Draft River Hull Flood Risk Management Strategy

May 2010

River Hull Flood Risk Management Strategy Report

River Hull Flood Risk Management Strategy Report

Draft River Hull Flood Risk Management Strategy

Strategy Report

May 2010

Halcrow Group Limited has prepared this report in accordance with the instructions of their client, for their sole and specific use. Any other persons who use any information contained herein do so at their own risk.

© Halcrow Group Limited 2010 . Document History

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River Hull Flood Risk Management Strategy Report

River Hull Flood Risk Management Strategy Report

Contents Section Page Glossary of terms i At a glance vii 1. Introduction 1 1.1 The Environment Agency vision 1 1.2 Creating a better place – priorities and targets 2 1.3 Strategy policy links 2 1.4 Strategy aims and objectives 3 1.5 Benefits of a strategic approach 4 1.6 Strategy – development and review 5 2. Catchment overview 7 2.1 The River Hull catchment and definition of the study area 7 2.2 Environmental context 12 2.3 Definition of catchment areas 15 2.4 Links to other plans – opportunities and constraints 18 3. Flood risk 25 3.1 Definitions 25 3.2 Causes of flooding 25 3.3 Flood history 29 3.4 Flood management in the River Hull catchment 30 3.5 Assessment of current flood risk 35 3.6 Flood risk in the future 39 4. Appraisal of options 45 4.1 Appraisal criteria for River Hull Strategy options 45 4.2 Options for consideration 49 4.3 Options appraisal 50 4.4 Strategy elements and final options 56 4.5 Summary of economics 60 4.6 Summary of Strategic Environmental Assessment 64 4.7 Impact of climate change 65 5. Our Plan 67 5.1 Introduction 67 5.2 Proposed flood risk management measures 67 5.3 Strategy action plan 68 5.4 Procurement Strategy 71 5.5 Strategy risks 71 5.6 Strategy review 72

River Hull Flood Risk Management Strategy Report

List of Tables Table 1.1 Our objectives for the River Hull Flood Risk Management Strategy 3 Table 1.2 Reasons for a strategic approach 4 Table 2.1 River Hull Strategy area overview 7 Table 2.2 Hull and Coastal Streams CFMP Policy units and preferred policies 18 Table 3.1 Recorded flood events in the River Hull catchment 29 Table 3.2 River Hull flood defence assets 31 Table 3.3 Onset of fluvial flooding for River Hull catchment (taking into account the effect of the defences) 38 Table 4.1 Summary of initial flood risk management options 49 Table 4.2 Benefit cost ratio for pumping station appraisal in the maintain option 53 Table 4.3 Benefit cost ratio for pumping station combinations appraisal in the maintain option 54 Table 4.4 Summary of Strategy options (combinations of Strategy elements) 56 Table 4.5 Summary of economic damages (Whole Catchment) 61 Table 4.6 Summary of economic damages (upper and middle catchment areas only) 12 63 Table 4.7 Summary of economic damages (lower catchment area only) 12 64

List of Figures Figure 1-1 Stages in the development of the River Hull Flood Risk Management Strategy 6 Figure 2-1 Strategy location and study area 8 Figure 2-2 Topography of the Strategy area 9 Figure 2-3 Upper River Hull from Wansford Bridge 10 Figure 2-4 Lower River Hull through Kingston-upon-Hull 11 Figure 2-5 Key features of the River Hull system 12 Figure 2-6 River Hull catchment areas 16 Figure 2-7 Local Authority boundaries in the River Hull Strategy study area 20 Figure 3-1 Overtopping of River Hull at Wilfholme 26 Figure 3-2 Flooding near Wilfholme caused by Beverley and Barmston Drain being unable to discharge 27 Figure 3-3 Location of natural springs 28 Figure 3-4 Surface water flooding in Hull 29 Figure 3-5 Flood defences in the study area 33 Figure 3-6 Predicted extent of flooding (present day) 37 Figure 4-1 Options appraisal process 46

Appendices Appendix A – Options Appraisal Report Appendix B – Environmental Report

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Glossary of terms

Term Meaning / Definition Appraisal The process of defining objectives, examining options and evaluating costs, benefits, risks, opportunities and uncertainties before a decision is made. Biodiversity The 1992 Biodiversity Convention in Rio led to the formation of the UK Biodiversity Action Plan Steering Group which created action plans to conserve 116 species and 14 habitats (BAP) together with recommendations for future Biodiversity Action Plans (BAPs) as well as a number of Local Biodiversity Action Plans (LBAPs). The Environment Agency has an obligation to report to Government on all losses and gains of habitats and species protected by Biodiversity Action Plans that result from its flood and coastal defence work, and therefore any flood defence policies that are formulated for the catchment should seek to protect, or where possible, enhance sites which are important for BAP habitats and species. Catchment A surface water catchment is the total area that drains into a river. Catchment Catchment Flood Management Plans (CFMPs) are a large-scale strategic planning Flood framework for the integrated management of flood risks to people and the developed and Management natural environment in a sustainable manner. The Aire CFMP will incorporate flood risk Plan (CFMP) policy into strategic and local plans and ensure its local implementation through development control. This will prevent inappropriate development in the floodplain, thereby reducing the risk of flooding. Conservation A Conservation Area is an area of special architectural or historic interest, the character Area (CA) or appearance of which it is desirable to preserve or enhance. County A County Structure Plan sets out policies and major proposals to guide new Structure Plan development, and conserve the natural and built environment. It must implement national and regional polices, in particular the Planning Policy Guidance (PPG) notes, and shapes planning and development. Critical Ordinary A watercourse which is non main river, but which the Environment Agency and operating Watercourse authorities deem critical as they have the potential to put large numbers of people and (COW) property at risk from flooding. Environment Our vision for the environment and a sustainable future is: ‘A healthy, rich and diverse Agency environment in England and Wales, for present and future generations’ To achieve the Environmental targets that will make the ‘vision’ a reality the Agency has identified nine key ‘themes’ or Vision ‘frameworks for change’ through which it will work for a more sustainable future. 1. A better quality of life: the Agency will work with all sectors to enhance the quality of the environment and the services it provides – for business, anglers, the boating community and other users of the waterways, farmers, planners and all sections of the community. 2. An enhanced environment for wildlife: the Agency will ensure that its activities and those it authorises do not threaten key species and habitats; 3. Cleaner air for everyone 4. Improved and protected inland and coastal waters: the Agency will work to clean up polluted waters and to reduce the risk of further pollution; 5. Restored protected land with healthier soils. 6. A ‘greener’ business world 7. Wiser sustainable use of natural resources 8. Limiting and adapting to climate change 9. Reducing flood risk: the Agency will improve flood defences and information on flood risks For further information refer to our website http://www.environmentagency.gov.uk/aboutus/286233/106775/106809/ Environmental And Environmental Impact Assessment is a statutory process for a development which is Impact likely to have an adverse environmental impact, with the impacts identified and assessed Assessment to determine their significance. (EIA) Flood A scheme designed to reduce the risk of flooding in a specific location. Alleviation Scheme (FAS) Flood Defence A structure (or system of structures) for the alleviation of flooding. Floodplain Any area of land over which water flows or is stored during a flood event or would flow but for the presence of flood defences.

