Local flood risk management strategy

www.portsmouth.gov.uk 2 • Local flood risk management strategy Foreword

This document has been prepared with the work in the city aimed at reducing flood residents, businesses and visitors of risk to properties from surface water, and Portsmouth in mind. we will shortly be investigating levels of groundwater around the city to determine Working from guidance given in recent whether or not this will be an increasing government legislation (The Flood and Water problem in the future. Management Act 2010) this strategy sets out for the first time how Portsmouth City This is an exciting time for Portsmouth and Council works with the Environment Agency, we cannot afford to be complacent. The neighbouring local authorities, emergency council will ensure the work we do takes into services and water companies to reduce flood account all the existing plans we have for the risk in the city. city and we will maximise any opportunity that allows us to work with other Our flooding problems are quite clearly organisations both public and private, so we defined, we have no real issues associated have a safe environment to live and work in with either main river or ordinary watercourse, both now and in the future. and we focus our attention on coastal flood risk, surface water and groundwater. Whilst flooding can never be fully eliminated, I believe this document sets out our plans for The strategy sets out to explain these different the reduction of flood risk and how we are types of flooding and how we are working to working in a co-ordinated approach with our reduce the risk from them. This work will partners and stakeholders to provide the encourage regeneration and bring inward greatest levels of flood protection possible for investment to the city as flood defences and the city. drainage networks are improved. Our strategy focuses on flood risk on a ward by ward basis. It identifies known flooding problems and how we are dealing with them along with on-going issues where we are working to find a solution. Gerald Vernon-Jackson We are already gaining momentum for Leader, Portsmouth City Council refurbishment of the sea defences at Southsea and North Portsea Island, and have begun to look at how this should be done. Southern Water is also undertaking major

Foreword • Local flood risk management strategy • 3 Contents

Introduction 6

Historic flooding in Portsmouth 9

Location 10

Flood risk in Portsmouth 12

Interactions between different types of flooding 21

Climate change 22

Citywide flood risk measures 24

4 • Local flood risk management strategy • Contents Flood risk ward by ward 35

Protecting individual residential properties and flood insurance 64

Action plans 66

What you can do to minimise the effects of flooding 72

References 73

Glossary of terms 74

Contents • Local flood risk management strategy • 5 Introduction

Flooding is one of the biggest natural challenges facing Portsmouth. Our position as a coastal city brings great benefits and these are reflected in the council’s goal to shape the great waterfront city. However, the risk of flooding from the sea, along with that from surface water, are significant issues facing the city due to their potential to threaten people, property and the environment. This risk will increase as a result of climate change. Whilst we cannot entirely eliminate the risk of flooding, this strategy aims to locally manage flood risk for the people, economy and environment of Portsmouth.

Why has the strategy been written? As a unitary authority, Portsmouth City Council is designated as a Lead Local Flood Authority (LLFA) under the Flood and Water Management Act 2010 (the ‘act’). The act places a statutory duty on LLFA’s to develop, maintain, implement and monitor a Local Flood Risk Management Strategy (hereafter referred to as the ‘strategy’) to manage local flood risk in its area. The strategy aims to locally manage flood risk for the people, economy and environment of Portsmouth by working in partnership to identify and deliver feasible and timely actions.

What are the guiding principles behind the strategy? The strategy is focused on the following principles as set out in the ‘National Flood and Coastal Erosion Risk Management Strategy (NFCERM)’ with which our local strategy must be consistent. • Community focus and partnership working • Catchment and coastal cell based approach • Sustainability • Proportionate, risk-based approaches • Multiple benefits • Beneficiaries should be allowed and encouraged to invest in local flood risk management

6 • Local flood risk management strategy • Introduction What is included in the strategy?

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S OUT H PAR CL ADE AREN CE ES PLAN ADE © Crown Copyright and database right 2013. Ordnance Survey licence number 100019671. Copyright and database right 2013. Ordnance © Crown

Introduction • Local flood risk management strategy • 7 What are the strategy objectives? The strategy objectives set out below were agreed by the strategy working group, which included representatives from PCC Drainage, Planning and Coastal teams, the Environment Agency and Southern Water. 1. We seek to improve the knowledge and understanding of all 4. Ensure that planning decisions are properly informed by flooding sources of flood risk across Portsmouth, to include (in no issues, by avoiding development at inappropriate locations and particular order of importance): reducing flood risk wherever possible.  Surface water and run-off 5. Maintain, and improve where necessary and affordable, flood risk  Groundwater management infrastructure and systems to reduce flood risk.  Ordinary watercourses 6. Identify through an action plan, appropriate measures, and schemes to manage flood risks providing balanced community  Fluvial (main rivers) and environmental benefits, and establish who is responsible for   Coastal delivery of these measures.   Reservoir 7. Compile a funding plan for schemes listed on the action plan   Sewer overload 8. For identified schemes, demonstrate compliance with the EU  Mains water supply bursts Water Framework Directive through a Strategic Environmental 2. Identify and work in partnership with other authorities, Assessment and Habitats Regulations Assessment. stakeholders and the community who have a role in flood risk 9. Detail all procedures in place to mitigate a flood event, including management. flood response and recovery 3. Increase public awareness of all flood risk across Portsmouth.

8 • Local flood risk management strategy • Introduction Historic flooding in Portsmouth © City Development and Cultural Services, Portsmouth City Council

Southsea Common after ‘The Great Gale’, 1910 Broad Street, Old Portsmouth circa 1900-1920

Broad Street, Old Portsmouth 1989 Clarendon Road, Southsea, 2000

Historic flooding in Portsmouth • Local flood risk management strategy 9• Location

© Crown Copyright and database right 2013. Ordnance Survey licence number 100019671.

Portsmouth is bordered by four district boroughs, all within Hampshire County Council, which is the designated LLFA for each of these areas. However, as explained later in the strategy, Portsmouth has only minor flood risk interaction with our neighbouring authorities. Comments from the drainage departments in the adjacent authorities are shown overleaf. They describe from a localised perspective, any flooding which may be common with Portsmouth and its neighbours.

10 • Local flood risk management strategy • Location Interactions with surrounding boroughs Southern Water have confirmed that there is very little surface or i. Havant Borough Council: foul water interaction between Fareham and Portsmouth as the Havant has a partial land boundary with Portsmouth, but the western boundary of Budds Farm’s drainage catchment follows southern part of the boundary (Hayling Island) interacts with Portsmouth City Council’s western administrative boundary. Langstone Harbour by means of surface water, treated waste Reach 1 of the Portchester Castle to Emsworth Coastal Strategy water and occasionally in times of extreme weather events, extends into Fareham Borough Council catchment by 3670m partially treated dilute wastewater which is discharged via (PCC = 1945m) consented storm overflows. Anecdotal evidence indicates that: The Westways estate [Havant iv. Gosport Borough Council: Road] drains (foul and storm water) into Portsmouth systems – the There is no drainage interaction between the catchments as storm water goes to the PCC/HBC boundary ditch which drains Gosport does not have a land boundary with Portsmouth. Both south under the railway and the A27 into Farlington Marshes. The authorities interact with Portsmouth Harbour by means of surface private drainage from Farlington Redoubt (in HBC’s area) comes water, treated waste water and occasionally in times of extreme into PCC catchment down the access road, and probably so does weather events untreated waste water. Fort Purbrook foul water, assuming that’s not on cess pools. Fort Purbrook storm drainage travels north away from PCC. Summary: Reach 3 of the Portchester Castle to Emsworth Coastal Strategy Portsmouth has very limited interaction with other boroughs in terms extends into Havant Borough Council catchment by 880m of surface and groundwater. This is due to the topography, geology (PCC = 8180m) and the manner in which the drainage system works. Both Bedhampton Springs, which are the source of Portsmouth’s water Portsmouth and Langstone Harbours are tidal and are influenced by supply, are within Havant Borough Council catchment. the River Walllington and Hermitage Stream respectively. Due to the size of both harbours, the impact of flows from the rivers are minimal ii. Winchester City Council: and any pollution would be quickly diluted and its effect minimised. Anecdotal evidence indicates that: The River Wallington flows The Portchester Castle to Emsworth Coastal Strategy includes behind Portsdown Hill and into Portsmouth Harbour at interactions with Fareham and Havant Borough Councils. The Eastern Wallington, so this may have an impact on the flow in the harbour Solent Coastal Partnership covers all three areas, allowing the actions but it would be minimal given the harbour’s size. for the cells to be addressed across council boundaries. iii. Fareham Borough Council:

Location • Local flood risk management strategy • 11 Flood risk in Portsmouth

Surface water Surface water flooding or surface run-off, is also known as pluvial flooding. This type of flooding occurs when rainfall cannot soak into the ground and then overwhelms the local drains and flows across the surrounding area. This type of flooding is often (but not exclusively) associated with high intensity rainfall and occurs very quickly during or after the rainfall event. Surface run-off refers to the overland flow of surface water until it reaches a point where it can enter a watercourse or sewer. These flows can be significant depending on their depth, direction and velocity and are represented in Flood Hazard mapping. Surface water flooding is often quite localised and is much more difficult to predict than river or coastal flooding. There is often limited advance notice of this type of flooding and it generally occurs after prolonged heavy rainfall or high intensity thunderstorm events.

Typical surface water flood incidents in Portsmouth

12 • Local flood risk management strategy • Flood risk in Portsmouth Surface water flood risk map An extract from the Environment Agency’s ‘Areas Susceptible to Surface Water Flooding’ (AStSWF) map was used to help determine areas of surface water flood risk for Portsmouth’s Surface Water Management Plan. The map was produced on a national scale using set parameters, and was considered more accurate by the Surface Water Management Plan stakeholders than the ‘Flood Map for Surface Water’ (FMfSW), which was produced as a follow up to the above. There appeared to be more correlation with known flooding issues in Portsmouth with AStSWF. A further map, the ‘Updated Flood Map for Surface Water’ (uFMfSW), is being produced by the Environment Agency which takes into consideration local level information and modelling. This is due for publication in December 2013. These maps are frequently used by the insurance industry to identify properties at risk of surface water flooding.

A road gully not functioning

Flood risk in Portsmouth • Local flood risk management strategy • 13 Coastal flooding Flooding from the sea (coastal flooding) tends to occur as a result of high tides, surges in sea water and strong winds which raise the sea level above the ground level of the coast or the level of any infrastructure present e.g. flood defences. Coastal flooding can also occur as a result of failure of infrastructure. Coastal flooding is generally well understood, can be predicted to some extent, and flood protection measures are in place at many locations at risk from these types of flooding. The Eastern Solent Coastal Partnership currently manages improvements to and maintenance of the majority of the city’s sea defences on behalf of Portsmouth City Council. Some are owned and maintained by third parties e.g. MoD maintain the defences around HM Naval Base. The main coastal flood risk occurs during a high tide event in stormy Tidal flood overtopping on the ‘wet’ side of the flood gates at Old Portsmouth. conditions with a south-westerly prevailing wind.

Wave overtopping Southsea seafront is exposed to the open Solent water where wave action can be heavily influenced by weather conditions and shipping movements. This can give rise to flooding by overtopping of the sea defences, leading to floodwater inundation behind the defences. Two sections of Southsea frontage can be closed to vehicular traffic by road gates during, or in anticipation of such events, as wave overtopping can spray shingle onto the road, making it unsafe to pass. NOTE: tide heights are measured in Chart Datum (mCD) around Portsmouth, which can be calculated by adding 2.73m to the Above Ordnance Datum (mAOD) level.

Wave overtopping on Southsea seafront

14 • Local flood risk management strategy • Flood risk in Portsmouth Coastal squeeze Coastal squeeze is the term used to describe what happens to coastal habitats that are trapped between a fixed landward boundary, such as a sea wall, and rising sea levels and/or increased storminess. The habitat is effectively ‘squeezed’ between the two forces and diminishes in quantity and or quality. In the Solent it is the saltmarshes that are perhaps under the greatest threat from this effect. Coastal habitats will naturally adapt to a changing climate by migrating inland but, in highly populated areas like the Solent, there is no room for this process to happen as the land is used for industry, housing or recreation, and will be defended due to its high commercial value.1

Natural habitat migration

Saltmarsh erodes at Saltmarsh ‘migrates’ the seaward edge landwards

Defences in Old Portsmouth to prevent coastal erosion

Mean sea level Coastal erosion Sea level rise and increased Intertidal zone Coastal erosion is the wearing away of land and the removal of beach storminess or dune sediments by wave action, tidal currents, wave currents, or drainage. Waves, generated by storms, wind, or fast moving motor craft, cause coastal erosion, which may take the form of long-term losses of sediment and rocks, or merely the temporary redistribution of coastal Coastal squeeze Saltmarsh Area ‘squeezed as cannot migrate sediments. Erosion in one location may result in an accumulation of the saltmarsh erodes at Sea landwards due eroded sediment nearby. the seaward edge wall to presence of sea wall Portsmouth’s southern frontage experiences a natural process called ‘longshore drift’, meaning the sediment and shingle on Southsea Mean sea level beach is redistributed over time along the coastline by tidal currents Sea level rise and and storms. This effect is regularly monitored to ensure the extent increased Intertidal zone of the erosion is not detrimental. The sediment is redistributed by storminess machinery as necessary.

Flood risk in Portsmouth • Local flood risk management strategy • 15 Coastal flood risk map EA flood zone 3 (1/200) 0.5% AEP This map shows Environment Agency Flood Zone 3, which has been produced on a national scale. The hatched area shows the areas that could be affected by flooding, either from rivers or the sea, if there were no flood defences. These areas could be flooded from the sea by a flood that has a 0.5 per cent (1 in 200) or greater chance of happening each year.2 The probability or likelihood of flooding is described as the chance that a location will flood in any one year. If a location has a 0.5% chance of flooding each year, this can also be expressed as having: • a 1 in 200 chance of flooding in that location in any year • odds of 199 to 1 against a location being flooded in any year However, this does not mean that if a location floods one year, it will definitely not flood for the next 199 years. Nor, if it has not flooded for 199 years, will it necessarily flood this year.3

© Crown Copyright and database right 2013. Ordnance Survey licence number 100019671.

The coastal flood response team (Colas and ESCP) monitoring a high tide in Old Portsmouth

16 • Local flood risk management strategy • Flood risk in Portsmouth Groundwater Groundwater may be present within permeable geological formations (aquifers) and permeable worked or filled ground (sometimes referred to as made ground). Under certain conditions the groundwater table can rise significantly above its normal level and cause flooding of property and structures both above and below the ground surface. When this happens due to natural processes (rather than a leaking water main for instance) it is known as groundwater flooding. Groundwater flooding is usually preceded by long periods of heavy rainfall but does not occur rapidly in the same way as fluvial flooding, so the potential hazards to life and health are not as immediate or severe. However, once groundwater flooding has begun, it often takes a long time to recede, and may result in significant property damage and disruption.

