Management of Irrigation and Water Supply Under Climatic Extremes

This chapter will provide the overall context and setting for the volume. Based on available empirical data, it will discuss the issue of variability in rainfall and other climatic parameters in India. It will illustrate the need for assessing the impact of climate variability on water resources, by discussing its implications for the design of water management systems vis-à-vis the stress they induce on water flows and alterations they affect in the demand for water in various sectors, including domestic sector. It will also discuss the need for assessing the climate-induced risk in WASH (water, sanitation, and hygiene systems), particularly due to extreme climatic conditions and events, for designing water supply and sanitation systems that are climate-resilient, risk informed and sustainable. The chapter will also present the objectives and scope of the book, and the outline of individual chapters.

This chapter first presents the water sector development paradigm followed in India since the country’s independence with a focus on the institutional set up, and also the current national policies in the water management sector, with particular reference to the provisions to deal with climate change and variability. The chapter then describes the phenomena of climate variability in India—using analysis of spatial and temporal variation in rainfall and pattern of occurrence of rainfall; intra-day, inter-seasonal, and inter-annual variability in temperature; relative humidity and wind speed; and spatial variation in solar radiation—and discusses their implications for managing water for drinking water supply and irrigation. Finally, it reviews the available empirical analysis of the long-term trends in temperature and precipitation in different regions of the country. It also describes the basic character of irrigation and water supply and sanitation systems existing in different regions of the country.

The chapter discusses water resources management issues and challenges in the Mahanadi river basin, particularly those posed by climate variability and climate change. The chapter analyses the long-term changes in the basin hydrology, along with its inter-annual variability, and implications for the sustainability of irrigation systems and drinking water sources are drawn. The current water uses in irrigation, industrial and rural and urban domestic water supply sectors are also evaluated against the potential supplies from the existing water systems. A base case scenario of future water balance for the projected changes in socio-economic conditions and climate variables is developed using Water Evaluation and Planning (WEAP) system. The base case scenario is compared with scenarios that consider different water management interventions and the potential impacts of the water management interventions in reducing water stresses in the basin under various climate scenarios including severe drought scenario, and demand growth scenarios were assessed. Accordingly, the strategies for reducing the water stresses induced by demand growth and hydrological changes resulting from climate change and extreme events are also discussed.

This chapter analyses the institutional set up for water management in the Mahanadi river basin against the backdrop of current water uses in irrigation, industrial and domestic sectors and management challenges in the basin. The analysis is done for its effectiveness in ensuring sustainable water use, including resolving water conflicts between sectors and between states. A framework for analysing the effectiveness of water institutions as proposed by Saleth and Dinar (The institutional economics of water: a cross-country analysis of institutions and performance. The World Bank, 2004) and the institutional design principles for sound water resources management as proposed by Frederiksen (Institutional principles for sound management of water and related environmental resources. In: Asit K. Biwas (ed) Water resources: environmental planning, management, and development. McGraw-Hill company, 1997) are used for analysing the impact of institutional and policy framework related to water use and management. Based on the current water management challenges and the additional challenges that the basin is expected to face in future, institutional alternatives for water management are proposed.

Luni River Basin in western Rajasthan experiences extreme climatic conditions with very hot summer and extremely cold winter, compounded by high inter-annual variability in rainfall and other weather parameters that cause severe droughts and occasional floods. Pali is one of the districts in this hyper-arid river basin. Excessive withdrawal of groundwater and surface water for irrigation has caused aquifer mining and environmental water stress. In order to identify the water management options for the basin that can help mitigate droughts and arrest groundwater depletion, a water accounting study was undertaken. This helped assess the quantum of water being used in various sectors, and evaluate the opportunities available for augmenting the supplies and reducing the demand for water in consumptive use sectors. Further analysis was carried out for a district, which falls fully in the basin, to analyse the extent to which each one of these interventions would help augment replenishable groundwater resources and reduce the demand for water in irrigation. The policy reforms required in the irrigation sector for affecting the implementation of these interventions are also identified.

The chapter discusses why it is important to consider the climatic and socio-economic factors in the planning of rural water supply schemes and how the consideration of these factors can influence the regional water supply planning, particularly the assessment of water demands in various sectors. It discusses the norms used currently for planning rural water supply, especially the norm relating to per capita water supply for human consumption and livestock. Based on the evidence available from scientific literature on the impact of physical and socio-economic factors on water requirement in rural domestic and livestock sectors and kitchen gardening, it defines certain criteria for assessing water demands in domestic and livestock sectors in per capita terms in different regions based on climatic conditions, per capita income, occupational profile and water prices, and describes how the per capita water demands in the domestic and livestock sector in a region could change according to these criteria. Finally, the implications of this analysis for drinking water supply policy for the rural areas of the country are discussed.

