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Works on or Adjacent to Water

Designers Knowledge Base

Relationship to works

Is there is a water course on or adjacent to the site and will it be affected by the works? ( a water course includes rivers, canals,ditches, ponds, lakes and harbours).


A water course has several significant hazards, such as those shown below associated with it.

Hazards and risks

  • immersion: consider the risks of cold water shock, hypothermia and possible drowning
  • health hazards: consider possibilities of contaminated water and water borne diseases such as Weil's Disease
  • flooding: consider possibility of site or excavation flooding
  • falls from height: possibility of falls from height into water
  • electrocution or explosion: caused by power cables in contact with the water
  • moving water: consider the effects of currents, scour or flood water
  • pollution: Will any of the operations to be carried out give rise to possible pollution of the watercourse?
  • The Contractor shall not dispose of any substance which could cause pollution of a water course contrary to the Rivers (Prevention of Pollution) Act 1951-1961 or subsequent.

Design considerations

The designer should give consideration to the following design options to minimise or reduce the effects of some of the identified hazards:

  • specify a prefabricated construction to avoid/reduce fabrication over water
  • divert or exclude water by dams or pumping
  • specify sequences of work to minimise exposure
  • select more durable materials and finishes to minimise time spent on maintenance operations
  • include provision for maintenance access