Rain Water HarvestingVigyan Ashram Pabal

No maintainence and electricity required Less time required for implementation Water available from rain is free from

bacteria Safe and pure drinking water available Less cost involved in implementation

Benefits of Rainwater harvesting

Rainwater Harvesting

DomesticThis type also known as rooftop rainwater

harvesting.Water is collected from rooftop into storage

tanks for each family

CommunityThis involve larger catchments for collecting

water runoff like reservoirs , village ponds

Types of Water harvesting

Diversion Rainwater collected is diverted to storage

through pipes

FiltrationRainwater is filtered to remove impurities like

dried leaves,dust, bird dropping etc Storage Water collected from rooftop is stored in tank

Steps in Water Harvesting

Following Image describes Rainwater harvesting techniques

Images for Rainwater harvesting

Planning and design of water harvesting

Water harvesting Potential = Rainfall(mm) x Collection efficiency x rooftop or catchment area

This is explained in next slide

Planning and Design

Example A building having 100 sq meter rooftop

areaRainfall = 600 mm per year(0.6 meter)Assume that collecting efficiency is 70 % due

to leakage etc

Volume of water harvested = 0.6x100x0.7 = 42 cubic meter/42000 liter per year

Rainwater Harvesting Potential

Catchment/Collection Drain Pipes Down Pipes Gutters First Flush pipe Filter Unit Collection unit Pumping Unit

Components of Water Harvesting

Rooftop water harvesting Percolation tanks Contour trenching and nala bunds Khadin , Johad in dry regions of Rajasthan Bandharas or bundings on river in

Maharashtra Kuls in glacier region of Himachal Saza kuva or jointly owned wells in Aravali

region of Rajasthan

Types of Water Harvesting methods