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Term Meaning / Definition Flood Risk The activity of modifying the frequency or consequences of flooding to an appropriate Management level (commensurate with land use), and monitoring to ensure that flood risks remain at the proposed level. This should take account of other water level management requirements, and opportunities and constraints. Flood Map Maps showing the Agency’s best estimate of the extent of the floodplain. These cover all Main Rivers and some ordinary watercourses. The floodplain is defined as the area having a 1% per annum risk of fluvial inundation, or a 0.5%p.a risk of tidal inundation. Defended areas are also shown. These maps are sometimes referred to as the Indicative Flood Map. Flood Storage An area of land which may be used to temporarily store an increased depth or extent of Area floodwater to reduce flood risk to communities downstream. Flood Zones This map shows natural floodplain 'zoned' into three areas based on risk for the purpose of PPG25. They show the flooding that would occur if there were no flood defences and have been created from a combination of detailed models where available, generalised models based on the national Digital Terrain Model and relevant historic flood data. Watercourses that have a catchment size of less than 2 square kilometres have not been included. Geographical A GIS is a computer-based system for capturing, storing, checking, integrating, Information manipulating, analysing and mapping spatially referenced data. System (GIS) Land Use Various types of activities, developments, cropping types, etc, for which land is used. Local A local agenda (produced by the local authority) with plans and targets to protect and Biodiversity enhance biodiversity and achieve sustainable development. The Agency is committed to Action Plan Biodiversity Action Plans and works with central government (Rio Earth Summit, 1992) to (LBAP) realise LBAP objectives. Biodiversity Action Plans are split into those concerning habitats (Habitat Action Plans) and those concerning species (Species Action Plans). While LBAPs may have been developed for species or habitats of particular local interest, those species or habitats for which there is a BAP on a national level will also be conferred protection even where a LBAP may not exist. Local The Local Development Framework (LDF) is a non-statutory term to describe a folder of Development documents which includes the local planning authority’s local development documents. Framework (LDF) LiDAR LiDAR (Light Detection and Ranging) is an airborne mapping technique which uses radar to measure ground elevation, resulting in a terrain map used to assess flood risk. Listed Building In England, Listed Buildings are designated by English Heritage. They are buildings or permanent structures with special architectural or historic interest (exterior or interior), and are graded I, II* and II. National Nature National Nature Reserves are designated under the National Parks and Access to the Reserve (NNR) Countryside Act 1949 or the Wildlife and Countryside Act 1981 (as amended) primarily for nature conservation, but can also include sites with special geological of physiographic features. All NNRs are “nationally important” and are all among the best examples of a particular habitat, They are usually owned or leased by Natural England, or managed in accordance with a Nature Reserve Agreement with the landowner or occupier or an approved body such as a wildlife trust. Further information about NNRs can be found on Natural England’s website site: http://www.naturalengland.org.uk/ourwork/conservation/designatedareas/nnr/default.aspx National The National Property Database (NPD) gives address-point (location) data of all types of Property properties, in order to calculate economic damages of flood events. Database

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Term Meaning / Definition Planning Policy One of a series of Planning Policy Guidance notes (PPGs) issued by DTLR to advise Guidance Note local planning authorities and developers. While PPGs are not statutory, planning 25: authorities are obliged to consider them in preparing plans and determining planning Development applications. PPG25, issued in July 2001, raises the profile of flood risk, which should be and Flood Risk considered at all stages of the planning and development process and on a catchment- (PPG25) wide basis. It emphasises the need to act on a precautionary basis and to take account of climate change. It provides advice on future urban development in areas subject to flood risk, subjecting proposals to a sequential response (dependent on the degree of risk) and promotes the concept of Sustainable Drainage Systems (SuDS) in new development or re-development. For further information please refer to the Office of the Deputy Prime Ministers planning website: http://www.planning.odpm.gov.uk/ppg25/ Planning Policy This is a draft revision of PPG25, to clarify and strengthen the core policies, making it Statement 25: easier and clearer to understand. This will include the clarification of the sequential test. Development For further information please refer to the Department for Communities and Local and Flood Risk Government website: http://www.communities.gov.uk/index.asp?id=1161570 (PPS25) Preliminary A high level review of flood risk management issues in a catchment or part of a Strategic catchment, based on existing information. Used by North-East region of the Environment Review (PSR) Agency to identify urgent flood defence works to be progressed in areas of very high risk, and as a first step in preparing Flood Risk Management Strategies. The PSRs for the Upper Aire and Lower Aire have also provided information for use within the Aire CFMP. Ramsar Site Ramsar sites are wetlands of international importance designated under the Ramsar Convention (1971) and meeting those criteria for identifying wetlands of international importance. The Ramsar Convention is an intergovernmental treaty providing the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources, especially as waterfowl habitat. Ramsar sites previously received SSSI designation status but the majority of these sites are also designated under the EU Birds Directive, and are currently managed as protected areas through the Habitat Regulations. Further information can be located on the Ramsar convention on wetlands website: http://www.ramsar.org/ Regional Regional Spatial Strategies (RSS) provide a spatial framework to inform the preparation Spatial Strategy of local development documents, local transport plans and regional and sub-regional strategies and programmes that have a bearing on land use activities (Government Office for Yorkshire and the Humber, 2004). Scheduled To protect archaeological sites for future generations, the most valuable of them may be Monuments “scheduled”. Scheduling is the process through which nationally important sites and (SMs) monuments are given legal protection by being placed on a list, or ‘schedule’. English Heritage identifies sites in England, which should be placed on the schedule by the Secretary of State for Culture, Media and Sport. The current legislation, the Ancient Monuments and Archaeological Areas Act 1979, supports a formal system of Scheduled Monument Consent for any work affecting a designated monument. Further information can be found on English Heritage’s website: http://www.english-heritage.org.uk Site of Special Sites of Special Scientific Interest (SSSIs) are notified under the Wildlife and Countryside Scientific Act 1981 (as amended) and the Countryside and Rights of Way (CROW) Act 2000 for Interest (SSSI) their flora, fauna, geological or physiographical features. Notification of a SSSI includes a list of operations that may be harmful to the special interest of the site. The Wildlife and Countryside Act 1981 (provisions relating to SSSIs) has been replaced by a new Section 28 in Schedule 9 of the CROW Act. The new Section 28 provides significantly enhanced protection for SSSIs. Government policy is to give land, notified as SSSI, protection through the statutory planning system. Planning Policy Guidance on Nature Conservation (DoE, PPG No. 9, 1994) makes it clear that nature conservation can be a significant material consideration in determining planning applications, especially in or near to SSSI. It goes on to state, “the key importance of SSSI means that development proposals in or likely to affect them must be subject to special scrutiny”. The Agency is notified of SSSIs by Natural England under Section 8 of the Environment Act (1995). For further information refer to Natural England’s website: http://www.sssi.naturalengland.org.uk/Special/sssi/index.cfm