A recent groundwater flood event in Portsmouth

Local rise in water table due to Groundwater emergence low permeability obstruction

Water table

Ground level Water table

Non-aquifier Groundwater flow

Aquifier

Flood risk in Portsmouth • Local flood risk management strategy • 17

Groundwater flood risk map Figure 20 Target Areas and Regions for groundwater flood risk management

The map here is a combination of Target Areas for Groundwater information used to determine groundwater Flood Risk Management Target Regions areas for investigation. The Environment Target Areas Agency ‘Areas Susceptible to Groundwater Surface Water LFRZs Strategic Development Sites 44 Flooding’ map was considered too short of Portsmouth Plan 151 detail for Portsmouth, as it was determined SHLAA 10 on 2km square grids. 11 161 76 01 47 This map includes the latest strategic 159 48 development planning information like the 7 165 39 03 ‘Strategic Housing Land Availability Assessment’ 02 (SHLAA) and Surface Water Management 101 164 04 Plan Local Flood Risk Zones (LFRZs). 146 8 05 6 These areas will be targeted by Portsmouth Tipner 06

City Council to determine current and future 07 levels of risk through data monitoring. 09 10 Portsmouth City Council will be undertaking 08 5 a data gathering exercise at various 9 locations around the city which will measure 6 groundwater levels where there may be risk. This data will help us assess the level of risk now and into the future. 4

Somerstown and North Southsea 152 168 11 1 City Centre 3 29 172 12

13 127 178 2 143 85 49 10 14 176 0 0.25 0.5± 1 163 2 Kilometers Reproduced from Ordnance Survey material with the permission of Ordnance Survey on behalf of Her Majesty's Stationery Office. © Crown Copyright. Portsmouth City Council, 2013 100019671.

18 • Local flood risk management strategy • Flood risk in Portsmouth Sewer surcharge Sometimes referred to as hydraulic overload or foul flooding, flooding from sewers often occurs at the same time as other types of flooding (particularly surface water flooding) and can be a result of blocked drains or the sewer network being unable to hold all the water flowing into it. It can be identified by water escaping from a manhole. This type of flooding is the responsibility of the pipework owner, normally the local sewerage company. Portsmouth City Council maintains good working relationships with Southern Water and assist them in the investigation of any flooding from sewers.

A sewer manhole surcharging in Portsmouth Fluvial flood risk (rivers) Fluvial flooding is also known as river flooding. It occurs when a river cannot hold the volume of water which drains into it from the surrounding land (known as a catchment) as water is not able to be conveyed within the channel and overflows onto the adjacent floodplain. In the context of this strategy, we refer to fluvial flooding as flooding from main rivers. A ‘main river’ is defined in the Water Resources Act 1991 as ‘a watercourse shown as such on a main river map and includes any structure or appliance for controlling or regulating the flow of water into, in or out of the channel’. Portsmouth has two designated main rivers (Great Salterns Drain and Farlington Marshes Gutter), but neither effect properties during a flood event as they are in floodplains which have no development.

Great Salterns Drain, an EA designated main river

Flood risk in Portsmouth • Local flood risk management strategy • 19 Ordinary watercourses Aftermath of a burst water main. Debris, water and sunken footpaths are visible An ‘Ordinary watercourse’ is defined in the act as ‘a watercourse that does not form part of a main river’. This includes lakes, ponds or other areas of water that flow into an ordinary watercourse. Portsmouth has a small number of ordinary watercourses, which do not pose a flood risk to properties.

Reservoirs The Reservoir Act 1975 states ‘a reservoir is a ‘raised reservoir’ if it is designed to hold, or capable of holding, water above the natural level of any part of the land adjoining the reservoir’. Portsmouth Water operates one underground reservoir within Portsmouth’s catchment which according to the act does not require consideration as a flood risk as it is below ground.

Water mains The act also states that ‘a flood caused by a burst water main’ is not required for flood risk consideration. This is because burst water mains are almost impossible to predict and generally occur randomly, most likely as a result of infrastructure failure.

Reservoir and burst water main flooding are not investigated in Portsmouth’s strategy. Main river and ordinary watercourse flooding is also considered low risk and are not actively investigated in the strategy. A typical ordinary watercourse in PCC

20 • Local flood risk management strategy • Flood risk in Portsmouth Interactions between different types of flooding

The interaction between different water sources can have an impact on flooding. These are explained below: Surface water and groundwater Groundwater and sewer surcharge Differentiating between groundwater flooding and surface water Many of Portsmouth’s sewers are of Victorian brick construction and which cannot infiltrate can be difficult. Groundwater flooding need are liable to groundwater ingress, especially those at significant depth not occur after a local rainfall event; rainfall falling further away from the surface. If the pipe joints are not properly sealed, ground may cause groundwater levels to rise over a much wider area, e.g. water enters the sewer network reducing its capacity and increasing due to an extensive aquifer, and thus cause groundwater flooding flood risk. It is difficult to quantify the amount of groundwater in at other locations. Again, if the ground is already saturated and the sewers. causing groundwater flooding, then any further local rainfall will Groundwater and tide be unable to infiltrate and result in surface water flooding. PCC has Tidal levels are often mirrored in groundwater levels. High tides experienced a groundwater flood incident (95% certainty) in Baffins can mean high groundwater levels especially in proximity to the ward in early 2013. coast. This can be difficult to quantify as considerations such as the Surface water and tide permeability of the sub-soil and the condition of sea defences are Surface water flooding is also exacerbated at locations where seepage recognised as having an influence. Generally there is a slight time occurs beneath the defences, which contributes to maintaining a high delay between peak tide level and peak groundwater level. water table. The ground geology indicates that this may be the case on the southern part of Portsea Island, which would result in high Old Portsmouth Tide and Ground Water Level (GWL) comparison groundwater levels at Southsea. ‘Tidelocking’ can also occur, when 25 November 2009 to 30 November 2009 a gravity flow surface water network cannot discharge to the sea 5.00 during a high tide causing surface water to back up and increasing flood risk. Tidelocking is exacerbated by sea levels if sea water is not 4.50 prevented entering the sewer through the outfall e.g. dysfunctional 4.00 flap valve. 3.50 Surface water and sewer surcharge Recorded Borehole

GWL (mCD) Large parts of Portsea Island are served by combined sewers. This 3.00 means surface water uses the same trunk sewers as foul water, during Sea Level (mCD)

a rain event diluted foul water may be surcharged from a combined Water Level (m) 2.50 sewer manhole. This poses a health and safety concern and often 2.00 results in a lengthy and costly clean up operation.

1.50

1.00 17:00 22:00 03:00 08:00 13:00 18:00 23:00 04:00 09:00 14:00 19:00 00:00 05:00 10:00 15:00 20:00 01:00 06:00 11:00 16:00 21:00 02:00 07:00 12:00 17:00 22:00 03:00 08:00 13:00 18:00 23:00 04:00 Time

Interactions between different types of flooding • Local flood risk management strategy • 21 Climate change

Evidence: Thames Barrier Closures 1983 – 2010 4

There is clear scientific evidence that global climate change is Closures due to Year Total closures happening now. It cannot be ignored. Tidal flooding Fluvial flooding Over the past century around the UK we have seen sea levels rise and 1983 1 0 1 more of our winter rain falling in intense wet spells. Seasonal rainfall 1984 0 0 0 is highly variable. It seems to have decreased in summer and increased 1985 0 1 1 in winter, although winter amounts changed little in the last 50 years. 1986 0 0 0 Some of the changes might reflect natural variation; however the 1987 1 0 1 broad trends are in line with projections from climate models. 1988 1 0 1 Greenhouse gas (GHG) levels in the atmosphere are likely to cause 1989 0 0 0 higher winter rainfall in future. Past GHG emissions mean some 1990 3 3 6 climate change is inevitable in the next 20-30 years. Lower emissions 1991 0 0 0 could reduce the amount of climate change further into the future, 1992 0 1 1 but changes are still projected at least as far ahead as the 2080s. 1993 5 4 9 1994 1 0 1 We have enough confidence in large scale climate models to say that we must plan for change. There is more uncertainty at a local 1995 3 2 5 scale but model results can still help us plan to adapt. For example 1996 4 0 4 we understand rain storms may become more intense, even if we 1997 0 0 0 can’t be sure about exactly where or when. By the 2080s, the latest 1998 3 0 3 UK climate projections (UKCP09) predict that there could be around 1999 3 3 6 three times as many days in winter with heavy rainfall (defined as 2000 4 6 10 more than 25mm in a day). It is plausible that the amount of rain in 2001 11 4 15 extreme storms (with a 1 in 5 annual chance or rarer) could increase 2002 2 2 4 locally by 40%. 2003 11 8 19 One example of climate change occurring is the increasing frequency 2004 2 0 2 of closures of the Thames Barrier. This clearly shows four closures in 2005 5 0 5 the whole of the 1980s, rising to 19 separate closures in 2003 alone 2006 1 0 1 and five for just the first three months of 2010. 2007 11 0 11 2008 3 0 3 2009 1 4 5 2010 (up to 20 March) 0 5 5 Total 76 43 119

22 • Local flood risk management strategy • Climate change The future: The current National Planning Policy Framework is likely to be replaced. Following an external review, ministers have proposed a new streamlined planning practice that will provide support for the growth and creation of jobs and homes that the country needs. It will also provide clearer protections for our natural and historic environment by giving power back to communities who are generally best placed to make local decisions.5 This is currently in the public domain for consultation and comment. In order to allow consideration of the effects of climate change, Map Set 1E of the Partnership for Urban South Hampshire Strategic Flood Risk Assessment shows revised outlines for Flood Zones 2 and 3 for a number of years over the next century. The outlines were produced for 2025, 2055, 2085 and 2115. This is in line with recent Defra guidance on climate change, which provided allowances for sea level rise to 2025, 2055, 2085 and 2115 and indicative sensitivity ranges for increased river flows due to climate change from 2025 onwards. In tidal areas, these climate change outlines were derived by projecting the Environment Agency extreme sea levels inland, using a methodology defined by the Environment Agency. The map here shows the extent of Flood Zone 2 or 3 in the year 2115, given the predicted impacts of climate change. Although planning decisions are taken using the present day Flood Zones, PPS25 states that flood risk should be considered throughout the lifetime of a development. In certain areas, climate change may mean that the flood zones could encroach upon areas that would otherwise be considered suitable for development. This may be an important issue for local planning authorities. At the sub-regional scale, the climate change outlines can be used to show which areas of the sub-region are most vulnerable to rising sea levels, indicated as those areas where there is greater variation between each climate change outline from 2025 to 2115. © Crown Copyright and database right 2013. Ordnance Survey licence number 100019671.

Climate change • Local flood risk management strategy • 23 Citywide flood risk measures

Portsmouth City Council departments that help reduce PCC seafront management flood risk and how The Seafront Masterplan is intended to guide improvements to Portsmouth City Council has a number of measures in place to the seafront area of the city, which stretches for 3.7km between mitigate the risk of flooding. These range from planning policies to Portsmouth and Langstone Harbour entrances. It contains proposals management and reactive actions in response to a flood event. that respond to the overarching vision and aims of the Seafront Strategy. In the context of the Local Flood Risk Management Strategy, ‘the plan seeks to establish a high quality baseline for proposals including design principles …’

It is anticipated that detailed proposals for enhanced coastal defences at the seafront will be informed by the masterplan which identifies opportunities to utilise coastal defence structures to deliver wider benefits to the public in terms of amenity and aesthetics. The Seafront Masterplan is wholly within Flood Cell 1 of the Portsea Island Coastal Strategy, which has attracted funding for improved sea defences.

Colas (contractors working with PCC on PFI agreement) • Gully cleansing programme, especially in autumn leaf fall period. • Maintain PCC owned drainage assets e.g. highway drainage. • Coastal flooding response team for the Coastal Partnership.

24 • Local flood risk management strategy • Citywide flood risk measures PCC Drainage Team The act imposes a number of new duties on PCC as a Lead Local Other duties: Flood Authority. The Drainage Team undertakes many of these duties. • Checking areas of the city susceptible to flood risk. Statutory duties: • Respond to flooding incidents in the city. • To prepare a Local Flood Risk Management Strategy (FWMA S9). • Vital role in setting up and running of the emergency response • To investigate flood incidents (FWMA S19). room during heavy rainfall events and co-ordinating the response with contractors. • To establish and maintain a register of structures that affect flood risk (FWMA S21). • Seek external funding through Environment Agency Flood Defence Grant in Aid (FDGiA) scheme for major schemes. • To designate third party assets that affect flood risk and give notice to owners that they have been designated (FWMA Schedule 1). • Work with Eastern Solent Coastal Partnership in overlapping matters. • Responsible for consenting and enforcing works on ordinary watercourses (FWMA Schedule 2 Para. 33). • Design solutions to improve the drainage capability of the city. • New role as SuDS Approval Body (SAB) requiring LLFA to approve, • Assist TES Major Projects with drainage requirements (Technical adopt and maintain SuDS on new developments (FWMA Schedule 3). advice and Guidance – e.g. Tipner, Northern Road Bridge). • Prepare a Flood Hazard map (FRR Part 3). • Act as a liaison between Southern Water, the Environment Agency, PCC departments and elected members (e.g. Southern Water • Prepare a Flood Risk Management Plan (FRR Part 4). surface water separation schemes). • Work with Colas to identify localised flooding and suggest possible remediation / mitigation measures. • Increase resident understanding of local flood risk. • Increase our historic knowledge of Portsmouth drainage in liaison with the central library and city museum. • Continue works as a shared service with Southampton City Council and Isle of Wight. • Respond to residents’ enquiries with regards to flood and drainage. • Promote SuDS. • Promote schemes which reduce flood risk. • Promote Flood Action Group (FLAG) schemes with the EA. • Investigate unresolved flooding issues

© Crown Copyright and database right 2013. Ordnance Survey licence number 100019671.

