requirements (NIR), and gross irrigation requirements (GIR) using scientific approach incorporating the climatic parameters has provided valuable insights into water allocation. CWR was re-estimated for different crops covering selected states in India. Comparing the NIR and GIR, at 60% efficiency level, only 66% more water is needed to meet the NIR, at 50% efficiency level, 100% more water is needed, at 40% efficiency level 150% more water is needed and at 30% efficiency level 233% more water is needed to meet the crop irrigation requirements indicating the importance of improving the project efficiency under growing water scarcity situations. Use of the re-estimated CWR is expected to alter the future irrigation demand scenarios in the country.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 9. Up-Scaling Micro Irrigation

Abstract

Micro irrigation (MI) is one of the key interventions in water saving, energy saving, and improving the crop productivity and is gradually emerging as a demand management technology in India. The MI potential in the country varies from 42 to 72 M.ha by various estimates. At all India level, the MI area covered to the potential till 2019 is only about 17.4%. Among the drip and sprinkler coverage, the potential covered under drip is 28.2% and sprinkler is 12.9%. In terms of actual area coverage to the total MI area in the country, five states viz., Rajasthan, Andhra Pradesh, Maharashtra, Karnataka, and Gujarat have shared more than 10% each. Regarding MI implementation models, Gujarat Green Revolution Company (GGRC) model is comparatively performing better. The major suggestions to up-scale the MI adoption include provision of technical support for MI operation after installation, relaxation of farm size limitation in providing MI subsidies, supply of liquid fertilizers, improved marketing facilities and access to more credit, direct benefit transfer (DBT) scheme, MI in canal command area, and better implementation models like GGRC.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 10. Expanding Hill Water Management

Abstract

The hilly region presents a paradoxical situation of scarcity amidst plenty on the water front. The hills and mountains are spread over five major regions viz., Himalayas (Western and North-Eastern ranges), Vindhya region, Western and Eastern Ghats, and Satpura ranges. Though sufficient rainfall is received in most parts of the region during monsoon season (June to September), most of it flows down the steep slopes as runoff and is not available for practical use. Improvements in hill agriculture will minimize the irrigation water demand to some extent. Of late, due to various developmental activities and degradation of catchments, water resources in the Himalayan region have been adversely affected. Deforestation, depleting fertility status of soil, erosion of some river banks, degraded common and grazing lands, inappropriate land use, fire resulting from shifting cultivation, fragmentation of land holdings, frequent droughts and floods, uncontrolled mining activities, and depleting groundwater resources are some of the major problems encountered in the hill agriculture. In view of the limited water resource availability in the hilly regions, soil and water conservation, rainwater harvesting and use of micro irrigation are important interventions. Suggestions are made to address the researchers and design engineers, local communities, implementing agencies, and policy makers in making needed interventions to improve the hill agriculture and water management.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 11. Reworking on Cost Sharing and Irrigation Subsidies

Abstract

The irrigation subsidies are attributed almost exclusively to the irrigation sector even though many of these systems serve multiple sectors like domestic, industrial, fisheries, and recreation. It is therefore necessary to apportion the capital and operation and maintenance costs (O&M) so that actual subsidies to irrigation and other user sectors could be realistically assessed for suitable policy interventions. Case studies of three irrigation systems in Andhra Pradesh, namely, (i) Sri Ram Sagar Project (SRSP), (ii) Nagajunasagar Project (NRSP)-Right canal, and (iii) Tungabhadra Project (TBP)-Lower level canal were undertaken. The adjusted separable costs remaining benefits (SCRB) method was used to apportion the O&M cost to different uses(sectors). The results indicated that the current total O&M cost reported was Rs 177 per ha in the case of SRSP, Rs 98 per ha in the case of NRSP, and Rs 579 per ha in the case of TBP. However, using the SCRB method, the adjusted O&M cost per ha. for irrigation was only Rs 144, Rs 48, and Rs 274 respectively for these three projects. Accordingly, the actual subsidy per ha. with O&M irrigation component of the projects was Rs 55, Rs 48, and Rs 506 respectively. Hence, separating the irrigation part of the O&M cost and reworking the subsidy in different sectors are recommended in order to plan the irrigation water charges and design effectively the future canal investment programmes.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 12. Learning from Success Stories and Best Practices in Water Management

Abstract

Water resources development and management are taking many turning points in terms of their size and scale of investment, approach and methodologies used, varying levels of interventions and their impacts. However, past experiences indicate not all is going well with the investment and management aspects of the irrigation projects. There are many best practices and success stories realized in different regions over years. Adoption of such practices is expected to minimize the cost of wrong implementation decisions and shows the ways for higher project performance. This chapter gives a briefing on the new initiative viz., Support for Irrigation Modernization Program (SIMP) in MMI modernization and outlines several best practices at national and international levels. Also the cases of private sector participation in irrigation project modernization under five different irrigation typologies are presented.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 13. Strengthening Institutions, Policies, and Governance

Abstract

Irrigation institutions in India are facing several constraints and challenges as the existing policies, laws/legislations, acts are complex to understand and implement. River basin planning and management through institutions has been emphasized in various policy papers and it is yet to become a reality. Water-related laws, acts are introduced from time to time but implementation aspects are weak. The water governance phase of the India’s water future with embedded investment and management phases is expected to address the emerging challenges to address both the water security and sustainability. The risks of climate change, interstate conflicts and increasing level of water pollution are making the policy interface further a complex phenomenon. However, these are the key areas where the Centre and the states need to work in a partnership mode involving institutions and regulatory mechanisms. Good governance needs to strengthen the institutions, implementable programmes, relevant policies related to water resources development and management in the country. This chapter discusses the issues related to water institutions, river basin organizations, existing acts, agricultural and water policies, government programmes and schemes. Finally, the chapter indicates how good governance can be a reality to address India’s water future with a positive note.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Chapter 14. India’s Water Future—A Way Forward

Abstract

Problems and challenges faced by the Indian water sector warrant both potential supply and demand-side interventions. Several interventions have been suggested and these interventions have also been ranked by experts to know their importance in bridging the future supply–demand gap. A matrix of main as well as a sub-set of interventions highlighting their specific focus/purpose, their coverage in the past, and their potential in bridging the supply–demand gap covering in the short and long-term implementation phase is also presented. The supply-side interventions could bridge the supply–demand gap by about 40% and the demand-side (mostly technology and institutions related) interventions could bridge the gap by about 60%. Selection of these interventions to suit different segments of the river basins is emphasized. Need for a portfolio of implementable policies and programmes that could integrate both supply and demand-side interventions supported by well-functioning water institutions (governance) is also emphasized.

Kuppannan Palanisami, Udaya Sekhar Nagothu

Titel: India's Water Future in a Changing Climate
verfasst von: Kuppannan Palanisami
Udaya Sekhar Nagothu
Verlag: Springer Nature Singapore
Electronic ISBN: 978-981-9717-85-9
Print ISBN: 978-981-9717-84-2
DOI: https://doi.org/10.1007/978-981-97-1785-9