Rain Water Harvesting

[vc_row][vc_column width=”1/3″][vc_single_image image=”4480″ img_size=”full” style=”vc_box_border”][/vc_column][vc_column width=”2/3″][vc_column_text]Hyderabad Metro Water Supply and Sewerage Board (HMWSSB) solicits the cooperation and participation of all citizens and started the common cause of implementation of a massive programme on Rainwater Harvesting/Conservation this year. The Board is offering applications from the interested Residential Welfare Associations for conducting Awareness Programmes in the colonies for technical guidance to construct Rain water Harvesting / Conservation Structures themselves in their own premises at their own cost.
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.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_text_separator title=”Artificial Recharge in Urban Areas” title_align=”separator_align_left” align=”align_left”][vc_column_text]Artificial Recharge is to augment the natural infiltration of rainwater into the ground by artificial methods. The methods suggested to recharge the ground water 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.[/vc_column_text][vc_text_separator title=”Do You Know?” title_align=”separator_align_left” align=”align_left”][vc_row_inner][vc_column_inner width=”1/2″][vc_column_text]Reasons for ground water depletion

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

[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/2″][vc_column_text]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 rain water should be channeled into recharge structures.
  • Protection and conservation of open areas, parks and surface water bodies.

[/vc_column_text][/vc_column_inner][/vc_row_inner][vc_column_text]Figure showing storage sump and recharge pit[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column width=”1/3″][vc_single_image image=”4487″ img_size=”full” style=”vc_box_border” onclick=”link_image”][/vc_column][vc_column width=”2/3″][vc_column_text]In independent houses and apartments, where there is sufficient open place, we can have recharge pit/ trench with storage sump for rain water harvesting and storage. Excess rain water filling the sump shall be conveyed to the recharge pit for ground water recharge.
Like this, the rain water 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 rain water through pipes, which could be directly used.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_text_separator title=”Methods of Rainwater Harvesting” title_align=”separator_align_left” align=”align_left”][vc_column_text]

Roof top water collection and recharge

[/vc_column_text][vc_row_inner][vc_column_inner width=”1/3″][vc_single_image image=”4493″ img_size=”full” style=”vc_box_border” onclick=”link_image”][/vc_column_inner][vc_column_inner width=”2/3″][vc_column_text]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.[/vc_column_text][/vc_column_inner][/vc_row_inner][vc_column_text]

Design of Pit

[/vc_column_text][vc_row_inner][vc_column_inner width=”1/3″][vc_single_image image=”4497″ img_size=”full” style=”vc_box_border” onclick=”link_image”][/vc_column_inner][vc_column_inner width=”2/3″][vc_column_text]The trench/ Pit is to be partially filled with permeable material like well rounded pebbles, gravel and topped with river sand for better percolation[/vc_column_text][/vc_column_inner][/vc_row_inner][vc_column_text]

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.
  • Roof top area and the estimated cost Rs. 3010/- per cubic metre

[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_text_separator title=”Do you know the potential of rooftop water harvesting in Hyderabad?” title_align=”separator_align_left” align=”align_left”][vc_column_text]

Considering annual rainfall is 800 mm

[/vc_column_text][vc_single_image image=”4498″ img_size=”full” style=”vc_box_border”][vc_column_text]Approximate rainfall yields in liters, for various roof top areas in sq.mts.
(Note: Rainfall yield (in litres)= Roof area (in sq.m) x Rainfall (in mm))[/vc_column_text][vc_column_text]

Meter Tables

[/vc_column_text][vc_single_image image=”4501″ img_size=”full” style=”vc_box_border”][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

Filter Unit Details

[/vc_column_text][vc_row_inner][vc_column_inner width=”1/3″][vc_single_image image=”4504″ img_size=”full” style=”vc_box_border” onclick=”link_image”][/vc_column_inner][vc_column_inner width=”2/3″][vc_column_text]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.[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_text_separator title=”Maintenance Tips” title_align=”separator_align_left” align=”align_left”][vc_column_text]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.

2. 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 rain fall depending on the intensity of 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

[/vc_column_text][vc_column_text]To know further about the programme you can contact
Assistant Director (Ground Water) Rain Water Harvesting
Cell: 99899 85102
Public Relations Officer: 99899 94501
HMWSSB Customer Care: 155313[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column width=”1/3″][vc_single_image image=”4506″ img_size=”full” style=”vc_box_border” onclick=”link_image”][/vc_column][vc_column width=”2/3″][/vc_column][/vc_row]