preliminary flood risk assessment drain london

3.3.3 Consequences
Very few details were provided as to the consequences of specific historic flood events, making
the assessment of the past significant events difficult to undertake.
3.4 Security, Licensing and Use Restrictions
A majority of the data provided for this study has been specifically provided for this study (for
use by the LLFA and their consultants) is not publicly available; therefore there are restrictions
on data use. A number of specific agreements have been put in place for the PFRA and SWMP
to facilitate the sharing of data between partners:
� GIS licences for mapping and data supplied by LBB
� British Geological Society (BGS) licence for geological data supplied by GIS - Usage
limited to work undertaken on behalf of GLA. Specific conditions relating to use of
DIGMap
� British Waterways - Canal network is only for use by Tier 2 Consultants for the SWMPs
as part of Drain London programme.
� Environment Agency - Data was supplied with the restriction “access only for: GLA, Local
Authorities and their consultants for Geo-Portal. Only for surface water management
plans, strategic flood risk assessments or preliminary flood risk assessments".
� GLA – Only to be used for Drain London programme and in accordance with OS
Contractor License issued by GLA.
� Highways Agency - Data provided to GLA for use under Drain London programme.
Users must abide to the Memorandum of Understanding.
� London Fire Brigade - Only to be viewed by the Council and Tier 2 consultants
� London Underground – Subject to own Terms & Conditions
� Natural England - Standard Natural England terms of use apply
(http://www.naturalengland.org.uk/copyright )
� Network Rail - Only to be viewed by the Council and Tier 2 consultants
� National Health Service – None Identified
� Transport for London – None Identified
� Thames Water - All data subject to conditions. Sewer flooding incidents (DG5 register)
were supplied collated by 4 figure postcode area in order to prevent identification of
individual properties at risk
3.5 Quality Assurance
Flood historical data was assessed for its data quality and suitability for use in the Assessment
of Significant Risk as per the Environment Agency’s PFRA Guidance. Further quality checks
were undertaken as part of the PFRA in accordance with DEFRA guidance xi .
UA002334 - Drain London— London Borough of Brent PFRA
Hyder Consulting (UK) Limited-2212959 Page 11
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