London Surface Water Strategy

London's first surface water strategy is published here London's Surface Water Strategy | London City Hall This data forms part of the data and evidence base used to form the strategy.

• Strategy Catchments

Surface Water Catchment Partnerships (SWCPs) boundaries where relevant organisations should create the conditions to share resources, plan jointly and manage resources effectively. 

• Flood Impact Assessment

This dataset is a London-wide dataset which provides an assessment of the impacts of flood risk across London. The data is presented using  Hex Grids as its spatial unit (350m x 350m),  ensuring an assessment which considers exposure, vulnerability, and consequences to inform decision making where risk is greatest. 

Figures 10 (current risk) and Figure 13 (future risk) from the Strategy are generated using this dataset, using the methodology described in Appendix F. Refer to metadata for column headings and descriptions

• Solutions Needs Assessment

This dataset covers part of London which is considered to be at greater than average risk of flooding, as defined in Appendix B of the strategy.  

The dataset sets out which interventions are most effective in a particular subcatchment to reduce surface water flood risk, using the ‘Capture, Control, Adapt and Respond’ intervention framework as shown in Figure 15 in the Strategy.  

Subcatchments represent the indicative source, or receptor, areas in which action (‘Capture’, ‘Control’, ‘Adapt and Respond’) should be taken to address strategic priorities. These strategic priority areas are those areas which manifest either as flooded, or which provide a source of runoff that manifests flooding elsewhere. Further information can be found in Appendix J of the Strategy