St. Inez Creek and Urban Flooding
St Inez creek can play a dual role: beneficial and/or detrimental writes DR. ANTONIO MASCARENHAS
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“A city located on the banks of a river fails to discharge flood waters”. This would be a likely headline within a month. It is a paradox that, despite all scientific advances and lessons learnt from natural hazards, urban flooding still persists. It is indeed a humiliation for a modern society that monsoon inundations constitute one of the foremost natural hazards of our times.
Through this article, the author addresses two topics, with particular reference to the ancient St Inez creek: the use and significance of gradients in the form of antecedent drainage, and the beneficial role of coastal wetlands in the alleviation of inundations. It also states that natural hazards culminate as disasters, only when human development interferes with the functions of natural systems.
Do we have methods to avoid urban flooding? If these inundations cannot be neutralized, such phenomena can be curtailed. The distinctiveness of coastal landforms governs the impacts of flooding and the antecedent drainage patterns play a critical role. The major factors that control the damage potential of storm waters are geomorphology, elevation, drainage, and the role of natural ecosystems, the wetlands in particular.
The Survey of India (SoI) toposheet of 1964 reveals interesting facts: (1) The environment of Panjim constituted a natural coastal wetland. The Campal -Miramar sector was a marshy lowland with sparse swellings. Similarly, the Mala Lake was a permanent wetland where rain water used to accumulate. The overflow emptied itself into the adjacent creek that connected itself, under the road, to the main Ourem creek. Mala lake therefore functioned as a flood bay, probably over the centuries. (2) The other ancient asset was the St. Inez creek. Fully operational till about two decades ago, this water body originated from the foothills of Dona Paula plateau, and wound its way through Tonca and St. Inez, before debouching into the Mandovi. Interestingly, the tidal effect could be felt as far as Tonca. (3) On the eastern side, the Patto – Ribandar stretch comprised a network of backwaters, supported by an intricate system of creeks and canals, all linked to the Mandovi. That was the scenery of yesteryears.
The geological significance and the ecological importance of wetlands are documented globally. Wetlands comprise features such as mudflats, marshes, with water bodies as lagoons, creeks, lakes and backwaters. Each of these units has a definite role to play and specific functions to perform. These ecosystems help in the retention as well as supply of water and hence alleviate flooding problems. Swampy ecosystems are highly productive, support a diverse heterotrophic food chain, act as spawning and breeding grounds and hence nurseries for marine biota. Wetlands also serve as storehouses of nutrients. Wetlands maintain the health of a region and play a protective role. Hence, these ecosystems are of immense value to mankind.
St Inez creek can play a dual role: beneficial and/or detrimental. Being a water pathway, the creek can function as channel to empty city flood waters into the Mandovi, provided rainwater is diverted towards the creek. Conversely, the blocked creek can also enhance urban flooding if creek water overtops its banks after a torrential downpour, an episode similar to the deluge that occurred in Canacona in 2009.
Unfortunately, frenzied development in the form of insatiable greed has drastically changed the landscape around Panjim. The St Inez creek is choked beyond redemption; several parts are characterized by filth and squalor. Similarly, the Mala lake resembles a bombed site, and appears beyond all bounds of restoration. The city bus terminus comprises reclaimed lowlands, and represents the largest reclamation in the history of Goa. At all these sites, recurring flooding proves that the resilience of natural ecosystems of Panjim has collapsed.
Human interference has contributed to the environmental breakdown of wetlands and water bodies. These systems are under threat due to several reasons: Mangrove swamps are being filled rapidly; cutting of hills has resulted in siltation and sedimentation of mud in wetlands; effects on traditional farming and fishing activity are routinely reported; uncontrolled settlements and dwellings have resulted in indiscriminate reclamation of lowlands and water bodies; natural drainage systems which were in place for centuries have been altered irreversibly. Therefore, a rapid decrease of coastal wetlands is a major cause for concern.
To cap it all, the recent news that a large low-lying area at Tonca has been filled and a road laid over it, is nothing but a mockery of ecological principles. A tall building in the same area is bounded by a retaining wall that is projecting by a meter into the St Inez creek. Obviously, commercial avarice has thrown the prevailing ecological regulations to the winds.
Also, it is shocking to learn that our local authorities still doubt whether the tide gets into the St Inez creek. We have already proved that the Survey of India (SoI) Toposheet published in 1964 shows that St. Inez creek was clearly functional during the early 1960’s. The daily tidal ingress of saline waters was then routinely observed up to and even beyond Tonca; the same partly holds today. Obviously, when the creek was functional, the tidal effect was experienced twice daily. The presence of fish also proves that the creek was productive, oxygenated and nutrient-rich even in the late 1970’s. St. Inez creek was a part and still constitutes the antecedent drainage of the area.
