Sustainable Management of Natural Resources | Class 10 CBSE | Web Notes | Part 3: Water for All
WATER FOR ALL
Water is a basic need for all terrestrial forms of life.
Besides rainfall patterns, human intervention influences water availability.
Rainfall in India is largely due to monsoons that occur in a few months. Sustaining underground water has failed due to loss of vegetation cover, diversion for high water-demanding crops, and pollution from industrial effluents and urban wastes.
Local people managed irrigation methods like dams, tanks, and canals for agriculture and daily needs, with strictly regulated use of stored water.
When the British arrived, they implemented large-scale projects like large dams and canals, a practice continued after independence, neglecting local irrigation methods. The government took over administration, causing local people to lose control over water sources.
Kulhs is a local system of canal irrigation in Himachal Pradesh. Water from streams was diverted into man-made channels to supply villages down the hillside. During planting season, water was first used by the farthest village, then progressively higher villages. Kulhs were managed by 2–3 people and also fed springs by percolating into the soil. After being taken over by the Irrigation Department, most kulhs became defunct.
Dams
Large dams ensure storage of adequate water for irrigation and generating electricity.
Canal systems from dams can transfer water over great distances. E.g., the Indira Gandhi Canal in Rajasthan. However, mismanagement causes unequal distribution, allowing people near the source to grow water-intensive crops like sugarcane and rice, while those downstream receive no water.
Narmada Bachao Andolan (‘Save the Narmada Movement’) protested the height increase of the Sardar Sarovar Dam on the river Narmada.
Criticisms of large dams address three problems:
Social problems: Displaces many peasants and tribals without adequate compensation or rehabilitation. E.g., oustees of the Tawa Dam (1970s) still fight for promised benefits.
Economic problems: Dams use huge public funds but yield no proportionate benefits.
Environmental problems: Cause deforestation and loss of biodiversity.
Water Harvesting
Watershed management emphasizes scientific soil and water conservation to increase biomass production, aiming to develop land and water resources to produce plants and animals without ecological imbalance.
Benefits of watershed management:
Increases production and income of the community.
Mitigates droughts and floods.
Increases the life of downstream dams and reservoirs.
Various organizations rejuvenate ancient water harvesting systems as alternatives to mega-projects like dams, using methods like small pits, lakes, watershed systems, earthen dams, dykes, sand and limestone reservoirs, and rooftop water-collecting units. These recharge groundwater and revive rivers.
Ancient water-harvesting structures still in use include khadins, tanks, and nadis in Rajasthan; bandharas and tals in Maharashtra; bundhis in Madhya Pradesh and Uttar Pradesh; ahars and pynes in Bihar; kulhs in Himachal Pradesh; ponds in the Kandi belt of Jammu; eris (tanks) in Tamil Nadu; surangams in Kerala; and kattas in Karnataka.
Giving people control over local water resources reduces mismanagement and over-exploitation.
In largely level terrain, water harvesting structures are crescent-shaped embankments or low, straight concrete-and-rubble “check dams” built across seasonally flooded gullies. Monsoon rains fill ponds behind these structures, primarily to recharge groundwater.
Advantages of water stored in the ground:
It does not evaporate but spreads out to recharge wells and provide moisture for vegetation.
It does not provide breeding grounds for mosquitoes.
It is relatively protected from contamination by human and animal waste.
In two decades, Dr. Rajendra Singh (India’s “waterman”) built 8,600 johads and other structures in Rajasthan, bringing water back to 1,000 villages. In 2015, he won the Stockholm Water Prize for contributions to water resource conservation and protection.
