SuDS should be treated as an early design input on development in Birmingham, not a final drainage calculation. Large areas of Birmingham combine dense urban drainage networks with major brownfield and regeneration sites. Early drainage design needs to establish whether runoff can be reduced or managed on site before relying on a sewer connection.
What matters on a Birmingham site
- brownfield ground conditions and whether infiltration is appropriate
- the relationship between proposed levels, exceedance routes and neighbouring property
- space for source-control or attenuation features within a constrained urban layout
- the effect of highways, basements and phased construction on drainage sequencing
The current drainage framework
For development in England, the 2025 National Standards for Sustainable Drainage Systems set out a runoff hierarchy and design expectations covering flood risk, water quality, amenity and biodiversity. Local planning and flood-risk requirements still need to be addressed for the individual site.
National Standards for SuDS provides the national framework; the project still needs a site-specific strategy and evidence appropriate to the proposed development.
Where infiltration testing fits
If infiltration is being relied upon, testing should be located and designed around the proposed drainage features rather than used as a generic site-wide assumption. Where previous land use or made ground could affect water quality, review the ground-risk information alongside the drainage proposal.
What to send us
Send the site boundary, proposed layout, levels or topographical survey where available, drainage concept, planning or flood-risk comments, and any previous ground investigation. We can then identify whether infiltration testing, drainage support or linked environmental work is needed.
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