News - 24/05/16

Cowes Harbour Commission’s (CHC) public presentation and review of the Outer Harbour Project was held on 19th May 2016 at the Island Sailing Club in Cowes with an audience of over 100 stakeholders and harbour users attending. Hydrodynamic consultants ABPmer and programme managers Marina Projects were also present.

The purpose of the meeting was to deliver an update on progress with the Outer Harbour Project (OHP), report on the review carried out over the past year, and provide information on the consultation process that CHC is conducting regarding the proposed changes to the already consented Outer Harbour Project scheme. 

Following an introduction by recently elected Chairman of Cowes Harbour Commission, David Riley, the Harbour Master Capt. Stuart McIntosh gave a summary of the OHP review carried out and the optimisation proposed as a result of that review. A technical overview of the tidal and sedimentation modelling was delivered by Gordon Osborn, ABPmer’s Head of Modelling, supported by Managing Director Bill Cooper. After the ABPmer presentation, Stuart McIntosh summarised the proposed way forward and David Riley concluded with an explanation of the consultation process. The joint presentation was followed by a question and answer session.

OHP Presentation & Review – Supporting Documents
As advised at the Outer Harbour Project public meeting, Cowes Harbour Commission is publishing the following documents to ensure that stakeholders are fully informed during the month-long consultation process, which runs until Tuesday, 21st June.

Comments and feedback may be submitted by emailing CHC or the Advisory Committee (CHAC): chc@cowes.co.uk or chac@cowes.co.uk, or via your Advisory Committee representative.

– Cowes Outer Harbour Project Presentation 19th May 2016 (CHC)
– Cowes Outer Harbour Project Presentation 19th May 2016 (ABPmer)
– Video animations from the Cowes OHP Presentation 19th May 2016 – see below (ABPmer)
– Cowes Outer Breakwater Hydrodynamic Regime 2005 and 2014 (ABPmer)
– Regional model calibration report (ABPmer)
– Local model calibration report (ABPmer)
– Scheme test reports (ABPmer)
– Sedimentary Processes in the Medina Estuary May 2016 (Dr R Nunny)
– Appendices to Sedimentary Processes in the Medina Estuary (Dr R Nunny)
– Sedimentation Management Monitoring Set-up February 2016 (Dr R Nunny)
– Cowes Harbour – Flow Modelling Review December 2015 (HR Wallingford)
– Cowes Harbour – Summary Review of Sediment Transport Modelling May 2016 (HR Wallingford)

Isle of Wight Tide – ABPmer. Numerical tidal simulation of the area around the Isle of Wight. The animation illustrates a representative spring tide. Higher tidal flow speeds are shown as lighter colours. The water level plot shows the water level as predicted for Cowes.

Cowes Solent – ABPmer. Numerical tidal simulation of Cowes Solent. The animation illustrates a representative spring tide. Higher tidal flow speeds are shown as lighter colours. The water level plot shows the water level as predicted for Cowes.

Cowes Outer Breakwater – ABPmer. Numerical tidal simulation of Cowes Outer Harbour. The animation illustrates a representative spring tide after the construction of the new Outer Breakwater. Higher tidal flow speeds are shown as lighter colours. The water level plot shows the water level as predicted for Cowes.

Cowes Harbour Commission would like to take this opportunity to emphasise some key points from the OHP presentation, and to answer concerns that were expressed at the meeting:

1. CHC will undertake a public consultation over the next month on the proposed changes to the already consented Outer Harbour Project scheme. The OHP design change proposals cover optimisation of the Eastern Channel (to replace the Small Craft Channel), a Shrape breakwater extension, and the Homes and Communities (HCA) planned Victoria Marina.

2. Following the consultation process and stakeholder feedback, CHC will decide if the amended scheme should proceed as proposed for works commencing during the winter of 2016-2017. This will be subject to successful conclusion of the agreement between the HCA and the developers, Westcourt Real Estate and Camper & Nicholson Marinas, to which CHC is not a party. This agreement is, however, necessary to provide the funding for phases 2 and 3 of the OHP. Should an agreement not be concluded, CHC will review funding and delivery options and again consult with stakeholders.

3. CHC advised by ABPmer, and HR Wallingford (who carried out the peer review), are confident that ABPmer’s new, highly detailed and sophisticated hydrodynamic model is fit-for-purpose and provides good reproduction of measured tidal flows and the effects of the next proposed phases of the OHP scheme. The model’s results have been compared to extensive observed data, which align with the modelling results, as collated in Dr Rob Nunny’s report.

4. ABPmer’s sedimentation model has also been validated as fit-for-purpose regarding potential sediment effects, both resulting from the construction of the Cowes Breakwater and from the proposed amendments to the OHP scheme, which themselves have limited effect on the total harbour sedimentation. The indications of sedimentation effects are, however, relative and must be seen in the context of other potentially more significant factors, such as generally increasing silting along the south coast, increased turbidity in the Solent, the peak of the lunar nodal cycle, increased land run off due to periods of high rainfall, and normal silting that can be expected in areas that have been dredged.

5. CHC acknowledges the concerns regarding silting in the harbour, although believes from the extensive work carried out by different experts and available to stakeholders, that the effects of the Cowes Breakwater itself (excluding the new Victoria Marina, which will require maintenance dredging) are likely to be localised and overall neutral for the harbour and Medina Estuary. CHC, and the CHC Advisory Committee, welcome discussion on specific concerns with stakeholders.

6. Following the consultation and decision process regarding the next phases of the Outer Harbour Project, CHC will, in partnership with stakeholders, develop a medium-term maintenance dredging plan for the harbour. This plan will benefit from the extensive modelling that has been developed, based on detailed surveying, and also the estuarine analysis carried out by Dr Rob Nunny.

David Riley, Chairman
Capt. Stuart McIntosh, Harbour Master
24th May 2016

Further information:
ABPmer’s Bill Cooper mentioned that stakeholders may also wish to refer to www.channelcoast.org, the Channel coastal observatory, with regard to coastal monitoring on the south coast.