Flood Risk & Development

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We work with developers across the UK to deliver practical, sustainable solutions for all types of projects. Our team provides Flood Risk Assessments (FRAs) and mitigation strategies that support planning applications, reduce water-related risks and unlock development opportunities.
flood risk assessment

Flood Risk / Consequences Assessment

Since 2004, our team has delivered Flood Risk Assessment (FRA) reports for clients across the UK. We provide clear, accurate and practical guidance to support planning approvals, strengthen emergency response plans and help insurers assess risk.

Our FRAs are designed to minimise the impact of flooding, enhance resilience, and create safer, more sustainable development environments.
Planning application support

We produce detailed, site-specific FRA reports that address policy requirements, assess all relevant flood sources and provide clear evidence to support successful planning submissions.

Critical infrastructure protection

We develop flood mitigation strategies and continuity plans to safeguard essential infrastructure, maintain operational capacity and ensure resilience during flood events.

Emergency and business continuity planning

We support developers in creating robust response frameworks, covering evacuation procedures, flood warning triggers and recovery strategies to minimise disruption and accelerate post-event restoration.

Waterco Datrys

SuDS Approval Body (SAB) Support

New legislation under Schedule 3 of the Flood & Water Management Act in Wales requires developers to secure SuDS approval from a SuDS Approval Body (SAB) before any construction can begin.

Our team provides expert, site-specific guidance to ensure drainage designs fully comply with statutory SuDS standards and support planning success. From early strategy through design, submission and approval, we help developers, architects and planning consultants navigate the SAB process efficiently and confidently.
SAB Support
End-to-end SAB application support

We provide full guidance through strategy development, detailed design, submission and liaison with the SAB to streamline approval and reduce programme risk.

Compliance with statutory SuDS standards

Our drainage solutions are designed to meet Welsh Ministers’ mandatory standards for surface water management, ensuring robust and compliant outcomes.

Site-specific SuDS strategy development

Tailored attenuation, infiltration, conveyance and water-quality solutions that integrate seamlessly with proposed layouts and meet SAB expectations.

Early engagement and programme management

Proactive planning to address the approval timeframe, reduce delays and identify technical issues at pre-application stage.

Flood Mapping

Hydraulic Modelling

We provide specialised hydraulic modelling as a key part of flood risk assessments. This gives developers robust, evidence-based insights into how water will behave across a site under different flood scenarios.

By simulating fluvial, coastal and surface water flows, hydraulic models highlight potential risks, guide design decisions and ensure compliance with planning requirements. The results support the creation of resilient infrastructure and effective mitigation strategies to protect people, property and future investments.
Detailed flow simulations

We assess river, coastal and overland flood pathways to understand site-specific risks.

Climate change allowances

We incorporate future rainfall and sea-level rise scenarios to ensure long-term resilience.

Flood hazard mapping

We provide detailed visualisations of flood extents, depths and velocities to guide safe and sustainable development.

Design support for mitigation measures

Our team informs the placement and effectiveness of defences, drainage systems and resilience features.

Breach / Inundation Analysis

We have a proven track record in delivering site-specific breach assessments to evaluate flood risks caused by failures in existing flood defences.

We support clients throughout the feasibility stages using industry-standard 1D and 2D flood modelling software – MIKE FLOOD, Flood Modeller, and TUFLOW – approved by the EA, NRW, and SEPA. These tools simulate breach and overtopping hydraulics to predict flood extent, depth and hazard.

We provide detailed flood risk maps along with 3D animations and videos to effectively communicate flood impacts to all stakeholders. Our services include:
Flood risk new developments
Breach Analysis

We carry out detailed breach analyses to assess how failures in flood defences could impact surrounding communities and infrastructure.

Riverbank Breach Modelling

Overtopping Analysis: the Environment Agency (and UK counterparts) often require an overtopping or breach analysis to inform flood hazard mapping and support the planning process.

Flood Hazard Mapping

We produce clear hazard outputs that show how floodwaters may spread and intensify across an area. We assess how sudden bank failures could alter flow paths and increase local flood impacts.

Reservoir Inundation Modelling

We simulate how reservoir‑failure floodwaters move through the catchment and present clear 3D visuals showing how a breach forms and develops over time.

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Flood Risk & Development Team

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Frequently Asked Questions

A Flood Risk Assessment checks if a site is suitable for development by evaluating its risk of flooding. Requirements vary by region, but usually depend on the site’s location, size, and type of development. In England and Scotland, it’s called a Flood Risk Assessment; in Wales, it’s a Flood Consequence Assessment.

A Flood Risk Assessment is typically required when any of the following applies:

1. The site is over 1ha.

2. Can be classed as a major development.

3. Located in Flood Zone 2 or 3.

4. Drainage area is classed as critical.

A Drainage Strategy (SuDS report) is needed if your site is over 1ha, a major development (10+ units), in Flood Zone 2 or 3, in a critical drainage area, or if building a new structure.

Local planning authorities may request one to ensure your project complies with regulations and avoids future issues. Checking early helps prevent delays, and our team can guide you through the process.

In certain areas the LLFA, EA, SEPA or NRW may not hold sufficient information for your site to inform their decision on flood risk, flood sources and flood hazards. We can support your Flood Risk Assessment in-house with hydrology assessments and detailed hydraulic modelling.

Hydraulic modelling simulates how water behaves under changing conditions to assess flood risks. Using software such as MIKE FLOOD, Flood Modeller Pro, TUFLOW, and HEC-RAS, we predict flood depths, velocities, inundation rates, and hazard ratings. These insights inform UK flood maps and help clients develop effective flood management strategies.