Closing Retail Parks: Drainage, Infiltration and the Path to Repurpose

Hardstandings hide drainage surprises

Retail parks and big‑box stores often sit on expansive hardstandings with complex legacy drainage. When occupiers leave and repurposing begins—trade counters, mixed‑use, last‑mile logistics—surface‑water strategies change significantly. Planning officers will expect evidence that new layouts won’t overload networks. That’s why measured Infiltration Testing and a sitewide Phase 1 Desktop Study are the first technical steps after heads of terms are signed.

Infiltration Testing confirms whether soakaways, permeable paving or infiltration basins are feasible and at what design rates. The Phase 1 Desktop Study brings together flood mapping, known sewer connections, contamination constraints and receptor sensitivities. Join the two and you can size SuDS correctly, position features where ground conditions allow and avoid conflict with hot‑spots highlighted by the risk screen.

Design once, submit once

On a multi‑unit repurpose, early tests showed good infiltration in the southern plots and poor rates in the north. The team designed hybrid drainage—permeable paving to the south, attenuation with controlled discharge to the north—and explained the logic clearly in the planning statement. Validation was smooth; there were no RFIs about drainage because the data was there from day one.

Where car parks are to be broken up, plan WAC Testing sampling for sub‑base and soils to avoid mixing clean and impacted materials. If the site lies in a former mining area, a proportionate Coal Mining Risk Assessment prevents late‑stage surprises for foundations and utilities.

Evidence that unlocks planning

EnviroSolution’s fast Infiltration Testing and Phase 1 Desktop Study give designers the numbers they need and planners the confidence they want—so repurposing can move from concept to consent without delay.