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Term Meaning / Definition Special Special Protection Areas (SPAs) are strictly protected sites classified in accordance with Protection Area Article 4 of the EC Directive on the conservation of wild birds (79/409/EEC) , also known (SPA) as the Birds Directive, which came into force in April 1979. They are classified for rare and vulnerable birds, listed in Annex I to the Birds Directive, and for regularly occurring migratory species. SPAs are designated for their international importance as breeding, feeding and roosting habitat for bird species. The Government is required to consider the conservation of SPAs in all planning decisions. SPAs receive SSSI designation under The Countryside and Rights of Way (CRoW) Act 2000 and The Wildlife and Countryside Act 1981 (as amended). For further details refer to the European Commission: website: http://europa.eu.int/comm/ environment/nature/spa/intro_en.pdf and The Joint Nature Conservation Committee website at http://www.jncc.gov.uk/ukspa/sites/spalistA-C.htm Strategic A systematic appraisal of the potential environmental consequences of policy/ planning/ Environmental strategy decisions prior to approval. The SEA is, in effect, an environmental assessment Assessment of certain plans and programmes in compliance with the SEA Directive 2001/42/EC. The (SEA) SEA directive is implemented through the Environmental Assessment of Plans and Programmes Regulations , making SEA mandatory for plans that are likely to have significant environmental effects. While it shares some similarity with Environmental Impact Assessment, the SEA goes further through considering wider impacts such as those on population, human health and cultural heritage. Strategic Flood A Strategic Flood Risk Assessment (SFRA) is intended to provide an understanding of Risk flood risk, outlining the extent and nature of flooding within the flood risk zones. Assessment (SFRA) Sustainability Sustainable development is ‘development which the meets the needs of the present without compromising the ability of future generations to meet their own needs’ (From ‘Our Common Future (The Brundtland Report)’ – Report of the 1987 World Commission on Environment and Development). The government’s Securing the future: delivering UK sustainable development strategy report (March 2005) presents the set of shared UK principles that it will use to achieve the country’s sustainable development purpose: - living within environmental limits, -ensuring a strong, healthy and just society, -achieving a sustainable economy, -promoting good governance, -using sound science responsibly. Washlands Washlands are the area of the floodplain where water is stored during flood events. Artificial structures can be added to control the amount of water stored and the timing of its release downstream. The Wildlife and Under Section 28 of the Wildlife and Countryside Act 1981, areas of land considered to Countryside Act be of national importance for nature conservation, subject to a statement of their (WCA) 1981, scientific value, are notified as Sites of Special Scientific Interest (SSSIs). Although and the SSSIs are notified by Natural England (EN), the Statutory conservation body, Countryside management of a SSSI is the responsibility of the landowner, who is provided with a list and Rights of of Potentially Damaging Operations (PDOs), activities that may damage the scientific Way (CRoW) interest of the site. EN, as the regulatory body for SSSIs, must be given notice of any Act 2000 PDO which is proposed to take place on a SSSI. The CRoW Act 2000 increased the powers of statutory bodies to prevent damage to SSSIs, increased penalties for damage to sites and granted new powers to the courts to order the restoration of sites after they have been damaged. Statutory bodies have also been given new powers to refuse consent for PDOs without having to provide compensation payments to landowners. The Wildlife and Countryside Act is divided into four parts. Part I is concerned with the protection of wildlife, Part II relates to the countryside and national parks (and the designation of protected areas), Part III covers public rights of way, Part IV deals with miscellaneous provisions of the Act The designation of protected species is included in Schedules 1, 5 and 8 of the Act, which list protected birds, protected animals and protected plants, respectively.

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Term Meaning / Definition World Heritage World Heritage Sites receive designation from the United Nations Educational, Scientific Sites and Cultural Organisation (UNESCO) which “seeks to encourage identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity”. This is embodied in an international treaty called the Convention concerning the Protection of the World Cultural and Natural Heritage, adopted by UNESCO in 1972. They receive no additional statutory protection from such designation, although there is an assumption that they will already be of such importance to receive protection from their status alone, if not from existing Statutory arrangements and laws (such as Heritage, Conservation, Environmental, Planning etc. at national and local level). Planning authorities regard the status of World Heritage Sites as a material consideration in determining planning applications and applications for permission for development affecting listed buildings and their setting. For further details refer to the UNESCO website: http://whc.unesco.org/toc/mainf13.htm

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At a glance

The River Hull forms part of a complex network of rivers, drains, pumping stations and flood defence banks and walls stretching from above Driffield in the north to the Humber estuary in the south. The network is managed to provide flood protection for around 100,000 properties and around 5,500 hectares of land.

We have developed a draft strategy to identify the risk of flooding now and in the future, taking climate change predictions into account. We will use the findings to make the case for future investment in order to manage flood risk.

In developing the draft Strategy we have carried out detailed technical and economic analysis. We have also met and talked with local people and partner organisations and have taken their views into account.

Key characteristics and issues of the Hull catchment

• Much of the area is low lying and the relationship between the rivers and drains, the Humber Estuary, groundwater and surface water is very complex. • Extensive flood defences along the River Hull and the Humber estuary frontage greatly reduce the risk of flooding to people, properties and land. Without these defences the area would be very vulnerable to flooding. • The defences in the lower part of the catchment in Kingston upon Hull are largely privately owned and are in a variable state of repair. Some are in a very poor condition. • The flood banks in the central part of the catchment are in reasonable condition. Some of the flood banks in the upper part of the catchment are in poor condition. • The Environment Agency own and operate five pumping stations in the catchment. Some of these do not reduce the risk of flooding to property, although they do play an important land drainage role by reducing the frequency and duration of water logging of 1400 hectares of agricultural land in a typical winter. Much of this land is already prone to flooding.

Challenges and opportunities

• Flood risk benefit to people and property in Kingston Upon Hull and surrounding area means flood protection schemes in this area are very likely to attract funding. • Funding for flood risk management activities comes from tax payers and is given to us each year by government. • We need to prioritise to make sure we get the best value for the money we have. The assessment process gives priority to work that protects people and property. • Our maintenance policy ensures that we direct spending to the most important flood defences. • In the longer term we can not continue to fund pumping stations that do not reduce the risk of flooding to property. These are Wilfholme, Hempholme and Tickton pumping stations.

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• The costs of maintaining some of the flood banks in the upper catchment are greater than the financial benefits of doing so. • In situations where we can no longer justify long-term funding, we propose to provide funding for up to five years while we work with communities and partner organisations to explore options for alternative funding.

Our proposed strategy We will continue to maintain and, in some areas, improve those flood banks, walls and other structures for which we are responsible and can obtain funding. This will require an investment of £109 million over the next 20 years and will protect the vast majority of people, property and agricultural land. We will continue to operate and maintain the Hull Barrier and our pumping stations at East Hull and Great Culvert. This will include work such as the £10 million investment currently underway at the Hull Barrier. We will work with Hull City Council and the owners of riverside land to develop a plan for repairing and improving the defences beside the River Hull through the city.

We will continue to maintain and operate our other pumping stations for a period of up to five years while we work with the local authority, Internal Drainage Boards, landowners and others to find a longer term funding solution. We will continue to maintain the flood banks in the upper catchment for a period of up to five years while we work with East Riding of Yorkshire Council, Internal Drainage Boards, Natural England, landowners and others to develop a longer term plan for water level management in this area.

We have produced a draft action plan to implement the Strategy. This is included in the draft Strategy and Strategy summary document.

How to comment You can have your say on the draft Strategy by attending one of our events or sending us an email or letter with your comments. You can view the draft Strategy documents including a summary document at:

- Libraries at Hull Central, Beverley and Driffield; - in some East Riding of Yorkshire council and Hull city council Customer Service Centres; - some Environment Agency Offices.

To find out more the consultation, including event and exhibition details or to obtain consultation documents visit our website www.environment-agency.gov.uk/riverhullstrategy or contact us on 08708 506 506, [email protected]

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1. Introduction This section explains why we are developing a flood risk management strategy for the River Hull. It covers:

• our wider national vision, and how the Strategy can contribute to achieving its goals; • the links to our wider work, which deal with flooding or other issues in the study area and the wider catchment; • the aim and objectives of the Strategy; • the reasons and benefits for taking a strategic approach to flood risk management; and • the stages and timescales of the development of the strategy .

1.1 The Environment Agency vision We have a vision for the environment: “a better place for people and wildlife, for present and for future generations”. To achieve our vision, we will work towards the following five key areas,

Key area Our aims • Act to reduce climate change We play our full part in helping England and Wales meet and its consequences greenhouse gas emissions targets in ways that minimise other environmental impacts. • We help people and wildlife adapt to climate change and reduce its adverse impacts. • We put reducing and adapting to climate change at the heart of everything we do. • Protect and improve water, land The quality of surface, ground and coastal water and wetlands and air continues to improve for the benefit of people, the economy and wildlife. • Land is managed sustainably; protecting soils, water and biodiversity and contributing positively to reducing and adapting to climate change. • Biodiversity is enhanced and fish stocks are managed sustainably for the benefit of wildlife and people. • Businesses and other organisations reduce the impacts of their activities on water, land and air and are responsible operators. • We improve how we work as regulators to maximise environmental outcomes while minimising the cost to businesses. • Work with people and Flood risk and coastal erosion are effectively managed and communities to create better people and property are better prepared and protected. places • Better local environments enhance people’s lives and support a sustainable economy. • New and existing developments have a reduced environmental impact and well-planned environmental infrastructure. • All sections of society have opportunities to enjoy water and wetlands through angling, navigation, sport and other recreation.