The crisis of city flooding needs to be understood. In London, streets never get flooded; the Thames takes care of it. In Paris, whenever the Seine rises above the danger limit, the flood gates are opened, and water is diverted into flood bays. Potential hazards are thus managed. In contrast, the Worli creek of Mumbai is packed to the brim with garbage; natural outlets having disappeared, rain water routinely invades people’s homes. Similarly, the fields of Caranzalem remain submerged for weeks simply because rain water has nowhere to go.
On July 26 2005, Mumbai was paralyzed. The heavy downpour of the day flooded the metropolis. The ancient Mithi River, now an open sewer, was in spate. The waters rose so treacherously, overflowed the concrete banks, and flooded the area around the airport. The primary reason was that Mithi River course has been altered and narrowed so drastically that the flow of storm water was blocked at every bend, and as such, rain water had nowhere to go. Even the Santa Cruz airport runway was under 50 centimetres of water. That was how Mithi River struck back. By analogy, an identical situation may emerge in Panjim if St Inez creek is not restored to its past glory.
In brief, coastal wetlands are nature’s flood reservoirs as channels, lakes, ponds and wetlands can contain and distribute flood waters. Natural water bodies can also hold large amounts of rain water. Such interlinked drainage systems alleviate the impacts of heavy rainfall by receiving, accommodating and leading excess waters back into the sea. Coastal wetlands have an inherent hazard prevention value, assist in the retention (as well as supply) of water and hence alleviate flooding. For this reason, wetlands have to be designated, and their role in dispersing flood waters needs recognition as critical areas to be preserved.
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The Tamarind Tree
By Auriel Ribeiro Sa
There she stands, in the corner of my huge building complex, aged yet strong, her withered bark curled and crusty. A strong sturdy tree she once was and decades have not diminished that power. But there is a deep sorrow in her form these days as memories of years gone by creep up, causing her wrinkled brow to frown with disdain.
Once, long, long ago, there was a wild forest around her. She was one among many and her days were filled with the merry singing of birds in her hair, the gurgling of a little brook at her feet and the prancing of tiny animals up and down her trunk. As seasons changed, the world around her changed from green to yellow to red. She revelled in it and in the Artist of Life who had created her and her companions. She basked in the hot summer sun, shivered when gusty winds swept around her body and teased her hair, smiled at the rain pouring down her back and waved out with dainty hands to the clouds that brought relief to the scorched earth.
Birds would seek refuge in her, making homes for their tiny ones in the nooks and crannies of her magnificent body. She protected them with the fierce love of a mother for her child. And delighted with the mother birds when the fledglings took their maiden flight, falling clumsily to her lower branches. Often, squirrels ran up and down her trunk, calling out to each other as they played ‘Catching Cook’ and ‘Hide-n-Seek’ in gay abandon. They would nibble nuts and berries hidden in her cavities for the winter nestling contently, safe in her warmth.
Ah, those days were long gone and so were the birds and the squirrels. Her companions had been chopped down mercilessly to make way for the concrete jungle that was homes to the human race. ‘Why did you spare me’, the tamarind tree seems to cry to them. ‘I can’t bear this life’. I watch her weighed down by the abundant fruit she yields every summer and can almost feel her sadness. It bespeaks of the horror that is called progress. Development at the cost of Life.
The children of my complex run to the tamarind tree every morning and pelt her with stones. She endures their unkind ways because she knows they desire her fruit. Maybe that is why I am still alive, she muses. Because I am useful to them. My friends were not needed anymore. And not for a single moment did they consider the life of those innocent, helpless birds and squirrels.
Once in a blue moon, a band of monkeys come and assemble in her branches. They too are out for the fruit and leaves, it appears. The tamarind tree shows delight to see a shadow of her former life reappear but it is short-lived. Having used her, they leave without even a ‘Thank You’. They ravage and plunder just like their human cousins.
Still, the tamarind tree smiles her sad smile as she awaits the final stroke of doom. It almost seems as if she wants it now and I can understand why.
When you are unwelcome, you do not want to prolong your stay. You hope for a better place, a warmer welcome somewhere else. Life is like a prison for a living entity like her. Life hurts when she knows the future of human life without her and her kind is destined for extinction. They will realize their error too late, she fears. Can they survive without her? Maybe Yes. But without her kind? Certainly and absolutely not!