Citywide flood risk measures • Local flood risk management strategy • 25 The Eastern Solent Coastal Partnership The Coastal Partnership was formed through a shared service The Coastal Partnership surveys and carries out research relating to agreement signed in April 2012 between the four local authorities of coast protection and sea defence; designs and supervises new sea Portsmouth City Council, Havant Borough Council, Gosport Borough defence and coast protection projects; arranges and supervises coastal Council and Fareham Borough Council. protection works and advises private individuals on minor problems with coast protection and flooding where these are the consultee’s The Coastal Partnership’s aim is to: responsibility. Reduce the risks to people and the developed and natural The Coastal Partnership maintains this with the help of land owners environment from flooding and coastal erosion by encouraging the whose land adjoins the shoreline. provision of technically, environmentally and economically sound and sustainable defence measures along the entire 162km coastline The Coast Protection Act 1949 and the Land Drainage Act 1991, contained within the Coastal Partnership’s authority boundary. This is provide maritime Councils with permissive powers to carry out coastal achieved by undertaking a number of functions: defence works. Coastal defence is an encompassing term for both ‘coast protection’ and ‘sea defence’; where coast protection is the • ensure the development of strategic plans for the future protection of the land from the risk of erosion and sea defence is the management of the coastline and ensure their implementation. defence against the risk of flooding by the sea. • ensure that any development within the coastal zone does not adversely effect the environment. A major task is the production of Management Plans in association with the Environment Agency (EA). Shoreline Management Plans, • ensure that any development within the coastal zone does not Flood and Coastal Erosion Risk Management Strategies and Beach disrupt natural processes, such as the transport of sediment along Management Plans contribute to the continuing maintenance of the shoreline. the Borough’s assets and protection of property. The Plans are used • avoid committing future generations to inflexible and expensive to provide the framework within which maintenance works and options for coastal defence. new schemes are identified and prioritised. The Department for • monitoring the evolution of the coastline and the forcing Environment, Food and Rural Affairs ( DEFRA ) can award Capital parameters affecting it. Grant towards Strategies, preliminary studies and Capital Schemes. The Coastal Partnership also works to protect assets against coastal More information about the Eastern Solent Coastal Partnership can erosion and flooding from the sea, without conflicting with the above. be found at the following link: www.escp.org.uk

26 • Local flood risk management strategy • Citywide flood risk measures PCC planning The Portsmouth Plan, the strategy for development in the city up to • Requiring surface water to be separated within the site and the post 2027, includes two specific policies that influence how flood risk is development rate of discharge of both surface and foul water to the considered in new development: combined system should be no greater than the existing rate. Policy PCS12 (Flood Risk) confirms that the council, in planning • Mitigating the residual flood risk that remains after other steps future development in the city, will follow the flood risk management have been considered by ensuring that the design and layout of hierarchy establish in Planning Policy Statement 25: assess, avoid, development minimises the risk to people and damage to property substitute, control, mitigate. This applies both to plan making and to in the event of flooding and having in place effective emergency the determination of planning applications. The council through this response plans. policy has committed to: Other policies in the Portsmouth Plan also contribute, more indirectly, • Assessing the level of flood risk in making allocations for to the management of flood risk: Policy PCS15 – Sustainable Design development, and avoid flood risk by prioritising those sites for and Construction expect new development to meet BREEAM or development which are at lower risk of flooding. Code for Sustainable Homes standards, which include measures on water efficiency, flood risk and drainage; and Policy PCS13 – Greener • Assessing the level of flood risk in considering planning Portsmouth protects open spaces from development, encourages applications and requiring the development to demonstrate that it green roofs and green walls will be safe over its lifetime. Where necessary, controlling flood risk in new development and

on individual sites through on site flood risk management requires new open space to measures. be provided in larger new • Maintaining and improving the city’s flood defences; and seeking developments, all measures contributions towards flood defences from development. which help with effective The Portsmouth Plan

• Seeking opportunities to improve the capacity problems of the drainage across the city. Portsmouth's Core Strategy existing sewer system, including through the promotion of a link www.portsmouth.gov.uk The Community Infrastructure separating the mainland waste water from Portsea Island wastewater. Levy (CIL) is a new levy that • Permitting new developments only where the necessary surface PCC can choose to charge on water drainage, foul drainage and sewage treatment capacity is new developments in their available, or where additional capacity will be provided in time to area. The money can be used serve any individual phase of the development without to support development by unacceptably reducing the level of service to existing users, or funding infrastructure that causing harm to the environment. the council, local community and neighbourhoods want, this includes flood defence structures. 1

Citywide flood risk measures • Local flood risk management strategy • 27 The South East 7 PCC Flood Risk Strategy Group PCC sits on a panel of LLFAs called the South East 7, which includes A biannual meeting of Risk Management Authorities held at the all the unitary and county authorities from the South East stretching Civic Offices between PCC elected members, strategic directors, from Hampshire through to Kent. As a joint venture, the SE7 has PCC Planning, PCC Drainage, Eastern Solent Coastal Partnership, delivered a Sustainable Drainage System (SuDS) Masterplanning Environment Agency and Southern Water to inform and update on Guidance document for all those connected with implementing new progress in matters relating to flooding. developments. The document is intended to provide a blanket for SuDS across the whole of the South East, giving consistent guidance Partnership for Urban South Hampshire (PUSH) to developers on how to address and choose SuDS under differing PUSH is a partnership dedicated to delivering sustainable, economic- site conditions. led growth and regeneration to create a more prosperous, attractive and sustainable South Hampshire offering a better quality of life for The SuDS Approval Body everyone who lives, works and spends their leisure time here. Under the Act, Portsmouth City Council has a duty to implement a Working in partnership, PUSH is determined to tackle these issues SuDS Approval Body (SAB) which is tasked with reviewing drainage and bring about a renaissance of the cities of Southampton and submissions of new developments. This is in addition to the existing Portsmouth as well as some of our older urban areas.6 planning process. The SAB has the power to refuse a planning application on drainage grounds alone, and can also inspect the construction of a drainage system to ensure it is built as designed and as approved by the SAB. This duty is presently not scheduled to be enacted by Defra until April 2014.

Highways • Incorporate SuDS in all major highway development in conjunction with LLFA. • Promote impermeable paving and reduce hard standing areas. • Work with Southern Water to reduce water flow into sewers.

Civil Contingencies Unit • Preparation of Multi Agency Flood Plan and Flood Response Plan. • Inform the public on how to prepare for and manage a flood event. • Circulate Met Office weather warnings. FRP June 2009, due for review 2014 MAFP June 2011, due for review 2014

28 • Local flood risk management strategy • Citywide flood risk measures Business as usual functions of Portsmouth City Council and their potential water environmental impacts

The table below shows how activities can affect water quality in bodies, like the harbours.7

Local authority Point source Urban diffuse pollution Rural diffuse Physical Low flows Habitat functions and pollution Polluted runoff Drainage/ Sediment run-off Littering, Pollution from pollution e.g. man-made in water degradation services from sewerage e.g. from land e.g. dumping and contaminated land, from modifications bodies e.g. invasive impermeable misconnections, pollution down general neglect including disturbance agriculture, to water non-native urban surfaces etc surface water drains of watercourses during development septic tanks, etc bodies species Local planning policies ◊ ♦ ◊ ◊ ♦ ♦ ◊ ◊ Determination of planning applications and ◊ ♦ ♦ ♦ ◊ ♦ ◊ ♦ ◊ ◊ building control inspections Local authority drainage and flood risk management functions, and future ◊ ♦ ♦ ♦ ◊ ♦ ◊ ◊ SuDS approval body role Environmental health and pollution ◊ ♦ ♦ ◊ ◊ ◊ control functions Managing local authority buildings ◊ ♦ ♦ ◊ ◊ ◊ and assets Open space and green infrastructure, ecology and ♦ ♦ ♦ ◊ ◊ recreation Highways design, maintenance and ♦ ◊ ◊ ◊ ◊ cleansing operations Local authority community leadership and ♦ ♦ ◊ ♦ ◊ ◊ ◊ ◊ advocacy roles, including education ♦ = has significant potential effect on causes of poor water body status ◊ = has less significant potential effect on causes of poor water body status

Citywide flood risk measures • Local flood risk management strategy • 29 The Environment Agency Environment Agency main rivers The Environment Agency is responsible for managing warnings of potential tidal and fluvial flooding. The flood warning system is based on geographical flood warning areas and indicates the level of predicted risk. It advises the public and responders on the likelihood of flooding through a staged approach to warning and taking action. The Environment Agency has split the coastal floodplain in Portsmouth into warning areas, based on the level of defences and flood risk. The Environment Agency uses three flood codes to indicate the level of predicted risk: flood alert, flood warning and severe flood warning. Environment Agency flood warnings are issued directly to the public, responders and the media through a 24-hour warning system called Floodline Warnings Direct. If a flood warning or severe flood warning is issued in the Portsmouth area a recorded message is sent directly to all landline numbers, including ex-directory, in that flood warning area. Members of the public and businesses can also sign up to receive warning messages through phone, fax, text, email or pager. Members of the public can also call the EA 24-hour phone line Floodline service, where they can listen to recorded information about flood warnings in force or speak to an advisor on 0845 988 1188. When the flood threat has receded the EA will issue Warning Removed messages. This will tell people the flood threat has passed and no further flooding is expected in their area. They will be issued through Floodline Warnings Direct, Floodline and the internet. The Environment Agency is the operating authority for flood defences on designated main rivers: • Great Salterns Drain • River Wallington (tidal) – flows • Great Salterns Drain (tidal) into Portsmouth Harbour • Farlington Marsh Gutter • Hermitage Lake (tidal) – flows into Langstone Harbour • Farlington Marsh Gutter (tidal) © Crown Copyright and database right 2013. Ordnance Survey licence number 100019671.

30 • Local flood risk management strategy • Citywide flood risk measures Reducing the risk of flooding Protecting the environment • Building river and sea defences. • Ensuring that farms, factories and other businesses don’t release too • Warning when flooding is expected from rivers or the sea. many chemicals into the air, rivers and streams or land. We work with people to help them meet their legal responsibilities, and we prosecute • Helping people understand what they can do to protect anyone who wilfully breaks the law and damages the environment. themselves and their property from flooding. • Licensing waste processing centres, such as recycling centres, • Helping the emergency services during a flood. rubbish dumps and waste incinerators. Before granting a licence, • Working with local councils and water companies to reduce the we assess whether they meet strict environmental standards, and risk of flooding from heavy rainfall. then we make sure they continue to meet them. • Advising local councils on whether proposals for new buildings will • Licensing the removal of water from rivers and underground, to increase the risk of flooding. make sure there is enough water for wildlife as well as for homes, • Using science and research to identify areas at risk from flooding farms, factories and other businesses. Every drop of water you use and plan the best ways of reducing flooding in the future. at home and work is taken from the environment, and we make • Advising government on policies affecting the risk of flooding. sure water companies are able to supply their customers without • Working closely with the Met Office, who provide weather harming the environment. forecasts and warn when heavy rain is expected. • Carrying out scientific research to set standards for the quality of air, land and water, and prove whether these standards are being met. Our advice to government and businesses is based on sound science.

Improving the environment • Cleaning up after major pollution incidents, such as chemical spills on land or in rivers, and cleaning up places damaged by industry or neglect in the past. • Working with conservation organisations to create and restore important wildlife habitats, and protect the plants and animals that live in them. Habitats include rivers, ponds, pastures, marshes, mudflats and woods. • Licensing fishing by rod in all of England and Wales. The fees help pay for work to make rivers a healthy place for fish and other wildlife to live, and mean that people can continue to enjoy fishing. • Licensing boating for the Thames and some rivers in Kent and East Anglia. We charge boat registration fees to help pay for work to

The Environment Agency responding on site to a flood event © Eastern Solent Coastal Partnership keep these waterways open for boats to use.

Citywide flood risk measures • Local flood risk management strategy • 31 Adapting to climate change Substantial flood risk New flood defences must be able to cope with future rises in sea levels, • Issue flood warnings to professional partners, media and at risk as well as current conditions. Science is at the heart of everything we members of the public via Floodline Warnings Direct. do, and our plans are based on solid scientific research. • Contact Response Working Group Local Resilience Forum partners to discuss activation of Adverse Weather Office. Reporting incidents and emergencies Severe flood risk The EA deals with things that affect the natural environment. Other organisations deal with buildings, roads, the water supply and • Issue Severe Flood Warnings to professional partners, media and at keeping the neighbourhood safe and clean. risk members of the public via Floodline Warnings Direct. • Contact police and other partners to discuss activation of the Business as usual Strategic Control Group. • Prepare and maintain Hampshire Local Flood Warning Plan. Flood waters receding • Contribute to multi-agency plans. • Review EA duty officer procedures. • Maintain EA duty officer procedures. • Record locations of coastal/fluvial flooding. • Update flood risk maps for coastal and fluvial flooding. • Advise on waste disposal issues. • Maintain EA flood defence. • Maintain and operate Eastern Road pumping station. EA live flood warnings link • Maintain and clear grills on Great Salterns Lane. Go to www.environment-agency.gov.uk and search ‘live flood • Monitor fluvial and coastal conditions. risk map’. • Respond to pollution incidents. Strategic overview: Moderate flood risk • Co-ordinating flood and coastal erosion risk management activities. • Issue Operational Instructions to Portsmouth City Council • Provide flood warning service. indicating levels reached for gate closure. • Support emergency responders during a flood. • Issue Flood Alerts to professional partners on flood risk. • Managing flood risk from main rivers, estuaries, the sea and • Provide advice to professional partners on flood risk. reservoirs. • Consider contacting Response Working Group Local Resilience • Planning flood risk management activities. Forum partners to discuss activation of Adverse Weather Office. • Power to undertake works to reduce flood risk. • Record details of flood events • Power to designate features.

32 • Local flood risk management strategy • Citywide flood risk measures Hampshire Constabulary Responding to a severe flood event. • Activate Hampshire and Isle Of Wight (HIOW) Local Resilience Forum (LRF) strategic multi-agency management. • Provide chair of Strategic Control Group (SCG). • Co-ordinate media and public information in accordance with HIOW LRF Media Plan for Major Incidents. • Liaise with Highways Agency, local highways authorities and co-ordinate resources to minimise disruption on the highways and maximise emergency services access. • Assist with co-ordinated risk assessed evacuations. • Set up casualty bureau documentation teams as appropriate. • Notify Special branch who will assess the potential impact on any Critical National Infrastructure sites within HIOW. Hampshire Constabulary responding to a flood event © The Eastern Solent Coastal Partnership Hampshire Fire and Rescue Service Responding to a severe flood event: • Activate HIOW LRF strategic multi-agency management. • Assist in the co-ordination of media and public information in accordance with HIOW LRF Media Plan for Major Incidents. • Continue with co-ordinated risk assessed evacuations, implement long term flooding protocols.

