Our earth is 2/3 water And 1/3 landOf the 71% of water on our planet most issea water, which cannot be used fordomestic, agricultural and industrial use.Less than 3% is fresh water of which 98%is locked in Glaciers and Polar IceCaps.Freshwater in lakes and rivers amtsto 0.0028%, while 0.09% is stored asground water.Just 0.03% has to be shared between a 6Billion humans, millions of trees, plantsand other animals!Of the 71% of water on our planet most issea water, which cannot be used fordomestic, agricultural and industrial use.Less than 3% is fresh water of which 98%is locked in Glaciers and Polar IceCaps.Freshwater in lakes and rivers amtsto 0.0028%, while 0.09% is stored asground water.Just 0.03% has to be shared between a 6Billion humans, millions of trees, plantsand other animals!
Importance of waterWater is essential for all lifeforms. For example it makes up60 to 70% by weight of all livingorganisms and is essential forphotosynthesis. The viability ofall life on Earth is determinedchiefly by the presence of water,which is not evenly distributedon the planet. If it were, it wouldcover the entire surface to adepth of 3 km.
Causes of Water Crisis in IndiaBefore British era People managed waterthemselves. Rich people had their own wells, whilepoorer people had a common village well.From 19thcentury onward the state became the sloeprovider of water.People forgot the traditional systems of managingwater resources.Today growing population, urbanization,industrialization, have led to a water crisis in India.India has the highest number of fresh water bodiesas per the surface area of any country.
Solution to the Water Crisis=Rain Water Harvesting.•Cost-effective method ofcatching and holding rain whereit falls and using it.•Extremely essential for theNatural balance & ground-waterlevel maintenance.•4 million liters of Rainwater canbe collected from an averagerainfall of 1,000mm.•Feasible in regions that receivemoderate to heavy rainfall.
Why to harvest rain?Why to harvest rain?•An ideal solution for areas where there isAn ideal solution for areas where there isinsufficient waterinsufficient water•Reduces load on treatment plantsReduces load on treatment plants•Reduces urban floodingReduces urban flooding•Improves the quality of existing groundwater.Improves the quality of existing groundwater.
The way forwardMany countries use subterranean supplies ofgroundwater instead of rainfall and surface water.When groundwater is depleted, rivers, wetlands andlakes that depend on it can dry out, saline seawatermay flow in to replace the fresh water that has beenpumped out and emptied aquifers can be compressedcausing subsidence - a problem familiar in Bangkok,Mexico City and Venice.Groundwater levels should be carefully monitored tostop over-pumping.Rain Water harvesting through Recharging SystemsImproves the Ground Water levels.Many countries use subterranean supplies ofgroundwater instead of rainfall and surface water.When groundwater is depleted, rivers, wetlands andlakes that depend on it can dry out, saline seawatermay flow in to replace the fresh water that has beenpumped out and emptied aquifers can be compressedcausing subsidence - a problem familiar in Bangkok,Mexico City and Venice.Groundwater levels should be carefully monitored tostop over-pumping.Rain Water harvesting through Recharging SystemsImproves the Ground Water levels.
Objectives of Rainwater Harvesting• To conserve surface run-off during monsoons.• To recharge aquifers and increase availability ofgroundwater.• To overcome the problem of flooding and stagnation ofwater during monsoon season.
Why is it needed?• Water scarcity - A serious problem throughout the worldfor urban and rural communities.• Urbanization has led to overexploitation of groundwaterreserves & the quantity of rainfall is not certain anytime.
Traditional Types of Water Harvesting.The type used depends onconditions including both physicaland human:- KULS-• Water channels found inprecipitous mountain areas.E.g.:- Himachal Pradesh, Jammu. VIRDAS-• Shallow wells dug in lowdepressions called jheels (tanks).E.g.:- Great Rannof Kutch in Gujarat
Bamboo Drip Irrigation-• Tapping of stream & spring water usingbamboo pipes to irrigate plantations.E.g.:- Meghalaya Eri-• These are tanks to collect water, preventsoil erosion & wastage of runoff.E.g.:-Tamil nadu. Kunds-• Underground tanks developed to tacklewater problems.E.g.:- Thar desert in Rajasthan.
