Rainwater harvesting and recharging

In Kerala generally every household has an open well, which provides adequate water security at household level. Water security at household level will be ensured by strengthening with recharge facilities of the household sources, which will be used when the piped water supply scheme fails. A recharge pit allows the rainwater to replenish groundwater by recharging the underground aquifers. It can be built to recharge a bore well or just to help the water infiltration in an area. A recharge pit can be totally invisible when finished. As it is filled of stones, it doesn’t present any danger (contrary to an open well for example). The percolation rate of a recharge pit is much less than of an open well. The water percolates slowly because there is no hydrostatic pressure in the pit.

Preparation:

Materials required

Site specification

Site selection for infiltration

Many factors affect the suitability of a site as an infiltration facility for the disposal of recharge pit. Among these, the following are most important:

In coastal areas of Paravur Taluk where there is an important layer of sand under the first layer of clay – are fit to the making a recharge pit (sand has a high level of percolation). The simplest way to recharge is to dig a pit in the ground and make a filtering system so that clean rain water can reach underground and can be reused. Location of the pit should be on a clean ground surface so that polluted water doesn’t go underground through the pit. The pit should be deep enough so that rain water would reach the porous layer of soil as it allows the water to pass though it and get added to the underground water. But water flowing through the street will still be polluted so we need a filter layer in the pit. First we need a clean big stone or boulders layer of specific thickness. Then above that layer we put a layer of clean gravel which is almost as thick as the first layer of boulder. Then finally on the top we put the clean sand to make the sand layer almost as thick as other layers. This completes the filter system and the pit is called a recharge pit. A recharge pit is usually 10 to 15 feet deep.

Recycling and reuse of water

Water reuse (also commonly known as water recycling or water reclamation) reclaims water from a variety of sources then treats and reuses it for beneficial purposes such as agriculture and irrigation, potable water supplies, groundwater replenishment, industrial processes, and environmental restoration. Water reuse can provide alternatives to existing water supplies and be used to enhance water security, sustainability, and resilience. Sources of water for potential reuse can include municipal wastewater, industry process and cooling water, storm water, agriculture runoff and return flows, and produced water from natural resource extraction activities. These sources of water are adequately treated to meet “fit-for-purpose specifications” for a particular next use. “Fit-for-purpose specifications” are the treatment requirements to bring water from a particular source to the quality needed, to ensure public health, environmental protection, or specific user needs.

Water recycling is an effective approach to conserve water and minimize on water expenses. There are various applicable home water recycling methods which can be implemented.