Hampshire Fire and Rescue Service clearing a flood in The Phoenix’s basement, Duncan Road, Southsea

Citywide flood risk measures • Local flood risk management strategy • 33 Southern Water Southern Water collects and treats waste water (including surface water) in Portsmouth. It owns and maintains a range of assets which are essential to effective flood risk management in the city. These assets themselves may be affected by surface water and groundwater flooding in some instances. Southern Water is the licensed sewerage undertaker regulated by the Environment Agency and, financially regulated by Ofwat. Southern Water is expected to take a lead in resolving all failures of the sewerage service irrespective of cause. SW will liaise with other agencies as necessary to effect a solution leading to a number of partnership schemes with both surface water and sewerage benefits in due course.

Responding to a severe flood event • Implement incident team. • Incident team liaise with police and Portsmouth City Council to A petrol interceptor being installed, Copnor Road scheme implement appropriate multi-agency level of management. • Activate severe weather plan. • If activated, send representative to SCG. • Increase standby staff if possible. • Check plans for detailed actions for high risk assets/areas. • Provide advice to the public as developed and agreed by the STAC.

Surface water separation Southern Water is delivering a £20m investment including surface water separation schemes in Portsmouth by 2015, to reduce the risk of sewer flooding in parts of Portsmouth and Southsea. The scheme will divert a significant amount of rainwater away from combined sewers by sending it to the sea, as well as refurbishing some of the existing equipment on the network, including the construction of two new underground pumping stations. This work will benefit the whole city but in particular, those areas that have suffered flooding in the past. The new well in Stamshaw Park, Gruneisen Road scheme

34 • Local flood risk management strategy • Citywide flood risk measures Flood risk ward by ward

How to use the ward pages Abbreviations Our strategy has taken the approach of considering each of the 14 PEMS: Portchester Castle to Emsworth Coastal Strategy wards individually for ease of reference. The information for each PICSS: Portsea Island Coastal Strategy Study ward has been set out as follows: SWMP: Surface Water Management Plan FBC: Fareham Borough Council HA: Highways Agency Ward name HWT: Hampshire and Isle of Wight Trust

Brief overview of the ward Baffins Brief overview of the ward drainage Baffins ward is located on the eastern side of Portsea Island and is Flooding predominantly of low topography. There are large open spaces in the Baffins ward has a number of separate surface water drainage form of the southern side of Great Salterns golf course, Milton networks but is largely served by combined drainage networks. characteristics including some of Common, allotments and various other green spaces. The developed and coastal characteristics, and an Baffins ward forms part of two separate areas identified for targeted area is largely set back from the coast to the west of Eastern Road. The groundwater investigation. coastline runs from the Harvester to Milton Common on Langstone Harbour frontage. The ward also includes Great Salterns Lake which There are a few pockets of surface water flooding recorded, and there the defining areas acts as the main surface water drainage outlet for approximately one have been incidents of wave overtopping along the Eastern Road overview of flooding that has quarter of Portsea Island. The lake and its tributary culvert feeding into frontage which causes disruption to one of the arterial roads of it from the golf course to the north are designated as a main river. It Portsmouth. It is highly likely that there was groundwater influence has pumps which trigger at a certain water level in times of high tide. on one of the more recent events. occurred historically This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page. 4j Key areas targeted for 8 PICSS flood cell 4 groundwater investigation Aerial shot of the ward showing Ward boundary SWMP hotspots

Surface Water Management Plan 5 4i Photo showing an example of flooding Local Flood Risk Zones, areas 4 or flood aftermath within the ward identified for groundwater

investigation and coastal flood cells 3h Wave overtopping along the Eastern Road frontage 38 • Local flood risk management strategy • Baffins

Coastal

Residential Overlap Sea defence properties presently Proposed measures (target standard Responsible Completion Area with other Background information Funding type(s) at risk (0.5% annual of protection 0.5%) authority date wards probability flood) Milton Bund to n/a Seawalls, Frontage protects to residential properties 23 Raise crest wall and embankment, PCC 2017 Flood Tangier Road revetments, and Milton Common (former landfill site). provide shoreline protection Defence Coastal flood risk table with actions, responsible authority and funding information seawall (4i) embankments Existing standard of protection 0.5%) Grant in Aid Eastern Road Copnor Seawalls, Frontage protects to A2030, golf course, Strengthen existing walls and raise PCC 2017 Flood bridge to Great revetments housing estate and some commercial defences to provide a sustained Defence Salterns Quay (4j) properties. Existing standard of protection standard of protection accounting for Grant in Aid 0.5%. sea level rise.

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records 8 – Great n/a Golf course regularly floods when EA main river 1 11 Good Great Salterns Scheme addressing the Southern by 2015 Salterns golf running through the centre of the course bursts its issues. Additional storm water channel, Water course banks additional culvert and upgrade of existing pumping station Tangier Road n/a Southern Water have identified a scheme to remove n/a n/a Some Tangier Road Scheme under construction Southern by 2015 Surface water flood risk information with actions (not in SWMP) surface water from the combined sewer network Water Total 1 11

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 5 – Great Copnor Low topography, likely to have high groundwater table. Determine and agree with partners how PCC with support requested from Environment end 2014 Salterns Highlighted as susceptible to groundwater emergence due best to gather groundwater information Agency, Southern Water, PCC planning to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership 4 – Milton Milton Low topography, likely to have high groundwater table. Determine and agree with partners how PCC with support requested from Environment end 2014 Highlighted as susceptible to groundwater emergence due best to gather groundwater information Agency, Southern Water, PCC planning to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership Stanley Avenue n/a Flooding to garages along the rear access road. PCC is investigating possibilities PCC end 2014 Areas identified for groundwater investigation and monitoring Investigations have found that the likely source is groundwater with 95% surety.

Baffins • Local flood risk management strategy • 39

NOTE: Only short term actions are shown as the strategy is due to be reviewed in 2018. For medium and long term actions please refer to PICSS / PEMS.

Flood risk ward by ward • Local flood risk management strategy • 35 Paulsgrove

Paulsgrove ward is dominated by the side of Portsdown Hill and the Flooding M27 which splits the densely populated area into two sections. There Paulsgrove has largely separate surface water drainage networks with are large open spaces towards the top of the hill, King Richards and sparse records of surface water flooding, most of which are likely to St Pauls schools, Port Solent and along Southampton Road frontage. be caused by localised issues like blocked gullies. The south coast railway line runs through the south of the ward. The There have been historical incidents of wave overtopping along coastline is wholly within Portsmouth Harbour and includes Trafalgar Southampton Road frontage which causes localised disruption to Wharf, Southampton Road, Port Solent and Horsea Island. traffic and residential areas along the frontage. The area to the south of the railway line has been identified for targeted groundwater investigation. This area features in the recently approved Portchester Castle to Emsworth Coastal Strategy – actions are outlined on the next page. Key PEMS flood cell 1a Ward boundary PEMS flood cell 1b areas targeted for PEMS flood cell 2 groundwater investigation PEMS flood cell 3 SWMP hotspots

1

11

Southampton Road frontage after a combined high tide and storm event

36 • Local flood risk management strategy • Paulsgrove Coastal

Dwellings presently Overlap Sea defence at risk from a 0.5% Responsible Completion Area with other Background information Proposed measures Funding type(s) annual probability authority date wards flood event Portchester Fareham Concrete wall, Frontage provides protection to 66 (408 across Raise defences to interim EA/English Works Medium likelihood of funding to Borough concrete bag residential and commercial entire flood cell) height from Portchester Castle Heritage/ required by through Flood Defence Grant in Aid. Paulsgrove Council wall, revetment, properties and A27. Defences in to Paulsgrove PCC/FBC 2020 Contributions likely to be required. (Reach 1) embankment good to fair condition. Present Any development of the Trafalgar and sheet piling standard of protection 5-10% Wharf site, included in the draft Site Allocations document, could be a potential source of funding Horsea n/a Concrete block Frontage provides erosion 0 Maintain current defences with PCC/MoD Ongoing Island revetment (Port protection to landfill site. replacement, refurbishment (Reach 2) Solent), Gabions Defences in very good to good and general repairs as required (MoD and condition. Present standard of landfill site) protection <0.5%

Surface

Surface water Properties presently at risk (1% Overlap with Historic flood Completion management Background information annual probability rain event) Proposed measures Project lead other wards records date plan area Residential Commercial none n/a EA AStSWF map shows railway line acts as a 0 0 Sparse Low surface water flood n/a n/a bund trapping water. Very little evidence to risk. Potential for high support this velocity overland flows due to hill topography

Groundwater

Groundwater Overlap with Completion desktop study Background information Proposed measures Project lead other wards date targeted area 11 – Cosham Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from end 2014 Cosham and emergence due to a geological permeability gather groundwater information and exactly where Environment Agency, Southern Water, PCC Paulsgrove boundary within the area planning department, Eastern Solent Coastal Partnership

Paulsgrove • Local flood risk management strategy • 37 Cosham

Cosham ward is dominated by the south side of Portsdown Hill and Flooding the railway line dissects the area. There are large open spaces towards Cosham has a number of separate surface water drainage networks along the top of the hill, King George playing fields and the Lakeside with a number of combined drainage networks. There are some localised commercial development. records of surface water flooding, most of which are caused by localised The coastline runs along the south side embankment of the M27 issues like blocked gullies or overland flows from the hill. and is wholly on the north side of Portscreek which separates the There have been very few historical incidents of wave overtopping along mainland from Portsea Island and connects Langstone and the M27 frontage which acts as a barrier. The area to the south of the Portsmouth Harbours. railway line has been identified for targeted groundwater investigation. There is potential for tide-locking to occur, however there are very few instances where this is thought to have contributed to flooding. This area features in the recently approved Portchester Castle to Emsworth Coastal Strategy – actions are outlined on the next page.

Key PEMS flood cell 3 Ward boundary areas targeted for groundwater investigation SWMP hotspots 1

11

10

A localised surface water flood event in Cosham ward

38 • Local flood risk management strategy • Cosham Coastal

Overlap Sea Residential properties Proposed measures* (target Responsible Completion Area with other defence Background information at risk (0.5% annual Funding standard of protection <0.1%) authority date wards type(s) probability flood event) (Part of) Drayton Concrete M27 frontage provides protection to strategic infrastructure 1863 Maintenance of M27 revetment HA Ongoing HA M27 and and block of M27/A27 and the South Coast railway. Refurbishment Farlington Farlington revetment works recently completed by the Highways Agency means the (Reach 3) condition of the revetment here is currently good. Current standard of protection <0.1% *Refer also to measures required for overlapping wards due to interdependency of flood cells

Surface

Surface water Properties presently at risk (1% Overlap with Historic flood Completion management Background information annual probability rain event) Proposed measures Project lead other wards records date plan area Residential Commercial 1 – Drayton and EA mapping shows railway line acts as a 481 90 Sparse Area considered too large PCC ongoing Cosham Farlington bund trapping water. Very little evidence to to treat as one group. support this. A recent flood event in this area Further investigation is not thought to have been influenced by the needed railway line

Groundwater

Groundwater Overlap with Completion desktop study Background information Proposed measures Project lead other wards date targeted area 11 – Paulsgrove Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from end 2014 Cosham and emergence due to a geological permeability gather groundwater information and exactly where Environment Agency, Southern Water, PCC Paulsgrove boundary within the area planning department, Eastern Solent Coastal Partnership

Cosham • Local flood risk management strategy • 39 Drayton and Farlington

Drayton and Farlington ward is dominated by the south side of Flooding Portsdown Hill and Farlington Marshes to the south. There are The ward has a number of separate surface water drainage networks large open spaces towards the top of the hill in the area of the along with a number of combined drainage networks. There have underground reservoirs and Farlington Marshes itself, which is been a number of recent flooding events which affected some dissected by the A27. The developed area is largely to the north of residential properties and these have been well documented. the railway line which runs along the north side of the marshes. The coastline runs partly along the south side embankment of the M27 There have been very few historical incidents of wave overtopping and around Farlington Marshes and is partly on the north side of along the M27 frontage, while the marshes are allowed to flood at Portscreek and partly Langstone Harbour. high tide events due to their importance for rare bird species. The area around the north of Farlington Marshes has been identified for targeted groundwater investigation. It is likely that a combination of factors contributed to the three recent flood events at the same location in the ward, including groundwater, tidal influence, rainfall and inability for the sewerage system to cope. Investigations by PCC and Southern Water are ongoing. This area features in the recently approved Portchester Castle to Emsworth Coastal Strategy – actions are outlined overleaf. Work on the Farlington Marshes coastal defences are ongoing with the Environment Agency and the Eastern Solent Coastal Partnership on behalf of PCC.

Key 1 PEMS flood cell 3 11 10 Ward boundary 2 areas targeted for groundwater investigation SWMP hotspots

A recent flood event in Drayton and Farlington ward

40 • Local flood risk management strategy • Drayton and Farlington Coastal

Overlap Sea Residential Proposed measures (target standard of protection Responsible Completion Area with other defence Background information properties Funding <0.1% at M27; 20% for 20 years at Farlington) authority date wards type(s) at risk (Part of) Drayton Concrete M27 frontage provides protection to 1449 Maintenance of M27 revetment HA Ongoing HA M27 and and block strategic infrastructure of M27/A27 and Maintenance of Farlington Marshes revetment EA in the Ongoing EA Farlington Farlington revetment the railway. Refurbishment works mean short term (Reach 3) the condition of the revetment is good. Current standard of protection <0.1%. Provision of vehicle underpass flood gate and culvert PCC/EA/ 2018 Flood Defence Farlington frontage provides protection flaps beneath A27 at Farlington Marshes HWT Grant in Aid to the Farlington Marshes SPA. Defence secured condition is poor – regular overtopping Undertake Solent-wide study to identify economic, EA/PCC/HA Required by High probability occurs, and repair/maintenance required environmental and social impacts of either improving 2020 of attracting annually. Standard of protection 20% existing revetment at Farlington Marshes, or undertaking Flood Defence managed realignment Grant in Aid

Surface

Surface water Overlap Properties presently at risk (1% Historic Project Completion management with other Background information annual probability rain event) flood Proposed measures lead date plan area wards Residential Commercial records 1 – Cosham EA mapping shows railway line acts as a bund 481 90 Sparse Area considered too large to treat as one group. PCC ongoing Cosham trapping water. Very little evidence to support this. Further investigation needed A recent flood event in this area is not thought to have been influenced by the railway line 2 – Farlington n/a The marshes act as a drain to a number of 0 4 Sparse Clearance of surface water pathways. PCC/EA ongoing Marshes properties in the Drayton and Farlington areas Environmental designations and the importance of the marshes as a wetland habitat for bird species may restrict work Station Road n/a Three separate flood incidents in the winter of 50 0 Very PCC and Southern Water are investigating the PCC/ ongoing (not in 2012/13. Extends to over 50 properties. Manhole good cause with a view to providing a long term Southern SWMP) surcharge witnessed on each occasion. Exact cause solution Water not yet known Total 531 94

Groundwater

Groundwater desktop Overlap with Completion Background information Proposed measures Project lead study targeted area other wards date 10 – Farlington n/a Low topography, likely to have high groundwater Determine and agree with partners how PCC with support requested from Environment end 2014 (excluding marshes table. Highlighted as susceptible to groundwater best to gather groundwater information Agency, Southern Water, PCC planning south of A27) emergence due to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership A recent flood event in Drayton and Farlington ward

Drayton and Farlington • Local flood risk management strategy • 41 Hilsea

Hilsea ward is located in the northwest corner of Portsea Island and is Flooding predominantly of low topography. There are large open spaces in the Hilsea ward has a number of separate surface water drainage form of Alexandra Park, various playing fields and around the Hilsea networks along with some combined and a small number of privately Lines scheduled ancient monument. owned drainage networks. There have been very few historical The developed area is largely set back from the coast. The coastline incidents of wave overtopping along the frontage which is well runs from the Mountbatten Centre on Tipner Lake to the railway sheltered by the motorway embankments of the M27 and M275. bridge on the south side of Portscreek. Hilsea ward forms part of two separate areas identified for targeted groundwater investigation. There have been a number of recent flooding events which affected 11 some private properties externally and these have been well documented. It is likely that a number of factors have contributed to 4k the flooding including defective sewer systems, groundwater, impermeable ground, rainfall and tide-locking. PCC and Southern Water are working together to investigate and take corrective actions. This area features in the Portsea Island Coastal Strategy Study – 4l actions are outlined on the next page.

