Rainwater Harvesting• What is it?Rainwater harvesting is the accumulation and deposition of rainwater for reuse on-site, rather than allowing it to runoff.

• What are its uses?Uses include water for garden, water for livestock, water for irrigation, water for domestic use with proper treatment, and indoor heating for houses etc.

Rainwater Harvesting Systems

A rainwater harvesting system has six main functions:

• To collect rainwater from the roof and gutters• Transport the water through the downspouts and piping• Remove debris and pre-clean the water• Store the water• Pressurize the water to the intended use• Disinfect the water if the water is being used for potable (drinking)

Various Traps Used

Rooftop rainwater harvestingIn rural areas, this is most often done at small-scale. It is a simple, low-cost technique that requires minimum specific expertise or knowledge and offers many benefits. Rainwater is collected on the roof and transported with gutters to a storage reservoir, where it provides water at the point of consumption or can be used for recharging a well or the aquifer.

Basic Components:• Rainfall• A catchment area or roof surface.• Delivery systems (gutters) • Storage reservoirs or tanks • An extraction device (depending on the location of the tank - may be a tap, rope

and bucket, or a pump)

• Catchment Area:

To be ‘suitable’, the roof should be made of some hard material that does not absorb the rain or pollute the run-off.

Tiles, metal sheets and most plastics are suitable, while grass and palm-leaf roofs are generally not suitable.

If a roof does not provide enough catchment area, plastic sheets can be used to enlarge the catchment surface.Select materials that are non toxic and inert.

• Delivery System: The delivery system from rural rooftop catchment usually consists of gutters hanging from the sides of the roof sloping towards a down pipe and tank.

Gutters should be made of inert materials. The most common gutters are continuous, baked aluminum gutters made and installed on site. Half-round vinyl is also excellent.

When installing gutters make sure that there is a continuous slope towards the downspouts, and that there is no impediment to slow the flow of debris into the downspouts. These are areas where the water can pool or collect insects, organic materials and bacteria. Think of a gutter as a river - not a wetlands or swamp.

• Gutter Guard: It keeps some debris out, but it also protects the debris that collects in the gutter, from the sanitizing and self cleaning of sun and wind.

• Downspout: Anything from chains to traditional aluminum downspouts can be used to get the water down from the gutters.

• Debris Traps: Debris traps and filters are necessary to clean the water as much as possible before it enters storage.

• Final Sediment Filtration: For potable water systems the water is usually passed through some form of fine mesh screen filter as a final cleaning before entering the storage tank or cistern.

• First Flush Diverter: Routes the first flow of water from the catchment surface away from the storage tank. Designed to fill with contaminated water from a rain event and empty itself over a 24 hour period so that it is ready for the next time it rains.

• Surge/Pump Tanks: It is used where it is not possible for roof water to run by gravity to the cistern. The tank sizing depends on the roof size, the pump size and the desired storage capacity.

Water Storage

• Harvested rainwater is stored in storage tanks or cisterns.• The most common storage tanks are the above ground molded polyethylene tanks

ranging in size from 300 to 3,000 gallons.

Steel polypropylene-lined cisterns 4,000-30,000 gallons that are made of culvert steel, structurally engineered, and easily transportable to most sites.

Groundwater storage system

• It involves using a piece of surface of ground for harvesting rainwater for small communities.

• Catchment area is made smooth and impervious using clay tiles, tiles, plastic or asphalt sheets.

• Land has to be altered for contouring, clearance of rocks and vegetation etc. to reduce infliteration.

Extraction Devices:• Sanitary Rope and Bucket System• Bucket Pumps• Chain Pumps• Hand pumps

• Micro basins: Small pools are surrounded by stone walls and/or soil ridges on all sides to collect the rainwater and surface run off .

• Bunds: They are built along contour lines to collect surface run-off. Thus, enhancing infiltration and moisture content of soil.

• Retention Basins: They are used to collect surface runoff and to improve the quality of water by natural processes such as sedimentation, decomposition solar disinfection and soil filtration.

Other traps

Methods of Rural Sanitation

"Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine and feces”.

The word 'sanitation' also refers to the maintenance of hygienic conditions, through services such as garbage collection and wastewater disposal.

The Joint Monitoring Programme for Water Supply and Sanitation of WHO and UNICEF has defined improved sanitation as follows:• Flush toilet• Connection to a piped sewer system• Connection to a septic system• Flush / pour-flush to a pit latrine• Ventilated improved pit (VIP) latrine• Pit latrine with slab• Composting toilet

Sanitation Systems

Pipe Fittings• Elbows: Used to change the angle or direction of the pipe run.

• Street Elbows: One end of the fitting has male threads and the other end has female threads.

• T-fittings: Allow branching of lines and are shaped like the letter T.

• Couplings: Used to join two straight pieces of pipe of the same diameter.

• Reducers: Reducers join pipes of different diameters.

• Bushings: Used to make the diameter of a pipe fitting smaller.

• Unions: Used to join pieces of pipe where pipes cannot be turned or when a piece of equipment may have to be removed for maintenance or replacement.

• Adaptor fittings: These used to change the end of a non-threaded pipe to male or female threads as needed.

• Caps: Used to close the end of a dead end pipe.

• Plugs: Close an opening on a pipe fitting normally used for inspection and cleanout.

• Wyes: Used primarily to gain inside access to DWV systems

Testing of pipes

• Before pipe connections are made, pressure tests and bacteriological tests are done.