Glossary

Catchments: The catchment of a water harvesting system is the surface which directly receives the rainfall and provides water to the system. It can be a paved area like a terrace or courtyard of a building, or an unpaved area like a lawn or open ground. A roof made of reinforced cement concrete (RCC), galvanised iron or corrugated sheets can also be used for water harvesting.

Charcoal filters: Made in-situ or in a drum using pebbles, gravel, sand and charcoal.

Collection sump: A storage provision to collect filtered water from the tank through the filter channel for storage and collection.

Conduits: Conduits are pipelines or drains that carry rainwater from the catchment or rooftop area to the harvesting system. Conduits can be of any material like polyvinyl chloride (PVC) or galvanized iron (GI), materials that are commonly available.

First flush unit: First flush device is a valve that ensures that runoff from the first spell of rain is flushed out and does not enter the system. This needs to be done since the first spell of rain carries a relatively larger amount of pollutants from the air and catchment surface.

Groundwater: This is water found beneath the earth’s surface in soil pore spaces and in the fractures of rock formations. It can be found in sand, gravel, silt, clay or sedimentary rocks. On the surface of the earth, it can be seen in wells and as springs. The water percolates downward in response to gravity or differences in pressure.

Gutters: Gutters are channels all around the edge of a sloping roof to collect and transport rainwater to the storage tank. Gutters can be semi-circular or rectangular in shape.

Percolation pit/tank: An artificially created surface water body submerging a highly permeable land area so that the surface runoff is made to percolate and recharge the ground water storage.

Personal cleaning: It include activities such as brushing teeth, bathing, hand washing.

Rainwater harvesting potential:  The total amount of rainwater that is received in the form of rainfall over an area is called the rainwater harvesting potential.

Recharge: It is a natural process through which water percolates and moves downward from surface water to groundwater.

Recharge pits: The excavated pit lined with a brick/stone wall with openings (weep-holes) at regular intervals.

Recharge pond: A standing body of water made manually or naturally on the low lying area.

Recharge structure: Suitable structures through which rainwater get its way to groundwater aquifers and help to recharge it.

Recharge trenches: A continuous trench excavated in the ground and refilled with porous media like pebbles, boulders or broken bricks.

Recycled wastewater: In many places the generated wastewater is treated and used again for secondary purposes such as cleaning, flushing, mopping, etc. The water is rarely of potable use. This water is called recycled wastewater.

Sand gravel filter: Constructed by brick masonry and filleted by pebbles, gravel, and sand.

Soak pit: Soak pit is a covered, porous-walled chamber that allows water to slowly soak into the ground.

Surface water: The water present of the uppermost part of the earth surface, such as streams, rivers, lakes and wetland. The surface water is replenished mainly by rainfall.

Total strength in school: This is calculated by adding permanent members and visitors.

Permanent member are students, teachers, technical and administrative staff, guards, etc

Visitors are students from other schools, teachers from other schools, NGOs, contractors and laborers, vendors, chief guests, etc)

Water efficient fixtures