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Key area Our aims • Work with business and other Businesses and other organisations know what the best organisations to use resources environmental options are for managing waste and using wisely resources wisely. • The right waste and resource management infrastructure is in place. • Businesses and other organisations are resource efficient, minimise pollution and manage their waste responsibly. • Safe, secure water supplies are used efficiently to meet the needs of the public, business and the environment. • Be the best we can We will provide a first class customer service. • We will work effectively with partners to deliver shared environmental outcomes. • We will use evidence and knowledge to guide and inspire our own actions and the actions of others. • We will equip and train staff to achieve their potential and maximise their productivity. • We will be acknowledged as leaders in managing our own environmental impact. • We will make the best use of our funding to deliver more for people and the environment.

1.2 Creating a better place – priorities and targets Our Corporate Strategy 1 sets out what we need to do over the five years (2010-2015) to work towards our vision. We have called our Corporate Strategy ‘Creating a better place’. It identifies priorities for action under each of the five key areas of the vision. For each of these priorities we have set national targets against which we will measure our results over the next five years. For example, one of our priorities for ‘work with people and communities to create better places’ is to ensure flood risk and coastal erosion are effectively managed and people and property are better prepared and protected. We have set a national target of our flood and coastal risk management programme delivering at least £5 of benefits for each £1 invested. We will deliver part of our Corporate Strategy at a national level, for example by advising the Government on policy. However, many of the improvements that we desire must be achieved at a regional and local level, where people and wildlife live. Each of our seven English regions and Environment Agency Wales has prepared a ‘local contribution’. This shows how each region will create a better place locally, and contribute to the five key areas of our vision. Our local contribution for north east region sets out the targets and actions that we aim to achieve as our contribution to the national targets.

1.3 Strategy policy links In autumn 2004, the Government set out its new national strategy for flood and coastal erosion risk management, called ‘Making Space for Water’ 2. This applies the principles of sustainable development to flood risk management. It considers how we should adapt to future climate change and seeks ways to help all communities and individuals prepare for and live with flooding.

1 Our vision and our corporate strategy ‘creating a better place’ can be obtained from www.environment- agency.gov.uk/strategy Or telephone 08708 506 506. Our north east local contribution can be found at www.environment-agency.gov.uk/regions/northeast , under north east corporate strategy or telephone 08708 506 506. 2 Defra (2004), ‘Making Space for Water – Developing a new Government strategy for flood and coastal erosion risk management in England: A Consultation Exercise.’ Also, Defra (2005), ‘The Government’s first response to the consultation exercise’: http://www.defra.gov.uk/environ/fcd/policy/strategy.htm

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Making Space for Water promotes an integrated approach to flood risk management. This means considering whole river catchments and adopting flood risk management measures that provide environmental, social and economic benefits. As far as possible, solutions will work with natural processes and make more space for water in the floodplain. This may involve restoring wetlands or setting development back from river corridors, for example. Making Space for Water aims for flood risk management to be undertaken in ways that contribute to the implementation of the European Water Framework Directive. Catchment Flood Management Plans (CFMPs) form the highest level of flood management planning. The draft Hull and Coastal Streams CFMP sets the proposed overall direction of flood risk management at the catchment scale for the next 50 to 100 years. The draft Hull and Coastal Streams CFMP is to be subject to further consultation at the time we consult on our draft River Hull Flood Risk Management Strategy. The draft CFMP presents our recommended policies for flood risk management for the whole River Hull catchment and other areas, and provides a framework for this Strategy. Working together with the CFMP, we are committed to developing a single, integrated plan for flood risk management in the River Hull catchment. This Strategy seeks to encourage co-operation and partnerships, and we have consulted with a wide range of organisations. By considering issues other than flood risk, such as biodiversity, land use and management, natural resources, fisheries, amenity and development, we may be able to achieve wider benefits. Some of the other plans that we have taken into account in developing the draft River Hull Flood Risk Management Strategy are described further in Section 2.4. Any construction of flood risk management measures recommended by the draft River Hull Flood Risk Management Strategy will be carried out under our powers under the Water Resources Act (1991), and will be subject to all necessary approvals and availability of funding. We will continue to consult and work in dialogue with other organisations and local communities as we implement these measures.

1.4 Strategy aims and objectives

Our overall aim for the River Hull FRM Strategy is to provide sustainable flood risk management for people, properties and the environment within the River Hull catchment over the next 100 years.

We We have defined strategic objectives which are in line with our vision to set out what we will do to deliver our overall aim, these are listed in Table 1.1 below. Table 1.1 Our objectives for the River Hull Flood Risk Management Strategy

To develop a plan for the catchment’s flood risk management that is sustainable, taking into account future changes in the environment (human, built or natural) and the climate.

To ensure that all proposals are technically feasible, economically viable, socially acceptable and environmentally appropriate (by meeting the strategic environmental objectives).

To work in partnership with and encourage co-operation between other organisations.

To understand and raise awareness of the risk of flooding within the River Hull catchment, both now and in the future.

To seek environmental enhancement opportunities wherever possible through the recommendation of integrated flood risk management measures.

To seek, where possible, economic development and employment opportunities, including in the wider countryside through diversification, tourism and recreation.

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1.5 Benefits of a strategic approach

We have adopted a strategic approach to flood risk management in the River Hull to fit with the Government’s integrated approach promoted nationally in ‘Making Space for Water’. By ‘a strategic approach’, we mean looking at a problem in a comprehensive way, for example: taking account of all associated impacts; considering the interests of other parties; and, evaluating the widest possible set of potential options.

We have prepared this strategy in accordance with Flood and Coastal Defence Project Appraisal Guidance (FCDPAG) 3 published by the Department for the Environment Food and Rural Affairs (Defra). Volume 2 of this guidance sets out the framework for this Flood Risk Management Strategy. A revised Appraisal Guidance was issued in March 2010 and is a ‘living draft’ until December 2010. We will continue to review our work in light of the new guidance to satisfy ourselves that the strategy meets any changed requirements. We first had to determine whether it was appropriate to take a strategic approach for the River Hull. The guidance from Defra provides examples of when such an approach is recommended. We have listed these in Table 1.2, together with specific reasons to demonstrate why a strategic approach is appropriate for the River Hull. We will refer to ‘strategic options’ throughout this report; this means an option that will deliver flood risk management benefits to several areas. Table 1.2 Reasons for a strategic approach When is it How is this relevant to the River Hull? appropriate to develop a strategy? When problems are We estimate there are around 100,000 existing properties in the study widespread across area that would be at future risk of flooding from a 1 in 100 (1%) AEP the catchment. flood event, taking into account climate change. Approximately 99% of these are protected by purpose-built flood defences, although the standard of protection varies. When there is an Flood risk may change in the future due to climate change and changes advantage in in the catchment such as urban growth. Our Strategy will help us identify considering problems and plan for these impacts. This Strategy also allows us to work at the and solutions in the same level with, and therefore influence, other long term plans such as long term. Development Plans. When works will be We aim to set out a sustainable approach to flood risk management for carried out over a people, property and the environment over the next 100 years. Due to the long timescale. widespread nature of the flooding problems, investment to tackle these will need to be planned over the long-term. The Strategy will help us to prioritise investment, reflecting existing levels of flood risk. When there are The catchment is very flat and there are several low lying areas which multiple areas which naturally act as floodplain. Utilisation of these natural floodplains could may benefit from a benefit other areas within the catchment. single option. When there are Flooding in the River Hull catchment is influenced by factors including connections between natural floodplain storage and the contribution of flow from many different parts of the tributaries. We are aware that our actions in one part of the catchment catchment and could affect flood risk elsewhere, so we must use a strategic approach to different sections of identify solutions. work.

