SuDS Drainage, Attenuation and Water Neutrality Calculation Services

Navigating the SuDS hierarchy can appear a daunting process.  We provide all the tools to simplify the process in a neat, inexpensive and methodical manner. 

We offer a comprehensive and streamlined SuDS Assessment and Calculation Consultancy Service which include: 

• Infiltration (percolation/Soakaway) test to BRE 365
• SuDS attenuation tank sizing
• Flow regulator selection: Vortex, Orifice, Floating Orifice or Pumped.
• SuDS soakaway sizing to BRE 365
• Drainage Design Plan, Manhole Schedule, Drainage Plan, supporting calculations
• Overland/Surcharge/Flow Exceedance analysis
• Wastewater Drainage Field Soakaway Sizing Calculation
• Flood Risk Assesment. 
• Sustainable Urban Drainage Systems (SuDS) Report

We also provide complementary assessments which can be considered during the SuDS appraisal stage: 

• DROP level 3 rainwater harvesting calculation
• Water Efficiency Calculation
• Water Neutrality Assessment
• Rainwater harvesting tank overflow analysis
• Irrigation sizing design

We're often asked to review drainage designs which may have resulted in overly complicated drainage systems. We are able to advise on existing designs on a site by site basis. Please get in touch so we can quote for a design review.

If your drainage design is complete and you require a quote for supply of the main components please get in touch.

• Above ground SuDS can be found here
• Below Ground SuDS can be found here
• Rainwater Attenuation Flow Control Can be found here

If you're at the pre planning stage, have a planning condition or need to satisfy building control you may require an Attenuation tank sizing design. This may have been completed by an Architect or a drainage engineer. 

In order to complete the calculation we require: 

• Roof Area (m2)
• Other hard (ground) surfaces area (m2)
• Postcode of development 
• Allowable discharge rate (l/s)
• Climate change factor (if specified) 
• Storm profile/duration (if specified) 

If you are combining attenuation with rainwater harvesting the additional info is required:  

• No of bedrooms of proposed development
• Use of rainwater - toilet flushing, toilet flushing and irrigation, toilet flushing machine washing and irrigation

Get in touch today to start the Water Neutrality and SuDS process.