Flood Risk Assessment (FRA) Services

If  the site is located in England and the proposed development is over one hectare in size and located within Flood Zone 1 a flood risk assessment is required.  For all developments located in  Flood Zones 2 and 3 a Flood Risk Assessment is required.  If you are not sure which flood zone you are located in please call  01743 355770 or  emailand we can advise you on this. For sites in Wales, where the proposed development is located within Flood Zones C1 or C2 then a Flood Consequence Assessment is required.  In Flood Zone B a Flood Consequence Assessment may be required however the level of detail will be dependant upon the location and it location relative to the extreme flood event extent (1 in 1000-yr event). For sites within Scotland where the proposed development site is  located in a low to medium risk area and had a high probability of flooding or where the nature of the development  indicates a higher risk a Flood Risk Assessment is required. For all proposed developments within the Scottish Environment Protection Agency (SEPA) Flood Zones (1 in 200 year or greater chance of flooding) a Flood Risk Assessment is required. Please feel free to contact a member of our experienced and approachable team to discuss your requirements and how we can help.

Qualitative Flood Risk Assessment

If the need for a flood risk assessment has been identified then the initial approach will be qualitative, this is known as a Stage 1.  Results will conclude whether no further assessment is required or numerical methods need to be undertaken.  Many developments do not require numerical methods and a qualitative approach will be appropriate.  These require less technical input and therefore generally cost less than quantitative assessments.

Quantitative Flood Risk Assessment

Quantative assessments can range from simple calculations to assess surface water  run-off volumes to complex flood modelling. Flood modelling is undertaken using proprietary software  ISIS or HECRAS, both of which are approved by the regulatory authorities in the UK.

Sustainable urban drainage systems (SuDS) are designed to ameliorate run-off rates and reduce total volumes of water requiring discharge.  Consideration of SuDS is required for developments of notable size. Our range of experience and practical approach ensure that our FRAs are highly targeted, address the specifics of each site and are, therefore, cost-effective.  We have engaged with the regulatory authorities on numerous sites throughout the UK and are well-placed to represent clients effectively on all flood risk issues. Clients of our FRA services range from individuals to City Councils and large PLCs. Hafren Water has undertaken Flood Risk Assessments and Flood Consequence Assessments for many clients including: URS Consultants Persimmon Homes Lafarge Tarmac Hanson Ltd D K Symes Associates GP Planning Roger Parry & Partners.