EVERY DROP MATTERS

Synoptic view of the RWH Lake at the Goa University.

Read on to find out more about rainwater harvesting attempts being made across Goa.

Annually, most of Goa receives around 250 cm to 400 cm of rainfall with the average being 320 cm per annum. Harvesting rainwater is an attempt at sustainable water management which is the ‘need of the hour’, given the rampant usage and consequent decline of the natural water resources.

Rainwater Harvesting (RWH), is an attempt to store and save rainwater for a later use. This water can be used for all purposes, except cooking and drinking in its unfiltered form. Goa is not only a tourist hub, but also has strong industrial & institutional presence along with the high density of population.

The two most common ways to harvest rainwater for long term storage and use are: surface water & rooftop rain harvesting and recharging. In Goa, we have both these mechanisms at work at several locations. The writer spoke to a few people associated with several RWH projects in the state. One of the pioneers behind the rainwater harvesting project in Goa is Professor Chachadi from Goa University. The Goa university campus has implemented both the previously stated methods of harvesting rainwater. The Goa University RWH plant was also one of the first across the entire western coastal region.

In a typical surface water harvesting project, you need a catchment area (a pond in the instance of the university), a deep trench at the centre of the catchment area, a sand filter and a recharge well trench. Such a system is more apt for institutional and industrial purposes. Large housing societies can also effectively use this method.

In a rooftop RWH project, the catchment area is the roof, from where water is diverted to the storage tanks (surface or sub surface) through pipes. Such a system is highly useful for housing societies and individual houses. It can also be used for industrial and institutional purposes. At MES College in Goa, this mechanism is at work since 2012. The rooftops of the buildings have been joined with the pipes through which the rainwater reaches the storage tank.

In Goa, the threat to groundwater quality arises from, industrial effluent disposal, urban sewage and solid waste disposal, mining and related activities, sea water intrusion into fresh water aquifers, and agricultural activities which involve the use of pesticides, fertilisers and agricultural waste disposal. Given this scenario, RWH is very important for Goa.

At present, the Goa government is also offering subsidies to individual households, residential and commercial complexes, and several other establishments, a subsidy if they were to adopt the practice of RWH. At the State level, RWH has been undertaken at several prominent water projects, like the Anjunem Dam, Salaulim Dam, Rivona village and more.

We all feel that, considering it rains heavily in Goa, the government should have no problem in supplying water throughout the year. This attitude is very wrong, as during the monsoons, water filtering at municipal water supply plants is more time taking and difficult because of increase in contaminants & unwanted constituents. Thus, it is all the more important that as individuals, we make an effort. As is rightly said, ‘Start Acting & Stop Complaining’.