3 FCDPAG is a series of documents that set out best practice in the evaluation of flood defence projects, with a view to promoting a consistent approach to the management of flood risk. The principal guidance document used for developing a flood risk management strategy is MAFF(2001), ‘FCDPAG2: Strategic Planning and Appraisal.’

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When is it How is this relevant to the River Hull? appropriate to develop a strategy? When several small There are a number of distinct communities at risk of flooding along the problems can be course of the Hull and its tributaries, as well as interconnected flood risk tackled together. areas. Considering flooding problems in an integrated way allows us to assess the impact of options across a wide area. When environmental An integrated study enables us to better understand the wider or other implications implications of the various approaches to flood risk management, in extend beyond the terms of their potential environmental impacts (positive or negative), as immediate area of a well as their effectiveness in reducing flood risk. For example, we look at scheme. the potential to improve the connectivity of river and wetland habitats along the Hull and its tributaries. When there is the The Strategy enables us to explore links and opportunities between flood potential to achieve risk management, environmental and amenity improvements, wider opportunities. development planning and economic regeneration within a river basin context, bringing several local authority areas together. Consequently, a strategic approach to flood risk management in the River Hull catchment has been adopted.

The benefits of a strategic approach include improved long-term planning of flood risk management and improved ability to work with natural flooding processes. We can also identify and achieve wider social and environmental opportunities, working in partnership with others. We have a target that all flood risk management projects will be identified through strategy studies or strategic thinking.

1.6 Strategy – development and review The stages in the development of this Strategy are illustrated in Figure 1.1. This is our recommended Strategy which is published, in draft, with the Environmental Report for consultation so that individuals and organisations, who have an interest in the study area, can comment. We will consider all comments received during the consultation period and, where appropriate, amend our plan to address them. The requirements for flood risk management will almost certainly change over time. In addition, our knowledge of the processes within the study area and wider catchment will increase. To reflect this changing environment, we will review and update the findings of this strategy every five years or as appropriate to reflect changes in flood risk management policy, for example.

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Figure 1-1 Stages in the development of the River Hull Flood Risk Management Strategy

Flooding and environmental problems examined and better understood, including the potential future impacts of climate change

Potential options developed and evaluated to form a shorter list of feasible options. Consultation undertaken to agree the key issues to be considered when assessing the impact of the options on the environment. (Scoping Stage). Scoping report produced in May 2006. Comments received from consultees during the ongoing development of the strategy.

Options assessed for technical feasibility, their impact on the environment, and for economic viability. Consultation workshops held to gain views on appraisal process.

Where we are now Our preferred Strategy and Environmental Report will be published in draft for consultation and includes: • Recommendations for short, medium and long-term investment in flood risk management • Recommendations for further studies/detailed appraisals • Other recommendations to achieve long term success in managing flood risk

River Hull Flood Risk Management Strategy - 2011. The Strategy is a live document which will be reviewed approximately every 5 years or as appropriate, for example, to reflect major policy changes.

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2. Catchment overview

This section describes the River Hull Flood Risk Management Strategy study area. It includes: • a brief description of the catchment of the River Hull, its tributaries and associated drainage system, and a definition of the boundary of the River Hull study area; • a summary of the environmental issues, drawing on the Strategic Environmental Assessment process; • details on how the study area is divided up for the purposes of identifying and assessing flood risk and flood risk management options; • an explanation of the links with other plans and policies, and where these may provide opportunities or present constraints.

2.1 The River Hull catchment and definition of the study area

2.1.1 The study area The River Hull FRM Strategy location and study area is shown in Figure 2-1. The study area covers approximately 980km 2, with the Yorkshire Wolds to the west and north and the Humber Estuary to the south. The main catchments within the study area are the River Hull and the Holderness Drain catchments. These catchments fall within the administrative areas of Kingston- upon-Hull City Council, East Riding of Yorkshire Council and a small area of Ryedale District Council/North Yorkshire County Council. Kingston-upon-Hull is the main urban centre within the study area. Other settlements within the catchment include the market towns of Beverley and Driffield as well as many small villages. Table 2.1 provides a summary of the key physical and environmental features of the Strategy area. This should be used as an approximate overview of the catchment, the derivation of the ‘at risk of flooding’ values is discussed in Section 3.5. Table 2.1 River Hull Strategy area overview Watercourse 233 km designated as main rivers Average annual rainfall Between 625 to 825mm Chalk underlies most of the River Hull Strategy area; away from the Geology Wolds the chalk is buried under a layer of glacial deposits. Urban areas Kingston-upon-Hull, Beverley, Driffield At risk of flooding Assets Total for Strategy area At Risk of flooding* (%)* Population 386,000 217,000 56 Area 980 km 2 155 km 2 16 Agricultural grade land (1-3) 858 km 2 96 km 2 11 Residential properties 165,000 99,000 56 Motorway 0.0 km 0.0 km - A-class roads 202 km 30.5 km 15 Railway 56.7 km 13.8 km 24 Canals 13.3 km 7.5 km 56 Sites of Special Scientific 415 ha 66 ha 16 Interest (SSSIs) (ha) Schedule Monuments (SMs) 185 12 6 (number)

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* Based on 1% Annual Exceedance Probability (AEP) fluvial flood extent for the River Hull and Holderness Drain system if flood defences are not present (based on future climate), this does not include smaller areas of more localised flooding on smaller tributaries away from the main river valley.

Figure 2-1 Strategy location and study area 2.1.2 Topography Topography has a direct impact on flood risk through its influence on catchment response to rainfall. Steeper slopes tend to cause a faster speed of flow, both below and over the ground surface. Topography also influences the extent of flooding as in flat areas floodwaters can spread over much larger extents than in narrow valleys. This is particularly relevant in the River Hull Strategy area. The land in the River Hull Strategy area rises from mean sea level (or just below) to nearly 250m above sea level (see Figure 2-2). The highest land is in the Yorkshire Wolds, which run in an arc across the north and west of the catchment. The topography of the Wolds is typical of chalk landscapes with a gently rolling plateau that falls gently eastward towards the low flat area of

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Holderness. A complex network of often steep-sided and deep valleys run out of the Wolds to the low lying areas. Away from the Wolds the remainder of the River Hull Strategy area is dominated by flat and low lying land. Much of this land is only just above mean sea level. The River Hull has almost no slope in the middle and lower reaches and the tidal influence extends up to Hempholme Weir 30km upstream of the Humber.

Figure 2-2 Topography of the Strategy area

2.1.3 The river system The River Hull is fed by a number of springs and becks within the Yorkshire Wolds, which join together south of Driffield. The river flows through open countryside before it skirts past the eastern edge of the town of Beverley and reaches Kingston-upon-Hull. It flows through the centre of the heavily populated and industrial area of the City of Kingston-upon-Hull before joining the Humber estuary at Victoria Pier near to The Deep and the Tidal Surge Barrier. The River Hull is

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embanked for most of its length, in some places the embankments are over 5m high and the bed of the river is above the level of the surrounding land. The River Hull’s main tributaries are West Beck, Kelk Beck, Old Howe, Frodingham Beck, Driffield Beck, Skerne Beck, Nafferton Beck, Scurf Dike, Mickley Dike, Watton Beck and Catchwater Drain/Arram Beck. Together with the River Hull, these form the River Hull “high level system”. The numerous drains in the low lying land predominantly to the west of River Hull, including Beverley and Barmston Drain form the River Hull “low level” system. Holderness Drain is not a tributary of the River Hull but is an important part of the drainage network in this area as it discharges flows from areas to the east of the River Hull directly into the Humber estuary. Similarly to the River Hull, Holderness Drain comprises a high level and a low level system. Monk Dike, Catchwater Drain, Bowlams Dike and the lower part of Holderness Drain form the Holderness Drain high level system. The numerous drains in the low lying land to the east of River Hull, including the upper and middle parts of Holderness Drain form the Holderness Drain low level system. The embankments on the Holderness Drain high level system are much lower than those on the River Hull high level system, typically 1 or 2m high compared to 4m high. Many of the river systems are complex due to a long history of modification. The response of the catchment to extreme rainfall is also complex because of the interaction of ground and surface water as well as the large tidal influence of the Humber Estuary.