3 7 Key 6 PEMS flood cell 3 PICSS flood 8 cell 4 5 6 Ward boundary areas targeted for groundwater investigation SWMP hotspots 10

A flood event affecting garages in Hilsea ward

42 • Local flood risk management strategy • Hilsea Coastal

Residential Overlap Sea properties at risk Proposed measures (target Responsible Completion Area with other defence Background information Funding (0.5% annual standard of protection 0.5%) authority date wards type(s) probability flood) Portscreek Copnor Seawalls, Frontage provides protection to commercial and residential 1704 Raise existing embankment and PCC 2017 Flood Defence South (4k) revetments properties, and Hilsea Lines scheduled ancient monument. Existing maintain existing walls and Grant in Aid standard of protection 10% revetments Hilsea n/a Seawalls, Frontage provides protection primarily to residential properties. Replace existing structures with PCC 2017 Flood Defence Lido to revetments Existing standard of protection 10% higher levels to provide a Grant in Aid Tipner sustained standard of flood Lake (4l) protection against sea level rise (Part of) Drayton Concrete M27 frontage provides protection to strategic infrastructure of 1863 Maintenance of M27 revetment HA Ongoing HA M27 and and block M27/A27 and the South Coast railway. Refurbishment works Farlington Farlington revetment recently completed by Highways Agency means condition of (Reach 3) revetment here is currently good. Current standard of protection <0.1%

Surface

Surface water Overlap Properties presently at risk (1% Historic flood Completion management with other Background information annual probability rain event) Proposed measures Project lead records date plan area wards Residential Commercial 3 – War Copnor Exact location and function of 1920s 0 5 Sparse Further investigation required PCC/Southern ongoing department sewer is unclear Water sewer 5 – Northern n/a This area is a natural low point and the 0 4 Very good Clearance of blockages in the sewer PCC/Southern ongoing Parade (Alex first point of emergence of flood network undertaken by Southern Water. Water Way area) waters when the sewer system is at Responsibility for the private sewer has capacity. Regular flooding to residents’ for the meantime been taken on by PCC/ garages Colas for maintenance purposes

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 7 – Hilsea n/a Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from Environment end 2014 emergence due to a geological permeability gather groundwater information and exactly where Agency, Southern Water, PCC planning boundary within the area department, Eastern Solent Coastal Partnership 8 – Alexandra Nelson Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from Environment end 2014 Park and Tipner emergence due to a geological permeability gather groundwater information and exactly where Agency, Southern Water, PCC planning boundary within the area department, Eastern Solent Coastal Partnership

Hilsea • Local flood risk management strategy • 43 Copnor Copnor ward is located on the northeast corner of Portsea Island. Flooding There are large open spaces on the northern part of Great Salterns Copnor ward has a small number of separate surface water drainage golf course, various playing fields and a part of Hilsea Lines networks but is dominated by combined drainage networks. There scheduled ancient monument. The developed area is largely set have been very few historical incidents of wave overtopping along the back from the coast and is dominated by the railway line, industrial frontage which is sheltered by Eastern Road. estates and Anchorage Park housing estate. The coastline runs from the railway bridge on the south side of Portscreek to the Harvester Copnor ward forms part of two separate areas identified for targeted on the Eastern Road. groundwater investigation. There have been a number of historic flood events which affected some private property and a main road. It is likely that this is caused by a fault in the local sewerage network, which Southern Water are 3 currently rectifying. 4k This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page. Key 4 areas targeted for 6 PICSS flood cell 4 groundwater investigation Ward boundary SWMP hotspots 4j 6

7 9 5

8

4l Copnor Road affected by surface water

44 • Local flood risk management strategy • Copnor Coastal

Residential Overlap Sea properties presently Proposed measures (target Responsible Completion Area with other defence Background information Funding at risk (0.5% annual standard of protection 0.5%) authority date wards type(s) probability flood) Portscreek Hilsea Seawalls, Frontage protects to commercial and residential 837 Raise embankment and maintain PCC 2017 Flood Defence South (4k) revetments properties, and Hilsea Lines scheduled ancient existing walls and revetments Grant in Aid monument. Existing standard of protection 10% Eastern Road n/a Seawalls, Frontage protects to A2030, golf course, housing Strengthen existing walls and raise PCC 2017 Flood Defence Bridge to revetments estate and some commercial properties. Existing defences to provide a sustained Grant in Aid Great Salterns standard of protection 0.5% standard of protection accounting Quay (4j) for sea level rise

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management plan with other Background information annual probability rain event) flood Proposed measures Project lead date area wards Residential Commercial records 3 – War department Hilsea Exact location and function of 1920s sewer 0 5 Sparse Further investigation required. PCC/Southern ongoing sewer is unclear Water 4 – Anchorage Park n/a High surface water flood risk due to low 34 6 Sparse PCC monitoring situation PCC ongoing topography and combined drainage system 6 – Copnor Road Hilsea Flooding to main A288 Copnor Road, 7 4 Good Copnor Road Scheme – new piped network Southern by 2015 (Amberley Road area) rendering impassable and pumping station Water 7 – Quartremaine n/a High flood risk as a large part of northern 0 4 Sparse Quartremaine Road Scheme – changes to Southern by 2015 Industrial Estate Portsea Island drains through the area infrastructure and new box culvert Water 8 – Great Salterns golf Baffins Golf course regularly floods when EA main 1 11 Good Great Salterns Scheme – additional storm Southern by 2015 course river running through the centre of the water channel, culvert and upgrade of Water course bursts its banks existing pumping station 9 – Copnor Road n/a Flooding in localised topographical low 36 8 Good Kiln Road Scheme addressing the issues. Southern by 2015 (Monckton Road area) spot Includes a new pumping station Water Total 78 38

Groundwater

Overlap Completion Area with other Background information Proposed measures Project lead date wards 5 – Great Salterns Baffins Low topography, likely to have high groundwater table. Determine and agree with partners how PCC with support requested from Environment end 2014 6 – Anchorage Park n/a Highlighted as susceptible to groundwater emergence best to gather groundwater information Agency, Southern Water, PCC planning due to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership

Copnor • Local flood risk management strategy • 45 Nelson

Nelson ward is located on the western side of Portsea Island and is Flooding predominantly of low topography. There are large open spaces in the Nelson ward has an extensive network of separate surface water form of Stamshaw Park, the MoD rifle range and the ferry ports. The drainage as well as some combined drainage networks. ward includes Tipner, Whale Island and the commercial ferry port. There have been very few historical incidents of tidal flooding to The developed area is largely set back from the coast to the east of properties which are well sheltered by the motorway embankment of the M275 motorway. The coastline runs from the Mountbatten the M275. Centre on Tipner Lake to Flathouse Quay which are on Portsmouth Harbour frontage. Nelson ward has been identified for targeted groundwater investigation along the coastal side. There have been a number of historic surface water flood events in 5m small pockets across the ward. It is thought that inadequacies in the localised sewerage system have contributed. These are presently being addressed by Southern Water and flooding has not occurred recently in the areas where it was previously an issue. 8 This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page.

Key 6o PICSS flood 10 cell 4 Ward boundary areas targeted 9 for groundwater investigation

6p SWMP hotspots

6n

A typical localised flood event which has not occurred recently

46 • Local flood risk management strategy • Nelson Coastal

Residential Overlap Sea Proposed measures (target standard properties presently Responsible Completion Area with other defence Background information of protection falls from 10% for Funding at risk (0.5% annual authority date wards type(s) Tipner as sea levels rise) probability flood) Tipner Lake n/a Seawalls, Frontage provides protection to some residential 32 Repair existing seawall and PCC/MoD/ Works to Uncertain to Rotten revetments properties, a school and MoD rifle range. Statutory re-profile flood embankment to developer secure Row (5m) requirement to maintain the coastal defences to minimise secure contaminated land. If the site contaminated the risk of any potential contaminates entering is regenerated, developers will land required Portsmouth Harbour’s water body. Portsmouth Harbour is replace and improve defences by 2018 designated SAC, SPA, Ramsar and SSSi under the Habitats Regulations. Improvements to the coastal defences will be necessary, if the site is redeveloped, to manage the long term flood risk. Existing standard of protection 10% Rotten n/a Seawalls, Frontage provides protection to M275, some commercial Monitor and maintain existing Landowner/ Ongoing Row to revetments properties and the commercial ferryport. Existing defences as required PCC Albert standard of protection 2-10% Johnson Quay (6n)

Surface

Surface water Overlap Properties presently at risk (1% Historic flood Completion management with other Background information annual probability rain event) Proposed measures Project lead records date plan area wards Residential Commercial 10 – Stamshaw Hilsea Flooding to a group of houses 116 2 Sparse Southern Water Gruneisen Road pumping station Southern by 2015 in the local area upgrade underway. PCC is monitoring the situation Water

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 8 – Alexandra Nelson Highlighted as susceptible to groundwater emergence Determine and agree with partners how best to PCC with support requested from Environment end 2014 Park and Tipner due to a geological permeability boundary gather groundwater information and exactly Agency, Southern Water, PCC planning where within the area department, Eastern Solent Coastal Partnership 9 – Stamshaw n/a Highlighted as susceptible to groundwater emergence Determine and agree with partners how best to PCC with support requested from Environment end 2014 due to a geological permeability boundary gather groundwater information and exactly Agency, Southern Water, PCC planning where within the area department, Eastern Solent Coastal Partnership

Nelson • Local flood risk management strategy • 47 Baffins

Baffins ward is located on the eastern side of Portsea Island and is Flooding predominantly of low topography. There are large open spaces in the Baffins ward has a number of separate surface water drainage form of the southern side of Great Salterns golf course, Milton networks but is largely served by combined drainage networks. Common, allotments and various other green spaces. The developed Baffins ward forms part of two separate areas identified for targeted area is largely set back from the coast to the west of the Eastern Road. groundwater investigation. The coastline runs from the Harvester to Milton Common on Langstone Harbour frontage. The ward also includes Great Salterns Lake which There are a few pockets of surface water flooding recorded, and there acts as the main surface water drainage outlet for approximately one have been incidents of wave overtopping along the Eastern Road quarter of Portsea Island. The lake and its tributary culvert feeding into frontage which causes disruption to one of the arterial roads of it from the golf course to the north are designated as a main river. It Portsmouth. It is highly likely that there was groundwater influence has pumps which trigger at a certain water level in times of high tide. on one of the more recent events. This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page. 4j Key areas targeted for 8 PICSS flood cell 4 groundwater investigation Ward boundary SWMP hotspots

5

4i

4

3h Wave overtopping along the Eastern Road frontage

48 • Local flood risk management strategy • Baffins Coastal

Residential Overlap Sea defence properties presently Proposed measures (target standard Responsible Completion Area with other Background information Funding type(s) at risk (0.5% annual of protection 0.5%) authority date wards probability flood) Milton Bund to n/a Seawalls, Frontage protects to residential properties 23 Raise crest wall and embankment, PCC 2017 Flood Tangier Road revetments, and Milton Common (former landfill site). provide shoreline protection Defence seawall (4i) embankments Existing standard of protection 0.5%) Grant in Aid Eastern Road Copnor Seawalls, Frontage protects to A2030, golf course, Strengthen existing walls and raise PCC 2017 Flood bridge to Great revetments housing estate and some commercial defences to provide a sustained Defence Salterns Quay (4j) properties. Existing standard of protection standard of protection accounting for Grant in Aid 0.5%. sea level rise

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records 8 – Great n/a Golf course regularly floods when EA main river 1 11 Good Great Salterns Scheme addressing the Southern by 2015 Salterns golf running through the centre of the course bursts its issues. Additional storm water channel, Water course banks additional culvert and upgrade of existing pumping station Tangier Road n/a Southern Water have identified a scheme to remove n/a n/a Some Tangier Road Scheme under construction Southern by 2015 (not in SWMP) surface water from the combined sewer network Water Total 1 11

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 5 – Great Copnor Low topography, likely to have high groundwater table. Determine and agree with partners how PCC with support requested from Environment end 2014 Salterns Highlighted as susceptible to groundwater emergence due best to gather groundwater information Agency, Southern Water, PCC planning to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership 4 – Milton Milton Low topography, likely to have high groundwater table. Determine and agree with partners how PCC with support requested from Environment end 2014 Highlighted as susceptible to groundwater emergence due best to gather groundwater information Agency, Southern Water, PCC planning to a geological permeability boundary and exactly where within the area department, Eastern Solent Coastal Partnership Stanley Avenue n/a Flooding to garages along the rear access road. PCC is investigating possibilities PCC end 2014 Investigations have found that the likely source is groundwater with 95% surety.

Baffins • Local flood risk management strategy • 49 Fratton

Fratton ward is located in the centre of Portsea Island and has no Flooding coastline. There are open spaces in the form of Kingston Cemetery, Fratton ward has a predominantly combined drainage network. various parks and school playing fields. The developed area is predominantly residential with a few commercial districts. There are a few pockets of surface water flooding recorded, but these are very localised and are most likely caused by blocked gullies or pipes. A large proportion of the ward has impermeable areas, meaning most of the rainfall falls on hard ground (roads, tarmac, paving, roofs) and There is limited tidal or groundwater influence, the ward is highly runs along the surface until it can find a way into the sewers. dependant on the sewerage network. 9 Fratton ward has not been identified for targeted groundwater investigation.

