ABSTRACT
For a design to be made, the hydrology of the water body or watercourse to be closed has to be fully understood. The main distinction is made between tidal and riverine regimes. Tides are characterized by short-term variations in water level and in flow direction. The design must cater for quick action during high or, more typically, low water periods and during the daily occurring slack water periods. River flows are steadier in the short term, generally one-directional and never cease. Damming rivers is therefore a completely different process. Comparison of the designs for breakwaters and closure dams shows some identical aspects but other aspects require a completely different approach. For instance:
Comparable: ∑ Many construction materials used are similar: bottom protection, quarry stone,
concrete blocks, specially designed concrete structures (caissons). ∑ In both cases the equipment used is either land based or water-borne: for example
hydraulic excavators and cranes, dump trucks and dump-vessels, barges and bulldozers.
