Goa: Landfilling, fragmentation of ancient system pushing khazans under water

PANAJI: Even as many parts of Goa went underwater during this week’s torrential rain, experts have warned that in a few years, vast stretches of low-lying khazan lands in Carambolim, Merces, Divar and Siridao are likely to go under water during extreme weather events. A combination of sea level rise, tidal influx and other factors could trigger unprecedented flooding, they said.
A geo-spatial study combined with spectral satellite image evaluation of Tiswadi taluka carried out by environmental architect Elsa Fernandes has indicated the areas at the most vulnerable level — an altitude of less than 2m.
Further, the vulnerable zones within a 5m-elevation in Tiswari, Bardez, and Salcete can be identified through satellite data provided by agencies like the Indian Space Research Organisation (ISRO). For the moment, the researcher, using maps from ISRO’s Bhuvan website, prepared a digital elevation model — perhaps the first such study for Tiswadi — to pinpoint areas within the most vulnerable 2m altitude.
“All these areas are khazan lands, now mostly barren, but once very productive granaries of food. However, some patches of these are already submerged, and the water level keeps rising,” Fernandes said.
The state action plan for climate change (SAPCC), a report by Nabard consultancy services (Nabcons) for the state, has listed Tiswadi, Bardez and Salcete as having the lowest altitude of within five metres, which face the highest danger of flooding due to sea level rise.
The architect’s study has helped zero in on the lowest level zones in the vulnerability-indexed areas.
“In reality, 70% of 98 sqkm of Tiswadi’s khazans are extensively in the range of a critical 2-3m elevation,” said Fernandes, who has a masters degree in environmental architecture and is researching khazans.
Massive landfilling in the name of development and fragmentation of the ancient khazan system carefully maintained by local comunidades is cited as a major factor for the surge. “It is easy to see how the old drainage system in the Merces-Santa Cruz area has been destroyed for highway expansion. The area and neighbouring low-lying Taleigao also identically reclaimed, will be submerged in the near future,” said environmentalist Nandkumar Kamat.
Some areas of khazans lie below sea level, but ancient streams, creeks and backwaters emptying from higher ground to the sea have been choked.
“The old box-type culverts and cross drains below roads have been neglected, while natural, porous drainage systems have been blocked with breakable, sinking RCC pipes,” Kamat said.
According to Fernandes, the danger lies in coincidental occurrence of certain events triggered by climate change dynamics that could raise the water level drastically. “If flood water level after heavy rain for a few hours is swelled by sea level rise, along with tidal inflow, normal drainage flow and altered run-offs from surrounding areas and hills at the same time, one can imagine the kind of inundation in khazans that will follow,” she said.
The taluka, insulated by nearly 2,500 sqkm of vast basin areas of Goa’s largest rivers, Mandovi and Zuari — and already impacted by worrisome flooding — is itself the most vulnerable zone in North Goa. Both rivers empty into the sea on Tiswadi’s north-western and southwestern tips, adding to the massive water flow.
To create awareness about the impending danger, Fernandes has been engaging Tiswadi’s village communities through a series of presentations of her research on the vulnerability of Goa’s khazans. Stakeholders formed a khazan society to campaign for protection of the unique age-old agricultural system in Goa.
The sea level rise is expected to progressively rise by half a metre every 50 years. But heat waves likely to hit India in 2025 are already happening. An event like the flood in Germany was unprecedented. Recent floods in Kerala (and earlier in Chennai) have heightened concern over expedient action for climate resilience.
Panaji has been listed as one of the most vulnerable cities in India. A slight increase in rain inundates large areas of its land and fields.
The Goa government has allocated Rs 100 crore for flooding in the 2022-23 budget. “But the khazan issues need immediate attention as most villages are already facing partial but dangerous submergence,” she said.
Carambolim, one of the worst-affected villages, has more agricultural than settlement area. Some patches of it are not far from the danger mark. Breaches and weakening of the outer bundh on Cumbharjua canal bundh has permanently submerged vast land for around two decades. “Nearly 70% of the khazan field area has been ravaged by flooding for years,” said a villager.
The crumbling of the frontline bundhs of Ofla, Cauzem and Domzo has in turn battered internal bundhs. “Our internal bundhs in Azossim-Mandur are collapsing, and money spent on repairs will continue to be a waste till the main bundhs are repaired,” said Zeferino Fernandes, chairman of a local tenants’ association said.