Key areas targeted for Ward boundary groundwater investigation 5

A localised highway flood, typical of Fratton ward.

50 • Local flood risk management strategy • Fratton Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records none n/a Fratton ward has not been identified for surface 0 0 Sparse none at present n/a n/a water investigation

If you would like to report a flood: There are a number of processes in place by which you can report a flood, or issues with the drainage system like blocked gullies:

• To report an issue with gullies anywhere in the city complete the • PCC City Help Desk 023 9283 4092. form by visiting www.portsmouth.gov.uk and search for • Colas 023 9231 0900. Many local issues, where appropriate, are ‘report it gullies’. You will need to supply an accurate address to passed to Colas by PCC to investigate under the terms of the allow us to find the gully and short description of the problem. Private Finance Initiative (PFI) agreement, which is in place until • Direct to the council’s Drainage Team at drainage.team@ 2029. In normal circumstances reported issues are investigated portsmouthcc.gov.uk or phone 023 9284 1588 which will be and actioned within 28 days but in reality it is highly likely to be picked up by a PCC Drainage Officer. much quicker. You may wish to call them directly. • If you believe a flood contains wastewater, PCC advises that you • For social housing, we recommend you contact your area housing contact Southern Water directly, by filling out an enquiry form at office in the first instance. Visitwww.portsmouth.gov.uk and www.southernwater.co.uk and search for ‘wastewater search for area housing office. enquiries’ or phone 0845 278 0845. PCC does not have the • IN AN EMERGENCY, CALL 999 IF YOU ARE IN DANGER OR power to work on sewers or structures owned by third parties or PEOPLE HAVE BEEN INJURED. other Risk Management Authorities, but we do work together to resolve issues.

Fratton • Local flood risk management strategy • 51 Charles Dickens

Charles Dickens ward is located on the western side of Portsea Island Flooding and includes the main shopping area of Commercial Road, HM Naval Charles Dickens ward has a predominantly combined drainage network Base and the Historic Dockyard. There are limited open spaces although there are a number of surface water and private sewers. although it does include Victoria Park and The Hard. There are a few pockets of surface water flooding recorded, but these The developed area is largely set back from the coast due to the are very localised and are most likely caused by blocked gullies or pipes. location of HM Naval Base. The coastline runs from Flathouse Quay to The Hard which are on Portsmouth Harbour frontage. The area is susceptible to tidal and groundwater influences to flooding during a rain event. Charles Dickens ward forms part of an area targeted for groundwater investigation. This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page.

6p 9 Key PICSS flood cell 6 areas targeted for PICSS flood cell 7 groundwater investigation 6n Ward boundary SWMP hotspots 7q

1 11

1a Anglesea Road affected by surface water flooding

52 • Local flood risk management strategy • Charles Dickens Coastal

Residential Overlap Sea defence properties presently Proposed measures (target Responsible Completion Area with other Background information Funding type(s) at risk (0.5% annual standard of protection 0.5%) authority date wards probability flood) Flathouse n/a Seawalls, Frontage provides protection to HM 0 Repair or replace seawalls as MoD/PCC by 2020 Alternative sources of funding Quay to revetments Naval Base, some commercial and required to a higher level to keep may be required to secure the The Hard residential properties. Existing pace with sea level rise money required to implement (7q) standard of protection generally these works, including from the 0.5% MoD

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records 11 – n/a Flooding to a cluster of properties 30 18 Sparse Southern Water sewer works have reduced Southern Completed Ordnance the frequency of flooding Water Row

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 1 – City Centre St Thomas Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from Environment end 2014 emergence due to a geological permeability gather groundwater information and exactly Agency, Southern Water, PCC planning boundary where within the area department, Eastern Solent Coastal Partnership

Charles Dickens • Local flood risk management strategy • 53 Milton

Milton ward is located on the eastern side of Portsea Island and is Flooding predominantly of low topography. There are large open spaces in the Milton ward has a combination of combined, surface water and form of Bransbury Park, St Mary’s and St James hospitals, Fratton Park private drainage networks. football ground, allotments and various other green spaces. There are a few pockets of surface water flooding recorded, but these The developed area is largely set back from the coast. The coastline are very localised and are most likely caused by blocked gullies or pipes. runs from Milton Common to the western edge of Eastney Lake on Langstone Harbour frontage. There are sparse records of tidal flooding. There is potential for groundwater and tidal water to influence flooding. Milton ward forms part of two areas targeted for groundwater investigation. This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page. An options appraisal for the coastline is to commence in summer 2014. Key 4i PICSS flood cell 3 areas targeted for 4 PICSS flood cell 4 groundwater investigation Ward boundary SWMP hotspots

2g 3

2e The seawall and frontage at the Thatched House

54 • Local flood risk management strategy • Milton Coastal

Residential Overlap Sea defence properties presently Proposed measures (target Responsible Area with other Background information Completion date Funding type(s) at risk (0.5% annual standard of protection 0.5%) authority wards probability flood) Milton Bund to n/a Seawalls, Frontage provides protection to residential 23 Raise crest wall and embankment, PCC 2017 Flood Tangier Road revetments, properties and Milton Common (former provide shoreline protection Defence seawall (4i) embankments landfill site). Existing standard of protection Grant in Aid 0.5%) Eastney Lake to n/a Seawalls Frontage provides protection to residential Maintain and monitor defences Landowner/ No capital works Landowner Thatched House and commercial properties. Existing PCC in first 10 years PH seawall (3h) standard of protection 0.5%

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records none n/a Milton ward has not been identified for surface 0 0 Sparse none at present n/a n/a water investigation

Groundwater

Groundwater Overlap with Completion desktop study Background information Proposed measures Project lead other wards date targeted area 3 – Eastney Eastney and Highlighted as susceptible to groundwater emergence Determine and agree with partners how best to PCC with support requested from Environment end 2014 Craneswater due to a geological permeability boundary gather groundwater information and exactly Agency, Southern Water, PCC planning where within the area department, Eastern Solent Coastal Partnership 4 – Milton Baffins Highlighted as susceptible to groundwater emergence Determine and agree with partners how best to PCC with support requested from Environment end 2014 due to a geological permeability boundary gather groundwater information and exactly Agency, Southern Water, PCC planning where within the area department, Eastern Solent Coastal Partnership

Milton • Local flood risk management strategy • 55 St Thomas

St Thomas ward is located on the southwestern side of Portsea Flooding Island and includes Gunwharf Quays shopping development. There St Thomas ward has a good surface water network with some are limited open spaces although it does include part of Southsea combined sewers. There are a few pockets of surface water flooding Common, HMS Temeraire naval sports facility and Ravelin Park. recorded, but these are very localised and are most likely caused by Residential developed areas are largely set back from the coast blocked gullies or pipes. except in the Old Portsmouth area. There are good records of coastal flooding to properties, especially in The coastline runs from The Hard to Clarence Pier which are on the Old Portsmouth area. Portsmouth Harbour’s entrance and the Solent. There is a high likelihood of groundwater levels influencing flooding. Old Portsmouth was, until recently, known to have significant seawater infiltration to the trunk sewers. Southern Water have now undertaken renovation of the sewer network to minimise the amount of seawater infiltration. St Thomas ward forms part of an area targeted for groundwater investigation. 11 Old Portsmouth has a network of over 30 tidal flood floodgates which raise the standard of protection to 0.5% AEP (in 2006). The Eastern 1 Solent Coastal Partnership is responsible for overseeing the operation and maintenance of the gates during high tide windows. A response is triggered by a messaging service from the Environment Agency. This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page. Key 12 PICSS flood cell 1 1a 13 PICSS flood cell 7 Ward boundary areas targeted 2 for groundwater 1b investigation SWMP hotspots Old Portsmouth floodgates during a high tide flood event

56 • Local flood risk management strategy • St Thomas Coastal

Residential Overlap Sea defence properties presently Proposed measures (target standard of protection Responsible Completion Area with other Background information Funding type(s) at risk (0.5% annual 0.5%) authority date wards probability flood) Spur St Jude Seawall, Frontage provides protection to 533 Raise seawalls where possible along landward edge PCC 2017 Flood Redoubt to revetments, residential and commercial properties of promenade, strengthen foreshore in areas that Defence Blue Reef groynes, and scheduled ancient monuments. rapidly lose beach material during storms and result Grant in Aquarium other Existing standard of protection varies in damage to promenade (Clarence Esplanade Aid (1b) between 10-100% additional rock toe protection). Final set of measures employed will be consistent with Seafront Masterplan Old n/a Seawalls, Frontage provides protection to No works planned – defences recently improved PCC No works in Portsmouth revetments, residential and commercial properties short term (1a) other and scheduled ancient monuments. Existing standard of protection 0.5%

Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records 12 – n/a Flooding to a cluster of properties 9 2 Sparse PCC is monitoring the situation. There may PCC ongoing Hambrook be a spring in the area which contributes Street

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 1 – City Centre Charles Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from Environment end 2014 Dickens emergence due to a geological permeability gather groundwater information and exactly Agency, Southern Water, PCC planning boundary where within the area department, Eastern Solent Coastal Partnership

St Thomas • Local flood risk management strategy • 57 Central Southsea

Central Southsea ward is located in the central southern area of Flooding Portsea Island and has no coastline. There are very limited open Central Southsea ward has a predominantly combined sewer network. spaces. The developed area is predominantly residential with a few shopping districts. There are a few pockets of surface water flooding recorded, but these are very localised and are most likely caused by blocked gullies or pipes. A large proportion of the district has impermeable areas, meaning most of the rainfall falls on hard ground and runs along the surface There is limited tidal or groundwater influence, the ward is highly until it can find a way into the sewers. dependant on the sewerage network. Central Southsea ward has not been targeted for groundwater investigation.

Key areas targeted for 1 groundwater investigation Ward boundary SWMP hotspots

2

An example of the type of surface water flood in Central Southsea ward

58 • Local flood risk management strategy • Central Southsea Surface

Surface water Overlap Properties presently at risk (1% Historic Completion management with other Background information annual probability rain event) flood Proposed measures Project lead date plan area wards Residential Commercial records none n/a Central Southsea ward has not been identified for 0 0 Sparse none at present n/a n/a surface water investigation

If you would like to report a flood: There are a number of processes in place by which you can report a flood, or issues with the drainage system like blocked gullies:

• To report an issue with gullies anywhere in the city complete the • PCC City Help Desk 023 9283 4092. form by visiting www.portsmouth.gov.uk and search for • Colas 023 9231 0900. Many local issues, where appropriate, are ‘report it gullies’. You will need to supply an accurate address to passed to Colas by PCC to investigate under the terms of the allow us to find the gully and short description of the problem. Private Finance Initiative (PFI) agreement, which is in place until • Direct to the council’s Drainage Team at drainage.team@ 2029. In normal circumstances reported issues are investigated portsmouthcc.gov.uk or phone 023 9284 1588 which will be and actioned within 28 days but in reality it is highly likely to be picked up by a PCC Drainage Officer. much quicker. You may wish to call them directly. • If you believe a flood contains wastewater, PCC advises that you • For social housing, we recommend you contact your area housing contact Southern Water directly, by filling out an enquiry form at office in the first instance. Visitwww.portsmouth.gov.uk and www.southernwater.co.uk and search for ‘wastewater search for area housing office. enquiries’ or phone 0845 278 0845. PCC does not have the • IN AN EMERGENCY, CALL 999 IF YOU ARE IN DANGER OR power to work on sewers or structures owned by third parties or PEOPLE HAVE BEEN INJURED. other Risk Management Authorities, but we do work together to resolve issues.

Central Southsea • Local flood risk management strategy • 59 St Jude

St Jude ward is located on the south coast of Portsea Island and Flooding includes highly residential areas and some commercial districts and St Jude ward has a largely combined sewer network. ancient monuments. There are some open spaces including Southsea Common and Clarendon Gardens. The ward was badly affected in 2000 by flooding, which is well documented. It is likely that the low topography of the Great Morass Residential developed areas are largely set back from the coast. The and Little Morass areas was a factor. Other factors include coastline of St Jude runs from Clarence Pier to Burgoyne Road and is groundwater, tide-locking and sewerage network issues. directly facing onto the Solent. The Seafront Masterplan outlines proposals to improve the amenity value of the promenade. There are sparse records of coastal flooding. St Jude ward forms part of a large area targeted for groundwater 1 investigation. This area features in the Portsea Island Coastal Strategy Study – actions are outlined on the next page.

