Rainwater and groundwater management

Rainwater and Groundwater Management

Water Crisis - About 71% of the earth's surface is covered with water, but 97% of this is seawater, 2% is locked in polar ice caps and glaciers and 1% of water is available as freshwater. We need to conserve every drop of water.

23/03/2014 Rainwater and Groundwater Management2

The Purpose - Rainwater and Groundwater Management

Rainwater Management

Rainwater harvesting is the accumulation and deposition of rainwater for reuse before it reaches the aquifer.

Uses include water for garden, livestock and irrigation.

Rainwater harvesting provides an independent water supply during regional water restrictions. It provides water when there is a drought, and reduces demand on wells which may enable ground water levels to be sustained.

In Pune , rainwater harvesting is compulsory for any new society to be registered.

The structures required for harvesting the rainwater are simple, economical and eco-friendly.

Rainwater Harvesting Systems Roof-Top Rain Water Harvesting System Catchment Transportation First flush Filter

Rain-Saucer, which looks like an upside down umbrella, collects rain straight from the sky. This decreases the potential for contamination

23/03/20144 Rainwater and Groundwater Management

Rainwater and Groundwater Management5

• Quality of collected rainwater is better than that of surface water. Contamination is possible by airborne dust, bird feces, and other debris, so some treatment is necessary, depending on how the water will be used.

Pre-chlorination - for algae control and arresting any biological growth.

Sedimentation - for solids separation, that is, removal of suspended solids trapped in the water.

Filtration - removing particles from water, Desalination - Process of removing salt from the water.

Disinfection - for killing bacteria.

• Some rain water harvesting agencies in India:

National Water Harvesters Network (NWHN).

Centre for Environmental Science, Delhi.

Central Ground Water Authority, Nagpur.

Groundwater Survey & Development Agency, Thane & Pune.

23/03/2014

Rainwater Management

Groasis Waterboxx

http://en.wikipedia.org/wiki/Groasis_Waterboxx



Groundwater is the water located beneath the earth's surface in soil pore spaces and in the fractures of rock formations. Groundwater is naturally replenished by surface water from precipitation, streams, and rivers when this recharge reaches the water table.

Groundwater is often cheaper, more convenient and less vulnerable to pollution than surface water. Therefore, it is commonly used for public water supplies like drinking and cooking.

The study of the distribution and movement of groundwater is groundwater hydrology.

Rain is the main source of ground water.Groundwater quality comprises the physical, chemical and biological qualities of ground water.

23/03/20146 Rainwater and Groundwater Management

Groundwater Management


Groundwater Recharge

• Recharge area – Rain, Drizzle, Snow melting, surface water rivers and lakes.

• Discharge Ares – Industrial waste and Human Waste.

• The Cycle of Ground Water is often due to the earth’s gravity.

• Water often finds space from rocks to travel and accumulate at a specific location forming aquifer.

23/03/2014


CENTRAL GROUND WATER AUTHORITY

23/03/2014

In India, Central Ground Water Board (CGWB), a subordinate office of the Ministry of Water Resources, is the Apex Agency entrusted wIth the responsibilities of providing scientific inputs for management, exploration, monitoring, assessment, and regulation of ground water resources of the country.

Regulatory Measures The CGWA is regulating withdrawal of ground water by industries/ projects in 839 Over-exploited and 226 Critical Assessment Units. List of these critical areas has been circulated to the State Pollution Control Boards and Ministry of Environment & Forests which refer the new industries/ projects to CGWA for obtaining permission.

Construction of new ground water structures is prohibited in the notified areas. Permission of drilling tube wells is being granted only to the Govt. agencies responsible for drinking water supply.


Ground water Management – Artificial Recharge

23/03/2014

Artificial recharge is the process by which the ground water is augmented at a rate much higher than those under natural condition of replenishment.

The basic requirement for recharging ground water is Source water availability.

Induced Recharge - Rainwater Harvesting

The rain water in urban area can be conserved through Roof Top Rain Water Harvesting Techniques for artificial recharge to ground water. This technique requires connecting the outlet/drop pipe from roof of the building to divert the rainwater to either existing wells.

Water Saving and Management

Do’s & Don’ts

Use a glass to rinse after brushing of teeth. It needs only half a litre of water. Keeping the washbasin tap open while brushing teeth wastes at least four litres of water.

Bathing needs only 20litres of water. Shower bath needs at least 80litres and tub bath 110litres of water. Washing clothes require 40litres of water; keeping the tap running during washing consumes 250litres of water.

Water plants with rinse water from the washing machine.

Sprinkling water on the ground needs 10litres of water but hosepipe watering consumes 50litres of water.

Use a bucket to wash the car, not a hose.

23/03/2014 Rainwater and Groundwater Management10

Conclusion

Therefore, the housing complexes should have proper rain water harvesting system and draw groundwater for non-drinking purposes. Even if water from bore-wells is used for toilet flushing (50lpcd) and cleaning (10lpcd), the load on the piped water supply will come down to 50%. This means that the same piped water supply will be sufficient for double the alarming population growth.


Rainwater and Groundwater Management.

Mahesh M Karane

Referencewww.environmentaljournal.orgwww.bcpt.org.inBombay Community Public Trustwww.wikipedia.orgwww.cgwb.gov.inCentral Ground Water Board

23/03/2014