‘Water Harvesters’ was established in the year 2000 in the capital city of India, New Delhi, with a sole objective of making people aware of the far reaching effects of ground water abuse and the consequential hazards related to ground water depletion and to demonstrate technological interventions to restore the traditional wisdom.

As a one-stop shop, Water Harvesters has become one of the largest integrated water management company offering products, services and complete outsourced water management programs in all major industries and communities using water.

Rainwater harvesting is a process involving collection and storage of rain water (with the help of artificially designed system) that runs off natural or man-made catchment areas e.g. roof top, compounds, rock surface or hill slopes or artificially repaired impervious/semi-pervious land surface. Undoubtedly a number of factors contribute to the amount of water harvested e.g. the frequency and the quantity of rainfall, catchments characteristics, water demands and the quantum of runoff, and above all speed and ease with which the rainwater percolates through the subsoil to recharge the ground water.

Due to deforestation and the consequent ecological imbalance coupled with urbanization and rainfall extremes due to climate change, the water level beneath the ground is getting depleted day by day. The constant rising demand of water supply does not match with the surface water sources, as a result of which the water reserves beneath the ground level are overexploited. This has consequently resulted in the water level depletion which has far-reaching influence on the overall quality of ground water threatening the health of millions of people of India.

Ground water exploitation coupled with reducing natural recharge to ground water due to increasing paved areas is inevitable is Urban areas which often resulting in over exploitation. India is the largest ground water user in the world; ground water contributes to more than 80% of the rural water supply and about 50% of total water used for irrigation.

The rainfall in the Indian subcontinent is limited to 30-45 days, the water conservation and recharge to ground water is the key to water and food security. The initiatives of “Water Harvester” as voluntary organization in promoting rainwater harvesting and recharge to ground water is commendable to meet the upcoming challenges of climate change and water security.

Hence, a strategy to implement the groundwater recharge, in a major way need to be launched with concerted efforts by various Governmental and Non-Governmental Agencies and Public at large to build up the water table and make the groundwater resource, a reliable and sustainable source for supplementing water supply needs of the urban and rural users.

Objectives and beneficiaries

Water harvesting, apart from recharging the ground water level, increases the availability of water at a given place at a given point of time. According to Water Harvesters, the recharging of ground water has several non-tangible environmental benefits and also reduces the power consumption as 1 m rise in water level results in saving of 0.4 KWH of electricity (as per recent finding). It further reduces the soil water erosion and run off which chokes the storm water drains, reduces flooding of water on the roads, improves the quality of water and reduces the chances of soil erosion.

Strong points of the practice

Rainwater harvesting is inevitable because: Surface water is inadequate to meet our demand and dependency on ground water has been increasing harmonically. Due to rapid urbanization, infiltration of rainwater into the sub-soil has decreased drastically and recharging of ground water has diminished. Our objective is to conserve water by harvesting plus managing this natural resource through technological interventions to enhance ground water storage so as to meet ever increasing demand for agricultural and drinking purposes.

Expected results and benefits for climate change adaptation and mitigation

- Improvement in infiltration and reduction in run-off.
- Improvement in groundwater levels and yields.
- Improvement in groundwater quality.
- Estimated quantity of additional recharge from 100 sq. m. roof top area is 55.000 liters.
- Savings on account of electricity consumption for lifting the water.
- Ensuring Water and food security keeping in view the climate variability.

Replicability potential of the practice

The storage of rainwater on surface is a traditional technique. The interventions used are underground tanks, ponds, check dams, weirs etc. The technique can be replicated anywhere considering the amount of rainfall and other site-specific conditions.

[Editor's Note: Information selected by ICCG and integrated with materials provided by the authors of the practices]