Flood Risk Assessments and Drainage Strategies

A flood risk assessment is needed for areas with high chance of flooding as seen in the photo where an area has flooded.

Our highly experienced team of Engineers offer key Flood Risk Assessments and Drainage Strategies. The team work for a range of clients and industries including Education, Commercial, Industrial, Residential, Local Councils, etc.

Previously completed projects range from, small-scale single-unit conversions to large-scale community developments of over 1,000 units. Having worked on a variety of projects, the team possess distinct, quality experience and expertise. They also practice within both the private and public sectors.

Our Services Cover:

  • Flood Risk Assessments
  • Sustainable Surface Water Drainage (SuDS) Strategies
  • Foul Drainage Strategies
  • Detailed Design of both Surface Water and Foul Drainage Networks
  • Environmental Impact Assessments

Who Carries out The Assessments?

All of our Flooding Risk Reports for Planning are undertaken by our dedicated team of experienced Engineers. Our Engineers work on projects from concept through to implementation, so you can be confident that the initial design is sustainable, efficient, and implementable when it comes to the Construction Stage.

What is The Process?

When commissioned to undertake a Flood Risk Assessment Report, our team will review the existing site conditions, and contact the relevant 3rd parties (incl. Lead Local Flood Authorities, Environment agencies, Water Authorities, etc.) to obtain the necessary information to undertake an informed assessment of the site. Once this information is available, our team will undertake a full Flooding Risk Report and come up with the optimum solution for your Development.

How Long Does an Assessment Take?

The time a Flood Risk Assessment Report can take varies depending on the size of the site, the Flood Zone in which it is located, and the site investigation required to enable the most sustainable and appropriate solutions to be identified. We will however always endeavour to meet our Client's requirements in terms of timescales.

A flooded street, water can be seen collecting under windows and against doors.

How Can We Help You?

We can provide innovative and sustainable drainage strategies for planning that set the project up for success from the early stages of our involvement.

Where possible, it is always preferable to consult us during the early stages of a project to ensure the design process considers the drainage and flood risk opportunities and constraints. Doing this avoids abortive work for layout generation and enables the sustainable drainage features to work with the design to maximise the developable area.

Get in touch with us today to optimise your development and let us work together to develop a sustainable efficient design.

Three people standing on a bench in an area that has flooded. Brown flood water threatens their safety.

Flood Risk Assessments – When are they required and what are they?

  • Flood Risk Assessments (FRAs) are a planning requirement when a site is:
  • Located in a medium or high-risk flood zone (2, 3a, or 3b)
  • Located in a critical drainage area
  • When a development site is over 1 hectare in size

The purpose of a Flood Risk Assessment for Planning is to assess the development proposals and determine the flood risk to the site and the surrounding catchments as a result of the development proposals.

More often than not mitigation solutions can be put in place to ensure the development remains safe for its lifetime and the surrounding catchments can realise betterment following the implementation of the scheme. To achieve these results, get in touch with our dedicated team of Engineers who would be happy to discuss your requirements. 

The Benefits of FRA for Planning

As above, Flood Risk Assessments are a planning requirement, so the obvious benefit of completing a Flood Risk Report for planning is that you can proceed in the confidence your development will be safe from flooding, which will not make things worse for the surrounding catchments, and you obtain Planning Permission! Assuming mitigation solutions are appropriate and implementable.

Flood Risk can be a significant constraint for development sites, and this is only likely to increase in the future. We are happy to discuss your proposals at the earliest stages of land acquisition and concept design to ensure all necessary considerations have been reviewed enabling developers to proceed with confidence, and us to provide a sustainable drainage strategy for planning that benefits the scheme.

Sustainable Drainage Strategies for Planning

If an FRA is not a planning requirement, the Local Planning Authority will still require a SuDS for Planning Strategy to understand how surface and foul water flows from the development can be managed. Managing surface water is essential for any new build or redevelopment project.

We are passionate about providing sustainable and space-efficient designs that improve the visual appeal of developments for future users, whilst providing the obvious benefits of improving biodiversity, amenity, water quality, and reducing flood risk.

Our designs will be tailored to your development's requirements and aim to maximise developable space by combining the landscaping and drainage strategy with effectively designed SuDS features.

Get in touch with us today to see how our SuDs for Planning Strategies can help.

Foul Drainage Strategies

If a Flood Risk Report is not a planning requirement, the Local Planning Authority will still require a Drainage Strategy to demonstrate how the surface and foul water flows from the development can be managed.

Foul Drainage Strategies can assist in informing the cost plan for development as we will assess how the foul effluent will be drained from your development. We will cover the proposed route of public sewers, where they will discharge, discharge rates, and sewer capacity, and specify the design criteria.

We can undertake Sustainable Surface Water (SuDS) and Foul Drainage Designs from feasibility through to detailed design and Construction. Refer to our Infrastructure Design section for more information.

Environmental Chapters

Mayer Brown provides Water Resources and Flood Risk Chapters for Environmental Impact Assessments. We will assess the potential impacts of development on water resources, flood risk, and drainage and examine them in accordance with national planning guidance and Environment Agency requirements.

A road that has flooded is being blocked by warning signs and bollards.

Flood Risk and Drainage Case Studies

Learn about how we undertook a Flood Risk Assessment to assess how the development can be implemented safely in terms of flood risk and establish appropriate measures. The Flood Risk Assessment included preparing a sustainable surface water and foul drainage strategy in support of the mixed-use application at a brownfield site at Wallis Road in Hackney Wick.

For more examples of recent Flood Risk and Drainage projects we have undertaken please view our case studies for Station Lane Milford Project - Residential DevelopmentWaterlooville River RestorationWaterlooville Berewood DevelopmentWaterlooville River Restoration - Flexiarch bridgeNewlands Common Sustainable Drainage System

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