Flood Risk Engineering
Flood Risk Engineering & Drainage Design
Engineering Solutions for Flood‑Affected Development & Industrial Sites
Flood‑risk‑affected sites don’t just need an FRA — they need engineered solutions that make a site safe, buildable and compliant. Arthian’s civil and structural engineers deliver flood‑resilient design, drainage strategies, SuDS, earthworks, and levels design that enable planning approval and long‑term operational performance.
For FRAs, modelling and planning support, see Flood Risk Services.
What We Deliver
Our civil engineering team provides the full suite of flood‑risk engineering services required for planning, detailed design and construction.
Flood Mitigation & Resilience Engineering
We design practical, regulator‑aligned mitigation measures that make sites safe and buildable:
- Finished floor level design and platform raising
- Site re‑grading and earthworks modelling
- Flood exceedance routing and overland flow paths
- Resilience measures (thresholds, bunds, materials, compartmentation)
- Mitigation strategies for planning (aligned with NPPF, LLFA and EA expectations)
Surface Water Drainage Strategy (SuDS)
We design SuDS systems that meet planning requirements and deliver long‑term performance:
- SuDS strategy development
- Attenuation design (tanks, basins, ponds, swales)
- Permeable paving & infiltration systems
- Runoff rate calculations & greenfield discharge assessments
- SuDS maintenance plans for adoption and compliance
Our designs balance hydraulic performance, environmental protection and operational practicality.
Detailed Drainage Design (Foul & Surface Water)
We provide full drainage design packages for planning, tender and construction:
- Foul and surface water drainage design
- Pipe sizing, gradients, cover levels and manhole schedules
- Backflow prevention and flood‑resilient drainage
- CCTV surveys and condition assessments
- Drainage optimisation for brownfield sites
All designs follow Sewers for Adoption, Building Regulations and LLFA requirements.
Earthworks, Levels & External Works Design
Flood‑risk sites almost always require careful levels and earthworks engineering:
- Cut‑and‑fill modelling
- Site re‑levelling to achieve safe FFLs
- External works design (yards, hardstanding, kerbs, falls)
- Overland flow management
- Integration with SuDS and drainage networks
Access, Highways & Road Drainage Design
Safe access during flood events is a planning requirement for many sites. We deliver:
- Road alignment and drainage design
- Section 38 / 278 approvals
- Emergency access route design
- HGV‑compatible drainage and surfacing
Integrated Site Layout, Levels & SuDS Design
We support masterplanning and site layout development with:
- Integrated SuDS + levels + drainage design
- Placemaking with water‑sensitive design
- Optimised layouts for exceedance and safe drainage
Environmental & Permitting Support
Where engineering works interact with watercourses or drainage networks, we provide:
- Environmental permit support
- Ordinary watercourse consent applications
- Construction Environmental Management Plans (CEMPs)
- Pollution control and fire‑water containment design
Why Choose Arthian for Flood‑Risk Engineering?
- Multidisciplinary civil, structural and environmental engineering capability
- Strong track record on industrial, logistics, energy and high‑hazard sites
- Clear, regulator‑aligned design documentation
- Practical, buildable solutions for complex brownfield sites
- Fast mobilisation for urgent drainage and flood‑risk issues