In the High Court case of Menston Action Group v City of Bradford Metropolitan District Council  the claimant challenged a planning permission arguing (amongst other things) that planning committee members were significantly misled by the committee report about the extent of the alleged benefits from the surface water drainage provision that was to be made by the development when they were advised that the development proposals would add a storage volume of more than 50% in addition to that presently available at the site.
The claimant said this claim was incorrect.
It omitted the additional requirement for 32.4m³ of storage for surface water discharge arising from the impermeable parts of the site. The claimant said that this amounted to a legal error.
The claimant said condition 5 of the planning permission required that the development be carried out in accordance with the details which were specified in the Flooding and Draining Assessment (“FDA”) which had supported the planning application. In particular the underground storage of 199.2m³ and the discharge flow or pass forward rate of 5 l/sec were required.
Condition 5 required the additional control of runoff or pass forward rates to retain a 50% uplift or increase in flood storage over the existing provision at the site.
The claimant said the details the Council approved to discharge one of the planning conditions changed the pass forward or runoff flow rate and the underground storage volume rendering the discharge unlawful.
The court said it was not possible to interpret condition 5 as requiring identical mitigation measures to those set out in the FDA. It sufficed that the mitigation measures were of the kind, or matched those identified in principle, within the FDA.
Had the conditions required the mitigation proposals to be exactly the same as in the FDA there would have been no need, for example, to provide for further finalising of runoff rates.
Other conditions required further details, calculations and fine tuning in relation to surface water drainage as the project progressed towards implementation.
The drawing mentioned in condition 5 was a “schematic” drawing. It was not intended to be a detailed engineering drawing for actually implementing the consent. “Schematic” laid down the principles but contemplated that:
– further detailed work would be provided, and
– the detail of what was depicted on the drawing would alter prior to the development actually being commenced.
The conditions provided for the Council to vet any further necessary and important detailed work.
The reality was that the details which had been discharged in relation to the conditions ensured that there would be a 50% increase in the site’s storage capacity since the reduction in the pass forward flow ensured that there would be no erosion of the flood storage available to the watercourse.
Condition 6 said:
“No development shall take place until details for proposals for dealing with any existing watercourses, culverts, land drains etc encountered during the works are submitted to and approved in writing by the Local Planning Authority….”
The claimant said the details which had been approved would not provide protection to the existing watercourse from additional discharge of water into it.”
Disagreeing with the claimant, the court said were the works to disclose any unknown watercourse, culvert or land drain which did not accord with the approved details, those details required an amended drainage drawing to be submitted to the Council to get any necessary consent prior to any further drainage work.
This safeguarded against any unknown watercourses being diverted to add to the load of the existing watercourses.
A recent appeal based on Condition 15 of the planning permission has been dismissed by the Court of Appeal (q.v.).
This blog has been posted out of general interest. It does not replace the need to get bespoke legal advice in individual cases.