Sustainable solution to Guwahati's waterlogging woes

Cleaning and desilting the rivers/streams and drains in Guwahati city is a routine pre-monsoon drive carried out by Guwahati Municipal Corporation (GMC) as part of its strategy to mitigate flash floods and prevent waterlogging in different localities. Preventing soil erosion in the hills in the city and neighbouring Meghalaya is the key to preventing crores of taxpayers' money from going down the drain in desilting operations every year. The drive carried out by the GMC this time marks a departure with the corporation doing it on its own and dispensing with contractors' service for the work. The GMC authorities have claimed that against the annual contractors' bill of whopping Rs 120 crore for the work, expenditures will be restricted to Rs 40-50 crore due to the corporation carrying out the drive on its own. The GMC has hired heavy machinery to undertake three-phase water-logging prevention work. Cleaning of five rivers and streams- Bharalu, Basistha, Mora Bharalu, Bahini, and Lakhimijan have been taken up in the first phase while the second and third phases involve cleaning of the city drains. The drive is aimed at increasing the water-holding capacity of the drains apart from improving the flow to reduce the time of waterlogging on city streets, but the actual outcome of the drive will be known only during the rainy season. Changing pattern of rains due to climate change impact and increasing events of excessive rains over a short duration instead of the total volume of rainfall spread out for multiple days will have to be considered for judging the effectiveness of discharge capacity of the rivers/streams and drains after desilting drive. Strategies adopted by the Soil Conservation Department to curb soil erosion in city hills include preventing splash and rill erosion due to rainwater falling on bare soil, reducing the speed of water cascading down a hill by channelling into drains, construction of water harvesting points with silt traps to prevent silts being carried into the rivers/streams and large drains. Illegal earth cutting on the hills for unauthorised construction of dwelling houses have resulted in cutting of hill slopes and leaving large tracts of the hill surface bare. The rapid expansion of the city and increasing commercial activities have triggered migration of people to the city and due to lack of affordable housing solutions, encroachment on the hills for construction of dwelling houses is on the rise. The problem of city hills going bare due to the clearing of trees and forest cover for the construction of houses will only be aggravated if the authorities continue to look the other way. As a result, the siltation problem in the city drains, Bharalu rivers, streams and wetland will only worsen in the days to come and render the desilting drive ineffective. Building awareness on the plantation of trees to have at least two layers of canopy cover, covering the open space by people living on the city hills and not cutting hill slopes are among strategies identified for preventing soil erosion. However, Guwahati hills having over 350 spots vulnerable to landslides and recurrence of incidents of landslides speak volumes about such awareness drive not achieving desired goals. Affordable and low-cost housing solutions by way of construction of multi-storeyed apartments with government support can be a sustainable solution as it will reduce illegal encroachment of hills for shelter. It will also reduce the recurring expenditure of desilting drive as the capacity of the drains for carrying stormwater will significantly increase. Ecological restoration of the hills after shifting the settlers to low-cost affordable housing blocks will also have to be undertaken in a mission mode to find permanent solutions to waterlogging in the capital city. Regular maintenance of silt traps at the foothills and timely removal of silt deposited in these traps is critical to checking siltation in the drains that outfall in main drains in the city. Building awareness among the residents near the silt traps to inform the authorities whenever they notice these structures becoming dysfunctional can ensure timely action. People dumping garbage, solid waste on open drains, Bharalu and Bahini rivers add to the menace of clogging of drains. When awareness campaigns fail to achieve the result, the imposition of heavy penalty remains the alternative to enforce it. The GMC can take a cue from successful enforcement of wearing helmets by drivers and pillion riders of two-wheelers and seat belts by car drivers by the State Government and embark on a sustained drive to prevent people from dumping garbage on drains, on streets, water bodies. Conscious citizens of each locality lending active support to GMC in such enforcement drives will help produce quicker results. On their part, the city authorities need to look beyond desilting drive and focus simultaneously on preventing soil erosion in the hills towards finding a sustainable solution to the waterlogging problem.