Regular maintenance will always be necessary for structures such as the lock, which operate in challenging coastal environments. The gate seals at the bottom of the lock gates at Sutton Harbour have deteriorated to the point of potential failure and therefore require these works to repair and replace the bottom gate seals to ensure the water can be maintained in the harbour and for flood protection to be maintained to the surrounding area.

This project involves replacing the existing four gate seal assemblies which are fixed to the bed of the lock, below the tidal gates at Sutton Harbour. Additionally, the adjacent stop logs across the original harbour entrance and the pedestrian walkway over the stop logs will also be replaced.

The tidal gates are a critical part of Plymouth’s coastal flood defences. Were they to fail this would pose a serious flood risk to the Sutton Harbour and Barbican area with more than 500 properties at risk.

The project will help to maintain flood protection and ensure the continuing functionality and viability of the tidal lock gate for another decade.

The works have been reprogrammed to be carried out in two phases, each lasting approximately three months.

Works to the outer gates will commence on 4^th September 2023 and are scheduled to be completed by 15^th December 2023.  Works involving restrictions to access through the lock are scheduled to finish on 21^st November 2023.

Work to the inner gates will commence on 11^th March 2024 and are scheduled to be completed by 17^th June 2024.  Works involving restrictions to access through the lock are scheduled to finish on 22^nd May 2024.

For clarity, and as noted above, it is emphasised that not all of the work affects normal operation of the lock gates. Full timetables of the works and lock opening and closings are available via the following link, and will be updated regularly in accordance with the progress of the project.

Work on the lock gates was initially planned to take place in one seven-month block. The Sutton Harbour Company, with participation by the Environment Agency and its contractors, led a consultation process with harbour users, including the fishing fleet and berth holders to determine a start date, with the aim of minimising disruption to harbour users, while also recognising the need to complete these essential works by spring 2024, to minimise the increased risk of failed cills beyond that point, and fully utilise the project funds available until that date.

The major part of the project is the repair and replacement of the four lock gate seals which will be carried out underwater by a team of specialist divers. They will be assisted by a shore-based support team and construction team carrying out elements of the project accessible from the quaysides.

This project aims to provide new gate seals which will ensure the effectiveness of the tidal barrage for another decade.

The project is being managed by the Environment Agency.

The works are being funded by UK Government through the Environment Agency Flood Defence Grant in Aid and participation by Sutton Harbour Company as agreed by the parties. Funding for the project has been secured and is available for application to the project through spring 2024.

The over-riding objective is to maintain “life in the harbour” as normal to the greatest extent possible, and minimise disruption to harbour users. Working groups have been established with key harbour users including the fishing fleet and berth holders, and independent expert consultants engaged. These groups and the work of the consultants have informed the project in finding an optimum time for the work to be carried out, and in drawing up mitigation measures where necessary in collaboration with the Sutton Harbour Company. Those mitigation measures can be viewed here.

Sutton Harbour Marina facilities and services will be unaffected. An access timetable has been agreed between the representative agent of the Environment Agency and the Harbour Master to allow for vessels to pass through at certain times of the day dependant on tides. This timetable has been drawn up in order to minimise disruption to leisure users to the greatest extent possible. Mitigation plans are being put in place to provide temporary “emergency berthing arrangements” for vessels arriving outside periods of access through the lock. Details of these arrangements are available here. It is estimated that there will be twelve 24-hour closures over the duration of the works, and no more than twelve 12-hour closures. A detailed timetable is available via the following link.

Plymouth Fisheries will continue to work very closely with the local and visiting fishing fleet, providing regular updates to ensure that any impact is minimised to the greatest extent possible. Mitigation plans include pre-arranged back-up “emergency” alternative landing sites with truck access to the Fish Quay for periods when vessels are not able to access the harbour. It is estimated that there will be no more than twelve 24-hour closures over the duration of the works, and no more than twelve 12-hour closures.

Details of these arrangements are available here. 

A detailed timetable is available via the following link.

Details on compensation requests from the fishing community are available here. 

Information on compensation requests from the fishing community is available here. 

The pedestrian footbridge will remain in operation for the majority of the project. The existing walkway over the stop logs is to be replaced which will mean pedestrian access will not be possible for a few days but this phase of works will be communicated well in advance to minimise any inconvenience caused. There will also be other periods when temporary limits on access are required to allow work to be undertaken without putting the safety of members of the public at risk. Again, any closures will be widely publicised in advance and during these periods pedestrian access to the east side of the harbour will be via the existing waterfront trail.