In order to ensure that the Surface Water Drainage Strategy
complies with the minimum requirements of the Technical
Standards, the following must be demonstrated as part of the
submission.
Runoff Destinations – PPG Paragraph 080
 Evidence must be provided to justify the proposed runoff destination.
Flood risk outside the development - Technical Standards S1

The design of the drainage system must demonstrate that it will not increase
flood risk.

Any planning application would need to be accompanied by evidence from an
appropriate authority or land owner indicating the acceptability of a discharge
location and consent to connect or consent to discharge. The requirement to
provide this evidence may be subject to a pre-commencement condition.
Peak flow control – Technical Standards S2 and S3

Evidence must be provided to establish the greenfield runoff rate for the site.

For previously developed sites, evidence must be provided where the greenfield
runoff rate cannot be reasonably practicably achieved.
Volume control – Technical Standards S4, S5 and S6

The drainage strategy as part of the planning application should clearly
demonstrate that the runoff volume is controlled.

Calculations must be provided to demonstrate that the maximum discharge
volume does not adversely affect flood risk.
Flood risk within the development– Technical Standards S7, S8 and
S9

The drainage strategy submitted as part of the planning application must
include design calculations to support all the design criteria together with
applicable drawings, plans and specifications.

Flow paths and attenuation components (including depths, velocities and
exceedance routes) should be clearly shown for the above and below ground
drainage system to demonstrate that flooding does not occur in any part of a
building or utility plant for the design areas and help mitigate risks to people
and property on and off site.
Structural integrity - – Technical Standards S10 and S11

Information must be submitted to the LPA so that they can be satisfied that
the drainage systems can be adequately maintained over the life-time of the
development.
Designing for maintenance considerations– Technical Standards
S12, PPG Paragraph 085

Information to support the planning applications must demonstrate:
o that the life expectancy of the various components of the drainage
system. Where life expectancy is less than the development life
expectancy, component replacement needs to be included in
maintenance cost estimates.
o that adequate access is available and practicable for personnel and
equipment either through an appropriate layout or legal agreement to
provide agreed access arrangements for the life-time of the
development.

Information to support the planning application should include indicative
maintenance requirements which may include, but not limited to:
o A list of all maintenance requirements that would be carried out over
the life-time of the development, including but not limited to system
monitoring, regular inspection and routine maintenance, occasional
maintenance and remedial maintenance.
o A specification which details the materials to be used, the standard of
work required a maintenance schedule of work, list of hazards, risk
assessments and control measures required to ensure maintenance
work can be safely undertaken in accordance with Health and Safety
legislation, regulations codes of practise etc. (including the Confined
Space Regulations etc.)
o Information on costs of on-going operation and maintenance activities
which requires specialist plant, materials or techniques.
o Information concerning hazardous waste arising from the ongoing
maintenance of the drainage system.
Construction– Technical Standards S13 and S14

The LPA may require submission of evidence to show compliance with these
standards.