Water management

SuDS (Sustainable Drainage Systems) and NFM (Natural Flood Management) are excellent surface water management techniques to help alleviate flooding, improve water quality and complement water security at the same time as enhancing the public realm.

Our approach to sustainable drainage combines traditional civil and infrastructure engineering with landscape-led approaches to deliver source control solutions in line with an integrated water management philosophy. In addition to the core aim of managing surface water on the surface within a treatment train, our solutions look to improve biodiversity while reducing urban heat island effects, the carbon footprint, and potable water demand – all essential in addressing the current climate and ecological crisis whilst achieving sustainable development that doesn’t compromise the ability of future generations to meet their own needs.

As co-authors of the CIRIA SuDS Manual, SuDS design is in our DNA. Our experts have years of experience and contributed to the development of current guidance relating to sustainable drainage.

As members of SusDrain we prioritise being part of the ongoing dialogue on sustainable drainage, providing the best-practice dissemination and training in these disciplines.

Our excellent track record in the delivery of exemplary and innovative designs speaks for itself, and we regularly support ongoing projects when specialist SuDS design is required.  EPG delivers certified CIRIA SuDS training.

Certified CIRIA SuDS training overview

Landscape architects and water engineers working together to provide innovative water management solutions.

An integrated approach – the benefits

Sustainable drainage and natural flood management have multiple benefits beyond effectively managing surface water runoff. By replicating natural drainage processes, surface water is more effectively managed. In addition to providing drainage solutions, SuDS and NFM provide multiple other benefits including improved water quality, biodiversity and amenity value. By working to the four pillars of SuDS, we ensure that we maximise the benefits delivered through each and every design. 


Can this approach be cost effective?

Yes. Whilst the far-reaching benefits of SuDS can be difficult to calculate, such as improvements in health and wellbeing, education opportunities, increasing physical activity and protecting and enhancing habitats, the capital cost is often less than traditional drainage methods.

How is climate change affecting surface water flood risk?

The climate is changing faster than ever as a direct result of human activity. Rising temperatures are fuelling environmental degradation, natural disasters and weather extremes, and we know that action is needed. The seeds of the climate emergency were planted in the early 1800s, when humans began releasing carbon into the atmosphere during the industrial revolution. In simple terms, carbon traps solar energy without releasing it (the greenhouse effect), meaning more energy in the environment, which in turn means more extreme weather events at both ends of the scale.  

Much of the focus is on the increasing temperature of the planet and prolonged periods of drought, however while the UK will experience unprecedented droughts it will also experience significantly more extreme storm events and flooding, as IS BEING evidenced at present. 

How can SuDS help?

Most SuDS solutions such as blue green roofs are designed to store enough rain for a 100 year storm event landing on the SuDS catchment area (a flood event that has a 1% probability of occurring or being exceeded in any given year) plus an additional margin to mitigate the effects of climate change. All SuDs are designed to discharge at a greenfield runoff rate which mimics the undeveloped state of the site, and additionally, vegetated SuDS can also be designed to provide irrigation using the collected rainfall.


Can this SuDS approach be cost effective?

When planning a large-scale project, cost management is of the utmost importance, and we will always work with our clients on costs in a clear and transparent way. As SuDS has increased in popularity, there has been an ongoing conversation around whether this increases the overall cost of a project.

Whilst the far-reaching benefits of SuDS can be difficult to calculate, such as improvements in health and wellbeing, education opportunities, increasing physical activity and protecting and enhancing habitats, the capital cost is often less than traditional drainage methods.

Defra has also undertaken a number of comparative studies on the costs and benefits of traditional drainage and SuDS. Clients, designers, engineers and quantity surveyors compared the capital (and sometimes the maintenance) costs for draining sites using sustainable drainage and more traditional approaches. All of the sites in these studies showed that the inclusion of SuDS was more cost effective than a traditional drainage system. (source: susdrain.org)

NFM and SuDS are both based on the philosophy of mimicking nature through catching water where it falls (including undeveloped land and farmland) to reduce flood risk either in this area or downstream of the catchment. The main principle of NFM is ‘slow the flow’ through tree planting, wetland creation, leaky dams and natural and nature based techniques to increase the surface roughness.

To talk to us about your project please fill in the form below, email us on enquiries@epg-ltd.co.uk or talk to us on 01925 652983.   

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