Hydraulic model study underway for new Saraighat Bridge

STAFF REPORTER

GUWAHATI: Although the Union Cabinet accorded official approval to the third double-deck rail-cum-road bridge across the Brahmaputra at Saraighat in Guwahati on Wednesday, spadework for the bridge had started in May this year when the Northeast Frontier (NF) Railway and the North Eastern Hydraulic & Allied Research Institute (NEHARI) of the Brahmaputra Board signed a Memorandum of Understanding (MoU) for a hydraulic model study for the project.

According to NF Railway sources, the MoU was signed on May 19 last and the hydraulic model study is supposed to be completed by September, 2023. An amount of Rs 149.54 lakh was earmarked for the study.

The sources informed that the study will evaluate data for facilitating the design of the bridge, including finding out the best alignment along with other allied parameters. The hydraulic model study will review supplied data/information about the existing and new bridge structures provided by NF Railway in or near the reach to be reproduced in the proposed model, which may affect the river regime such as embankments, spur, channel closing dyke, pilot channel, etc.

The study will also entail bathymetric survey of the Brahmaputra from 15 km upstream to 10 km downstream of the Saraighat Bridge, the sources said. The study will collect and analyze soil samples for bed and bank characteristics for determining particle size distribution and collect hydro-meteorological data - historical discharge, stage data, highest flood level (HFL) etc., - from the Central Water Commission and other organizations concerned.

According to the sources, a mathematical modelling alongside IIT-Guwahati, using HEC-RAS (Hydrological Engineering Centre – River Analysis System) or other similar application, will also be done. Further, a river morphological study using satellite imageries of the last 10 years will also be undertaken to know the river behaviour.

The study will include study of bank flood and erosion and suggest a feasible and lasting solution for preventive flood and erosion damage, along with safety measures in upstream and downstream areas of the proposed bridge site, the sources added.

Meanwhile, according to the 'Brief of All Projects' (as on August 31, 2022) prepared NF Railway's construction wing, this 7-km-long bridge was included in the Budget in 2017-2018 with an anticipated cost of Rs 1,126.67 crore. Subsequently, an amount of Rs 15.50 crore was allotted in the 2022-2023 Budget. In the meantime, the NF Railway sent a detailed estimate to the tune of Rs 1,473.77 crore to the Railway Board March 23 this year. It may be mentioned that National Highway Authority of India (NHAI) and the Ministry of Railways will share the cost of the bridge, of which NHAI will bear the Rs 322-crore cost for approaches/viaducts to the bridge.

Also Read:  Assam's Old Saraighat Bridge to Close Partially for Three Months

Also Watch: