In Epping Forest District, assess flood risk and proposed surface-water drainage separately. A Flood Risk Assessment addresses safety and the development's effect on flooding; the drainage design explains how runoff will be managed. The Environment Agency's application guidance and Essex County Council's drainage requirements address these related but different tasks. [1][2]
When is a Flood Risk Assessment needed?
Environment Agency guidance identifies development in Flood Zones 2 or 3 and sites of one hectare or more in Flood Zone 1 among the triggers. Smaller Zone 1 sites can also need assessment because of surface-water risk, future risk, critical drainage problems or relevant local assessment findings. Being outside a mapped river-flood zone is therefore not enough to conclude that no flood evidence is needed. [1]
The assessment should address the relevant sources of flooding, the lifetime of the proposal and climate change, not just the nearest river. Where there is a risk, the layout and safety response need to follow from the evidence. [1]
Who reviews the drainage?
Essex County Council has been the statutory surface-water drainage consultee for major development since 15 April 2015, acting as Lead Local Flood Authority. Its role concerns runoff and drainage matters within the planning process; the district council remains the planning authority for the ordinary council application route. [3]
Minor applications are not simply exempt from drainage consideration. Essex publishes separate guidance for them and may be consulted where flooding is a concern. The information should be proportionate, with attention to hard surfaces, disposal of runoff and effects beyond the site. [4]
What should a drainage submission contain?
Essex's guidance distinguishes outline evidence from the greater detail expected at full application stage. The proposed discharge route, storage, layout and feasibility must be addressed early; more detailed submissions identify the drainage network, levels, outfalls, climate allowances and maintenance arrangements. Leaving the discharge destination unresolved can leave the scheme's feasibility unresolved too. [2]
As a practical checklist, ask the drainage designer to show:
- Where rainfall from roofs and hard surfaces goes, and why that destination is suitable.
- How runoff is stored or controlled, including what happens if the system is exceeded.
- Who can access, inspect and maintain each component over time. [2][5]
Is a soakaway always the answer?
No. Essex's drainage hierarchy prioritises options such as reuse and infiltration before less preferred sewer disposal, but the choice needs evidence and must suit the site. Infiltration cannot simply be assumed. Where water crosses another owner's land or uses an outfall outside the applicant's control, permission and delivery arrangements need checking. [6][4]
Sustainable drainage is also wider than underground storage. The national standards cover water destination, runoff control, water quality, amenity, biodiversity and long-term operation. Consider these together rather than selecting a drainage product before the site assessment. [7]
What must be secured before implementation?
The August 2026 NPPF's policy F8 requires a proportionate sustainable-drainage response where development affects drainage, with suitable maintenance arrangements. For major development, the Lead Local Flood Authority's advice is relevant. The policy connects drainage design to the national standards rather than treating it as an optional drawing annotation. [8]
Agree responsibility and funding for maintenance instead of assuming that planning approval means a public body will adopt the system. Essex's guidance asks for clear arrangements for ongoing operation. [5]
Finally, culverting or obstructing an ordinary watercourse can require separate consent from Essex County Council. Planning permission does not replace that consent. Identify affected ditches and watercourses before finalising the construction drawings, rather than discovering a separate approval requirement when works begin. [9]