Teesta Barrage Project: Operation Manual

Location

Lalmonirhat District

Type of Project

Software for Barrage Operation

Period of Study

October, 1998 - June, 2000

Client

Bangladesh Water Development Board

Description

The Teesta Barrage, largest in Bangladesh having 44 vent radial gates of each 40 feet width was constructed across the Teesta River at Doani in Lalmonirhat District (northern part of Bangladesh). The main purpose of the Barrage is to divert water from the Teesta River to the project command area through a Canal Head Regulator (CHR) and associated canal system for irrigation by gravity. The CHR has started functioning from 1993. Till the year 1999 no concrete guideline was fixed for the operation of both the Barrage and the CHR. Operation of the gates of the barrage without a proper regulation schedule entails a considerable risk as the objective of the project may not be fully realized, apart form the danger to the structure itself. So it was thought necessary to have a set of guiding rules in the form of a Manual for the operation of the gates of the Barrage and CHR for a safe and efficient operation and maintenance of the structures. The present study undertook the development of an operation manual using a one dimensional river model, MIKE 11 for Teesta river including the barrage. The model was developed for Teesta river and it’s associated branches incorporating the barrage operation. Rigorous topographic, cross-sectional and meteorological data were collected for the development of the model. The model was calibrated for the period of September to November in the year 1997 and validated for the period of June to October in the 1998. Later this model was used to develop rule curves for the Barrage and CHE. The development of the rule curves for operation of the Barrage and CHR requires the establishment of outflow rating curve s from these structures depending on different downstream water levels. The rating curves so established are able to relate the downstream water requirements with the water level immediately downstream of the respective structures. Finally a Decision Support System was developed incorporating these rule curves to make the operation of the structures move efficient and user friendly.