Alverstoke Scheme FAQs
Global sea level has been rising over the past century, and it is the dominant factor of increased coastal flood risk. With continued ocean warming, sea levels are predicted to rise for many centuries at rates higher than that of the current century. Alongside this, flooding in the UK is often associated with extreme weather conditions, such as storm surges, which are becoming more common. The new sea defences at Alverstoke are being constructed to make sure it is protected in line with these predictions and threats.
For more information and a summary of the most recent climate projections for the UK visit here.
The sea defences will consist of a reinforced concrete wall and a floodgate which will span the width of Little Anglesey road. The new defences will be approximately 100m in length and 1m high. The outer face of the wall (east facing) will be matched to the appearance of the existing wall. They will be located at the western end of Stoke Lake, between Little Anglesey Road and Clayhall Road.
The floodgate will be the same height as the wall and span the road and associated footway. It will be a steel construction with timber cladding for the side which is visible when in the open position. A typical example of this is shown here.
It is estimated on average that the flood gate would need to be closed about once a year in the first ten years of its operation, but the exact number of times will depend on the variables such as the tide levels of weather conditions at the time. Due to climate change and sea-level rise, this frequency is likely to increase in future years.
The double leaf floodgate will be manually operated. GBC will close the gate in consultation with the Environment Agency Flood Incident team with support from Coastal Partners who have a duty officer system in place for Coastal Flood Response.
This setup occurs in other local authorities which form Coastal Partners and builds on 15 years of experience installing flood equipment and working with local authority emergency planning teams.
In a high-water event, when the floodgate is closed, there will be a diversion route signposted in the area for pedestrians and vehicles to travel around the closed road.
The scheme does not increase flood risk to any properties outside of the protected area.
The Jackie Spencer Bridge design option was discounted for a variety of environmental, technical, and economic reasons which can be read about here. Following assessment of this option by Coastal Partners, it was determined that the leading option remained as the most technically feasible, environmentally acceptable, and financially viable design option going forward.
Coastal Partners may bid for Defra grant to try and deliver property level flood resilience to those properties which are not likely to be protected by coastal defence structures in Gosport. However, there is no guarantee that funding will be available, and it is likely that homeowners will also need to contribute financially in some way towards any solution
Gosport Borough Council is a Risk Management Authority, like the Environment Agency, they are not legally required to do anything to protect against flooding and erosion, however they have permissive powers to carry out works where there is a wider public benefit, clear economic benefit and an achievable solution; such as at Alverstoke. In the absence of anything else private landowners have ultimate responsibility for protecting their own property from flooding and erosion, but must act within statutory planning regulations and other applicable legislation.
Further information is available here: https://coastalpartners.org.uk/flood-risk
A 'Section 19 Report' is an investigation carried out by a lead local flood authority (LLFA), after a flood issue, under the Flood and Water Management Act 2010. Hampshire County Council are the LLFA for Hampshire and have produced an investigation report covering the April 2024 Storm Pierrick flooding. Copies of the report can be obtained from Hampshire County Council. The project team are aware of the Hampshire County Council Section 19 report into these floods, which affected communities across the harbour. The report can be found via the link below:
Strategically, the scheme is an important part of Gosport Borough's adopted plans under two main strategic documents, and from which the scheme is derived - the Shoreline Management Plan (2010) and the River Hamble to Porchester Flood and Erosion Risk Management Strategy (2016).
More details can be found here: Alverstoke Scheme History — Coastal Partners
The scheme delivery is being led by Coastal Partners, Gosport Borough Council's coastal team. The project team is held to account by and reports into the Community & Environment Board, through the Head of Place at Gosport Borough Council.
In September 2022, on-site work was put on hold due to an insufficient budget to address buried services. The Environment Agency were requested to close this (£1M) funding gap and keep going on site, but the request was turned down. The project was placed on hold and demobilised on site.
In 2023, the Secretary of State sought to identify flood projects with funding gaps, and this project was submitted for consideration with an uplifted figure of £3.5M. The general election came and went with no announcement.
Then, in April 2025, the government announced this scheme would be eligible for more funding. Due to the time elapsed since the original estimates and submissions, the project costs needed to be updated again to reflect a new programme and the need to reapply for planning and environmental consents.
Using real pricing data from our 2025 Forton flood scheme and Stokes Bay seawall replacement scheme and adjusting for future inflation, the team forecast an updated funding need for Alverstoke at £7.8M. This allowed for the cost to relocate buried services, amend the existing design, reapply for planning approval, consents and then procure a contractor to build the flood wall.
We remain disappointed that the £3.5M funding gap could not be closed in 2022/23, as the works would have been completed, homes would have been protected from flooding in 2024 and the scheme delivered at lower cost to the public purse. We are pleased that our funding business case has now been approved by the Environment Agency, so that these funds can be released and the scheme can move forward again.
In 2026, Gosport Borough Council Community & Environment Board requested that more more updates to the community are provided. Even though there has been little change in the project status since April 2025 (as our business case has progressed through the Environment Agency process), we recognise that it would have been reassuring to the community for us to share what updates were available. We are now improving our update process and developing a community communications and engagement plan to guide us in future engagement. In the interim, we will provide updates to this project webpage.