Rehabilitation of the SonaGazi Regulator Wing Dyke

Location

Feni District

Type of Project

Hydraulic Study

Period of Study

February, 1997 - October, 1997

Client

Bangladesh Water Development Board

Description

With a view to retaining the runoff of the Muhuri, Feni and Kalidas River catchment in the dry period for irrigation and to protect the surrounding area from intrusion of saline water, a closure dam along with a regulator of 40 gates were constructed. Supplementing this Feni regulator, another regulator, known as Sonagazi regulator was also constructed at the 1.5 km downstream of Feni regulator. But it was reported that the retired wing dyke of this regulator has been severely attacked either by the incoming tide or by fresh water discharge through the Feni regulator or both and was getting continuously eroded. To protect Sonagazi regulator, two groynes (T-type) were constructed in 1995, one in upstream and the other at the downstream of the regulator. So, for maintenance purpose, rehabilitation of Sonagazi regulator was necessary. With this objective, mathematical modelling of Feni river was carried out to investigate the hydraulic condition near the regulator before execution of rehabilitation work. Applying MIKE21C modelling tool, critical areas of erosion and velocity distribution around the structure were highlighted.