Skip to main content

Water Courses

Hazard Related Topics

Relationship to works

Is there 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 associated with it. It is important that, where these risks cannot be eliminated or reduced during the design process and they are perceived as 'significant risks', details of them are passed to the principal contractor. The prospective principal contractors must outline the control measures proposed in respect of these 'significant hazards' in the construction phase plan. When a tender is accepted and the project reaches the construction phase the principal contractor must control the hazards and risks as outlined in his construction phase plan.

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

See Also