Flooding from other sources an update for LoTAG members

2. Flooding from other sourcesan update for LoTAG members Name Tom Sampson Job title Flood Risk Mapping Technical Specialist Date April 2009

3. Presentation outline • Quick intro to Drain London • Areas susceptible to surface water flooding • Collation of existing historic flood records • Future data collection • Links to Drain London Forum

4. Drain London Forum – gaps in flood risk understanding Well defined, high risk of fluvial flooding Well defined, low risk of tidal flooding Poorly defined, unknown risk of pluvial flooding

5. Drain London Forum – the partnership …all organisations with an interest in managing flood risk in London • Forum steering group to set direction. • Technical working group to deliver. • Requires a commitment from all partners. • Use of consultants as required. Greater London Authority Transport for London London Councils London Boroughs Highways Agency Environment Agency Thames Water

6. Pitt review report recommended we urgently identify areas at highest risk from surface water flooding. This map is the first deliverable from the national project set up in response. The Environment Agency made a commitment to deliver surface water susceptibility data to Local Resilience Forums in August 2008. In May 2009 the data will be licensed for non-emergency planning uses. Introduction to Environment Agency work

8. Historic data request (1) • Request sent to all organisations who may hold historic flood data • Sent to local authorities, water companies, emergency services etc. • Addressed to the drain London contact and chief executive. • Historic flood data will be used to validate and add value to areas susceptible data • We are aiming to have: • 80% of data by April 2009 • 100% of data by December 2009

9. Historic data request (2) • We are looking for point data such as property flooding and areas flooded. • We have set a format and data standards • Supply of data electronically allows more efficient collation • We will comply with the data protection act • Please specify sensitive datasets.

10. Future flood data collection • We are working with the Drain London Forum to recommend using these data standards for future flood data collection • Consistent data sets collected by all organisations will help response and recovery to flood events

11. Links to Drain London Forum • Environment Agency contributes to the forum steering group and technical working group • Drain London scoping report identifies data requirements for future strategic and local studies • Historic flood data is critical to prioritise and validate future work

12. London Technical Advisors Infrastructure Group Drain London Scoping Study and Data AssessmentStuart Fraser & Stuart Taylor Tuesday 21st April 2009

13. Drain LondonScoping Study and Data Assessment Study Background Objectives Findings Recommendations

14. Scoping Study and Data Assessment Background • Multiple organisations have responsibility for surface water management in London • 2007 summer flooding and Pitt Review • GLA formed the Drain London Forum for parties with an interest in flood risk management • Aspiration: to coordinate and plan surface water management across Greater London area • Scoping Study is the first phase of this work

15. Scoping Study and Data Assessment Objectives • Report on • Location, quantity, quality and ownership of data relating to the drainage network, flood incidents and ‘other’ data • The ‘right’ amount of data to meet the Drain London aims • Critical data gaps • Data accessibility issues • Display data in Spatial Metadata Database • Recommend options for managing data • Align with EA Historic Flood Event Data Capture

16. Scoping Study and Data Assessment Spatial Metadata Database

17. Scoping Study and Data Assessment Findings • 428 sources of information identified and described 53 by organisations • Relationships with organisations are critical to identifying and describing data • Critical Data Gaps were identified for • Flood event data • Critical infrastructure data • Private drainage infrastructure

18. Scoping Study and Data Assessment Recommendations • Adopt Hierarchical Approach to Risk Assessment (3 Stages of Modelling)

19. Scoping Study and Data Assessment Recommendation 1: Hierarchical Approach Step 1 - Surface model and historic flooding

20. Scoping Study and Data Assessment Recommendation 1: Hierarchical Approach Step 2 - Integrated model with simplified flood assessment

21. Scoping Study and Data Assessment Recommendation 1: Hierarchical Approach Step 3 - Integrated model with detailed flood assessment

22. Scoping Study and Data Assessment Recommendations • Address Critical Data Gaps • Prioritise management of gaps at Step 1 & Step 2 • Obtain flood event data and add to Spatial Database • Collect and score critical infrastructure data • Confirm availability of terrain data and models • Obtain additional sewer data through continued dialogue with private landowners/housing associations • Consider approach for addressing gaps in TWUL sewer data • Agree Common Format of Data Capture • Develop Spatial Data Infrastructure

23. Scoping Study and Data Assessment Recommendations: SDI – The Technology User Interface Business Logic Business Data Spatial Database Data-Centric Web-Enable GIS Spatial Data Infrastructure

24. Scoping Study and Data Assessment • Thank you…any questions?