Urgent Update – 17/504412/FULL– Iden Grange – Item 22 main agenda and Item 10 on the adjourned meeting agenda
Section 5 ‘Consultations’ add the following consultation response:
Given the density of the development and space available within the site we would agree that a workable drainage solution could be developed to ensure an adequate and acceptable drainage design. If your authority is minded to approve the application we would recommend three conditions that relate to provision of a detailed sustainable surface water drainage scheme, submission and approval of an operation and maintenance manual and submission of a Verification Report.
Add following as conditions 21 to 23.
Development shall not begin until a detailed sustainable surface water drainage scheme for the site has been submitted to (and approved in writing by) the local planning authority. The detailed drainage scheme shall demonstrate that the surface water generated by this development (for all rainfall durations and intensities up to and including the climate change adjusted critical 100 year storm) can be accommodated and disposed at an agreed discharge rate without increase to flood risk on or off-site. The drainage scheme shall also demonstrate that silt and pollutants resulting from the site use and construction can be adequately managed to ensure there is no pollution risk to receiving waters. The drainage scheme shall be implemented in accordance with the approved details prior to first occupation of the development (or within an agreed implementation schedule).
To ensure the development is served by satisfactory arrangements for the disposal of surface water and to ensure that the development does not exacerbate the risk of on/offsite flooding. These details and accompanying calculations are required prior to the commencement of the development as they form an intrinsic part of the proposal, the approval of which cannot be disaggregated from the carrying out of the rest of the development.
No building hereby permitted in any phase shall be occupied until an operation and maintenance manual for the proposed sustainable drainage scheme is submitted to (and approved in writing) by the local planning authority. The manual at a minimum shall include the following details:
• A description of the drainage system and it's key components
• A general arrangement plan with the location of drainage measures and critical features clearly marked
• An approximate timetable for the implementation of the drainage system
• Details of the future maintenance requirements of each drainage or SuDS component, and the frequency of such inspections and maintenance activities
• Details of who will undertake inspections and maintenance activities, including the arrangements for adoption by any public body or statutory undertaker, or any other arrangements to secure the operation of the sustainable drainage system throughout its lifetime The drainage scheme as approved shall subsequently be maintained in accordance with these details.
To ensure that any measures to mitigate flood risk and protect water quality on/off the site are fully implemented and maintained (both during and after construction), as per the requirements of paragraph 103 of the NPPF and its associated Non-Statutory Technical Standards.
No building on any phase (or within an agreed implementation schedule) of the development hereby permitted shall be occupied until a Verification Report pertaining to the surface water drainage system, carried out by a suitably qualified professional, has been submitted to the Local Planning Authority which demonstrates the suitable operation of the drainage system such that flood risk is appropriately managed, as approved by the Lead Local Flood Authority. The Report shall contain information and evidence (including photographs) of earthworks; details and locations of inlets, outlets and control structures; extent of planting; details of materials utilised in construction including subsoil, topsoil, aggregate and membrane liners; full as built drawings; and topographical survey of ‘as constructed’ features.
To ensure that flood risks from development to the future users of the land and neighbouring land are minimised, together with those to controlled waters, property and ecological systems, and to ensure that the development as constructed is compliant with the National Planning Policy Framework.