Reduced economic viability
The erratic flow of rivers coupled with the problems of erosion is effectively undermining the potential of irrigation projects, as is so evident in the Sri Lankan Mahaweli program. Several large dams were constructed for the generation of energy, as well as for irrigation and flood control downstream. However, the tree cover reduction in the relevant watershed areas has jeopardized the steady supply of water to the reservoirs, on which the success of the project is dependant. Projects are further undermined by siltation, a process that not only causes river basins to silt up (thereby reducing storage capacity), but also chokes hydropower dams and adversely affects coastal fisheries and sensitive coral formations