Water Budget For ensuring water security in a specific geographic region, it is essential to have an estimation for water inflow and outflow and demand-supply gap based on water availability and water requirements of that region. The Water budget is an important element for water manage-ment planning and adopts a data-driven estimation technique for water availability and water requirements of the region and assesses the gap between them. It can be a vital facilitator for integrated water resources management. Internationally, water budgeting has been attempted in many countries and it is done either for a region/ watershed/ river basin using precipitation, evapotranspiration, runoff, surface storage, groundwater recharge, soil moisture etc. and using information gathered from remote sensing/other available data. Countries namely Australia, Brazil Canada, Italy, UAE, United States have prepared the water budgets for specific regions/river basins/area. There are various water budgeting methods available, and practitioners have difficulty in identifying suitable methods for preparing water budget at ground level. Most of these methods are research oriented and require multiple primary information/inputs, satellite data/ remote sensing data, and hence, difficult to use these complex methods based on manual input feeding, calculations and synchronization for deriving results. Considering these aspects, it was important to develop a simple method automated in the form of a web application for water budgeting for applied purposes. Similar to the assessment of groundwater availability, Block has been adopted as a suitable administrative unit to get ready to use data inputs for water budgeting. It must be noted that the objective of the exercise is to keep the water budgeting. estimate simple and use the publically available sources of data for water. The exercise can further be upgraded using advanced methods. Indo-German Bilateral project implemented by GIZ India in partnership with Ministry of Jal Shakti, and Ministry of Rural Development, Government of India, "Water Security and Climate Adaptation in Rural India (WASCA) has developed a user-friendly scientific methodology to prepare water budget at Block level. This further led to the development of Varuni web application for water budgeting. The report titled "Water Budgeting in Aspirational Blocks," by NITI Aayog was prepared using the web app. It emphasizes the importance of water budgeting on quantifying water demand & supply. It outlines the methodology for estimating water demand across various sectors viz. human consumption, livestock consumption, agricultural use and industrial use. The report also assesses the water supply by evaluating various sources like run-off and hydrologic modelling, surface supply sources, groundwater supplies and water transfers. About Varuni App The Varuni Web Application has the potential to assist planning at the intermediate level by informing functionaries about the current water scenario at the Block level. It can alert them about water deficiency or surplus along with potential intervention areas. These insights will help practitioners employ scientific methods to understand Block characteristics through appropriate use of spatial and non-spatial datasets for preparing location-specific development plans. The application enhances accessibility to required datasets and has potential for raising awareness among stakeholders about water management, serving as a valuable tool for addressing India's water security challenges through informed, data-driven planning. It can be concluded that there is large scope for improvement of this exercise in future, which at present serves more as a prime-facie diagnostic tool that can help for immediate water management interventions. Components of water demand Domestic Water Demand: Domestic water requirements vary between rural and urban areas. In rural areas, the per capita daily requirement, as per the Jal Jeevan Mission guidelines is taken as 55 litres per capita per day (Ipcd), while urban areas it is taken as 150 Ipcd as per the CPHEEO norms. Water conveyance losses are estimated at 20 percent, though CPHEEO manual mentions the optimal losses to be considered at design stage at 15%. The population data are taken from the Census of India 2011, and estimate for current population is arrived at after applying appropriate decadal growth factor. Annual domestic water requirements are calculated by multiplying the total population by the daily per capita requirement, considering the rural-urban differentiation. Livestock Water Demand: The water requirements for livestock are calculated based on the latest livestock census data and daily water requirement coefficients established by ICAR for different animal types. The livestock population is taken from 2019 census report published by the Department of Animal Husbandry and Dairying. Annual domestic water requirements are calculated by multiplying the livestock population by the daily per capita requirement, considering the type of livestock. Agricultural Water Demand: Agriculture is the prime water consumer hence it is important to understand the water requirement of the sector. The key parameter is cropping water requirement (CWR). Water requirement of the country for irrigation in high demand scenario for 2025 and 2050 was assessed by National Commission on Integrated Water Resources Development-1999 as 611 BCM (Billion Cubic Metre) and 807 BCM respectively. As per the Land Use statistics, the Gross Irrigated Area is 122.3 million hectares. Accordingly, the crop water requirement is estimated to be 0.50 meters (Total irrigation water demands/Gross Irrigated Area). The crop water requirement is calculated by considering the gross irrigated area of the Block with appropriate growth factor and irrigated water requirement co-efficient of 0.5 m per hectare. Comments were received from multiple sources about the use of 0.5 m for estimation. However, considering the available data, it has decided to use this average value. Industrial Water Demand: For the purpose of Block level budgeting, Block and District officials provided inputs about industrial water requirements. Components of Water Supply Surface Runoff: Strange's Table method is a hydrological modelling technique, widely used by CGWB and IWMP (PMKSY-WDC), provides an empirical approach for calculating runoff based on catchment classification. The runoff quantity at Block level is calculated