The Coach House
We supported the client in discharging a SuDS Strategy condition for a site within a Critical Drainage Area in Richmond. The initial council feedback requested justification for not using infiltration measures and proposed a complex solution involving permeable paving with sub-base attenuation and pumping.
Our revised SuDS Strategy demonstrated that infiltration was unfeasible due to site constraints and groundwater conditions. Instead, we proposed rainwater planters providing 370L of above-ground attenuation, improving biodiversity, water quality and saving the client cost and construction time. The condition was discharged with no further comments.
We delivered a Sustainable Drainage Systems (SuDS) Strategy for a small residential site in Richmond, located in a Critical Drainage Area with increased susceptibility to groundwater flooding. The Council’s initial response raised several points of concern, including the lack of justification for not using infiltration methods, absence of rainwater harvesting, and no provision of hydraulic discharge control or flood exceedance routing.
Our updated SuDS report directly addressed these comments. We assessed the feasibility of the initially suggested permeable paving with sub-base attenuation and a pumped outlet and determined it to be impractical given the limited site levels, groundwater constraints, and construction complexity.
Instead, we proposed a pragmatic and policy-compliant alternative: the integration of rainwater planters delivering 370 litres of attenuation volume. These planters offer multifunctional benefits—supporting biodiversity, improving water quality, and offering visual amenity—while reducing capital cost and simplifying implementation.
Through this approach, we ensured compliance with Policy LP 21 and London Plan SI 13, and the condition was successfully discharged without further comment from the Lead Local Flood Authority.