Key areas targeted for PICSS flood cell 1 groundwater investigation 13 Ward boundary SWMP hotspots

2 14

1b

1c Submerged cars during the September 2000 flood event

60 • Local flood risk management strategy • St Jude Coastal

Residential Residual Life Overlap with Sea defence properties presently Proposed measures (target standard of Responsible Completion Area Background information of existing other wards type(s) at risk (0.5% annual protection 0.5%) authority date defences probability flood) 1b – Spur St Thomas Seawall, Frontage provides protection to 3310 10-15 years Reduce tidal flood risk from (existing) 5% PCC 2017 Redoubt to revetments, Southsea Common, residential and except 5-10 AEP to 0.5% AEP by improving coastal Blue Reef groynes, commercial areas and scheduled ancient years defences. Construct new wave return and Aquarium other monuments (Clarence splash walls, demountable defences Esplanade and Clarence Pier) 1c – Blue Eastney and Seawalls, Frontage provides protection to 10-15 years Reduce tidal flood risk from (existing) 5% PCC 2017 Reef Craneswater revetments, amenities and residential properties AEP to 0.5% AEP by improving coastal Aquarium to other defences. Proposed option(s): Construct a Southsea new wall landward of the promenade Esplanade (1.2km). Hold The Line - maintain (450m)

Surface

Surface water Properties presently at risk (1% Historic Overlap with Project Completion management Background information annual probability rain event) flood Proposed measures other wards lead date plan area Residential Commercial records 13 – Pier n/a Flooding of Southsea Common, a 4 2 Good It is thought the local sewer network is part of the PCC / ongoing Road (Little topographical low point. Localised issue. PCC is monitoring Southern Morass) carriageway flooding occurs regularly Water 14 – Eastney and The area is flagged as having high surface 163 36 Very Southern Water surface water separation schemes Southern by 2015 Southsea Craneswater water flood risk due to its low topography good across Portsmouth will significantly reduce the flows Water and combined drainage system. This is the arriving at Eastney pumping station during a rain event. first point of manhole surcharge if the This will raise the standard of protection for the area. Eastney pumping station were to fail Both PCC and Southern Water have undertaken property level flood protection measures in the area Total 167 38

Groundwater

Groundwater Overlap with Completion desktop study Background information Proposed measures Project lead other wards date targeted area 2 – Southsea Eastney and Highlighted as susceptible to groundwater Determine and agree with partners how best to PCC with support requested from Environment end 2014 Craneswater emergence due to a geological permeability gather groundwater information and exactly Agency, Southern Water, PCC planning boundary where within the area department, Eastern Solent Coastal Partnership

Eastney and Craneswater • Local flood risk management strategy • 61 Eastney and Craneswater

Eastney and Craneswater ward is located on the southeastern corner Flooding of Portsea Island. There are large open spaces in the form of Canoe Eastney and Craneswater ward has some separate surface water and Lake, Highland Road Cemetery, the seafront, Fort Cumberland and some combined sewer networks. The ward includes Eastney pumping some sports and recreational facilities. station and associated rising mains, outfalls and holding tanks, which The developed area is largely set back from the coast and is largely are critical to the drainage of Portsmouth. residential. The coastline runs from South Parade Pier to the western There are sparse records of coastal flooding, although some wave edge of Eastney Lake on The Solent and Langstone Harbour entrance. overtopping has occurred in the past. The Seafront Masterplan outlines proposals to improve the amenity value of the promenade. Tidal4i influence on the drainage network is particularly significant in this ward. Eastney and Craneswater ward forms part of two targeted areas for groundwater investigation. This area features in the Portsea Island Coastal Strategy Study – actions are outlined 3h on the next page. Key PICSS flood cell 1 PICSS flood cell 2 2f 2g Ward boundary 3 areas targeted for groundwater investigation SWMP hotspots

2 2e 14

1d

1c Pier Road rock armour and frontage

62 • Local flood risk management strategy • Eastney and Craneswater Coastal

Residential Overlap Sea defence properties presently Proposed measures (target Responsible Completion Area with other Background information Funding type(s) at risk (0.5% annual standard of protection 0.5%) authority date wards probability flood) Blue Reef Aquarium to St Jude Seawall, Frontage provides protection to amenities 1872 New flood wall on landward PCC 2017 Flood Southsea Esplanade (1c) revetments, other and residential properties. Existing standard side of promenade Defence Southsea Esplanade (1d) n/a Seawalls of protection varies between 0.5-100% Grant in Aid Melville Road caravan n/a Seawalls, Frontage provides protection to amenities Raise and strengthen existing Landowner/ Landowner/ site to Fraser Battery revetments, and residential properties and some defences developer developer (2e) groynes, critical infrastructure. Existing standard of embankments protection 100% at Fraser Battery Eastney Outfall to n/a Revetments, Frontage provides protection to Replace structure fronting Landowner/ Landowner/ Langstone Channel (2f) groynes, gabions residential properties and amenity. Eastney outfall at risk of developer developer Existing standard of protection 0.5% failure with a new revetment and seawall Langstone Channel to n/a Seawall, revetment, No works in short term n/a n/a n/a Eastney Lake (2g) gabions

Surface

Surface water Overlap Properties presently at risk (1% Historic Project Completion management with other Background information annual probability rain event) flood Proposed measures lead date plan area wards Residential Commercial records 14 – St Jude High surface water flood risk due to its 163 36 Very Southern Water surface water separation schemes will significantly Southern by 2015 Southsea low topography and combined drainage good reduce the flows arriving at Eastney pumping station during a rain event Water system. First point of manhole surcharge if – raising the standard of protection for the area. PCC and Southern the Eastney pumping station were to fail Water have undertaken property level flood protection measures

Groundwater

Groundwater Overlap Completion desktop study with other Background information Proposed measures Project lead date targeted area wards 2 – Southsea St Jude Highlighted as susceptible to Determine and agree with partners how best to PCC with support requested from Environment Agency, Southern 3 – Eastney Milton groundwater emergence due to a gather groundwater information and exactly where Water, PCC planning department, Eastern Solent Coastal end 2014 geological permeability boundary within the area Partnership

Eastney and Craneswater • Local flood risk management strategy • 63 Protecting individual residential properties

23 properties in Southsea have been fitted with special equipment, with the final property completed in February 2013. The properties were among the worst affected by floods that hit Southsea after a freak rainstorm in 2000. The work was successfully undertaken after the council’s flood and drainage team successfully won a grant from the Environment Agency, the national body which deals with flooding. Protection such as sealant for brickwork, special front doors, and flood resistant airbricks was put in place. It has been designed to cope with the kind of exceptional rainfall that has a 2% or more probability of occurring in any given year. This can be referred to as a 1 in 50 year standard of protection. The work package included training for residents on how to manually deploy their flood defences in anticipation of a flood event, and ‘wet’ testing of the features once installed.

Flood doors across an internal garage, with removable central support post A freshly installed flood door being ‘wet’ tested

64 • Local flood risk management strategy • Protecting individual residential properties Flood insurance

The ABI and the government have recently agreed a Memorandum of Understanding (MoU) on how to develop a not-for-profit scheme – Flood Re – that would ensure flood insurance remains widely affordable and available. The MoU is a first step towards establishing Flood Re, and confirms it as the government’s preferred option. Key elements of the framework are: • Flood Re will be run and financed by insurers as a not-for-profit fund which will cover the cost of flood claims from high risk homes. • Insurers will pass the flood risk element from those households deemed at high risk of flooding to the fund. Premiums for the flood risk will be calculated based on council tax banding up to a maximum limit depending on the band. • Flood Re would charge member firms an annual charge of £180million. This equates to a levy of £10.50 on annual household Automatic airbricks installed premiums and represents the estimated level of cross-subsidy that already exists between lower and higher flood risk premiums. • Flood Re will be designed to fully deal with at least 99.5% of years. Even in the worst half a percent of years, Flood Re will cover losses up to those expected in a 1 in 200 year – a year six times worse than 2007 – with government taking primary responsibility – working with the industry and Flood Re – for distributing any available resources to Flood Re policyholders should claims exceed that level. Providing operational issues, including governance and regulatory approval, are resolved, the aim is for Flood Re to be up and running by summer 2015, with regular progress reviews taking place to ensure Flood Re can proceed. For now ABI members will voluntarily continue to meet their commitment to continue to offer flood cover to existing customers under the previous Flood Insurance Statement of Principles.8

A flood door being tested for leaks during the installation phase

Flood insurance • Local flood risk management strategy • 65 Portsmouth City Council Coastal Partnership action plan

Level of Current status and/or proposed mitigation of flood risk Responsible Funding Funding likelihood Expected assessment authority source completion 1a – 1d Southsea Intermediate Reduce tidal flood risk from (existing) 5% AEP to 0.5% AEP by improving Portsmouth Capital Likely 2017 (Harbour Railway to (Strategy) coastal defences City Council – FCRMGiA Royal Marines Museum) 2e – 2g Eastney Intermediate Reduce tidal flood risk from (existing) 10% AEP to 0.5% AEP by improving Private Private Uncertain 2022 Spit (Royal Marines (Strategy) coastal defences Museum to Eastney Lake) 3h Eastney Lake Intermediate Existing coastal defences provide tidal flood risk management up to 0.5% Portsmouth Maintenance Unlikely, contributions More likely (Strategy) AEP. Continue to monitor and maintain condition of existing sea defences. City Council – PCC required beyond 2025 Future capital improvements to coastal defences may be necessary to keep and private Revenue, pace with sea level rise Improvements – FCRMGiA Portsea and private Island 4i – 4l North Intermediate Reduce tidal flood risk from (existing) 10% AEP to 0.5% AEP by adapting Portsmouth Capital – EA Likely 2017 Coastal Portsea Island (Strategy) to keep pace with sea level rise City Council FDGiA Strategy (Twyford Avenue to Study Milton Common) 5m Tipner (Harbour Intermediate Statutory requirement to maintain the coastal defences to minimise the Private Private Uncertain Flood Way to Twyford (Strategy) risk of any potential contaminates entering Portsmouth Harbour’s water improvements Avenue) body. Portsmouth Harbour is designated SAC, SPA, Ramsar and SSSi under only achievable the Habitats Regulations. Improvements to the coastal defences will be with necessary, if the site is redeveloped, to manage the long term flood risk regeneration 6n – 6p Continental Intermediate In order to maintain port operations the existing standard of flood risk Portsmouth Capital Unlikely, contributions Beyond Year 10 Ferry Port (Strategy) management (1.3% AEP) is to continue. This can be achieved by adapting City Council – FCERMGiA required flood risk assets to keep pace with sea level rise 7q HM Naval Base Intermediate Reduce tidal flood risk, to properties landward of HM Naval Base, from Portsmouth Capital Unlikely, contributions Beyond Year 10 to Harbour Railway (Strategy) (existing) 2% AEP to 0.5% AEP by adapting to keep pace with sea level City Council – FCERMGiA required rise. The Ministry of Defence will continue to maintain it’s own National Defence operations at the HM Naval Base

66 • Local flood risk management strategy • Portsmouth City Council Coastal Partnership action plan Portsmouth City Council Coastal Partnership action plan (continued)

Level of Current status and/or proposed mitigation of flood risk Responsible Funding Funding likelihood Expected assessment authority source completion 1a – 1b Portchester Intermediate ‘Hold The Line - Improve years 0-20 and Sustain 21-100’ PCC / FBC/ FDGiA and FDGiA available to part 2015-2019 Castle to (Strategy) private contribution fund scheme cost. Paulsgrove Shortfall required to be fulfilled by contributions or cost savings. Development at Trafalgar Wharf being considered 1c Horsea Island Intermediate All epochs ‘Hold the Line - maintain years 0-100’ Private MoD Uncertain Uncertainty due (Strategy) to private ownership M27 and Farlington Intermediate M27 All epochs ‘Hold The Line - Sustain years 0-100’ Private Highways Uncertain Uncertainty due Marshes (Strategy) Agency to private Portchester ownership to Intermediate Farlington Marshes ‘Hold the Line – Maintain years 0-20 with a Solent Portsmouth Revenue – Uncertain Short term Emsworth (Strategy) wide study to determine the long-term recommendations for the site. Hold City Council maintenance. study Strategy the Line – Sustain or Managed Realignment years 21-100, based upon the Possible completion Solent wide study recommendations’. In addition to a study looking across capital years 2013 to the context of the wider strategic network of sites, a study is required to – realignment 2018. Spend confirm the future management of the site. This is likely to be a range of following options from HTL to MR. This is likely to result in doing something outcomes of different, to recognise coastal change. The study will address the studies at latest economic, environmental and social implications and flood management after 2030 issues of the site. To be reflected in the implementation plan of strategy and Action plan of the SMP. SMP, Strategy and Sustainability study are to have clear engagement plans. The SMP and Strategy will be advising the Regional Habitat Creation Plan of the likelihood of the need to provide compensatory habitat for the features and amenities of Farlington Marshes, and given the uncertain timescales this needs to be taken account of now

Portsmouth City Council Coastal Partnership action plan • Local flood risk management strategy • 67 Portsmouth City Council drainage team action plan

Level of Ward(s) Current status and/or proposed mitigation of flood risk Funding Funding Expected assessment source likelihood completion Cosham Intermediate Paulsgrove, This is a large area flagged due to the topography used in the model. The EA first PCC high GW end (north of Cosham, generation flood map AStSWF was used which doesn’t take into account drainage revenue 2014 railway line) Drayton and systems. It also treats the railway line as a bund, which is not the case as water can Farlington pass underneath the railway in several places through culverts. Recommended (in part) for groundwater investigation Farlington Intermediate Drayton and There are no properties on the marshes to flood. The sea wall surrounding the marshes PCC high ongoing Marshes Farlington is nearing the end of its design life which the Coastal Partnership are addressing with revenue / the Environment Agency through a feasibility study. It has been discovered that a Southern surface water sewer drains into the marshes via Station Road, Sainsburys and under Water the railway and A27. Investigations into the sewer function and integrity of the reactive network, culverts and ditches are ongoing Surface War Intermediate Hilsea, A very small number of properties are effected by the low frequency flooding that Not yet not ongoing PCC water department Copnor occurs along its 2km length. Exact location and function of sewer is unclear but it is known identified drainage management sewer identified as a Southern Water asset. Further investigation required team plan Anchorage Intermediate Copnor There are no significant historic flooding events recorded here. The area is flagged as PCC not GW end Park having high flood risk due to its low topography. The risk is further increased by the revenue identified 2014 estate having a combined drainage system. Any surface water separation scheme would be very costly to implement. Recommended for groundwater investigation Northern Intermediate Hilsea PCC are aware of the service road flooding and it has been documented numerous PCC high ongoing Parade (Alex times. Residents’ garages are routinely flooded but internal properties are unaffected. revenue / Way area) Access to the sports facilities is affected but this is unadopted highway and is presently Southern leased to Parkwood Leisure. The surface water catchment that feeds into the Alex Way Water sewer is relatively large for the pipes that currently serve it. A detailed model of the reactive catchment has been produced by PCC, no easy solution has been found. Southern Water are aware of the issues and ongoing works to repair found blockages have not resolved the situation so far

68 • Local flood risk management strategy • Portsmouth City Council drainage team action plan Portsmouth City Council drainage team action plan (continued)

Level of Ward(s) Current status and/or proposed mitigation of flood risk Funding Funding Expected assessment source likelihood completion Copnor Road Detailed Hilsea, Southern Water surface water scheme addressing the issues Copnor Road Scheme 2014 (Amberley Copnor Road area) Quartremaine Intermediate Copnor Southern Water surface water scheme addressing the issues Quartremaine Road 2014 Industrial Scheme Estate Southern Great Intermediate Copnor, Southern Water surface water scheme addressing the issues Great Salterns Scheme Water via Underway 2014 Salterns Golf Baffins OFWAT Course Copnor Road Detailed Copnor Southern Water surface water scheme addressing the issues Kiln Road Scheme 2014 (Monckton Surface Road area) water Stamshaw Intermediate Nelson Southern Water pumping station upgrade addressing the issues Gruneisen Road Scheme 2014 management PCC plan Ordnance Intermediate Charles The flooding at this location has been addressed by Southern Water through sewer Completed drainage Row Dickens cleaning and maintenance team Hambrook Intermediate St Thomas We believe this was a one off incident caused by the flood of 2000. No further records PCC high GW end Street of flooding in the area exist. Southern Water undertook sewer renovations in the area revenue 2014 in 2007. Within area recommended for groundwater investigation Pier Road Intermediate St Thomas, Pier Road is a natural flood plain which floods during heavy rainfall, no properties are PCC high GW end (Little St Jude affected. Access to sea front is affected but there are numerous alternative routes. revenue 2014 Morass) Within area recommended for groundwater investigation Southsea Detailed St Jude, The Southern Water surface water separation schemes will help reduce the flows to the PCC high GW end (Great Eastney and existing systems. The recent Blue Flag sewer renovation works carried Southern Water revenue 2014 Morass) Craneswater has improved the capacity of the current system which has further reduced the flood risks. Within area recommended for groundwater investigation SuDS Approval Body Detailed ALL A sub-element of planning applications which requires separate drainage submission Fee charged high start April citywide for new developments. High potential to reduce flood risk to developers 2014 Groundwater Information Desktop ALL Groundwater monitoring information in partnership with other agencies at strategic Revenue high GW end gathering study citywide locations 2014 PCC / Highway drainage local level ALL Reactive and proactive maintenance of highways drainage PFI funded high 2029 Colas citywide

