II. FLOOD LOSS REDUCTION AND REVIEW OF PAST EXPERIENCES

[ II-A | II-B | II-C | II-D | II-E | II-F ]

B. General information on flood control projects

[ B-1 | B-2 | B-3 ]

1. Types of flood control projects

Depending on the measures adopted, flood control projects can be classified as follows:

Flood Control (FC) projects: This type of project involves the building of earthen embankments alongside rivers to prevent river flooding. There have been 29 FC projects constructed by BWDB covering a benefited area of 0.207 million ha as of 1994. The Brahmaputra Right Embankment (BRE) is an example of a large FC project employing about 220 km of embankments and covering a benefited area of around 225,900 ha. Low-height embankments in the north-east region are examples of partial flood control projects. There are 33 such projects employing about 900 km of submersible embankments and covering an area of 172,000 ha.

Flood Control and Drainage (FCD) projects: In most cases, drainage provisions are incorporated into flood control embankments in order to evacuate the unwanted rain water from behind the earthen embankment or from within the poldered area. Drainage provisions are mainly governed by gravity flow drainage through regulators and sluices. There have been 173 FCD projects constructed by BWDB covering a benefited area of 2.019 million ha as of 1994. The Coastal Embankment Project (CEP) is the biggest FCD project extending over approximately 1.3 million ha, comprising of around 115 polders in the south-west, south-central, south-east and Chittagong (CG) regions and employing about 4,000 km of embankments and 120 km of drainage channels.

Flood Control, Drainage and Irrigation (FCDI) projects: In general, FCDI schemes constitute earthen embankments around the periphery of the project areas (polders) to prevent inundation of cropland by riveraine floods and tidal floods; drainage through sluice gates in the embankments at the outfalls of the natural channels; and irrigation water made available by directing river water elevated by a barrage or lifting by pumps into a distribution canal network. Drainage is done mostly by gravity flow, particularly in smaller projects, or by pumps in bigger selected projects. There have been 42 FCDI projects constructed by BWDB covering a benefited area of 0.711 million ha as of 1994. Examples of some of the larger FCDI projects are the Pabna Irrigation Project Phase-I (covering benefited areas of 184,534 ha) in the north-west region, the Chandpur Irrigation Project (46,437 ha) in the south-east region and the Bhola Irrigation Project Phase-I (52,632 ha) in the south-central region.

Drainage (D) projects: This type of project aims to improve drainage through the construction of drainage channels, drainage regulators and sluices. There have been 128 drainage projects constructed by BWDB covering an area of 0.759 million ha as of 1994. Examples of some big drainage projects are the Dredging of Gumti River Project in the south-east region benefiting an area of 138,866 ha and the Comprehensive Drainage Structure Project for Faridpur in the south-central region benefiting an area of 151,822 ha.

Top