Water Scarcity and Resource Management

• Three-fourths of Earth's surface is covered with water, but only a small portion is freshwater usable for human purposes
• Freshwater is renewed and recharged through the hydrological cycle, making water a renewable resource

Water Scarcity and the Need for Water Conservation and Management

• Water scarcity is difficult to imagine given its abundance and renewability
• Water scarcity is commonly associated with regions of low rainfall and drought
• Rajasthan's deserts, where women travel long distances to collect water in 'matkas' (earthen pots), exemplify water scarcity
• Water resource availability varies across space and time due to variations in seasonal and annual precipitation
• Over-exploitation, excessive use, and unequal access to water among different social groups are the primary causes of water scarcity in most cases
• Freshwater can be obtained directly from precipitation, surface runoff, and groundwater, as highlighted in the hydrological cycle
• Water scarcity can occur even in areas with ample water resources, exemplified by many cities
• Water scarcity is an outcome of growing populations and their demands, coupled with unequal access
• A larger population needs water for domestic use and food production
• Over-exploitation of water resources for higher food-grain production leads to the expansion of irrigated areas, especially for dry-season agriculture
• Irrigated agriculture is the largest consumer of water, emphasizing the need to revolutionize agriculture
• Developing drought-resistant crops and dry-farming techniques represents a vital agricultural strategy

Water Quality and Conservation

• Water scarcity can arise from the poor quality of available water
• Water pollution from domestic and industrial wastes, chemicals, pesticides, and fertilizers poses a growing concern
• Such pollution makes water hazardous for human consumption
• Prioritizing the improvement of the quality of life, especially in rural India, is a key focus of the Government of India
• The Jal Jeevan Mission (JJM) aims to provide every rural household with a potable piped water supply of 55 liters per capita per day on a long-term basis
• The conservation and management of water resources is essential to prevent health hazards, ensure food security and livelihoods, and prevent the degradation of natural ecosystems
• Over-exploitation and mismanagement of water resources can lead to ecological crises with significant impacts

Multi-Purpose River Projects and Integrated Water Resources Management

• Historical records suggest sophisticated hydraulic structures like dams, reservoirs, and canals have been constructed for irrigation since ancient times
• Building dams in the river basins continues this tradition in modern India
• In the first century B.C., Sringaverapura, near Allahabad, had a complex water harvesting system that channeled the floodwaters of the Ganga
• During Chandragupta Maurya's reign, dams, lakes, and irrigation systems were extensively built
• Evidences of sophisticated irrigation systems were found in places like Kalinga (Odisha) and Nagarjunakonda (Andhra Pradesh)
• Bhopal Lake was one of the largest artificial lakes of its time in the 11th century
• The tank in Hauz Khas, Delhi was constructed in the 14th century by Iltutmish to supply water to the Siri Fort area
• Dams impound rivers and rainwater, traditionally for agricultural irrigation
• Dams are now used for electricity generation, water supply, flood control, recreation, inland navigation and fish breeding
• Dams are now identified as multi-purpose projects integrating multiple uses of impounded water
• The Bhakra Nangal project on the Sutluj-Beas river basin utilizes water for hydel power production and irrigation
• The Hirakud project in the Mahanadi basin integrates water conservation with flood control

Negative impacts and modern water management

• Multi-purpose projects launched after independence were seen as vehicles for development and progress
• In recent years, multi-purpose projects and large dams have faced scrutiny and opposition
• Regulating and damming rivers affects their natural flow, causing poor sediment flow and reservoir sedimentation, which impacts aquatic life
• Dams fragment rivers, hindering aquatic fauna migration for spawning purposes
• Reservoirs on floodplains submerge existing vegetation and soil, leading to decomposition
• Sardar Sarovar Dam, built over the Narmada River, is a water resource project covering four states: Maharashtra, Madhya Pradesh, Gujarat, and Rajasthan
• The Sardar Sarovar project aims to meet the water requirements of drought-prone and desert areas
• Supplying irrigation facilities to 18.45 lakh hectares of land in Gujarat and 2,46,000 hectares in the desert districts of Barmer and Jalore (Rajasthan) is a focus
• Supplying irrigation of 37,500 hectares in the tribal hilly sections of Maharastra through lift irrigation
• Around 75% of command area is drought prone in Gujarat, along with entire command in Rajasthan
• Irrigation has changed cropping patterns, leading farmers to shift to water-intensive crops, causing ecological issues like soil salinization
• The Pradhan Mantri Krishi Sinchaee Yojana aims to provide access to protective irrigation for all farms, promoting rural prosperity
• Enhancing physical access to water on farms, expanding cultivable land under assured irrigation, and improving on-farm water use efficiency are objectives of Pradhan Mantri Krishi Sinchaee Yojana
• The Krishna-Godavari dispute is due to objections raised by Karnataka and Andhra Pradesh regarding water diversion at Koyna by Maharashtra

Dam issues and Rainwater Harvesting

• Dams constructed to control floods have ironically triggered floods due to reservoir sedimentation
• Big dams have mostly failed to control floods during excessive rainfall
• These floods devastate life and property and cause extensive soil erosion while floodplains are deprived of silt, a natural fertilizer, exacerbating land degradation
• Multi-purpose projects have been observed to cause earthquakes, water-borne diseases, pests, and pollution from excessive water use.
• Water harvesting systems were considered in the past to be a viable choice for both socio-economics, but also environmentally
• An ancient Indian society had extraordinary knowledge of water harvesting systems alongside their hydro structures
• Indians used a large variety of techniques to harvest rainwater in different conditions
• In the hills they built diversion channels like 'guls' or "kuls for agriculture
• 'Rooftop rainwater harvesting' was common to store drinking water, particularly in Rajasthan
• In the flood plains of Bengal, locals developed inundation channels to irrigate their fields
• Using arid regions agricultural fields were converted into rain fed storage structures that allowed water to stand and moisten the soil like the 'Khadins' in Jaisalmer and 'Johads' in other regions of Rajasthan
• Underground tanks or tankas were traditionally used for storing drinking water in almost all the houses especially in Bikaner, Phalodi and Barmer of Rajasthan
• Tanks could be as large as a big room

Modern Rainwater Harvesting

• Rainwater can be stored in tanks for use until the next rainfall, making it an extremely good drinking source when others wear out, specifically in the Summer
• Rainwater, or palar Pani is regarded to be the purest form of natural water.
• Used underground rooms adjoining the tanka to keep heat out
• Rooftop water is typically collected using a PVC pipe
• It is filtered using sand and bricks
• Underground pipe sends water to sump for usage immediately
• Excess water from the sump is added to a well or reservoir in the ground
• The most common practice of Rooftop is in Shillong, due to having high rainfall
• Rooftop rainwater harvesting structure is available
• There are some houses in Rajasthan that don't care for taps, but maintain rooftop rainwater harvesting in order for water tastes
• Gendathur receives 1000 mm of rainfall, 80% efficiency and fillings for 50000 liters of water for each house

Bamboo water systems

• Bamboo is used in some unique drip irrigation systems
• In Meghalaya a 200 year old drip system of tapping stream is used
• 18 to 20 L enters the bamboo pipe, transported over 100s of meters, and finally is reduced by 20 to 80 drops per minute
• This makes a controlled way to send water around various pipes

Examine factors contributing to water scarcity, including rainfall, population density, and pollution. Investigate the impact of urbanization and river projects on water resource utilization. Focus on water management in regions like Rajasthan.