The advisory of May 2019 from the IMD, that monsoon rain would be deficient this year as well, was very distressing. That is because the rain scenario since the last few years shows nothing to cheer about: In 2014 rainfall was normal (+3%), in 2015 it dropped (-20%), in 2016 we had normal rains (-1%), in 2017 rains were deficient (-14%), in 2018 scarcity rose again (-19%).
On June 15, 2019, the rain deficit in Goa was -51% in the beginning of the monsoon itself (source: IMD, Goa). It is obvious that the rains are playing truant, as rainfall patterns have altered drastically, as evidenced by scarce rains for 5 consecutive years, the alarming reasons for which were since sounded in the scientific domain.
For three consecutive days, India Today TV channel projected the grim water crisis the country is facing. It was appalling to see scores of people jamming at a single well in which there was no water! We have also noted people collecting water in which buffaloes were bathing! And other cases where water from a filthy drain was being used! It is all the more distressing to note that Bangalore is running out of water by next year, and that 11 other Indian cities will follow. Goa is not lagging behind as proved by the unusual drying of hundreds of village wells and streams.
The unscrupulous borewells and indiscriminate pumping of water is disturbing; borewell and water tanker mafias are ransacking ground water reserves, major reasons for depleting water table all over the country. Aggressive water harvesting is the only option.
Every year, irrespective of the total rainfall, 3-5 peaks of torrential downpours are observed during the monsoon every year. In 2017, there were 4 major episodes of heavy rains: June 1, 105mm; July 13, 100mm; July 20, 90mm; and September 19, 70mm. Consequently, inundations along ‘khazans’ and wetlands of Goa occur every year. Although (man-made) flooding of urban areas may be annoying, transitory submergence of fallow low-lying wetlands must be welcome. The gradual seepage of rain water through soft sediments in marshlands will contribute immensely towards the replenishment of the water table, and in turn feed the potable wells in the surrounding villages through the year.
The functions of lowlands as water reservoirs has universal acceptance. India is drying up by the minute. As such, the water retention capacity of wetlands needs to be accorded top priority, by designating them as key areas to be preserved for water harvesting.
A common complaint from the public appears to be the submergence of local houses. In 2015, some houses in Majorda and Benaulim went under water after torrential rains filled up a ‘khazan’. There was a hue and cry by people asking for compensation from the government. It was later found that all these dwellings were built without approvals, as town planning regulations do not permit constructions with the precincts of wetlands. Many of these houses were in fact located on reclaimed marsh within the wetland; laws of the land do not favour reclamation of ‘khazans’. Several examples can be cited. As such, if such houses get submerged, it is not due to flooding, but because these dwellings were built within lowlands, in dangerously vulnerable areas.
In 2005, Goa University built a water harvesting structure, the first of its kind in Goa. Adjacent to the main road, the site is located at the starting point of a natural drainage with a natural depression in which rainwater collects forming a natural pond. A protective rubble wall has been built around this natural depression which receives uncontaminated water from the surrounding land as well as rooftops. A small depression of 20m x10m and 2m deep has been made with a retaining wall of 0.5m height around this pond. After getting through the sand filter the water enters the main recharge well trench of 3m x 3m x 4m size. The deep borewell is perforated both at the surface as well as at the bottom where it is exposed to the aquifer. Water enters through these perforations and directly enters into the aquifers at deeper levels. The borewell has been drilled to a depth of 89 metres below ground in such a way that the water is fed directly to the aquifer between 65m and 89m depth (source: Chachadi, 2009).
It is obvious that the groundwater reserves in Goa have drastically declined, and crossed the tipping point. Our well in my ancestral village of Raia had dried out by May 20, 2019, for the first time in the history of that well. On Verna plateau, multiple bore wells are drilled as factories use huge quantities of potable water. These boreholes are so deep that continuous pumping has led to sucking of water and drying of private wells in Loutolim village, down the hill. Several villages in Goa went dry in April itself. It was long predicted that future wars will be fought on water. Country’s rainfall is weakening every year, and will dwindle further. Instead, the flooding of vacant lands is cursed, rather than welcoming it as a benediction. The role of wetlands is known globally.
In brief, if and when water accumulates in low lying areas, it should be confined, until it seeps into the ground; water table will profit. Our lakes need to be rejuvenated. Alternatively, excess water can be diverted into dedicated water bays, or collected in tankers and emptied into the village wells, a simple method by which ground water can be (re)charged directly. Rainfall is tax-free; rain water has to be retained within the State rather than allowing this resource to flow into the sea.
(Dr Antonio Mascarenhas is a former Scientist,NIO, Goa)