Portsmouth City Council drainage team action plan • Local flood risk management strategy • 69 Southern Water Services action plan

Scheme / procedure Level of Primary type of Ward(s) Current status and/or proposed mitigation of flood risk Funding Funding Expected assessment flood risk source likelihood completion Kirtley Close CSO Detailed Drayton and New flap valves, access route and renovation to prevent tide Completed Farlington locking influence Spice Island Detailed St Thomas Lining of sewers to reduce seawater infiltration and some remedial Completed gully rerouting Gruneisen Road Detailed Nelson Pumping station upgrade and capacity increase OFWAT 2014 Great Salterns Detailed Copnor, New channel and culvert to handle additional flows from schemes OFWAT 2014 Baffins to the north of the area. Pumping station upgrade AMP5 Business Tangier Road Detailed Baffins Surface water separation OFWAT 2014 Surface water Plan 2010-2015 Copnor Road Detailed Hilsea, 2014 Surface water separation. New pumping station OFWAT Copnor Awarded Quartremaine Road Detailed Copnor Surface water separation. Upgrade Great Salterns pumping station OFWAT 2014 Kiln Road Detailed Copnor Surface water separation. New pumping station OFWAT 2014 HM Naval Base Detailed Charles 2014 Surface water separation OFWAT Dickens Rodney Road Detailed Milton Surface water separation, may be shelved depending on flow 2014 OFWAT savings at Eastney being achieved by the above AMP6 Business Information not yet High level n/a Information not yet available OFWAT high covers period Plan 2015-2020 available 2015-2020 AMP7 Business Information not yet High level n/a Information not yet available OFWAT high covers period Plan 2020-2025 available 2015-2020 High level ALL Information not yet available – To inform AMP applications SW high covers period Drainage Area Plan Foul water citywide Revenue 2015-2020 High level ALL Information not yet available – To inform AMP applications SW high covers period Long Term Sewerage Plan citywide Revenue 2015-2020 n/a ALL Ongoing – reactive and proactive fixes to main sewers Revenue high ongoing Drainage Maintenance citywide

70 • Local flood risk management strategy • Southern Water Services action plan Environment Agency action plan

Scheme / procedure Level of Primary type of flood risk Ward(s) Current status and/or proposed mitigation of flood risk Funding Funding Expected assessment source likelihood completion Detailed Fluvial and coastal ALL citywide EA to continue with flood warning activities and improvements EA high ongoing Flood Warning Service to improve resilience to flooding Detailed Coastal Baffins, EA to continue current maintenance activities, pending future EA high ongoing Sea wall maintenance Drayton and management decisions in some locations (e.g. Farlington Farlington Marshes) Detailed Coastal Drayton and Installation of flood control structures to vehicle/cattle underpass EA high End of Farlington Marshes culvert works Farlington and culvert beneath A27 at Farlington Marshes to reduce risk of 2013 tidal inundation Detailed Fluvial Copnor, Permissive powers to undertake work as necessary; issue of EA high ongoing Baffins, permits under Water Resources Act 1991 and Southern Region Main river management Drayton and Byelaws Farlington Production and updating of national High level Surface water, main river, ALL citywide Hazard mapping for rivers and sea, and UFMfSW (Updated Flood EA high ongoing flood maps reservoir and coastal Map for Surface Water), both available at the end of 2013 Production of national flood plans, High level Surface water, main river, ALL citywide Responsible for the delivery of national plans and strategies like EA high ongoing strategies and guidance reservoir and coastal River Basin Management Plans, Catchment Flood Management Plans, Portchester to Emsworth Flood and Coastal Erosion Risk Management Strategy Advice on flood risk to new Detailed Surface water (pending ALL citywide EA to continue to provide advice on strategic planning EA high ongoing development SAB), main river, coastal, documents and site specific development proposals in relation to reservoir, groundwater flood risk Respond to pollution incidents Detailed All ALL citywide Reactive and proactive (e.g. bathing water quality sampling) EA high ongoing

Environment Agency action plan • Local flood risk management strategy • 71 What you can do to minimise the effects of flooding

Environment Agency advice on preparing for a flood9

Sign up to Flood Warnings Direct (see also page 60) To register by telephone, or if you need help during the registration Flood Guidance Statement 10:30hrs 19 December 2012 process, please call Floodline on 0845 988 1188. Our assessment of daily flood risk for England and Wales is below.

Make a personal flood plan Plan in advance what you will do if your property floods. You can complete a personal flood plan online by visiting www.environment-agency.gov.uk and search floods. 10:30 - 23:59hrs 00:00 - 23:59hrs 00:00 - 23:59hrs 00:00 - 23:59hrs 00:00 - 23:59hrs Wednesday Thursday Friday Saturday Sunday 19 December 2012 20 December 2012 21 December 2012 22 December 2012 23 December 2012 Complete a community flood plan This is so community members and groups know how they will work Headline Significant river and surface water flooding likely from Wednesday evening through Thursday. This is a period of together to respond quickly when flooding happens. This advice is for raised flood risk generally, with further significant disruption possible over the weekend. people active in the local community, leaders of community groups, General Overview of Flood Risk Successive periods of rain moving across England and Wales are falling on wet ground leading to the potential for significant schools, hospitals or residential care homes and anyone else involved disruption across much of southern and central England and southeast Wales on Wednesday into Thursday. For southern coastal counties and in Northamptonshire the flood risk is MEDIUM, as coloured amber on the maps above, while the flood in supporting communities to be better prepared for flooding. risk is LOW where the counties are coloured yellow. Residual flood risks are then maintained for Friday as river response is likely to be ongoing, particularly in Northamptonshire and along the Rivers Severn, Thames and Trent. Prepare a flood kit Further rainfall is then expected on Saturday. This is most likely to affect southwest England and parts of Wales and following on from wet conditions on Wednesday and Thursday there remains the potential for some significant impacts here and so the Put together a kit of essential items you’ll need to hand if it floods. flood risk is currently LOW. Ongoing flooding issues on the Somerset Levels and in Dorset and Wiltshire may be exacerbated by further rainfall.

The FGS will be updated this afternoon. Would you need extra support during a flood? Warnings and Alerts in force in England and Wales at 10:30hrs

As part of your flood planning we recommend you think about who Flood (click here) you can ask for assistance before, during and after a flood. The EA 0 Severe Flood Warnings / 4 Flood Warnings / 37 Flood Alerts Severe Weather (click here) can also deliver flood warnings for your property to a relative or Alerts - Yes / Warnings - Yes friend, so that they are aware when you may need help. You can set Best Judgement this up by phoning Floodline on 0845 988 1188.

Prepare your property for flooding It’s impossible to completely flood-proof a property but there are lots of things you can do to reduce flood damage. Some useful information and advice on buying flood protection products is © Crown, Met Office and Environment Agency 2012 Page 1 of 3 http://www.ffc-environment-agency.metoffice.gov.uk available at www.environment-agency.gov.uk and search floods. An example of a Flood Guidance Statement issued by the Met Office

72 • Local flood risk management strategy • What you can do to minimise the effects of flooding References

1. www.solentpedia.info/our_changing_coast/coastal_squeeze 2. www.environment-agency.gov.uk/homeandleisure/37837.aspx If you would like to report a flood: 3. www.environment-agency.gov.uk/homeandleisure/floods/31680.aspx There are a number of processes in place by which you can report a flood, or issues with the drainage system like blocked gullies: 4. en.wikipedia.org/wiki/Thames_barrier 5. www.gov.uk/government/news/ • To report an issue with gullies anywhere in the city complete new-streamlined-planning-guide-launched-online the form by visiting www.portsmouth.gov.uk and search for ‘report it gullies’. You will need to supply an accurate 6. www.push.gov.uk address to allow us to find the gully and short description of 7. Environment Agency the problem. 8. www.abi.org.uk/News/News-releases/2013/06/ABI-and- • Direct to the council’s Drainage Team at drainage.team@ Government-agree-Memorandum-of-Understanding-on-scheme- portsmouthcc.gov.uk or phone 023 9284 1588 which will be to-safeguard-UK-flood-insurance picked up by a PCC Drainage Officer. 9. Environment Agency • If you believe a flood contains wastewater, PCC advises that 10. Environment Agency you contact Southern Water directly, by filling out an enquiry form at www.southernwater.co.uk and search for ‘wastewater enquiries’ or phone 0845 278 0845. PCC does not have the power to work on sewers or structures owned by third parties or other Risk Management Authorities, but we do work together to resolve issues. • PCC City Help Desk 023 9283 4092. • Colas 023 9231 0900. Many local issues, where appropriate, are passed to Colas by PCC to investigate under the terms of the Private Finance Initiative (PFI) agreement, which is in place until 2029. In normal circumstances reported issues are investigated and actioned within 28 days but in reality it is highly likely to be much quicker. You may wish to call them directly. • For social housing, we recommend you contact your area housing office in the first instance. Visitwww.portsmouth. gov.uk and search for area housing office. • IN AN EMERGENCY, CALL 999 IF YOU ARE IN DANGER OR PEOPLE HAVE BEEN INJURED. Southsea Castle sea defences. © ‘The News’, Portsmouth

References • Local flood risk management strategy • 73 Glossary of terms

Term Meaning The ‘Act’ The Flood and Water Management Act 2010. AEP Annual Event Probability – see SoP / Standard of Protection. Aquifer A source of groundwater comprising water bearing rock, sand or gravel capable of yielding significant quantities of water. AMP5/6 Asset Management Plan – A plan for managing water and sewerage company (WaSC) infrastructure and other assets in order to deliver an agreed standard of service. AMP5 covers the period 2010-2015, AMP6 2015-2020. BREEAM BRE Environmental Assessment Method is the world’s foremost environmental assessment method and rating system for buildings. CFMP Catchment Flood Management Plan: A high-level planning strategy through which the Environment Agency works with their key decision makers within a river catchment to identify and agree policies to secure the long-term sustainable management of flood risk. Climate Change Long term variations in global temperature and weather patterns caused by natural and human actions. Combined sewer A sewer that drains both rainwater and foul water. CSO Combined sewer overflow. When a combined sewer reaches capacity it can overflow into another sewer (often a surface water sewer) at strategic points to relieve pressure and reduce the risk of foul water flooding. Culvert A channel or pipe that carries water below the level of the ground. Defra Department for Environment, Food and Rural Affairs. EA Environment Agency. ESCP Eastern Solent Coastal Partnership. FDGiA Flood Defence Grant in Aid – Environment Agency controlled national funding stream for flood defence works. Flood defence Infrastructure used to protect an area against floods, such as floodwalls and embankments; they are designed to a specific standard of protection (design standard). Flood Risk Area An area determined as having a significant risk of flooding in accordance with guidance published by Defra and WAG. FRR Flood Risk Regulations 2009; Transposition of the EU Floods Directive into UK law. The EU Floods Directive is a piece of European Community (EC) legislation to specifically address flood risk by prescribing a common framework for its measurement and management. HIOW Hampshire and Isle of Wight. HRA Habitat Regulations Assessment. Impermeable A surface, geology type or structure through which water can NOT travel. LDF Local Development Framework. LLFA Lead Local Flood Authority – Local Authority responsible for taking the lead on local flood risk management.

74 • Local flood risk management strategy • Glossary of terms Term Meaning LRF Local Resilience Forum – a multi-agency forum of all the organisations that have a duty to cooperate under the Civil Contingencies Act 2004, and those involved in responding to emergencies. They prepare emergency plans in a co-ordinated manner. LPA Local Planning Authority. MoD Ministry of Defence. OFWAT The economic regulator of the water and sewerage sectors in England and Wales. PCC Portsmouth City Council. PEMS Portchester Castle to Emsworth Coastal Strategy. Permeable A surface, geology type or structure through which water can travel. PFRA Preliminary Flood Risk Assessment. PPS25 Planning Policy Statement 25: Development and Flood Risk. PICSS Portsea Island Coastal Defence Strategy Study. RBMP River Basin Management Plan – South East. RFCC Regional Flood and Coastal Committee – Portsmouth is within the Southern RFCC region. Risk In flood risk management, risk is defined as a product of the probability or likelihood of a flood occurring, and the consequence of the flood. RMA Risk Management Authority – specifically for Portsmouth these are the EA, LLFA, water company and the highway authority. SAB SuDS Approval Body. SEA Strategic Environmental Assessment. SE7 South East Seven. SFRA Strategic Flood Risk Assessment. SMP Shoreline Management Plan. SoP / Standard The standard to which an area is protected against flooding. This is generally expressed as a Annual Event Probability (AEP). of Protection10 For example, an SoP of 10% means an area is protected against a flood with a 10% probability of occurring in any given year. An SoP of 0.5% AEP means an area is protected against a flood with a 0.5% probability of occurring in any given year. The flood with a 0.5% AEP has a lower likelihood of occurring than a flood with a 10% probability, but will be greater in severity (higher water levels). A 0.5% AEP standard of protection is therefore higher than a 10% standard of protection. The ‘Strategy’ PCC Local Flood Risk Management Strategy. SuDS Sustainable Drainage System – Methods of management practices and control structures that are designed to drain surface water in a more sustainable manner than some conventional techniques. For example, releasing rainwater directly back to the environment instead of traditional piped networks. SWMP Surface Water Management Plan. WFD EU Water Framework Directive.

Glossary of terms • Local flood risk management strategy • 75 Coatal and Drainage Team Transport and Environment Portsmouth City Council Civic Offices Guildhall Square Portsmouth PO1 2NE Telephone: 023 9284 1588 Email: [email protected]

äà åã You can get this Portsmouth City Council information in large print, Braille, audio or in another language by calling 9284 1588.

Designed by: [email protected] Published: November 2013 Ref: 3723