Coastal Flooding. Reducing the risk to Southsea. Coastal Flooding Reducing the risk to Southsea 1

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1 Coastal Flooding Reducing the risk to Southsea Coastal Flooding Reducing the risk to Southsea 1

2 Introduction This booklet provides a concise overview of the Southsea coastal defence scheme (the scheme) and a summary of the leading options being put forward for public consultation. The 8 week public consultation runs from the 3rd November 2014 to the 29th December During this time key stakeholders and the public are invited to review the proposals and provide feedback on the scheme. For more detailed information on the Southsea Scheme please visit: Contents Southsea Coastal Scheme... 3 Scheme development... 4 The scheme area... 5 Flood risk from the sea... 6 High tides and flooding across Southsea... 7 Short listed defence options... 8 Material types Seafront Masterplan Funding and contributions Summary & next steps Find out more Typical 3D visual of a short listed Southsea scheme option Copyright: Ordnance Survey data Crown copyright and database right 2014 PUSH SFRA Crown copyright. All first rights reserved. License No. LA , 2014 Aerial Map data google 2014 Funding: This project has been funded from Flood & Coastal Risk Capital Grant in Aid awarded to Portsmouth City Council from the Environment Agency. Coastal Flooding Reducing the risk to Southsea 2

3 Southsea Coastal Scheme Aim of the scheme On behalf of Portsmouth City Council, the Eastern Solent Coastal partnership are developing draft designs to improve coastal defences along Southsea over the next 100 years. Implementation of the Southsea Scheme will reduce the risk of flooding and erosion from the sea to assets worth 654m. Southsea scheme area The scheme covers 2.8 miles (4.5km) of coastal defences from the Royal Garrison Church to the Royal Marines Museum. Have your say... From 3rd November to 29th December 2014 a public consultation is being held to showcase the shortlist of design options. We would like to hear your views on the future of the coastline and invite you to attend one of our consultation events or fill in the questionnaire on our website. Defence options We have worked with our partners to develop a short list of coastal defence options for Southsea. This is a example of how they could look. Flood risk Residential properties Commercial properties Critical infrastructure Total Value of Assets at Risk ( M cash) Time Horizons ,311 3, roads, utilities, 1 pumping station, 18 sub stations roads, utilities, 1 pumping station, 20 sub stations 654 Properties at risk of flooding end erosion over the coming century if we do nothing (based on 1:200 (0.5% annual chance) flooding) Find out more at Coastal Flooding Reducing the risk to Southsea 3

4 Scheme development In order to build a coastal flooding and erosion risk management scheme in England, there are several stages that must take place. These are shown on the diagram opposite. The North Solent SMP covers the coastline from Hurst Spit in the west to Selsey Bill in the east. It recommends a Hold the Line policy for Southsea over the next 100 years. The Portsea Island Coastal Strategy study identified North Portsea Island and Southsea as priority areas, where there is a significant risk of coastal flooding to properties, businesses and key infrastructure. It therefore proposed that a Scheme should be developed in both areas. We are currently developing leading defence options for Southsea s coastline. Your views will contribute towards selecting the overall preferred design. The preferred defence option that is selected will be technically and environmentally sound, affordable both now and in the future and adaptable to future changes in climate. Coastal flood and erosion risk decision making process, Southsea Shoreline management plan North Solen SMP North Portsea Scheme Strategy Portsea Island Coastal Strategy Scoping / data collection Option development Southsea Scheme Coastal Flooding Reducing the risk to Southsea 4

5 Southsea scheme area The scheme covers 4.5km (2.8 miles) of Southsea s coastline, from the Royal Garrison Church to the Royal Marines Museum. The scheme are has been divided into 7 sub-frontages. Each sub-frontage has different coastal defence types and has a different character to it s neighbour. The benefit of separating the frontages is to allow flexible phasing of future construction that minimises local disruption. Coastal Flooding Reducing the risk to Southsea 5

6 Flood risk from the sea The Portsea Island Coastal Strategy Study estimates that by 2115, assets worth 654m will be at risk of flooding from the sea during a significant, 1 in 200 year flood event. The map on this page shows the extent of flooding from a coastal flood event of this size, if no defences were in place. Interested to know if your property is at risk from flooding? Visit Coastal Flooding Reducing the risk to Southsea 6

7 High tides and flooding across Southsea Why do floods happen? In Southsea, tidal flooding can occur during different weather conditions. Low air pressure increases the height of the tide and this can cause low lying land to flood. This is often called a tidal surge. Strong winds create large waves. If this coincides with a high tide, the sea can flood land by overtopping sea defences. Heavy rain can further increase flood water levels, when combined with tidal flooding. Storms Over the winter of 2013/14, the combination of high tides, gale force winds and low air pressure caused localised flooding as well as significant damage and over-topping to Southsea s sea defences. 1 January 2014 A 5.3m CD* high tide and strong south-easterly winds caused the sea wall along Southsea seafront to be over-topped. 3 January 2014 Tides reached 5.5m CD*. This, combined with high winds caused defences to be over-topped again at a number of locations along Southsea frontage. *Chart Datum = local tide height measured from the height of water at lowest possible tide. Coastal Flooding Reducing the risk to Southsea 7

