Outline application requirements
Application details
- Application number.
- Site address.
- Site co-ordinates and/or What3Words reference.
- Site are in hectares.
- Existing site usage.
- Proposed development.
- Existing site plan.
- Proposed development plan/masterplan.
Flood Risk
Sufficient information should be submitted which shows, in principle, that the development will be safe from flooding for its lifetime and will not increase flood risk elsewhere. This should include as a minimum:
- A plan showing the flood zones of the site.
- A plan showing the surface water risk of the site.
- A Flood Risk Assessment which meets the requirements of the Environment Agency and DEFRA as set out in their online guidance: Flood risk assessments: applying for planning permission - GOV.UK.
- Outline information into how safe access during the design flood and emergency egress during the extreme flood could be achieved as part of the development.
We advise applicants that flood risk from all sources of flooding should be treated consistently, and no single source of flooding should be considered more important than another. In line with national guidance flood risk assessments should consider the design flood event from all sources as well as greater frequency flood events, especially the 1:30 flood event.
In areas of increased flood risk the level of detail required, even at outline application stage, is likely to be significant and may require site specific flood modelling.
It is advised that developers engage in pre-application discussions with the LLFA if their development incorporates more or highly vulnerable development and/or the site is subject to increased flood risk from any source.
Drainage
At outline application stage applicants should be able to provide evidence that, in principle, surface water drainage will be possible for the type and scale of development proposed.
We advise that infiltration drainage is generally difficult to achieve due to the poor infiltration potential of much of our geology and high groundwater levels found across the county.
As a minimum we would expect the following information/plans to be presented as part of an outline drainage strategy:
- Topographic survey.
- Details of existing drainage of the site (man-made and natural).
- Existing and greenfield runoff rates and volumes.
- Outline proposed runoff rates and volumes (based on impermeable/hard landscape areas of submitted masterplan layout).
- A plan showing the proposed outline drainage strategy, including proposed attenuation areas and discharge points.
- An outline drainage strategy report which demonstrates compliance with the national Planning Practice Guidance, the non-statutory technical standards and any relevant Local Planning Authority drainage policies.
- If infiltration drainage is proposed, then evidence that winter groundwater levels and infiltration potential of the site have been investigated and considered will be required.
