All about HMWSSB Rainwater Harvesting program.

Hyderabad Metro Water Supply and Sewerage Board (HMWSSB) started the common cause of implementation of a massive programme on Rainwater Harvesting/Conservation. The Board is offering applications from the interested Residential Welfare Associations for conducting Awareness Programmes in the colonies for technical guidance to construct Rainwater Harvesting / Conservation Structures themselves in their own premises at their own cost. In this Digital world, Students Focus plays an important role.

The initiative is helpful in not only bringing awareness on Importance of groundwater but also acts as a barrier in making groundwater an asset for future generations. The program tries to build a system where the precious groundwater is gathered to the maximum.

The government had already made mandatory for construction of Rain Water Harvesting / Conservation Structures in all premises where the plot area is more than 200 sq. mts vide APWALTA 2002 to promote water conservation and to protect and to improve the groundwater for sustainable yields in the bore wells.

This program since it started had a major impact on society and brought a drastic change in owning groundwater resources of Telangana. Follow us on Facebook.

Artificial Recharge in Urban Areas

Artificial Recharge is to augment the natural infiltration of rainwater into the ground by artificial methods. The methods suggested recharging the groundwater are pits, trenches, wells, shafts and directly diverting runoff water into the existing wells. The choice of any particular method is governed by local hydrogeology and soil conditions and ultimate use.

Reasons for groundwater depletion

  • Increasing demand for groundwater
  • Withdrawing more than recharge
  • Reduction of recharge area due to buildings, paved paths and roads
  • Diminishing surface water bodies
  • Uncertain rainfall

Techniques to improve groundwater through Rainwater Harvesting

  • Creation of recharge pits, trenches and shafts in building premises, open space, parks and along roads.
  • Use of existing dry wells as recharge structures.
  • Rooftop and road top rainwater should be channeled into recharge structures.
  • Protection and conservation of open areas, parks and surface water bodies.

In independent houses and apartments, where there is sufficient open place, we can have recharge pit/ trench with storage sump for rainwater harvesting and storage. Excess rainwater filling the sump shall be conveyed to the recharge pit for groundwater recharge.

Like this, the rainwater collected in a 2 cubic mts sump could be sufficient for 5 members of a family for direct use for a period of 4 to 5 days.

In places where there is hard rock or clayey soil within 2 mts depth from the ground level, we can have only storage sump of 4 cubic mts. capacity in 100 sq. mts. roof top area and divert rainwater through pipes, which could be directly used.

Methods of Rainwater Harvesting

Rooftop water collection and recharge:

Commonly runoff water from roof tops are let off into the drains. Instead of this the outlets can be connected through a pipe to storage tank and let into filter media filled trenches, pits or existing open wells, borewells etc.

 

Design of Pit

The trench/ Pit is to be partially filled with permeable material like well rounded pebbles, gravel and topped with river sand for better percolation.

Design aspects

  • Trenches of 0.5 mts. width along the compound wall, to a depth of 2 to 3mts pits of 1 metre dia to a depth of 2 to 3mts.
  • Suggested volume of trench/ pit is – 6 cubic mts.- for 100 sq. mts.
  • Rooftop area and the estimated cost Rs. 3010/- per cubic metre.

Cost: According to the experts the approximate cost of constructing percolation pits in a house would not be more than 0.5 percent of the total cost of the house.

Maintenance Tips:

  1. Rainwater Harvesting Structures
  • Structures should be identifiable by display boards and they should be maintained properly by fencing to avoid urination, littering with garbage dumps.
  • Periodical removal of top layer, cleaning and replacement.
  • Suggested to establish observation wells for monitoring of water levels and quality in influence zone.
  • The builders, NGO’s and academic institutions should be involved at all stages of programme i.e. to propagate importance of maintenance.
  1. Rain Water Storage Tanks
  • Drain the tank completely and clean the tank from inside thoroughly before the monsoon.
  • Clean the work channels (Gutters) often during rainy season and definitely before the first monsoon rain.
  • Avoid 15-20 min. of rainfall depending on the intensity o the rain. Use the first flush arrangement to drain the first rain water.
  • Change the filter media sand every rainy season.
  • Cover all inlet and outlet pipes with closely knot nylon net or fine cloth or cap during non-rainy season to avoid entry of insects, worms, and mosquitoes

Author: Elyuxen

Elyuxen, a student newspaper where students get to work as well as publish all the news related to colleges in and around Hyderabad. It is the first ever student newspaper in South India which is successfully running. The beauty and the tagline of this newspaper is it is *For the student, by the student, of the student

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