Dorset Coastal Forum Holes Bay FCERM Projects 17th June 2021 BCPMatt Mission Hosey statement here Head of Flood and Coastal Erosion Risk Management Overview • Holes Bay Saltmarsh Regeneration feasibility study • Poole Bridge to Hunger Hill flood defence scheme • Creekmoor and Sterte flood defence schemes Holes Bay Saltmarsh Regeneration Pressure on natural habitat Copyright of Poole Harbour Commissioners Saltmarsh decline 1924-1981 • 62% Spartina die back during that epoch • Significant losses since 1981 • Increasing pressure with SLR and sediment loss Image courtesy of: A J Pearson and J M Pearson Continued saltmarsh loss without intervention • Estimated around > 140ha loss between 1924 and 2019 • How many years until the saltmarsh erodes completely, especially with sea level rise? 1924 – Pearson & Pearson 2019 – courtesy of CCO Saltmarsh Regeneration Feasibility • £60k Local Levy bid • Average 10,000m3 dredged from Cobbs Quay, and Davis Boatyard • Average 1,000m3 dredged from RNLI ad hoc (typically every 3-5yrs) • Two key areas of eroding saltmarsh in close proximity to dredging operations • Environmental designations (SSSI, SPA, RAMSAR) Desktop studies/site visits Case studies • Lymington • Levington • Wallasea • Brightlingsea Lessons learned Extraction / Deposition / Plant & Materials / Sediment Retention / Constraints / Success & Evidence / Licencing / Challenges Methods change with experience • Clearer understanding of risks and impacts • Empirical evidence for licence approvals Methods for beneficial re-use/ deposition Market research for suitable methods and indicative costs Methods for silt retention Preferred option • Cutter suction dredging • Natural sediment barriers • E.g. heather bales • Stakeholder Liaison • Marina dredge campaigns • Licencing / consents • Funding parties • Monitoring • Habitat introduction Poole Bridge to Hunger Hill Flood Defence Scheme Scheme extents & flood risk • Historic expectation of flood defences through planning constraints on new development • Incentives still not encouraging delivery (0% CIL) Landowner / Stakeholder Consultation July 2019 – Presentation to Landowners • Scheme project management / EA / BCP planners • Proposal for single scheme led by BCP • Very positive feedback • Recognition of contribution need • Local Levy bid for OBC (£310k) • WSP lead via BCP framework agreement • Integrated delivery to address regen potential 14 Key factors in OBC Flowroute Poor wall condition Existing Defences 230 properties at risk by 2120. 50% AEP event in 2120 15 Poole Bridge to Hunger Hill Flood Defences • Historically awaiting developer led flood defence measures (including 0% CIL) • 2018 – Council led progression of single scheme • OBC submission in Oct 2020 (after Sep Cabinet approval) – £12.5 million scheme – Benefit from June project appraisal rule changes – Significant impact on regeneration / development opportunity – Place making scheme • EA Large Projects Review Group (LPRG) mid Nov • Approved Jan 2021 • Detailed design / stakeholder consultation underway Poole Bridge to Hunger Hill Flood Defences • Flood risk mitigation to unlock development • Enables delivery of planning aspirations • Promenade • Café front culture • Connectivity • Complements Twin Sails / power station site developments • Integrates existing Poole Town Centre with Holes Bay • BCP to manage asset going forwards Creekmoor and Sterte tidal flood defences Creekmoor & Sterte - Open channels into Holes Bay • OBC options for tidal and combined solutions • Preferred options at this point in time for tidal defences • Obvious benefits for Surface Water attenuation Layout of Defences Construction • OBC project delivery - Sterte £390k Creekmoor £250k • Procured under single contract • Avon Construction • Tendered combined construction value - £400k • Total cost – Sterte £322k Creekmoor £203k • Included new pump and flap valves at Sterte PS • Improved cycle access • Appetite for repeating at Fleetsbridge inlet Thank you [email protected].