Flooding – The Risks For Design Consultants

Managing Risk

As far as possible, a structured approach should be taken to minimise flood risks on construction projects which will involve:

o Assessing the risks

o Avoiding risks where possible

o Where risks cannot be avoided, taking due cognisance of the risks in the design and providing appropriate advice and warning to the client

Assessing the Risks

On any construction project there are likely to be two separate but related considerations:

o Is the proposed structure itself vulnerable to flooding?

o Is construction of the proposed structure likely to increase the risk of flooding elsewhere? This in turn requires consideration of the separate risks involved in the process of construction (risks arising from temporary works and which may or may not be the responsibility of the professional) and risks arising from the mere presence and/or operation of the permanent works.

Flood prevention works fall into a category of their own where the consequences of failure may be catastrophic. Any significant project is likely to involve a desk study of more or less detail. The desk study should include investigations into the flooding history of the site.

A desk study is likely to highlight risk factors for a locality which will need to be supplemented by site investigations such as ground investigations and topographical surveys.

If site investigations are provided by the client or commissioned from other consultants, the professional can generally expect to rely on them but he is not absolved of the responsibility to consider their adequacy. If they are inadequate, the client should be told. If the design is based on assumptions, the design assumptions should be spelt out.

Document the Risk

Whether or not formal reports are issued to a client, risks identified by the consultant should be discussed with the client and those discussions documented. A client may not be willing to incur the cost of flood mitigation measures which the consultant considers advisable. Such advice should be put in writing. An ‘audit trail’ will greatly assist the defence of any future claim.

Contractual Considerations

The first and most obvious advice point to make is that the consultant should ensure that he has a written contract which, amongst other things, clearly sets out the scope of the services that he has agreed to provide.

Liability arising from provision of those services can be limited or in some circumstances excluded. Contractual provisions that a consultant should consider as a matter of course (both in relation to flooding risks and more generally) include:

o Excluding liability for default of sub-consultants appointed with the agreement of the client

o Excluding liability for consequential losses

o Limiting liability to a specified sum (liability should be capped at a level not exceeding the amount of the consultant’s professional indemnity insurance cover)

o Restricting liability to the consultant’s fair share of a loss on the assumption that other responsible parties will meet their own fair share of the loss (by means of a net contribution clause)

o Appropriate exclusions or caveats, particularly where the consultant is acting in an advisory role or providing a survey report


Risks of flooding, like many other risks encountered in construction works can be managed provided that they are recognised and properly assessed. Liability for risks that cannot be avoided or designed out may be mitigated by appropriate use of contractual exclusions and limitations.