based on land use classification (forest area, non-agricultural uses, barren land, pastures, tree crops, culturable waste land, fallows, and irrigated land) and average rainfall data, applying the Strange's table percentage factors to determine runoff volumes. Surface Water Supply: The storage capacity of the surface water structures is an essential component in water supply estimation. The First Census of Water Bodies, conducted alongside the 6th MI Census provides the necessary details of surface water structures in the Block. Groundwater Supply: The INDIA-Groundwater Resource Estimation System (IN-GRES) is a web-based application developed by CGWB in collaboration with IIT-Hyderabad for ground water resource assessment, providing essential information for water budgeting at the Block level. The ground water profiling of the Block is sourced from IN-GRES. Water Sourced from Outside Geography: Post-independence irrigation projects and water transfers have become major contributors to improving water supplies. Recent drinking water projects, including Jal Jeevan Mission, and industrial projects also rely on long distance water transfers. This aspect must be considered in water supply estimation and budgeting. The required inputs include information about the extent of command areas of irrigation projects located inside/ outside the Block, drinking water schemes, and industries depending on external water sources. Since this information is not readily available in the public domain, Block and District officials provided these inputs for water budgeting. The above methodology and consideration led to the development of algorithms for Varuni Web Based Water Budgeting Application which pulls data automatically from relevant authentic portals and feeds in for processing to determine water demand and supply side. This application allows evaluation of water availability, ensuring accurate assessments of water budget (deficits or surpluses) at the Block level, and providing key insights for planning water conservation and management interventions. Major outcomes of the exercise The Application for Water Budgeting has been piloted in 18 aspirational Blocks across varied state/agro-climatic zones in India. Using Varuni App, this report provides Block-level water budget briefs for each of these Blocks, offering insights into their specific water demand-supply scenarios, challenges, and recommendations related to water resource management and facilitates, identifying suitable measures for enhancing water security in the Block. A comparative analysis of the water budgets across the 18 Blocks is also presented. The Block-level analysis across various regions reveals significant diversity in water resource availability, usage patterns, and associated challenges. Broadly, Blocks can be categorized based on their geographical and climatic contexts such as coastal, Gangetic plains, Himalayan, arid/semi-arid, and plateau regions-each with unique water management concerns. Coastal Regions: Blocks like Gangavaram (Andhra Pradesh) and Andimadam (Tamil Nadu) are marked by low irrigation coverage and a high dependency on surface water due to salinity issues. These areas face risks of sea water intrusion and require improved water use efficiency and protection of groundwater quality. Gangetic Plains: Blocks such as Fatehpur, Gangiri, Nindaura, and Kotwali show extensive agricultural land use and moderate to high water harvesting capacities. However, Blocks like Gangiri and Kotwali face substantial water deficits and heavy reliance on ground-water, placing them in semi-critical categories. Surface water from canal systems sup-plements local water needs, especially in Nindaura and Kotwali, but increasing external dependence raises sustainability concerns. Himalayan and Cold Desert Regions: Blocks including Nirmand, Rupsho, and Namchi exhibit unique characteristics, with spring and glacier-fed irrigation systems. Nirmand and Rupsho are water surplus due to low local demand and high-altitude water availability, while Namchi, despite its spring-shed management (Dhara Vikas), is water deficit, em-phasizing the need for better spring conservation. Arid and Semi-Arid Regions (Rajasthan and Bundelkhand): Water scarcity is acute in the following Blocks: Kotri, Abu Road, Bhim, Baldeogargh, and Buxwaha. Blocks like Kotri and Abu Road are overexploited with groundwater development stages exceeding 100%. Despite irrigation infrastructure, utilization remains low, indicating inefficiencies in surface water usage. Baldeogarh shows the highest deficit (-11,237.5 ha.m), needing catchment area treatments, surface storages and groundwater recharge strategies. Plateau and Central India: Chhaigon Makan and Narva Blocks demonstrate contrasting scenarios. While Chhaigon Makan Block has high groundwater reliance and is semi-critical, Narva is water surplus, supported by small and medium irrigation projects. The Vijaypur Block in Madhya Pradesh stands out as surplus despite high irrigation demands, observed largely due to conjunctive use of surface and groundwater. Reservoir-Dominated Blocks: Kukarmunda Block in Gujarat, despite having the Ukai dam with substantial surface water storage, heavily relies on groundwater (96%). This over-dependence poses future sustainability risks, despite the current "safe" groundwater status. Key action points This assessment clearly highlights the needs for integrated water resource planning, incor-porating region-specific strategies to enhance water security and resilience across diverse agro-ecological zones: Water Deficits: Water deficits are a significant concern in several Blocks. Namchi Block (94%), Gangiri Block (60%), Baldeogargh Block (53%) Andimadam Block (42%), Abu Road Block (41%), Kukarmunda Block (37%), Kotri Block (21%), Chhaigon Makan Block (14%), and Kotwali Block (11%). These deficits highlight the urgent need for improved wa-ter management strategies tailored to each region's specific context. Overexploitation: A few Blocks (e.g., Kotri, Abu Road) exceed 100% groundwater development. Underutilization: Surface water resources are underutilized in Blocks like Fatehpur, Bux-waha, and Abu Road, highlighting potential for better infrastructure and management. Regional Priorities: Tailored interventions needed, coastal Blocks should focus on salin-ity management, Bundelkhand on groundwater recharge and surface storage creation and Himalayan areas on spring protection. To access the complete report, click here.