We are experts in a range of flood risk management areas, from Flood Risk Assessments and associated Environmental Statement Chapters for Environmental Impact Assessments, surface water assessments, economic assessments and due diligence.
Our principal aim is to support our developer clients during the planning process, and our corporate and investor clients by assessing risk from all sources of flooding, as well as providing due diligence and technical advice on flood risk including mitigation measures and residual risks.
Services we offer
We undertake Flood Risk Assessments (FRAs) to determine site-specific flood risks from all sources of flooding, ranging from:
- Fluvial (main river and ordinary watercourses)
- Surface water
- Artificial drainage (reservoirs and sewers)
We determine the receptors at risk, the potential mitigation measures and residual risks to ensure the development or investment is safe from flooding, without exacerbating risk in the locality or downstream. Flood Risk Assessments can be implemented if your site is within a Flood Zone or greater than one hectare in size; we can offer services in a staged approach from a basic FRA through to standard or more detailed FRA, depending on the site and the level of detail required.
We also offer FRAs and Emergency Response Plans for due diligence purposes. With any land, property, purchase or disposal it is vital to undertake a range of due diligence checks to prevent the discovery of any unforeseen obstacles further into the process. We support and advise our clients to future-proof the assets and portfolios, considering current and future flood risks due to climatic change predictions.
FRAs can be used as an annex to an Environmental Statement (ES) as part of the ES process. In addition, we can complete the flood risk elements of the ES Chapter including water quality fundamentals such as Highways Agency Risk Assessment Tool (HAWRAT) routine runoff and spillage risk assessments, working with our geo-environmental team to deliver the groundwater components to provide a complete water services package.
A development should utilise Sustainable Drainage Systems (SuDS) unless there are practical reasons for not doing so. Options for SuDS may be required at high level within an FRA or in a stand-alone drainage statement to submit with outline planning. Working with a series of associates we can provide a complete drainage package from outline through to detailed design.
Ideally surface water should be managed as close to its source as possible, soakaways are high on the “drainage hierarchy” and the preferred option. Many Local Planning Authorities request confirmation at planning stage of the viability of soakaways as part of the surface water management scheme. Delta-Simons can provide soakaway testing to inform this and the drainage design.
We undertake surface water assessments, typically working with Lead Local Flood Authorities (LLFA) to complete a prioritisation matrix-style assessment to rank the surface water hotspots based on key criteria such as:
- records of historic flooding
- risk of surface water flood extents
- critical infrastructure (e.g. road, rail, schools)
- development sites (e.g. Strategic Housing Land Availability Assessment (SHLAA) and Employment Land Review (ELR)
Weightings can be added and the matrix tailored to your specification in order to best represent the areas for further assessment, such as problem definition or optioneering. Our team of specialists can complete additional reports for each prioritised hotspot to further understand the flood risk mechanisms, and to highlight potential options or mitigation measures to take forward to economic assessment.
We offer our clients a complete solution to surface water risk by providing an Economic Assessment service, calculating the baseline economic damages for residential and commercial properties, short-listing a range of options and calculating each option’s benefit-cost ratio to determine the most viable and cost-effective options to mitigate the risk.
For more on all our Water Services, contact Alex Perryman.