GUWAHATI, Sept 8 - The Expert Committee on Fluvial Morphology of River Brahmaputra, Sediment Management with Possibility of Dredging by adopting Modern Technology, formed by the State Government in February last, has, in its conclusive recommendation, maintained that dredging operations in the entire length of the Brahmaputra �will not be a feasible option for mitigating the flood and erosion hazards� caused by the mighty river. According to the available information, the committee has already submitted its report to the State Government.
The committee has said in its report, among others, that it has arrived at the above conclusion by applying its wisdom basing on the existing level of knowledge and understanding on the river.
The committee was headed by former Gauhati University Professor Dulal Chandra Goswami and it had Prof Arup Sarma of IIT Guwahati, Associate Professor Bibhash Sarma of Assam Engineering College, Director of the Inland Waterways Authority of India (IWAI), Guwahati, Vice-Chairman of the Brahmaputra Board, ex-Secretary of the Water Resources Department (WRD) Haren Kakati, Chairman of the WRD Technical Advisory Committee Anup Kumar Mitra, as members and the WRD�s Additional Chief Engineer in-charge of its Assam Water Resources Management Institute as the member secretary.
The committee is learnt to have maintained that the status of the available scientific knowledge and understanding in regard to the Brahmaputra river in Assam is grossly inadequate. It maintains that scientific and technical research publications, reports, dissertations available so far in this respect are conspicuous by the absence of studies based on serious intellectual commitment.
The present understanding about the Brahmaputra channel morphology and dynamics, besides the hydrological (including silt) observations, are also plainly inadequate and marked by large discontinuities.
The committee has referred to the IWAI�s dredging experiences in the river, which show that dredging alone in the river channel for flood moderation may be a difficult proposition. For, the Brahmaputra is an alluvial river. The river carries huge quantity of silt throughout the year. The dredged channel of the river has a tendency to get filled up due to the continuous flow of silt. The IWAI carries out dredging in select reaches of the river for maintaining the navigation channel.
The committee has also referred to the WRD experiences. The WRD undertook dredging operations in 1977 and 1978 at Dharapur near Guwahati, which also showed that removal of huge quantity of silt throughout the river in the plain section was not feasible and the dredged channels were again silted up in the subsequent flood waves. This made the WRD to discontinue the dredging operations.
The committee expressed the fear that massive dredging exercises in the entire Indian reach of the Brahmaputra may change the overall water quality status of the river and this may have harmful impact on its aquatic ecology.
The committee recommends, among others, continuous monitoring of the channel behaviour through bathymetric study, in order to have near real time information about channel migration, sand bar formation, bank-line shift etc. It underlined the importance of setting up a centre equipped with state-of-the-art technology and dedicated for this purpose.
Moreover, it also called for steps to continuously monitoring the channel of the river using satellite data of high resolution and bathymetric survey using precision instruments. It also called for an integrated watershed development programme considering the inter-State and trans-boundary character of the Brahmaputra and its tributaries.
