?All joints and bends in pipes should be regularly checked for leakage and repaired as necessary.
THE BASIC ELEMENTS OF A RAINWATER HARVESTING SYSTEM
?Collection area (usually roof of building)
?Conveyance system ( gutters and down pipes)
?Filtration / treatment (gravel, sand, charcoal, metal or plastic mesh installed in gutters or entry to
tank)
?Storage (tank or cistern)
?Usage / recharge (maintenance)
QUALITY OF WATER
Whether collected and stored rainwater is suitable for a particular purpose depends on the criteria or
standards of acceptable quality for that use. The physical as well as the chemical quality of water is
important to decide its suitability for drinking. Usually the parameters for water analysis include: ph,
conductivity, total dissolved solid, total hardness, calcium, magnesium, sodium etc. The standards would
usually indicate acceptable/ desirable standards as well as permissible standards. For these reasons it is
important to carry out an analysis of the water before deciding how it may be used.
It is important to ensure that the storage tank has a tight cover with dark storage conditions to prevent
growth of algae and breeding of mosquito larvae. Periodic cleaning of the tank is vital to maintain
water quality.
TREATMENT OF STORED WATER
Care must be exercised in treating water for drinking. Chlorine or alum has been used in treating water to
improve its quality. Advice from qualified health authorities must be sought before using these purifying
agents. In most places the collected rainwater is used without treatment by boiling the water for drinking
purposes. Even if the water is filtered by some means, it is vital that water must be boiled for drinking.
MAINTENANCE
Maintenance of rainwater harvesting systems is of great importance. Major concerns are prevention of
contamination of the tank during construction and while it is being replenished during rainfall. For this
reason proper materials must be used to construct the tank and finish its surfaces. It is important to
prevent entry of insects, bird and animal droppings into the collection tank. Note that the first flush after
rainfall should be diverted away from the tank. Usually water captured in the first ten minutes after rain
begins to fall is unsuitable for drinking. The storage tank must be checked and cleaned periodically.
Cleaning procedures consist of thorough scrubbing of the inner walls and floor. Use of a chlorine solution
(chlorine and water) is recommended for cleaning, followed by a thorough rinsing. Gutters and down pipes
must be inspected and cleaned periodically. Households must establish a maintenance routine that will be
carried out by family members. For more details of maintenance, see subheading; Operational
Precautions.
If the Ferro-concrete sides of the tank gets damaged. The tank can be emptied and fresh cement mixed
with a suitable waterproofing/bonding agent can be applied and allowed to dry and cure.
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