Figure 2-3 Upper River Hull from Wansford Bridge

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Figure 2-4 Lower River Hull through Kingston-upon-Hull

Most of the land adjacent to the river is low lying, including the majority of the City of Kingston- upon-Hull and significant parts of the East Riding of Yorkshire, and would suffer from frequent flooding without the presence of a variety of flood defences. This low-lying area is typically at risk from both fluvial and tidal flooding although in the north of the catchment, the risk is just from fluvial flooding. Coastal flooding, i.e. flooding directly from the Humber, is covered by the Government approved Humber Strategy. The River Hull FRM Strategy focuses on fluvial flooding in the inland parts of the catchment. A map of the various key components of the River Hull and Holderness Drain system is shown in Figure 2-5. The River Hull Tidal Surge Barrier, at the mouth of the River Hull, can be used to prevent surge tides overwhelming river defences. At the mouth of Holderness Drain and where Beverley and Barmston Drain, Scurf Dike and Watton Beck enter the River Hull, structures are installed which prevent reverse flow up the channels causing flooding. The figure also shows the pumping stations on the River Hull system. It should be noted that the River Hull high and low level systems are only connected at Wilfholme, Waterside and Hempholme Pumping Stations (PS) and High Flags outfall. On Holderness Drain, Tickton PS and Great Culvert PS pump flows along the drain to enable it to discharge into the Humber estuary. Great Culvert PS connects the Holderness Drain high and low level systems. East Hull PS can be used to pump flows into Humber estuary during high flows when the tide is too high for Holderness Drain to discharge. We are spending £900k on refurbishment of East Hull PS and also have a project underway looking at the best way of providing pumping capacity at East Hull PS into the future.

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Figure 2-5 Key features of the River Hull system

2.2 Environmental context This section outlines the main strategic features of the natural and human environment within the River Hull catchment. You can find further details in the Strategic Environmental Assessment (SEA) Environmental Report in Appendix B of this Strategy. 2.2.1 People and property The main centre of population is the urban area of Kingston-upon-Hull where approximately 243,600 people live in the city, in 104,300 households (2001 census). The area is a major focus for jobs, commercial interests, services and facilities, and has diversified into smaller industries to replace the loss of the fishing industry. High profile industrial and residential areas are also being developed to attract people to the city. Most of the city lies in the indicative floodplain.

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Smaller market towns of Beverley and Driffield (with population levels of about 25,000 and 11,000, respectively), and a number of villages e.g. North Frodingham, Leven and Wansford are within the study area. Beverley and Driffield have experienced significant growth over recent years, with new housing increasing commuters. 2.2.2 Land use and landscape Land form in the study area is generally low-lying and flat, which creates a broad and shallow river valley that is only perceptible on a local scale. The flat landscape offers few natural barriers to the flow of flood water on the floodplain. Trees and hedgerows are generally sparse, as agricultural improvement has led to the loss of most areas of semi-natural vegetation. There are smaller areas of pasture and parkland towards the towns of Beverley and Driffield. Greater coverage of vegetation is found to the north of the catchment, with plantations on the lower slopes of the Yorkshire Wolds. Much of the study area is in agricultural use; the Agricultural Land Classification of the land is mostly grade 2 (very good, 55%) and grade 3 (moderate, 42%), with small areas of grade 4 (poor, 3%) and non-agricultural land. Most of the holdings are large-scale, mixed arable cultivations with some intensive livestock farming. Kingston-upon-Hull is a major urban area, with industrial, commercial and residential land use. There are also large areas of contaminated/derelict land in Kingston-upon-Hull. 2.2.3 Recreation and amenity There are various sites that are important for formal and informal recreation and tourism in the study area, for example nature reserves such as Tophill Low, and disused gravel pits where sailing and fishing now takes place. Recreational activities along the River Hull include walking, bird watching, boating and fishing. There is a network of public footpaths including the regional Trans-Pennine Trail. To the south of the study area, a green network of footpaths and cycleways link the settlements in this area. The River Hull is navigable for leisure craft from Hull to beyond Beverley, along spurs to Corps Landing, Brigham and North Frodingham (freight can only go as far as Beverley). The Driffield Navigation Trust has been undertaking various restoration works to locks on the Driffield Canal for recreational usage. 2.2.4 Material Assets There are a number of transport routes in the study area, linking the urban centre of Kingston- upon-Hull and other settlements, and linking these to urban areas outside of the study area. • The main east-west route is the A63(T), and this forms the boundary between the River Hull FRM Strategy and the Humber Estuary FRM Strategy study areas. The A63(T) links Kingston-upon-Hull with Manchester and Leeds via the M62, and the A1033. North-south connections are provided by the A1079(T), A165, A1035 and A164. • A rail link connects Driffield and Beverley to Kingston-upon-Hull. • The River Hull is navigable for freight barges through Kingston-upon-Hull, as far as Beverley, with wharf facilities along the river in Hull and Beverley. The river connects to the busy commercial waterway of the Humber Estuary, and this provides access to the international ports of Hull (and others around the estuary), which are of prime importance to the regional and national economy. 2.2.5 Natural environment The whole of the Humber Estuary, which abuts the southern boundary of the study area, is internationally and nationally designated for its nature conservation importance (Site of Community Importance (SCI); Special Protection Area (SPA); Ramsar site; and Site of Special Scientific Interest, (SSSI)). There are no National Nature Reserves within the study area. There are 15 SSSIs within the study area. Of these, four are in or immediately adjacent to the River Hull corridor:

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• The River Hull Headwaters are designated as the most northerly chalk stream system in Britain, and include adjacent remnants of ecologically important habitats, such as riverside wet grassland, woodland and fen. • Tophill Low consists of two artificial storage reservoirs 10km south west of Driffield. The site is one of few inland standing open water bodies in the sub-region suitable for wintering wildfowl. • Pulfin Bog is 16.8 Ha of the last remnants of a fenland reed swamp community in the Hull Valley, with botanical and ornithological interest. • Leven Canal is a is 5km length of canal which cuts across marshland and meres of the Hull Valley, and following drainage of the surrounding land, is now a refuge for wetland plants. The water is fed by calcareous springs and is of very high quality. The following priority species in the study area have been identified as requiring protection and enhancement nationally by the UK Biodiversity Action Plan (BAP) short list. • otter and water vole - we are the lead partner for otter and water vole UK BAP species plans, and for the chalk rivers habitat plan; • great crested newt; 2.2.6 Fisheries The River Hull Headwaters are recognised as a valuable salmonid/fly fishery, with the main species in these upper reaches being brown trout, grayling and pike. A good coarse fishery is supported in the middle and lower reaches of the Hull, which are more embanked and canalised with some saline influence, and in the agricultural drains and ditches where flows are slower. Species include perch, roach, gudgeon, dace, chub, bream and occasional flounder upstream of the confluence with the Humber. Eels are found throughout the system but in common with most of Europe, populations are believed to be a small fraction of their historic levels, 2.2.7 Cultural heritage There are no World Heritage Sites in the study area. There are a significant number of Scheduled Monuments (16 of which are within 1km of the River Hull), which are nationally important and protected by law. Many of the existing settlements, for example Beverley, are Medieval in origin, and there are several settlements that failed and became deserted. These are mainly located in the headwaters but also extend as far south as Eske near Beverley. There are five Registered Parks and Gardens of Historic Interest wholly or partly in the study area, as listed below. • East Park, Hull – Grade II; registered April 2001; 48.64ha. • Pearson Park, Hull – Grade II; registered April 2001; 9.41 ha • Risby Hall - Grade II; registered March 1999; 33.31ha. • Dalton Hall – Grade II*; registered May 1984; 220.18ha. • Sledmere House – Grade I; registered May 1984; 300.24ha. The Conservation Areas wholly or partly within the study area are listed below, • Hull City – contains 21 Conservation Areas, covering 6% of the city; 2 of which, Charterhouse and Old Town, are in the immediate vicinity of the River Hull corridor. • Beverley Borough - Beverley, Bishop Burton, Lockington, and Walkington;

