The first SuDs manual was published in 2007, but we’ve been using techniques like French (gravel) drains and soakaways to brake flows and avoid localised flooding since the mid 1990s.
However, changes to planning policy and the establishment of Lead Local Flood Authorities (LLFA) in 2012 (who are generally the same body as the Local Planning Authority (LPA)) have led to the increased requirements for the use of Sustainable Drainage Schemes (SuDS) to be included in the design of all new developments. This change has been led by flooding and sewer capacity concerns due to the amount of green and brownfield sites being developed with conventional systems that increase flooding on any catchment.
So although new to many, we are adept and experienced in developing SuDS designs. A design is generally split into two phases. Firstly a site and development specific conceptual SuDS design is developed. This level of design is often the most cost-effective means for developers to include some detail on the proposed scheme at planning stage (that meets the standards of the Royal Institute of British Architects (RIBA) stage 2) and allows a planning condition from the LPA to be set for what is called a ‘developed design’.
Once planning approval has been obtained, the second phase begins with a detailed SuDS design, which will include more detail on the scheme at RIBA stages 3-6. Planning conditions will usually require the Council (as the LLFA) to approve the various stages and calculations for the scheme.
Peak Associates has experience in this area having worked on developments large and small across every LPA in the North West of England. Peak’s engineering team can provide vital help and support throughout the development’s progress to ensure that the design can remain flexible and incorporate any issues that are discovered as the build progresses (such as a groundwater spring found on a recent site).
Benefits and Summary of Services Provided:
- Sequential land use and exception tests as appropriate
- A site and development-specific report (conceptual or detailed design) tailored to meet your needs and completed to National Planning Policy Framework guidance to get your scheme approved
- This will be developed from the understanding of hydrology and flood risk, typically from an FRA
- Recommendations on adaptations to proposed designs by experienced professionals
- We favour the use of green solutions rather than hard-built engineering solutions where possible
- Such schemes deliver years of performance with a failsafe to a conventional route in high flows and low/no maintenance