Decision details

21/03380/FP Land To The North And East Of Great Wymondley, Hertfordshire

Decision Maker: Planning Control Committee

Decision status: For Determination

Is Key decision?: No

Is subject to call in?: No


RESOLVED: That the application 21/03380/FP be GRANTED planning permission subject to the reasons set out in the report of the Development and Conservation Manager and the removal of Condition 7, to be replaced with two further conditions. Therefore the current Condition 9 would become Condition 10, with the other Conditions included within the report changing number accordingly. The additional conditions were:


“Condition 7:

No development including ground works and ground preparation works shall take place until a surface water drainage scheme, based on suitable drainage principles and an assessment of the hydrological and hydrogeological context of the development, has been submitted to and approved in writing by the Local Planning Authority.  The drainage strategy should demonstrate the surface water run-off generated up to and including 1 in 100-year + climate change critical storm will not exceed run-off from the undeveloped site following the corresponding rainfall event.  The scheme shall subsequently be implemented in accordance with the approved details before the development is completed.

The scheme shall also include:

  1.  A detailed response to the Letter from the LLFA dated 15 November 2022 which addresses the points of concern with the proposed surface water drainage scheme and overland flow management scheme.
  2. Carry out any necessary amendments to the proposed surface water drainage scheme and hydraulic modelling for the overland management scheme for LLFA approval.  Once the baseline information is agreed the following information should be provided;
  3. Demonstrate an overall betterment of the existing pre-development overland flow paths for the 1 in 30-year event, ensuring the flow paths are maintained and not made worse for events above the 1 in 30-year event and up to the 1 in 100 year + climate change event.
  4. Detailed engineered drawings of the proposed SuDS/flood risk mitigation features including their location, size, volume depth and any inlet and outlet features including any connecting pipe runs and all corresponding calculations/modelling to ensure the scheme caters for all rainfall events up to and including the 1 in 100 year + 40% allowance for climate change event.
  5. Detailed engineered drawings of all proposed discharge locations including headwall details, evidence of land ownership and relevant permissions.  A condition survey of these specific locations should also be provided and any mitigation required should be carried out prior to development taking place.
  6. Demonstrate appropriate SuDS management and treatment and inclusion of above ground features.
  7. Provision of half drain down times for surface water drainage features within 24 hours.
  8. Silt traps for protection of any residual tanked elements where appropriate.
  9. Construction phase surface water and flood mitigation management plan.
  10. Details of how the scheme shall be maintained and managed after completion including adoption of details.

Reason: To prevent the increased risk of flooding, both n and off site in particularly to Priory Lane and Little Wymondley.


Condition 8:

Upon completion of the surface water drainage/flood management works for the site in accordance with the timing/phasing arrangements, the following shall be submitted to and approved in writing by the Local Planning Authority:

  1. Provision of a verification report (appended with substantiating evidence demonstrating the approved construction details and specifications have been implemented in accordance with the surface water drainage scheme).  The verification report shall include photographs of excavations and soil profiles/horizons, installation of any surface water structure (during construction and final make up) and the control mechanism.
  2. Provision of a complete set of built drawings for site drainage.
  3. A management and maintenance plan for the SuDS features and drainage network.
  4. Arrangements for adoption and any other measures to secure the operation of the scheme throughout its lifetime.

Reason: To prevent flooding by ensuring the satisfactory storage of/disposal of surface water from the site.”


Report author: Ian Fullstone

Publication date: 18/11/2022

Date of decision: 17/11/2022

Decided at meeting: 17/11/2022 - Planning Control Committee

Accompanying Documents: