The soakaway tank work started yesterday 100%
Condition 7:
Development shall not commence (other than site clearance and site preparation, and the demolition of properties and associated works in Wooderson Close)
i) other than in accordance with the submitted Flood Risk Assessment and Drainage Strategy (Mott Macdonald, 31st Jan 2018, document reference: 392351 MMD-00_RP-C-003) and Addendum to Flood Risk Assessment (Mott Macdonald, March 2018, document Ref: 392351-MMD-00-RP-C-004 Rev 001), and a memo and letter produced by Lyons O'Neil reference 22079/LON/230522 and 22079/LON/15072022; and
ii)
until a finalised drainage strategy has been submitted to and approved by the Local Planning Authority in consultation with the sewerage undertaker and the Lead Local Flooding Authority. No discharge of foul or surface water from the site shall be accepted into the public system until the drainage works referred to in the strategy have been completed. The drainage strategy required under paragraph ii) of this condition shall provide for the following:
1) Details of any on and/or off site drainage works;
2) Updated supporting calculations showing:
a. Proposed discharge rate of 12.93l/s for the 1 in 100 year plus 40% allowance for a climate change storm event without flooding, proposed storage volume to be updated accordingly; and
b. Details to be provided to show how the discharge rate for the 1 in 1 year and 1 in 30 year storm event will be limited to the equivalent 1 in 1 year and 1 in 30 year greenfield run-off rates respectively, including detailed design drawings of the flow control structure.
3) Details of the proposed mitigation measures for exceedance flows greater than the 1 in 100 year plus 40% allowance for a climate change storm event, and in the event of drainage system failure;
4) Evidence of confirmation from Thames Water that the proposed surface and foul water discharge rates and connections points are acceptable;
5) A Drainage Layout Plan (to scale) of the final drainage scheme in line with the requirements of a Drainage Strategy Layout Plan as stated in section 8.2 of Croydon's LLFA requirements for sustainable drainage proposals supporting Full Planning Permission, and in particular confirming the location and dimensions of all SUDS features;
6) An assessment of whether further permeable paving can be provided to the Selhurst Park car park and whether a rainwater harvesting tank (or grey water tank) is feasible for part of the works; and
7) Details of the management and maintenance for all SUDS and how they will be secured for the lifetime of the development (maintenance plan). Furthermore, detail to be provided with regards to upgrading, management and maintenance of the existing pumping stations, including details of the proposed addition of a back-up pump and telemetry system.
REASON: To ensure that the development achieves as close as reasonable greenfield run-off rates in line with policy and to prevent the development from causing flooding. The development in particular may lead to sewage flooding as such the condition is needed to ensure that sufficient capacity is made available to cope with the new development and in order to avoid adverse environmental impact upon the community.
Condition 29
No piling shall take place
until a Piling Method Statement has been submitted to and approved in writing by the Local Planning Authority. The Piling Method Statement must detail the depth and type of piling to be undertaken and the methodology by which such piling will be carried out, including measures to prevent and minimise the potential for damage to subsurface water infrastructure. Additionally the Piling Method Statement must demonstrate that there will be no resultant unacceptable risk to groundwater.
Any piling must be undertaken in accordance with the terms of the approved Piling Method Statement.
REASON: The proposed works will be in close proximity to underground water utility infrastructure. Piling has the potential to impact on local underground water utility infrastructure.