8 Southsea short list Sub-frontage 1 Long Curtain Moat Options considered Coastal Flooding Reducing the risk to Southsea 8

9 Southsea short list Sub-frontage 2 Clarence Pier Options considered Coastal Flooding Reducing the risk to Southsea 9

10 Southsea short list Sub-frontage 3 Clarence Esplanade Options considered Coastal Flooding Reducing the risk to Southsea 10

11 Southsea short list Sub-frontage 4 Southsea Castle Options considered Coastal Flooding Reducing the risk to Southsea 11

12 Southsea short list Sub-frontage 5 South Parade Options considered Note: Rocks used on this frontage will be buried under the beach. The rocks will protect the base of the structure if the beach is moved in extreme weather conditions Coastal Flooding Reducing the risk to Southsea 12

13 Southsea short list Sub-frontage 6 Lumps Fort Options considered Coastal Flooding Reducing the risk to Southsea 13

14 Southsea short list Sub-frontage 7 Eastney Barracks Options considered Coastal Flooding Reducing the risk to Southsea 14

15 Material types Which materials would you like to see? There are a number of different construction materials from which new coastal defences could be built. The images found below show examples of the types of structure we will be considering for the new coastal defences. Primary defence materials The examples below show material types that could be used in the construction of a primary defence. Set back defence materials The examples below show material types that could be used in the construction of a set back defence. Concrete block slope Interlocking concrete blocks Concrete wall Masonry wall Rock Concrete slope Steel sheet piling Stone block slope Stepped concrete Earth Embankment Coastal Flooding Reducing the risk to Southsea 15

16 Seafront Masterplan There is potential to enhance and improve the seafront in terms of the range and quality of leisure, cultural and recreational opportunities on offer, and its network of streets, footpaths and open spaces. Aspirations for the area are set out in Portsmouth City Council s Seafront Masterplan, which identifies opportunities for new development and for improving the public environment. The Masterplan document highlights the long-term vision for the Seafront and the important role that new coastal defences can play in Seafront regeneration. Coastal Flooding Reducing the risk to Southsea 16

17 Seafront Masterplan The Southsea Scheme links to the Southsea Seafront Strategy and the Seafront Masterplan and is one of the Shaping the future of Portsmouth infrastructure projects. Coastal Flooding Reducing the risk to Southsea 17

18 Funding and contributions Partnership funding How could you contribute? It is estimated that the costs of improving and maintaining coastal defences around Southsea could amount to 50million over the next 100 years 1. The government has put in place a mechanism for funding flood and coastal erosion risk management schemes called Partnership Funding. The principles are simple, encouraging local funding sources to supplement national grants. We are committed to working with others to explore alternative funding sources and capturing broader outcomes and objectives through our projects. We have been working within the council and with partners to explore opportunities to deliver joint benefits through this project and to maximise our funding for Portsea Island. Payment for outcomes 100% funded Although the project currently has a good case to attract Government Grant in Aid we always seek to do more to maximise value for money. This will allow the grant to go further and protect more properties from flooding. Raising funds may also allow us to increase benefits of our work such as: increasing the standard of height of the structures; improving the quality of materials to be used; increasing certainty and accelerating programmes for projects to be delivered; delivering other benefits to local communities. We are interested to hear your ideas on ways in which we could seek more value from our work. Examples may include: offers to work in partership to delilver combined outcomes; providing financial contributions or sponsorship; promoting contacts and networks with whom we should work; supporting the work by advertising and promoting its cause; offering access through private land or site set up arrangements; suggesting other ways to demonstrate savings. Value for money Partial funding available......savings or other funding required 100% 1. Portsea Island Coastal Strategy Study, StAR April 2011 Coastal Flooding Reducing the risk to Southsea 18

19 Summary & next steps Southsea s coastline Southsea s coastline is symbolic of Portsmouth, the great waterfront city. As a destination Southsea provides people with good access to events, amenities and recreation and attracts millions of visitors each year. Southsea is a densely populated area with a diverse community, vibrant economy and strong links with the sea. Southsea s maritime heritage, public open spaces and local environment are of local and national importance. Many of Southsea s coastal defences were built during the early 1900 s and are now reaching the end of their life. In order to consider the future of Portsea Island s coastal defences, Portsmouth City Council adopted the Portsea Island Coastal Strategy. The Strategy recommends improving Southsea s aging coastal defences to reduce flood risk from the sea. The aim of the scheme Together with our partners, we recognise the importance of communities, local businesses, cultural heritage and the environment in Southsea. The aim of the Scheme is to provide a cost effective solution for managing coastal flood and erosion risk, that is adaptable to climate change and maximises funding and contributions. The next steps Public consultation Review feedback and select preferred coastal defence option Submit business case to Environment Agency (EA) Detailed design, subject to EA approval Onsite construction Coastal Flooding Reducing the risk to Southsea 19

20 Find out more To monitor the progress of this scheme and to receive regular updates on our other projects and events, please follow us online via one of the links below. For more information please speak to a member of our team today. Visit our website: Like us on Facebook See our videos on Youtube Follow us on Coastal Flooding Reducing the risk to Southsea 20