WwNP / NCM - A Lead Local Flood Authority Guide

Transcription

1 - to report flooding online WwNP / NCM - A Lead Local Flood Authority Guide 3 rd May 2018 Shaun Wasik - CCBC Pedr Jones Waterco Ltd. shaun.wasik@conwy.gov.uk pedr.jones@waterco.co.uk

2 Setting the Scene 1. We have tried various WwNP elements 2. Kilkenny Flood Partnership 3. Choosing a Catchment 4. WwNP Handbook for Wales

3 Presentation Agenda 1. Project background 2. Project driver 3. Selecting a suitable catchment 4. Interventions that will make a difference 5. Next stages and lessons learnt

4 Project Background Local and National Strategy Commitments National Strategy for Flood and Coastal Erosion Risk Management in Wales (November 2011) constructing more and higher defences is not a sustainable solution environmentally By working with natural processes and applying the ecosystem approach, risk management measures can also be more sustainable.. Conwy s Local Flood Risk Management Strategy (March 2013) 7. Take a sustainable approach to flood risk management.. 8. Increase approaches that utilise the natural environment. 10. Identify projects and programmes which are affordable, maximising capital funding from internal and external sources.

5 LLFA Flood Alleviation The Traditional Approach 1. Respond to a Flood Event 2. Produce s19 Flood Investigation Report 3. Seek funding for Outline Business Case / PAR 4. Seek funding for Detailed Design 5. Seek funding for Construction Pros Levels of Protection can be Quantified Allowance for Climate Change Clear Understanding of Maintenance Duties Not many Uncertainties Cons Can be Expensive to Install and Maintain Long Process from Start to Finish Uncertainty for Communities WG and LLFA are only Funding Sources

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8 1580 Flooding Incidents Blue 202 OWC Enquiries - Magenta Assets

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10 CCTV and Telemetry Systems

11 Asset Maintenance

12 Working with Natural Processes Where to Start? 1. Identify a Community at Risk 2. Seek Funding to Investigate 3. Try to make WwNP the principle solution in our experience this does not work in islolation! We then tried.. 1. Using CCBC staff to utilise WwNP 2. Ad-hoc Community Events 3. Partnering with Consultants still did not work!

13 2017 / 2018 Pilot Work With Assistance from Welsh Government.. 1. Appoint Project Manager 2. Choose a Catchment 3. Develop Wales WwNP Handbook?????????????????????

14 Presentation Agenda 1. Project background 2. Project driver 3. Selecting a suitable catchment 4. Interventions that will make a difference 5. Next stages and lessons learnt

15 Project Driver Reduced Flood Risk Improved Water Quality Enhanced Biodiversity Increased Carbon Capture and Storage Improved Recreational, Education & Health Facilities Job Opportunities Enhanced Farming Opportunities.

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17 Presentation Agenda 1. Project background 2. Project driver 3. Selecting a suitable catchment 4. Interventions that will make a difference 5. Next stages and lessons learnt

18 Selecting a Suitable Catchment Where do you start? JBA Trust & Lancaster University

19 GIS Exercise Catchment LiDAR Extract FZ 2 & 3 Extract tidal flood risk Conwy flood records NRW Urban Areas Consider surface water maps Valid / Invalid Records Derive catchments Review catchment size and look for non-nested catchments

20 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

21 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

22 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

23 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

24 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

25 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

26 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

27 Catchment LiDAR Conwy flood records Valid / Invalid Records Derive catchments NRW Urban Areas Extract FZ 2 & 3 Extract tidal flood risk Consider surface water maps Review catchment size and look for non-nested catchments

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29 Hydrological Assessment

30 Chosen Catchment

31 Site Walkovers

32 Landowner Information

33 Presentation Agenda 1. Project background 2. Project driver 3. Selecting a suitable catchment 4. Interventions that will make a difference 5. Next stages and lessons learnt

34 Interventions that Will Make a Difference

35 Chosen Sub-Catchment Debris Dams 50k + Ecological Improvement 22k

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38 Additional Sub-Catchment Interventions Debris Dams 50k + Ecological Improvement 22k Storage Areas 80k Embankment 80k

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40 Key Observations A systematic approach can help set a local authorities appropriate targets for WwNP techniques and aid the Community Conversation accordingly

41 Presentation Agenda 1. Project background 2. Project driver 3. Selecting a suitable catchment 4. Interventions that will make a difference 5. Next stages and lessons learnt

42 Next Stages.. 1. Funding 2. Landowner engagement 3. Share methodology 4. Welsh WwNP Handbook consultation Lessons Learnt.. 1. Fulltime resources are required 2. Choose suitable catchments don t force fit 3. Understand future funding streams 4. Landowner engagement will be key 5. Still many questions to answer.

43 Areas still to be addressed 1. Will communities take ownership of local flood risk? 2. What funding is available in Wales? 3. How do we quantify a successful scheme? 4. What maintenance is required? 5. Who is responsible for maintenance? 6. Only green solutions? 7. How do we share our results? THANK YOU FOR LISTENING