|GMDA advised to use drain behind FCI godown to direct excess water to Bonda river|
GUWAHATI, Aug 18 - Studies have found that the storm water load from the Noonmati basin and Geetanagar area is about 35 cubic metres per second, and out of this, about 14 cubic metres per second comes from the Noonmati Refinery area, causing serious problem in Geetanagar and RG Baruah Road localities.
IIT Guwahati has advised the Guwahati Metropolitan Development Authority (GMDA) to use the open drain behind the Food Corporation of India (FCI) godown in New Guwahati area to direct the water from Jyotinagar, Bamunimaidam and Noonmati areas to the Bonda river.
It needs mention here that the Union Ministry of Urban Development (MoUD)–sponsored Centre of Excellence (CoE) with Professor Arup Kumar Sarma as the principal investigator for “Integrated land use planning and water resource management (ILPWRM)” has studied the flash flood problem of Guwahati.
A number of studies have been conducted by various reputed organisations and institutions to mitigate the flash flood in the city. In these studies, it has been observed that the flow from the Noonmati basin, especially from the Indian Oil Corporation Ltd’s (IOCL’s) refinery drain, which flows from the IOCL refinery and Sunsali Hills and drains through the Assam Small Industrial Development Corporation, and connecting with the flow from the Navagraha Hills, directly overloads the Bharalu river at the Jonali point.
On calculating, it was observed that the entire load from the Noonmati basin and Geetanagar area is about 35 cubic metres per second, out of which about 14 cubic metres per second comes from the Noonmati Refinery area. Egyptian expert group Tahal in its report stated that the storm water from the Noonmati basin should be diverted towards the Bonda river.
The Guwahati Metropolitan Development Authority (GMDA) was also planning to construct an RCC underground box drain from the Guwahati College point in Bamunimaidam area to the Guwahati Refinery, following the Tahal report.
The GMDA discussed the feasibility of this drain with Prof Arup Kumar Sarma, who advised the GMDA that it may not be a viable proposition as the storm water from the hilly areas of Guwahati carries a lot of sand and silt due to natural degradation and human abuse.
The GMDA requested Sarma to suggest alternative measures to divert the storm water from Bamunimaidam to the IOCL culvert at Noonmati. Sarma gave a proposal for a study and to provide a solution to the problems and GMDA accepted the proposal. IIT Guwahati engaged Y Not Associates, a local survey firm of Guwahati, to survey the area and advised PK Sarma, field expert under BP Chaliha Chair Professor, IITG, to guide the survey team.
The storm water from Jyotinagar watershed flowing to the main drain carries a lot of sediment and it accumulates in various stages and blocks the primary and secondary drains, resulting in flash floods in several areas of Guwahati.
Degradation of this watershed has resulted in problems of soil erosion and drainage congestion, waterlogging, landslide, water pollution and flooding of the adjacent areas, including RG Baruah Road (Zoo Road) and Mother Teresa Road (Zoo Narengi Road).
Therefore application of Ecological Management Practices (EMPs) as suggested in the conceptual DPR prepared by the MoUD-sponsored CoE, IIT, Guwahati, was advised for sustainable management of land and water.
In the survey, it was found that there is an open old drain behind the FCI godown and it was advised to use that drain to carry the water from Jyotinagar, Bamunimaidam and Noonmati areas to Bonda.
An improvised weir (inspired by the design of labyrinth weir), specially designed for regulating flow with increasing head over crest, was proposed and requirement of pumping facilities and structure of the drain was suggested. EMP application at Jyotinagar hill was also suggested as per the concept developed by the CoE of IIT-G.
The drain behind the FCI godown has been connected with the Bonda channel. But the pumping facilities near the Assam Jatiya Bidyalay are yet to be installed to full capacity. This resulted in flash flood on the RG Baruah Road and Mother Teresa Road localities on August 15.