Rain Water Harvesting & Flood Mitigation
Road side RWH structures

Metrowater identified some 45 water stagnating areas in Besant Nagar in the stretch of Alcot Kuppam to Odai kuppam, 14 locations on Kamarajar Salai and 4 locations in Chintadripet for implementing RWH structures. In the rainwater stagnated at the rains.

As the stagnant rainwater can be recharged into the ground, suitable RWH structures were installed to these locations as a measure of flood mitigation.
The newly constructed storm water drains provided with percolation pits for recharging the underground aquifers.
Storm water drains can be connected to nearby open wells / recharge pits and in nearby parks.
  

Maintenance Tips for Rainwater harvesting structures
  • Always keep the surroundings of the rank clean and hygienic
  • Remove Algae from the roof tiles and asbestos sheets before the monsoon
  • Drain the tank completely and clean from inside thoroughly before the monsoon
  • Clean the water channels (gutters) often during rainy season and definitely before
    the first monsoon rain
  • Avoid first 15 or 20 minutes of rainfall depending on the intensity of rain. Use the first
    flush arrangement to drain off this first rain water.
  • Change the filter media every rainy season
  • Cover all inlet and outlet pipes with closely knit nylon net or fine cloth or cap during
    non-rainy season to avoid entry of insects, worms and mosquitoes.
  • Withdraw water from the system at the rate of 5 litres/head/day. This will ensure availability
    of water throughout the water scarcity period.
  • Leakage of cracks in the ferrocement storage tank shall be immediately attended to by cement
    plastering. This will avoid major repairs due to the propagation of cracks.
  • Heavy loads should not be applied on the lid, particularly many people should not stand on t
    he lid.
  • Water should not be allowed to stagnate in the collection pit.
  • The tap should have lock system so that pilferage or waste of water is avoided.
  • The filter materials shall be washed thoroughly before replacing in the filter bucket
  • The coconut coir in the filter unit definitely needs regular replacement in rainy season,
    because, in wet conditions it rots and spoils water quality
  • In coastal areas, the tank may be painted outside by corrosion resistant paint once in 3 years
    and in other areas lime (Calcium Carbonate) based white wash may be applied not only for
    beauty but also for cleanliness

People may be educated by providing the above tips for maintenance of the system through pictures, handouts and wall posters. The implementing agency should visit the structures as a follow-up to monitor and motivate the users in the proper maintenance of the systems. there could be informal group discussions among the users on the maintenance aspects of the Roof top Rainwater Harvesting Systems.As a precautionary and preventive measure, the water from the storage tank may also be tested for the presence of disease causing micro-organism.But it is not practicable for a rural household to collect water samples and get them tested in nearby district centre on a regular basis. Therefore, this task may be taken up by the implementing agency as an immediate follow up of the construction of the systems. This helps the agency to find out the users' attention to the maintenance of the system as well as necessary awareness to be given on various maintenance aspects. Following section gives an idea of collection of water samples for testing and disinfection.

Back