R Dutta Choudhury
GUWAHATI, July 16 - Proper management of water bodies, total ban on hill cutting, improvement of the drainage system are some of the basic needs to deal with flash floods in Guwahati city. A report of the Assam State Disaster Management Authority (ASDMA) on the problem of water logging and flash floods in the city reveals several underlying factors.
Flash floods are triggered by factors like inadequate infrastructure, population increase, degradation of natural wetlands and forest zones, encroachment on hillocks, clogging of natural drains which used to carry off excess rainwater, and many more.
Sustainable long-term solutions may include wetland management system, prohibition of construction related activity around ecologically sensitive zones like wetlands and forests, and to strengthen and upgrade physical infrastructure that can meet demands of increasing population.
Wetland degeneration is a big problem in Guwahati as there is shrinking of wetlands due to encroachment, natural siltation, earth filing and garbage dumping. All such activities result in less water retention capacity. Ultimately, the degeneration of wetlands is leading to siltation in wetlands and drains; flash floods; water logging and depletion of flora and fauna.
The most prominent wetlands, known as beel, in the city include Deepor Beel, Hahsora Beel, Narangi Beel, Silasako Beel, Borsola Beel and Sarusola Beel.
Among these beels, Hahsora, Narengi and Silasaku are located in the eastern part of the city while Sarusola and Borsola in the middle part and Deepor Beel in the western part. Because of increasing pressure on these wetlands, the drainage capacity of these natural water bodies has decreased alarmingly.
The wetland management system can include steps like identification and demarcation of natural water bodies, creating legislative framework to preserve the integrity of these wetlands, etc. The report said the construction on the hills in Guwahati has resulted in the removal of vegetation cover in the forest area and exposed surface. The soil loss is 60 times more on the exposed slopes than on the vegetable-covered slopes. The problem of soil erosion is significant not only from the view point of loss of soil fertility, but also from many environmental issues like water logging, flash flood, decrease in ground water table and dusty environment on sunny days.
To deal with these conditions, forest areas need to be conserved with no further development whatsoever. Similarly, massive afforestation programmes are needed in these areas. The overall situation of hills around the city needs to be improved in terms of removing encroachment, prohibiting new construction and enforcing laws to protect further degradation.
The report pointed out that increasing population in Guwahati needs safe shelter that can be done with the help of effective planning mechanism. Encroachment on hill slopes result in landslides and loss of valuable assets. The study reveals that there is a need of strict guidelines on land use planning, structural stability of buildings in hilly areas and for the overall city.
Providing low cost accommodation to the people who are living in the slums and hazard prone zones of the city is a must and should be done on priority basis. As the Guwahati city had grown haphazardly, the ecologically sensitive zones have been an easy target for encroachers and these zones also have become sites for waste disposal. There is an urgent need to identify these zones and demarcate them as no activity areas. This target can be achieved through revised land use zoning in the upcoming master plan.
Development of satellite townships to ease the pressure of increasing population on the core areas of the city is the need of the hour.