II. FLOOD LOSS REDUCTION AND REVIEW OF PAST EXPERIENCES
B. General information on flood control projects
3. Development in flood control projectsBWDB has implemented 372 medium and large scale flood control, drainage and irrigation projects until 1994. Locations of some such projects are shown in Figure 4. There has been a steady growth in the benefited area since mid 60's through the construction of 7,668 km of embankments, 5,072 km of drainage channels and 493 sluices and regulators as per BWDB list of completed projects as of 1994. The growth of area benefited by flood control and drainage projects is shown in Figure 5(a). The net benefited area of about 3.7 million ha by these projects at the end of 1994 is equivalent to nearly 25 per cent of the total area of the country, and 60 per cent of total flood potential area.
More than 50 per cent projects have been constructed within 3 years; about 30 per cent projects required 4 to 6 years and 15 per cent projects required more than 6 years (Chowdhury et al., 1996). On average, projects having 5,000 and 10,000 ha of benefited area required more than 3 and 6 years respectively to construct. More than 50 per cent of total number of projects as well as of total benefited area have embankment of 25 to 100 km length with 2 to 8 km of embankment per thousand ha of benefited area (Chowdhury et al., 1996).
LGED has implemented 1,335 small-scale schemes up until 1996 through
construction of about 400 km of embankment, 4,000 km of canals and 300
regulators and sluices. The area benefited by these projects is approximately
0.27 million ha.