Transcript File - Natural Solutions

Training of Trainers
in Entrepreneurship Development
in Rain Water Harvesting
Techniques of rain water harvesting
Workshop Conducted
By
Eureka Forbes Institute of Environment
For
Maharashtra Centre for Entrepreneurship Development
Water Harvesting
Simplest rain water harvesting
During Rainy season, Drinking water needs of 35-house village
are met by a simple saree based rainwater harvesting system.
Kerala – 7 months of rainy season (Pic: Shree Padre)
Components of an urban RWH system
1.
2.
3.
4.
5.
6.
7.
Catchments
Channels/rainwater or down-take pipes
First flush devices / tricks
Storm water drains
Filter units
Storage tanks
Recharge structures
Terrace
SWD
Subsoil water
Ground water
Catchments
Roof tops or other suitable surfaces
Roof tops can give very clean water
Paved areas also give moderately good water
Un paved areas give water mixed with soil/ silt
Maintenance
Catchments should also be cleaned regularly to remove dust,
leaves and bird droppings so as to maintain the quality of the
product water.
Junk materials should not be dumped on it.
Catchments
Clean Roof
Haveli
Storage tank in the
Raised Plinth
Harvesting for Future Use – Storage in Tanks
Channels / rainwater down-take pipes
Channels
Are needed to collect water from sloping roof
Rain Water Down-take pipes
Are needed for flat roof
Spouts/ open pipes need to be converted to the
down-take pipes
Maintenance
Their slopes and sizing should be proper
They need to be cleaned before monsoon.
And realigned if disturbed
Channels / rainwater down-take pipes
Channels / rainwater down-take pipes
First Flush Devices
First Flush
Are needed to divert first few mm of rain water out of
the system
Simple capped pipes / plug bends can act as first flush
More complicated structures can also be devised
Maintenance
Timely opening and closing of the first flush gives
maximum good quality water for harvesting
First Flush Devices
Filter units
Filters
Are used for additional cleaning of rain water Or storm water
These can be passive like devas filter, screen filters, sand and
gravel filters
Or advanced passive multi-chambered filters
or Active like PSF, MGF (DMF) ACF etc
Maintenance
Passive filters are easy to maintain
Active ones are not so …particularly in housing society set up
Recharge Structures
Recharge Structures
Are needed for harvest for dry season approach
Harvested rain water is pushed under ground for retrieval
later in the dry season
These could be simple recharge pits, punctured storm
drains, recharge pits with bore holes, or recharge of wells/
bore wells with filtered rain water, WATs and ponds are
needed for extremely large areas
Maintenance
Appropriate cleaning recharge structures
Retaining porosity and cleanliness of the filter media
Harvesting for Future Use – Storage in Soil Strata-I
Recharge Pit 1
Terrace
Building
Simple Ground Water
Recharge Pit
Permeable strata
Subsoil water
Ground water
Use through well/
Bore well
Harvesting for Future Use – Storage in Soil Strata-I
Recharge Pit Type 2
Terrace
Building
Recharge Pit
With a deeper shaft
Impermeable strata
Subsoil water
Ground water
Use through well/
Bore well
Harvesting for Future Use – Storage in Soil Strata-I
Recharge Type 3 --- combination well
Combination well
Impermeable strata
Less Subsoil water
Main Source Ground water
Harvesting for Future Use – Storage in Soil Strata - II
Recharge through Dug well
Terrace
Building
Recharge through well
Use through well/bore well
Permeable strata
Subsoil water
Ground water
Harvesting for Future Use – Storage in Soil Strata - III
Recharge through Bore well
Terrace
Building
Recharge through bore well
Use through bore well
Ground water
Storm Water Drains
Storm Water Drains
Are usually ground level channels/ gutters for
specifically taking the storm-water out of an area
During harvesting exercise we may need to modify /
puncture these however safe exit must be kept for the
excess rain water
Maintenance
Cleaning before the rainy season and if need be during
the rainy season
Harvesting for Future Use – Storage in Soil Strata - IV
Recharge through trenches or punctured storm drains
Improved Ground water
Harvesting for Future Use – Storage in Soil Strata - V
Improving permeability of pavement
Terrace
Building
Recharge through soil
Use through well/bore well
Ground water
Storage tanks
Storage
Is needed for ‘Use when available’ and also for keep
for dry season approach
It can be man made like various types of tanks
Or it can be gaps in Mother Earth’s Crust
Maintenance
Appropriate cleaning for man made tanks
Retaining porosity and serenity of the earths crust
River Varuna
Modified from
Stephen Lemcke, 2002
Natural Solutions
River Varuna
Birth of water supply
department in Varanasi
Natural Solutions
River Varuna
Water scarcity on the
Banks of mighty Ganga
Natural Solutions
Varuna
River Varuna
Water works
Varuna
Water works
River Assi
One who makes and preserves ponds
gets to taste sweetness of water
Ancient water harvesting sites
• A few relics of once glorious tradition and
… a way of life
Jalashayanam Vishnu Temple … Mahabalipuram, sweet water pond hardly 200 ft from sea water
Rameshwaram shrine a few
hundred feet from sea.
Note the gaps (kept on
purpose in
Foundation and the
Sweet water in the
foundation reflecting
the Gopuram
Fort Dindigul, Tamil Nadu plenty amongst scarcity
Fort Dindigul, Tamil Nadu plenty amongst scarcity