Understanding Surface Water Runoff
Surface water runoff is any form of precipitation that doesn’t soak into the soil. When it rains, snows or hails, the water that doesn’t soak into the ground simply flows away over the surface. Construction sites tend to be very prone to surface water runoff, because the soil is often compacted and doesn’t absorb water very well.
When the water runs off a construction site, it carries away mud, silt and other debris that can cause problems for the public drains around it, as well as environmental harm.
How Construction Sites Affect Natural Drainage
Construction sites have a large impact on natural drainage. Heavy machinery and changes to the topography compact the soil and alter the way rainwater drains in a specific area.
This can cause existing drainage networks to fail and compacted soil can increase surface water runoff, meaning more water runs away into local drains and small waterways during rainy spells.
The Risks of Uncontrolled Water Runoff
When water runs off a construction site, it carries silt, mud and other debris with it. Without the proper controls, these materials can then be washed into public drains and natural waterways, causing blockages, flooding and environmental disruption.
Not only is this harmful to local residents and wildlife, it can lead to compliance issues and delays for housebuilders.
Why Runoff Regulations are Important
Reducing Flood Risk
Uncontrolled silt and mud runoff can clog drains and waterways, which can lead to flooding. This can harm infrastructure, disrupt wildlife and even damage peoples’ homes. Runoff regulations help keep construction site runoff in check, reducing the risk of flooding.
Protecting Rivers and Streams
Silt, mud and debris from construction site runoff can accumulate in local rivers and streams. This can lead to a range of issues, including rising water levels and flooding, wildlife disruption and can even cause waterways to change course, which can lead to further complications and damage.
Meeting Planning and Environmental Regulations
Construction site runoff regulations help housebuilders maintain compliance with broader planning and environmental regulations. This minimises setbacks and the likelihood of legal complications while ensuring a healthier environment.
Runoff Regulations for Housebuilders
National Planning Policy
National planning policy sets expectations for housebuilders, including that any construction activities and finished developments won’t contribute to unacceptable pollution. Planning policy also treats construction site runoff as a pollution risk. The expectations set out in planning policy are enforced by local authorities and the Environment Agency.
Flood and Water Management Act
The Flood and Water Management Act 2010 places responsibility on housebuilders to manage the flow of runoff from their sites in order to minimise flood risk and reduce pressure on public drainage. The Act encourages the use of sustainable drainage systems (SuDS) and requires that housebuilders demonstrate how they will control runoff from their sites.
Lead Local Flood Authorities (LLFAs)
LLFAs are central to managing flood risk associated with new developments. In most cases, the LLFA for a given area will be the county council or unitary authority. They work with planning authorities, the Environment Agency and water companies to ensure new housing developments don’t increase flood risk. For housebuilding projects, LLFAs must be consulted during the planning process to discuss surface water drainage. They will need to be satisfied that runoff from your site won’t harm local drainage infrastructure or the environment.
Local Planning Authorities (LPAs)
LPAs are responsible for overseeing construction projects within a local area, and housebuilders will need permission from the relevant LPA before construction can begin. Before granting permission, an LPA will usually require developers to submit:
- Flood Risk Assessments
- Surface Water Drainage Strategies
- Sustainable Drainage System (SuDS) designs
- Construction Environmental Management Plans
- Site-specific runoff management proposals
The LPA will make the final decision on your planning proposal, including whether you have sufficient runoff controls in place, based on information from other bodies including the LLFA.
Environmental Protection Policies
As well as regulations to prevent flooding, there are also a string of regulations to protect the environment and avoid unnecessary damage to ecosystems and biodiversity. As a housebuilder, it’s your responsibility to manage runoff from your site and ensure that your work doesn’t harm the local environment.
Runoff Management
Effective runoff management is a requirement for all construction sites, including housebuilding. You will need to create and implement a comprehensive runoff strategy from the beginning of your site development to minimise flood risk, prevent pollution and remain compliant with planning and environmental requirements. This includes the planning and implementation of temporary drainage systems, sediment control measures, silt fences, settlement ponds and designated washout areas.
You should produce a Construction Environmental Management Plan (CEMP) to outline your runoff control procedures, and staff should be trained and responsibilities made clear.
Do All Housing Developments Need a SuDS Strategy?
Strictly speaking, no, not all housing developments will need to submit a SuDS strategy. However, you will need to demonstrate how you intend to ensure suitable drainage management, and a SuDS strategy is often the most straightforward way to do this. As a result, SuDS strategies are usually the standard approach adopted by housebuilders for simplicity and peace of mind.
Who Approves Runoff Management Plans?
The specific organisation in question when it comes to approving your runoff management plan may vary, depending on the specifics of the project. However, the following organisations tend to be involved:
- Local Planning Authority
- Lead Local Flood Authority
- The Environment Agency
- The local water and sewerage company
Get in Touch
At BlueJay Solutions, we supply all the equipment you need to remain compliant with construction site runoff regulations. From silt traps and inspection chamber systems to manhole cover protection, we have everything you need to capture runoff materials from your site.
Browse our MuckStopper range and for more information, just contact our team by calling 01420 559888, emailing [email protected] or filling out our contact form.