Our flood services help people, companies and public organizations to understand their current and potential future flood risk, enabling them to mitigate and plan for flood events and minimize or prevent damage and disruption to homes, businesses and infrastructure.
Flood risk assessments
Flood Risk Assessments (FRAs) are a formal requirement to support many planning applications. We have huge experience in undertaking both FRAs and Flood Consequence Assessments (FCAs) for housing, commercial, agricultural, power, leisure and quarrying applications.
- Level 1 assessment: Desktop review to highlight the potential for development and issues that would need to be taken into account in any full FRA
- Level 2 assessment: Preparation of a report for submission with a Planning Application
- Level 3 assessment: Detailed modeling, such as hydraulic modeling for a formal flood map challenge
Flood hydrology and modeling
Flood hydrology entails the calculation of flood peaks or flood hydrographs for observed floods or for design floods for specified return periods. Our expert consultants use UK Flood Estimation Handbook (FEH) methods in undertaking FRAs and in support of hydraulic modeling, enabling us to appreciate situations in which the methods work well and critically, and the conditions in which they require some refinement.
Our staff are also able to offer expert advice on historical floods. We have undertaken a number of post-event investigations to understand flood mechanisms and quantify the return period of resultant flooding.
Our hydraulic modeling services provide accurate estimation of water levels and flood extents for rivers and watercourses. Detailed, site-specific modeling can be used to refine and challenge published flood maps. The models can also be used to estimate flow velocities and the associated flood hazard ratings.
Our experts have developed numerous 1D and 2D hydrodynamic models of watercourses and floodplains. We use industry-standard software packages, including HEC-RAS, ISIS and TUFLOW, in our modeling assessments. These have been used for establishing design flood levels, flood map challenges, rating extension, hazard ratings, breach analysis and design of mitigation works.
Flood mitigation is an essential component of the work that we undertake. Mitigation ranges from the design of drainage measures such as soakaways through to the design of flood balancing reservoirs.
Our expert analysts provide hydraulic design services for the following mitigation measures:
- Soakaways and infiltration basins
- Flood balancing tanks, including rainwater harvesting
- Flood storage reservoirs
- Flood walls and embankments
- Flood plain/wetland rehabilitation
- Geomorphological impacts