Whether you’re an architect, developer, builder, planning consultant, landowner or any other professional involved in a construction project, you need a drainage solution that:

• Ensures compliance with national and local planning policy
• Adheres to your timescales and budget
• Is tailored to your site’s specific requirements

At Nimbus Engineering, our holistic approach means we take care of your SuDS reports from start to finish, so you don’t have to.

Thanks to our strong relationships with Lead Local Flood Authorities (LLFAs) and our familiarity with their individual requirements, you can be confident we’ll deliver the right solution for your project — regardless of its size or location.

The use of Sustainable Drainage Systems (SuDS) is a key government initiative aimed at managing surface water run-off as close to its source as possible. This approach helps reduce the risks and impacts of both surface water and fluvial flooding by lowering the peak flows entering rivers and coastal waters.

SuDS design reports are a vital part of the planning process, supporting applications from initial concept through to the discharge of post-approval planning conditions. Involving a SuDS report specialist from the outset ensures a smoother planning journey, minimises delays, and helps avoid costly issues later in the development.

Select one of the links below to learn more about how SuDS reports can support your current or upcoming project:

• What Are SuDS Reports?
• The Nimbus Approach to SuDS Reports
• Why Are SuDS Reports Important?

SuDS reports are assessments requested by local authorities as part of their planning procedures, and they’re often required before a planning application can be validated.

Lead Local Flood Authorities (LLFAs) require that surface water arising from any proposed development is managed through Sustainable Drainage Systems. They expect an assessment of the existing and proposed surface water run-off rates, along with a solution that demonstrates the SuDS management train has been followed.

The SuDS report must set out the strategy being used to minimise the risk of flooding and pollution, both on the site and in the surrounding area.

The level of information an LLFA requires depends very much on the nature and scale of the development, the differing requirements of each individual authority, and local conditions — such as whether the proposed site falls within a Critical Drainage Area.

Sustainable Drainage Systems are a natural, sustainable approach to managing surface water. They work by slowing and holding back the water that runs off a site, and by discharging it to the ground, to ensure flood risk is reduced both at the proposed development and elsewhere. In line with planning policy, SuDS should be considered for all proposed developments — from minor extensions to larger schemes — unless there is a specific reason that prevents their use.

SuDS are designed to mimic nature, dealing with rainwater as close as possible to where it falls. Depending on the site, SuDS can convey surface water, attenuate and restrict run-off before it enters waterways, store water within the landscape, and allow rainwater to infiltrate into the ground or be lost through evaporation and transpiration from vegetation (a process known as evapotranspiration).

Nimbus Engineering’s SuDS reports and plans show how surface water will affect your proposed site and the surrounding area, ensuring you can present a clear sustainable drainage strategy to the relevant authorities.

As experts in this field, our assessments take into account the critical elements of your site — including whether it lies within an at-risk or Critical Drainage Area — to provide clear guidance and ensure compliance with the National Planning Policy Framework (NPPF) and Environment Agency requirements.

You’ll be provided with a finalised sequence of management practices, control structures and strategies, designed to drain surface water from your development efficiently and sustainably — while reducing pollution and minimising negative impacts on water quality in local waterways.

SuDS reports are an important element in achieving planning permission for new developments, especially those in critical areas that may be more prone to surface water flooding. SuDS drainage is particularly valuable for new developments in existing urban areas where the sewers are at or close to capacity, since the whole aim is to reduce run-off to sewers — and ultimately to rivers and the sea — lowering the risk of flooding at the site and elsewhere.

In natural environments, rain falls on permeable surfaces and soaks into the ground. In urban areas, however, where many surfaces are made impermeable by buildings and paving, natural infiltration is restricted. Drainage networks instead direct surface water to local watercourses, but this can cause downstream flooding and pollution, as the run-off entering watercourses from urban surfaces is often untreated.

National planning policy encourages the use of SuDS, and developments that incorporate SuDS are more likely to gain planning permission. Government and regulators have high expectations that SuDS will be integrated into new developments to help prevent flood damage and the disruption it causes.

SuDS design also contributes greatly to the local area, reducing flood risk, improving biodiversity and amenity value, and reducing pollution from surface run-off. SuDS strategies take an ecological approach to holding back run-off from a site, giving natural processes more time to treat pollutants before the water is released.

A well-considered SuDS design mimics natural drainage, reducing the burden on traditional sewerage and drainage infrastructure while being more environmentally and ecologically friendly.

Undertaking SuDS design at an early stage of a project not only helps identify site constraints but can also be highly cost-effective. Well-planned SuDS can deliver savings on the overall construction and maintenance costs of a drainage scheme, and the improved green infrastructure and visual appeal they create can enhance the value and desirability of a development.

Enhancing a development with features such as wetlands, ponds and living roofs assists in the uptake of water, minimising the risk of flash flooding while also filtering out pollutants. These natural settings attract wildlife back into the area and create a development that is a more appealing, natural place to live and work.

We always provide up-to-date advice on surface water drainage and SuDS, delivering fast, cost-effective reports and a drainage strategy that meets national and local planning policy. We’re confident we can produce a report that helps you achieve planning approval by providing the information local planning authorities need.

As Civil and Environmental Engineers, we can give you early-stage advice on sustainable drainage designs to integrate into your development, allowing you to work around any constraints or risks in a natural, ecological way. We then provide the reports and assessments that deliver your SuDS strategy — with the required level of detail to minimise surface water run-off from your development, using best-practice methods and calculations.