Rural water harvesting.A villagers house is about300 sq.feet.Rainwater can be collectedfrom the roof through pipes.They have made checkdams, johads,to harvest every drop of drainAlso, the potential oflakes, tanks and ponds tostore rainwater is immense.
Urban water harvestingRain water can be harvestedby two methods:- Store the rainwater incontainers above or abovegrounds or below grounds. Charged into the soil forwithdrawal later(groundwater recharging).
FACTORS Influencing urban rainwaterHarvesting Systems.• RAINFALL- Quantity- Pattern• CATCHMENT AREA CHARACTERISTICS• AREA CONTRIBUTING RUNOFF- How much is the area- Land use pattern• HYDROGEOLOGY- Soil cover- Depth to water levels- Chemical quality of ground water
Large Rain Water HarvestingSystems.Percolation pit is anartificial structure to divertrainwater into an aquifer.When the depth of claysoil is more, rechargethrough a percolation pitwith bore is preferable.Constructed using cementrings available in the market.
Dug cum bore pit(DCB):-• It is a type of percolationpit with a large chamberand deeper inwell bore.Trench cum Percolation(TCP):-• An ideal structure in open landtrap surface water & rechargethe aquifer.
Government Regulations In November 1998, the then-President of India,K R Narayanan invited CSE to suggest measuresfor water harvesting. The Government has passed an act so as to makerain water harvesting mandatory in all large buildings(public & private) in places like Rajasthan, TamilNadu,Delhi etc. Acts such as Groundwater Regulation Act, AndhraPradesh Water, Land and Trees Act have beenpassed.
NGO’s involved.The better known NGOs working in the field ofWater harvesting across India are:-• Centre for Science and Environment (CSE), Delhi• Tarun Bharat Sangh (TBS)in Alwar Rajasthan - Rajender Singh• DHAN Foundation - Madurai Tamil Nadu - Vasimalai• RS - Ralegaon Siddhi - Ahmednagar district - Maharashtra - Anna• SMSF - S.M.Sehgal Foundation- Gurgaon Haryana - Dr Suri Sehga• Akash Ganga Trust - ChennaiAnil Agarwal,Founderof CSE
Every society building can dorecharge of the Ground Water Table
Basic Uses of harvesting water. Groundwater gets recharged. Reduces strain on Special VillagePanchayats/Municipal bodies forwater supply. Leads to improvement ininfiltration & reduction in run-off. Is a cheap way to improve thegroundwater potential in that area.
Current ExampleRAN SINGHAge: 62Town: LahsediDistrict: ChuruState: Rajasthan He has done phenomenal work in Indian Thar desert ofRajasthan by placing kundis for water harvesting. Since the age of 13, he has made 450 kundis so far taking25 days for each kundi. Villagers rely on Ran singh and not the government forwater supply through kundis.
As more Forests are lost to agriculture and populationpressure, collection of water throughSurface Watershed Management is important.
Today Reuse of Waste Water canhelp solve the Water Crisis. How?
Biological treatment of waste water makes wastewater fit for washing, gardening, cleaning,construction and industrial use.Eg. Orchid Ecotel, Lotus Suites and Rodus.
EsselWorld and Water Kingdom India’s LargestAmusement park daily recycles 3,00,000 litres ofwater, which is reused to garden , clean toilets andfor flushing.
International water managementTechniques.Agricultural technology is constantlyimproving. For example we coulddevelop irrigation systems that dripwater directly onto plants andprecision sprinklers.In China, Israel, Peru, Brazil etcfarmers are using storage tanks tocollect rainwater in their fields,providing drinking water and extrairrigation for vast areas.