By Norma Cherry-Fevrier
Economist
Department of Planning and National Development
Castries, Saint Lucia

A dam can be defined as a barrier constructed across a river or stream to hold and control the flow of water for the purposes of water storage and supply, irrigation, transportation, electric power generation and flood control (River Keepers, 2005; Beck et al., 2012). Referred to as one of the oldest branches of engineering (Baxter, 1977) the construction of dams across rivers dates back to ancient times when the Sumerians dammed the Tigris and Euphrates Rivers to provide flood control and irrigation for their crops (Beck et al., 2012). In recent times, the world's growing population and the need to meet its accompanied growing water and energy demands, has resulted in almost half of the world's rivers having at least one dam constructed across them (Wijensundara and Dayawansa, 2011).