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: 

1. Infiltration (percolation/Soakaway) test to BRE 365
2. SuDS soakaway sizing to BRE 365
3. SuDS attenuation tank sizing
4. Comparative Pre and Post development SuDS attenuation tank sizing
5. Flow regulator selection: Vortex, Orifice, Floating Orifice or Pumped.
6. Drainage Design Plan, Manhole Schedule, Drainage Plan, supporting calculations
7. Overland/Surcharge/Flow Exceedance analysis
8. Wastewater Drainage Field Soakaway Sizing Calculation
9. Flood Risk Assesment.
10. 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.