| 1. | In conjunction with the submission of reserved matters application(s) for layout and landscaping, full details of a Surface Water Drainage Strategy (SUDS) shall be submitted to and approved in writing by the Local Planning Authority. Notwithstanding the details of the flood risk assessment and drainage scheme provided within the outline planning application, the scheme shall provide the following details and address the following matters:
I. Detailed infiltration testing in accordance with BRE Digest 365 (or equivalent) along the length and proposed depth of the proposed infiltration basin;
II. Provision of surface water attenuation storage, sized and designed to accommodate the volume of water generated in all rainfall events up to and including the critical storm duration for the 1% annual probability rainfall event including allowances for climate change in line with the submitted Drainage strategy;
III. Detailed designs, modelling calculations and plans of the drainage conveyance network in the:
· 3.33% annual probability critical rainfall event to show no above ground flooding on any part of the
site, and,
· 1% annual probability critical rainfall plus climate change event to show, if any, the depth, volume and storage location of any above ground flooding from the drainage network ensuring that flooding does not occur in any part of a building or any utility plant susceptible to water (e.g. pumping station or electricity substation) within the development;
IV. Plans to be submitted showing the routes for the management of exceedance surface water flow routes that minimise the risk to people and property during rainfall events in excess of 1% annual probability rainfall event;
V. Finished ground floor levels of properties, which shall be a minimum of 300mm above expected flood levels of all sources of flooding or 150mm above adjoining ground level, whichever is the more precautionary;
VI. Details of how all surface water management features are designed in accordance with the SuDS Manual (CIRIA C753, 2015), including appropriate treatment stages for water quality prior to discharge; and,
VII. A maintenance and management plan detailing the activities required and details of who will adopt and maintain all the surface water drainage features for the lifetime of the development. This will also include the ordinary watercourse and any structures such as culverts within the development boundary.
There shall be no commencement of development until the surface water drainage scheme has been approved in writing by the Local Planning Authority, and the development shall thereafter be carried out in full accordance with the details approved. The drainage shall thereafter be installed and made available for use prior to the first residential occupation of any dwelling within the development."
This application was supported by a Drainage Strategy and additional supporting documents submitted on 6th March 2024. The County LLFA has considered the information acceptable and therefore the condition can be discharged in part only.
Reason for partial discharge: -
The second part of the condition requires development to be carried out in accordance with these approved details and implemented prior to the occupation of any dwelling on site. |
