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surface water flooding

SURFACE WATER DRAINAGE 

Meridian are specialists in Surface Water design from planning and strategy to construction stage. 

Contact us now to get a free quote for your, Surface Water Drainage Strategy (SWDS), Sustainable Drainage System (SuDS) Assessment, Drainage report or Detailed Design project

WHAT IS A SUSTAINABLE SURFACE WATER DRAINAGE STRATEGY?

A Sustainable Drainage Systems (SuDS) Assessment or Surface Water Drainage Strategy (SWDS) is a report into how surface water, usually caused by rainwater runoff from development, affects a site and the surrounding area. It establishes how water behaves on a site and determines the runoff rate, flow pathways, and infiltration potential (the likelihood of water being soaked into the ground).

It then investigates what effect the development will have on these issues and outlines measures the developer can take so that runoff rates meet the requirements for the site set by national and local planning policy and/or specific planning conditions.

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Sustainable Drainage Systems (SuDS) are systems that:

  • deal with rainwater as close as possible to where it falls

  • store runoff and release it slowly (attenuation)

  • allow water to soak into the ground (infiltration)

  • slowly transport (convey) water on the surface

  • filter out pollutants

  • allow sediments to settle out by controlling the flow of the water

WHO NEEDS A SUSTAINABLE SURFACE WATER DRAINAGE STRATEGY?

National Planning Policy requires that developments of more than ten units, or a project deemed a major development (including industrial, commercial and mixed-use sites),  review the potential use of Sustainable Drainage Systems (SuDS) as part of the Surface Water Drainage Strategy (SWDS) to support a planning application. Minor development, or small sites in a known critical drainage area, may also be required to provide this assessment at planning stage. 

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If your development’s within an area designated as Flood Zones 2 and 3, or an area identified as having a surface water flooding problem, you’re also likely to need a drainage strategy. ​To check if your site is in Flood Zone 2 or 3, you can contact us or take a look at national flood maps here:

England: Environment Agency Flood Map for Planning​; Scotland: Scottish Environment Protection Agency flood maps; Wales: National Resources Wales flood risk map; Northern Ireland: Flood Maps (NI)

OUR SUSTAINABLE DRAINAGE REPORTS AND STRATEGIES:

  • Are compliant with the national planning policies for England, Wales, Scotland and Northern Ireland as well with the relevant environmental agency guidance and local planning policy

  • Can be written as separate reports or combined with our Flood Risk Assessments.

  • Are suitable for all sizes and types of developments

  • Identify appropriate surface water runoff management options

  • Outline recommendations for Sustainable Drainage Systems (SuDS) following consultation 

  • Provide initial design parameters for drainage components, such as soakaways, ponds and streams

  • Can include detailed designs to support Discharge of Planning Condition applications. 

BENEFITS OF USING MERIDIAN CIVIL ENGINEERING CONSULTANCY FOR YOUR SURFACE WATER DRAINAGE STRATEGY (SWDS) 

  • 25+years of experience in civil engineering and drainage design.

  • Practical solutions that can be implemented based on construction site experience.

  • Improve your chances of achieving planning consent or discharge of planning condition.

  • Avoid the costs of later design changes and additional planning applications.

  • Reduce the risk of flooding to the site and surrounding area.

  • Improve local amenities, reduce the risk of local flooding, and increase biodiversity.

  • We are able to offer Flood Risk Assessments.

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