Flood risk assessment and reporting

Flooding issues

  • $46 M per year in insurance claims in New Zealand
  • 23 building floors flooded in the Albany area on 3 July 2012
  • Over 20 significant flood events per year in Auckland causing flooding of building floor levels
  • Many house and other building sites have inadequate protection against flooding, for example:
    • badly designed ground levels adjacent to buildings resulting in trapping localized stormwater which can enter buildings
    • no provision on a site to allow overland flow from upstream areas to pass safely through the site
    • floor levels too low for protection against localized or area- wide flooding

Engineered overland flow path

Engineered overland flow path, Epsom

Services to assist property owners to avoid or minimise flood risk

  • Flood risk assessment and reporting for land and buildings including:
    • Identifying potential flood mechanisms e.g. ponding, overland flow, internal site management drainage blockages
    • Assessment of current level of protection and flood risk
    • Whether proposed development will worsen problems
    • Assessment for compliance with requirements of the Building Act and the relevant district plan
  • Flood risk avoidance and mitigation
    • Determination of proposed building siting location and minimum floor levels
    • Design of overland flow paths to convey stormwater through the site without flooding site buildings
    • Review of existing sites and buildings and design of flood avoidance and mitigation measures
Nigel Mark-Brown

BE (Civil) CMEngNZ Chartered Professional Engineer