Resilience measure: Seawall

definition

Seawalls are hard engineered structures with a primary function to prevent further erosion of the shoreline. They are built parallel to the shore and aim to hold or prevent sliding of the soil, while providing protection from wave action. Although their primary function is erosion reduction, they have a secondary function as coastal flood defences. The physical form of these structures is highly variable; seawalls can be vertical or sloping and constructed from a wide variety of materials. They may also be referred to as revetments
(Climatewiki, Seawalls, accessed on Sept. 2016).

Co-benefits and impacts

Seawall provides a high degree of protection against coastal flooding and erosion. A well maintained and appropriately designed seawall will also fix the boundary between the sea and land to ensure no further erosion will occur – this is beneficial if the shoreline is home to important infrastructure or other buildings of importance. As well as fixing the boundary between land and sea, seawalls also provide coastal flood protection against extreme water levels. Provided they are appropriately designed to withstand the additional forces, seawalls will provide protection against water levels up to the seawall design height. In the past the design height of many seawalls was based on the highest known flood level. Seawalls also have a much lower space requirement than other coastal defences such as dikes, especially if vertical seawall designs are selected. In many areas land in the coastal zone is highly sought-after; by reducing the space requirements for coastal defence the overall costs of construction may fall. The increased security provided by seawall construction also maintains hinterland values and may promote investment and development of the area. Moreover, if appropriately designed, seawalls have a high amenity value. In many countries, seawalls incorporate promenades which encourage recreation and tourism. Another advantage of seawalls is that it is possible to progressively upgrade these structures by increasing the structure height in response to sea level rise. Provided they are adequately maintained, seawalls are potentially long-lived structures
(Climatewiki, Seawalls, accessed on Sept. 2016).

Related Links


Scales (Show all)

City


Time scales (Show all)

Long term

Measure types (Show all)

Engineering

Problem types (Show all)

Coastal

Resilience measures (Show all)

Floodwall



Last modified: Sept. 14, 2016, 9:29 a.m.