Horizontal beam on a bulkhead used to laterally transfer loads against the structure and hold it in a straight alignment.


Water table

The upper surface of groundwater; that level below which the soil is saturated with water.



The geographically defined region within which all water drains through a particular system of rivers, or other water bodies; watershed are defined by “watershed divides” (high points or ridges on the land) and includes hills, slopes, lowlands, floodplains and receiving body of water.



 Wave - A ridge, deformation, or undulation of the surface of a liquid (sea water) 

Wave period

Time period of the passage of two successive crests (or troughs) of a wave past a specific point.

Wave refraction

The process by which a wave moving in shallow water at an angle to the bed contours is changed in direction.


Wave Trough

The lowest part of a wave.

Weep hole

hole through a solid revetment, bulkhead or seawall for relieving water pressure

Weir or Sills

Log, boulder, or quarrystone structures placed across the channel and anchored to the streambank and/or bed to create pool habitat, control bed erosion, or collect and retain gravel.



Low-lying vegetated areas that are flooded at a sufficient frequency to support vegetation adapted for life in saturated soils, including mangrove swamps, salt marshes, and other wet vegetated areas (often between low water and the yearly normal maximum flood water level).

White Paper

A report produced by the British Government setting out its proposals for, and providing information on, a particular policy issue, such as international development. The goals and directions of the British Government’s policy on international development are laid down in the 1997 White Paper on International Development. This is now built upon in the 2000 White Paper II

Willingness to accept WTA

The minimum amount of compensation consumers would be willing to accept for foregoing units of consumption.


Willingness to pay WTP

The maximum amount consumers are prepared to pay for a good or service. WTP can be estimated as the total area under a demand curve. Changes in WTP can occur when the demand curve itself shifts because of changes in income or in the prices of substitute goods.