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• Holderness District - Aldbrough, Bewholme, Brandesburton, Seaton, Dunnington, Hatfield, Sigglethorne and Swine • East Yorkshire Borough - Kilham, Cranswick, Hutton, Driffield (one covering North of town centre and market area, one covering south of town centre including upstream end of Driffield Canal), Nafferton, Garton on the Wolds, North Dalton and Wetwang. There are 1296 Listed Buildings in the study area. Of these, 36 are Grade I, 77 Grade II*, 1171 Grade II and 12 De-Listed. Listed Buildings are concentrated in Hull, Beverley and Driffield, with smaller clusters associated with Conservation Areas in Nafferton, Lockington, Bishop Burton, and Walkington. There is an Area of Archaeological Importance identified in the Hull Local Plan. There is also known to be a high density of heritage features and archaeological remains within the Hull valley, many of which are unusually well preserved. Therefore, there are likely to be other historic environment assets that are, or could be, considered significant. 2.2.8 Water There has been a long history of modifying the rivers within the catchment mainly to improve drainage so the catchment now is a network of largely artificial channels contained within embankments, often above the surrounding land, and low lying drainage channels. Only sections of river on the higher ground are in largely natural channels. The higher ground to the north and west is mainly chalk which has a major influence on water in the catchment. Rain easily soaks into the ground where it remains as groundwater. Where the level of groundwater is higher than the surrounding land it emerges as springs which feed the headwater streams and the main river. River levels in these chalk rivers are generally steady and rarely rise or fall quickly after rain. Most of the low lying ground is formed of poorly draining soils overlying the chalk and rain water mainly remains on the surface until it reaches the network of drains. Water from the chalk springs is usually very high quality, but as the rivers flow to the sea, water quality is influenced by fertilisers and agricultural chemicals, discharges from sewage works, fish farms, businesses, drainage from urban areas and finally, tidal water. Water quality in the low lying drains is moderate to poor. As the quality and quantity of groundwater is high, there are several abstractions for drinking water and spray irrigation. Water is also abstracted from the river at several locations for fish farming, drinking water, spray irrigation and industrial use. Under the Water Framework Directive, we published River Basin Management Plans for the whole of England and Wales in December 2009. This gives us a new way of measuring the quality of the water environment, in which we have to consider the chemical, physical and biological quality of each separate waterbody. The Directive requires us to identify the current condition and establish actions to restore natural waters to ‘good ecological status’ and heavily modified or artificial waterbodies to ‘good ecological potential’ by 2015, or later where this is not practical. The River Hull forms part of the Humber River Basin District. Of the 40 waterbodies (lengths of river, drain, or canal) in the Strategy study area, the majority (32) are classified as artificial or heavily modified The Humber River Basin Management Plan sets out what we and others will do to improve the quality of waterbodies across the whole district. We have assessed how the Strategy might influence how these actions are carried out in this catchment.

2.3 Definition of catchment areas One of the main benefits of developing a flood risk management strategy is that we can consider flooding processes in the study area as a whole, and understand how actions or changes in one part of the catchment may affect flooding in another area upstream or downstream. However, for some of our analysis we have divided the River Hull and its floodplain into 3 catchment areas, to

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allow us to evaluate flood risk and possible alleviation measures at a suitably detailed level. The River Hull catchment areas are illustrated in Figure 2-6.

Figure 2-6 River Hull catchment areas 2.3.1 Lower catchment area The lower catchment area covers the River Hull from the northern city limits of Kingston-upon- Hull, just downstream of Wawne on the east side of the River Hull and downstream of the B1233 / A1165 on the west side of the River Hull, to the Humber Estuary. The River Hull is embanked down to the industrial estate at Vulcan Road from which point the river’s defences become a mixture of concrete and timber walls. This area also includes the downstream reaches of Beverley and Barmston Drain and Holderness Drain where they outfall to the River Hull and Humber, respectively. These reaches and the River Hull are far more influenced by the tide than by fluvial flows in this area. The tidal surge barrier is dropped into the river during high tidal surges to protect parts of the city from flooding. The barrier is raised when tide levels have dropped enough to allow the river to discharge to the estuary.

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This area is predominantly urban and generally has a lower risk of fluvial flooding than the upper and middle catchment areas. 2.3.2 Middle catchment area The middle catchment area covers the River Hull from Hempholme Weir down to the city limits of Kingston-upon-Hull, just downstream of Wawne on the east side of the River Hull and to the B1233 / A1165 on the west side of the River Hull. The River Hull is heavily embanked through all of the middle catchment area with embankments 5m higher than surrounding ground levels in places. This area also includes the two major drains in the study area, Beverly and Barmston Drain and Holderness Drain, which both start near the northern boundary of the middle catchment area and flow in a southerly direction through to the lower catchment area. The River Hull and Beverley and Barmston Drain are tidally influenced in this area and the Holderness Drain is influenced by pumping. The middle catchment area contains the lowest lying land in the whole study area; the largest of which is Leven Carrs where ground levels are typically -0.5 to 0.0m AOD. This land is drained by Holderness Drain, which is pumped at Tickton and Great Culvert to maintain gravity discharge into the Humber. The middle catchment area includes the Orchard Park area of Kingston-upon-Hull, which lies between the A1079 and B1233 roads to the west of the River Hull. We have included this urban area because the flood risk here, particularly in the future, is influenced by the flood risk from Beverley and Barmston Drain further upstream due to the drain culverts through the A1079 road embankment. Including this urban area within the middle catchment area enables the full economic benefits of flood risk management options in the upper and middle areas to be properly considered. 2.3.3 Upper catchment area The upper catchment area covers the River Hull Headwaters down to Hempholme Weir. In this area the chalk streams and becks of the headwaters combine into the ‘West Beck’ reach of the River Hull near Driffield and Frodingham Beck further east. The upper reaches of the River Hull are not embanked because the surrounding ground is naturally higher. The River Hull starts to become embanked approximately 2km downstream of Wansford as the surrounding ground levels drop below 5m AOD. Further downstream, the surrounding ground levels drop to less than 0.5m AOD in places, therefore the embankments of the River Hull and Frodingham Beck can be up to 4m high. The lowest lying land in this area is the North Frodingham Carrs where ground levels are typically 0.25 to 0.5m AOD. This land is mainly drained by Roam Drain, which flows under the River Hull and into the top of Beverley and Barmston Drain near Hempholme Weir. Water in Roam Drain can also be pumped into Mickley Dike at Hempholme pumping station. The rivers and drains in the upper catchment area are generally not tidally influenced beyond Hempholme Weir – only a small influence is felt during floods. The southern embankments of Scurf Dike and Mickley Dike form the boundary between the upper and middle catchment areas. 2.3.4 Connectivity Although the three Strategy catchment areas have different characteristics, they are hydraulically connected in several places. This means that flooding in one catchment area can cause flooding in another. The main connections between the three catchment areas are: • Main watercourses that flow between catchment areas, these include the River Hull, Beverley and Barmston Drain and Holderness Drain • Smaller drains such as Engine Drain, which flows between the middle and lower catchment areas and Nafferton Drain, which flows between the upper and middle catchment areas connecting the floodplain in the Upper catchment area with Beverley and Barmston Drain.

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• Natural low ground between the middle and lower catchment areas, where water could flow during a flood. Flood risk management measures in parts of the River Hull system could produce environmental, social or economic impacts that extend into other areas of the study area due to the interconnectivity of the system. Where necessary, these wider consequences have been considered in our options appraisal.