This chapter discusses development of an analytical framework for assessing the public health risk associated with disruptions in water, sanitation and hygiene (WASH) services affected by climate-induced hazards related to water such as droughts and floods. For the development of the framework, the factors influencing the three different dimensions such as hazard, exposure and vulnerability in rural water and sanitation were identified and grouped as natural, physical, socio-economic and institutional. These factors and the relevant indicative variables are identified based on an extensive review of international literature and expert knowledge. This way, a total of 29 factors were identified, which included five natural factors affecting ‘hazard’; three natural, six physical, three socio-economic and three institutional and policy factors influencing ‘exposure’; and one natural, six socio-economic and two institutional and policy factors influencing ‘vulnerability’. The way in which these factors influence hazard, exposure and vulnerability are discussed, and the quantitative criteria for assigning values for these variables are also explained.

This chapter assesses the risk in WASH caused by climate-induced stresses such as droughts and floods at the district level in two divisions of Maharashtra consisting of 19 districts using the composite index of Climate Risk in WASH. The value of climate risk was assessed at the district level using data on a total of 29 indicators that correspond to a whole range of natural, physical, socio-economic and institutional factors, influencing the three dimension of WASH risk, viz., hazard, exposure and vulnerability, collected from a wide range of secondary and primary sources. The WASH risk index was estimated to be varying from 0.22 for Chandrapur in Vidarbha division to 0.35 for Parbhani in Marathwada division. The factors influencing high climate risk in certain regions and the physical strategies to make water supply and sanitation systems climate-resilient and the capacity building needed for affecting these changes are also discussed.

Climate change is manifest globally through extreme weather events, altered rainfall patterns and spread of viral diseases. The emergence and re-emergence of arthropod-borne viral diseases viz. dengue, chikungunya, West Nile, Japanese encephalitis and Zika are of global public health concern. Over the last decade India has faced a huge burden of Dengue and chikungunya with more than ten million individuals affected. This not only necessitates studies on the role of environmental effects on disease, but also requires policy-framing towards effective prevention or control of epidemics. In this chapter we are presenting the initiative taken by the Government of Maharashtra state, Republic of India to establish a pilot project to record and document disease outbreaks in the different districts of the state and to develop a predictive model that can analyse the effect of meteorological parameters on disease occurrences. A web portal has been developed for recording of data and online display and efforts are on to develop mathematical models for analyses and estimation disease occurrences. As a first, we have successfully developed a Poisson regression model to describe the effects of meteorological parameters on dengue occurrences in the Nagpur region of the Maharashtra state.

This chapter discusses the water supply and sanitation situation in Rajasthan, particularly the spatial variation in the characteristics of the water supply systems. It describes the natural, physical, socio-economic and institutional environment which influences the access to drinking water sources and use of water, and access to and use of improved sanitation facilities in Rajasthan. It also reviews the existing policies and norms pertaining to rural water supply in the state to know as to what extent they address the public health concerns associated with climate variability in the state. It then maps the climate-induced WASH risk in all the districts of Rajasthan using a modified analytical framework for assessing climate risk, and validates it using data on public health status, with respect to incidence of water-borne diseases across the state. The WASH risk index was estimated to be varying from a lowest of 0.20 for Jaisalmer District to 0.40 for Sirohi District. The key factors contributing to high climate risk in certain districts and very low risks in certain other districts are identified.

This chapter discusses the specific action plans to improve the climate resilience of Water Supply, Sanitation, and Hygiene (WASH) in two arid districts, viz., Barmer and Sirohi in western Rajasthan, that were found to be facing high WASH-related risk. The interventions take into account the variation within each district in the natural, physical, socio-economic, and institutional factors that affect WASH system performance. These factors included rainfall and its variability; temperature; frequency of flood-occurrence and drought proneness; geology of the area; water table conditions; groundwater salinity, presence of fluorides in groundwater; availability of surface water including imported water; characteristics of the dominant water supply system; percentage households (HHs) having access to water supply in the dwelling premise; percentage HHs having access to improved sanitation facilities; and percentage households having access to toilets with water supply connections. The institutional capacity building and policy reforms needed to affect the design and implementation of climate-resilient WASH are also analysed and discussed.

This chapter defines the key strategies for India to overcome the stress induced by climate variability and changes that affect water resources and water-related services. In the case of services, the focus is on irrigation and drinking water security. The analysis of water availability-demand situations and specific proposal for interventions that are aimed at reducing climate risk are made for distinct rainfall-climate zones. The spatial variation in geohydrology and topography is also factored in while doing the analysis. The chapter will also discuss the key institutional and policy reforms that are required to manage water resources and water-related services on a sustainable basis under climate extremes. The focus is on improving irrigation and drinking water security.

This chapter will summarize the key findings of all the individual chapters from Chap. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 and make policy recommendations for designing and building climate-resilient irrigation and water supply systems. This chapter will also focus on the areas of research in water and climate that would enable water managers to frame appropriate policies for planning and implementing irrigation and water supply systems that can perform well under extreme climatic conditions. The areas for future research identified are (a) analysis of variation in Potential Evapo-transpiration (PET) value of crops between a drought year and a wet year; (b) farmer behaviour with respect to cropping during drought years; (c) estimation of domestic water demand in different climatic conditions and seasons; (d) estimation of variation in water demand during the rainy season between typical rainfall years (dry and wet); (e) estimation of price elasticity of water demand under different climatic conditions and (f) analysis of the impact of volumetric rationing of water in the domestic water supply sector.