Colwyn Bay Waterfront Project Phase 3 – Phasing Review Draft Report for Stakeholder Distribution August 2019 Conwy County Borough Council Coastal Engineering UK Ltd Environment, Roads & Facilities 26 Rhodesway Conway Road Wirral Mochdre CH60 2UB COLWYN BAY LL28 5AB e-mail: [email protected] e-mail: [email protected] Tel. 01492 575337 Tel. (0151) 558 1956 Conwy County Borough Council Colwyn Bay Waterfront Project Phase 3 – Phasing Review August 2019 CEUK Project Ref: 03/1810 Document History Record This report has been issued and amended as follows: Issue Revision Description Date 1 0 Draft for Client Comment 11/04/19 2 1 Final Draft for Client Comment 12/06/19 3 2 Draft Report for Stakeholder Distribution 29/08/19 Coastal Engineering UK Ltd 26 Rhodesway Wirral CH60 2UB Tel: 0151 558 1956 e-mail: [email protected] http://www.coasteng.co.uk This report has been prepared by Coastal Engineering UK Ltd in accordance with the instructions of their Client, Conwy County Borough Council. Information contained in this report is confidential and shall not be used, without permission in writing from Conwy County Borough Council. Metadata Addressee Conwy County Borough Council Audience Council Officers Contributor(s) Coastal Engineering UK Ltd Coverage Colwyn Bay Creator Coastal Engineering UK Ltd Created: 2019-02-25 Draft Report Issued: 2019-04-11 Date Final Draft Issued: 2019-06-12 Draft Report for Stakeholder Distribution Issued: 2019-08-29 Report to review and update potential phasing arrangements for the 3rd phase of coastal Description defence and promenade regeneration improvements at Colwyn Bay Format Text, medium=digital file Identifier 03/1810 Keywords Colwyn Bay, Waterfront, Coastal Defence, Promenade Language English Conwy County Borough Council, Environment Roads & Facilities, Council Offices, Conway Location Road, Mochdre, Colwyn Bay, LL28 5AB Mandate Council Order Publisher Conwy County Borough Council Relation Colwyn Bay Waterfront Development Rights Copyright: Conwy County Borough Council Status Draft Subject Colwyn Bay Waterfront Coastal Defence Works Title Colwyn Bay Waterfront Project: Phase 3 – Phasing Review Type Text/report Date of metadata 29/08/2019 update Colwyn Bay Waterfront: Phase 3 - Phasing Review Conwy County Borough Council CONTENTS EXECUTIVE SUMMARY GLOSSARY OF TERMS AND ABBREVIATIONS 1. INTRODUCTION & BACKGROUND ............................................................................................................ 1 1.1 Background ..................................................................................................................................... 1 2. PHASE 3 CONDITIONS APPLYING ............................................................................................................ 5 2.1 Existing Frontage Description ........................................................................................................... 5 2.2 Historical Evolution .......................................................................................................................... 8 2.3 Current Behaviour and Impacts ...................................................................................................... 10 2.4 Risk Assessment ............................................................................................................................ 12 3. PHASE 3 ARRANGEMENTS ..................................................................................................................... 22 3.1 Objectives ..................................................................................................................................... 22 3.2 Hydraulic Performance ................................................................................................................... 22 3.3 Defence Options ............................................................................................................................ 26 3.4 Potential Phasing Opportunities ...................................................................................................... 29 4. PUBLIC SERVICE IMPACT REVIEW ......................................................................................................... 34 4.1 Introduction .................................................................................................................................. 34 4.2 Responses ..................................................................................................................................... 34 4.3 Future Actions ............................................................................................................................... 38 5. FUTURE COLLABORATION ..................................................................................................................... 39 6. WAY FORWARD .................................................................................................................................... 41 7. REFERENCES ........................................................................................................................................ 43 FIGURES Figure 1: General Location Plan ....................................................................................................................... 3 Figure 2: Colwyn Bay Waterfront – Phasing Arrangements (Completed and Future Proposed) ............................. 4 Figure 3: Phase 3 Frontage Plan ...................................................................................................................... 5 Figure 4: Photographs of Existing Coastal Defences and Promenade .................................................................. 6 Figure 5: Typical Cross Sections through Existing Rock Armour Protection to Sea Wall ........................................ 9 Figure 6: Examples of Current Behaviour ....................................................................................................... 11 Figure 7: Location of Assets Protected ........................................................................................................... 13 Figure 8: Typical late 19th/early 20th century Masonry Wall Construction (ex LMSR) .......................................... 14 Figure 9: Groundcheck Survey Summary Results ............................................................................................ 17 Figure 10: Existing Highway Gates ................................................................................................................. 19 Figure 11: Average A55 HGV/LGV Traffic Flows, 2012 ..................................................................................... 21 Figure 12: Typical suggested Phase 3 concept design defined from physical model tests .................................. 25 Figure 13: Proposed Works Extents – Option 2 ............................................................................................... 32 Figure 14: Proposed Works Extents – Option 3 ............................................................................................... 33 Figure 15: Beach Access Locations ................................................................................................................ 37 APPENDICES Appendix I: Utility Service Plans ................................................................................................................... 44 Appendix II: Letter from Welsh Government – March 2019 ............................................................................. 52 Appendix III: Key Stakeholders Contact and Response Details ........................................................................ 53 Coastal Engineering UK Ltd August 2019 Colwyn Bay Waterfront: Phase 3 - Phasing Review Conwy County Borough Council EXECUTIVE SUMMARY This report was commissioned by Conwy County Borough Council (CCBC) to investigate and review options for implementing the third phase of the proposed Colwyn Bay Waterfront Project (CBWP) and to examine potential arrangements to move the project forward with regard to partnering with key stakeholders to deliver the project. The Colwyn Bay Waterfront project was conceived in 2007 as a result of a strategic assessment of options for future flood and coastal erosion risk management and comprises the provision of improved coastal defence and associated waterfront regeneration, spread over three phases. Construction commenced in 2011 and to date the Phase 1 coastal defence and waterfront regeneration works, and Phase 2a waterfront regeneration works, comprising construction of a new shoreline promontory at Porth Eirias, importation of approximately 500,000m3 of sand beach recharge, sea wall improvements and the provision of improved shoreline infrastructure, have been completed at a total cost of £28.6 million. In late 2018 Welsh Government approval was given, to proceed with the detailed design of the Phase 2b beach recharge and associated works at an estimated cost of £14 million. This work is programmed for construction in 2020-21. The proposed Phase 3 works comprise raising the promenade and constructing approximately 1200 metres of linear rock revetment coastal defence between Porth Eirias and Cliff Gardens, Old Colwyn at a current estimated cost of £35 million, which includes a 30% contingency/estimate bias/risk allowance. The Phase 3 frontage comprises a near vertical masonry sea wall that dates from the early 1900s that abuts a generally sandy foreshore. The beach in front of the wall is vulnerable to erosion during storms that has required