2.4 Links to other plans – opportunities and constraints This section explores opportunities and constraints that could arise from other studies, strategies and plans. (See Section 1.4 for links with these other plans). Opportunities and constraints that relate to particular flood risk management options are discussed further in Section 4. Flood Risk 2.4.1 Hull and Coastal Streams Catchment Flood Management Plan As noted in section 1.4, the draft Hull and Coastal Streams CFMP sets out our policies for the long-term management of flood risk in the whole of the River Hull catchment. In the CFMP, recognition of our strategy areas has been used to help determine policy unit areas. However, because the upper and middle strategy areas are so closely linked, these two areas have been combined to form one policy unit. The recommended policies for the River Hull Strategy area have been developed in conjunction with the findings of the draft strategy and are presented in the following table and further described below: Table 2.2 Hull and Coastal Streams CFMP Policy units and preferred policies Policy Unit Preferred Policy

Upper and Middle Hull P3

Lower Hull P5

P1. No active intervention - no active intervention (including flood warning and maintenance), but continue to monitor and advise. We could select this policy for natural catchments where the river is connected to the floodplains and flooding has beneficial effects for habitat. P2. Reduce existing flood risk management actions - reduce existing flood risk management actions (accepting that flood risk will increase over time). We may select this policy where the current and future risks in all or part of these areas do not warrant as much intervention (for example on maintenance) and we can allow the risk of flooding to increase naturally over time. P3. Continue with existing or alternate actions to manage flood risk at the current level - continue with existing or alternative actions to manage flood risk at the current level. We may select this policy where the risks are currently managed appropriately and where the risk of flooding is not expected to increase significantly in the future. P4. Take action to sustain the current scale of flood risk into the future - take further action to sustain the current level fo flood risk into the furure (responding to the potential icreases in risk from urban development, land use change and climate change). We could use this policy where the risks are deemed to be currently managed in an appropriate manner, but where the risk of flooding is expected to significantly ris in the future. In this case we would need to do more in the future to reduce the increases in risk. P5. Take further action to reduce flood risk - take further action to reduce flood risk. This policy is about reducing the flood risk in areas where the existing flood risk is too high. We need to take action in the short term to reduce this level of risk. Alternatively it may be about reducing flood risk in locations where the future flood risk is high. We will need to take longer term action to recude flood risk in these locations.

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P6. Increase the frequency of flooding to deliver benefits locally or elsewhere - fthe aim of this policy is to attenuate water in those parts of the sub-area where there are multiple benefits from doing so. This could include storing water in part of the catchment in order to reduce flood risk to downstream communities. Alternatively it could include reducing run-off, restoring floodplains and improving habitats that contribute to reduce risk elsewhere. These policies recognise that there are many areas within the Hull and Coastal Streams catchment where existing (and potential future) flood risk to people, property and the built environment is a concern. The River Hull FRM Strategy is one of the first steps in ‘taking further action’. It provides a more detailed understanding of the nature and extent of the flood risk, and proposes our preferred measures for tackling flooding. 2.4.2 Other studies Within the strategy area the Environment Agency are currently working on a flood alleviation scheme at Western Drain, where in June 2007 heavy rain resulted in flooding to a large number of properties in Hessle and the tragic loss of a life. We are also carrying out a £10 million refurbishment of the Hull Tidal Surge Barrier and spending £900k on a refurbishment of East Hull Pumping Station. We also have a project underway looking at the best way of providing pumping capacity at East Hull pumping station into the future. Other organisations in the catchment are also involved in managing flood risk. Other flood related work being carried out in the strategy area includes the following: Surface Water Management Plan (SWMP) (Kingston-upon-Hull): this study was led by Hull City Council with involvement from a number of partners including Yorkshire Water, the Environment Agency, ERYC and Halcrow. The SWMP identified areas at highest risk of surface water flooding, and developed mitigation solutions. The objective of this project was to provide a long-term strategy for the City of Hull’s surface water management including an action plan. The use of Aqua Greens (dual purpose public recreation and surface water storage areas) were considered alongside other options. Hull City Council Aqua Greens Feasibility (Kingston-upon-Hull): this project leads on from the first two items on the SWMP action plan and is to look at the feasibility of providing aqua greens to mitigate flooding (specifically surface water flood risk) for two areas in the city Hull Flood Mitigation Investment Plan: this project is being led by Hull City Council in conjunction with the Environment Agency, Yorkshire Water, ERYC and Halcrow. The objective is to review all sources of flood risk (fluvial, pluvial, coastal, sewerage and groundwater) in the Hull and Haltemprice catchment (much of our lower catchment area), identify and evaluate mitigation options, identify existing and potential sources of funding and produce a programmed flood mitigation investment plan. East Riding Flood Review (East Riding of Yorkshire Council): following the flooding during June and July 2007 East Riding carried out a flood review to identify the source and potential causes of flooding. As a result of this review a number of potential improvement projects were identified and are currently being investigated further . Our partners in the local authorities, Yorkshire Water, and Internal Drainage Boards in rural areas have been involved in developing this Strategy. This has helped to identify interactions between sources of flooding, and the constraints to solving the problems. Constraints include the limited budget available for sewer and drainage improvement works. In Yorkshire Water’s case, investment is restricted by the price limits for water services imposed by Ofwat. There are important opportunities for the Environment Agency, Yorkshire Water and local authorities to work together to find the most effective solutions to flooding, particularly where flooding from drains, watercourses and surface run-off interact. These detailed solutions will not be identified within this high level strategy, which only deals with river flooding. However, they will be included in subsequent design of flood management schemes for local sites.

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2.4.3 Planning and development The majority of the study area falls within East Riding of Yorkshire Council, with Hull City Council covering the urban area of Hull. A very small area to the north west of the study area falls within the administrative boundary of Ryedale District Council and North Yorkshire County Council. These local authority boundaries are shown in Figure 2-7.

Figure 2-7 Local Authority boundaries in the River Hull Strategy study area

The existing statutory development plan for East Riding of Yorkshire and Kingston-upon-Hull Unitary Authorities is the adopted Joint Structure Plan (JSP), which functions as a Joint Core Strategy for both authorities until it is reviewed and replaced as part of the Local Development Framework (LDF). The JSP sets the framework for the development and use of land up to 2016 in the combined area of Hull and the East Riding of Yorkshire. East Yorkshire Borough, Beverley Borough, Boothferry and Holderness District Councils were amalgamated when the East Riding of Yorkshire Council was created in April 1996, but their Local Plans are still in force, as is the Local

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Plan for Hull City, until the East Riding LDF and the Hull City LDF are adopted. In addition, the Yorkshire and Humber Regional Spatial Strategy (RSS) provides the higher level strategic framework for planning decisions, and all Local Plans must conform to this. We have considered these plans, as well as the RSS, in developing this Strategy. The Local Plans and the JSP will eventually be replaced by the emerging LDFs for both East Riding of Yorkshire and Kingston-upon-Hull. The LDFs will be made up of various Development Plan Documents (DPDs) and Supplementary Planning Documents (SPDs), with the stages of adoption varying between the two authorities. The relevant LDF documents in the study area have yet to be adopted and are at the early consultation stages, although Hull is close to adopting its’ City Centre Area Action Plan (AAP). The AAP contains proposals for environmental enhancements, economic and retail regeneration and residential development in the city centre of Hull. Given the focus of development in the urban area of Hull we have considered the implications of the proposed development and potential concurrence between the emerging spatial plans and the flood risk management options recommended by this Strategy. Some of the opportunities and constraints are described below. Opportunities – greater awareness of flood risk Both regional and local development plans take direction from national government Planning Policy Statement PPS25 - Development and flood risk. This states that the potential for flooding of land is a significant consideration in the planning process. A sequential risk-based approach is set out for determining whether new development is appropriate in areas prone to flooding. To assist with testing the suitability of sites at flood risk, local authorities are encouraged to carry out Strategic Flood Risk Assessments (SFRA) for their area. Hull City Council has completed its SFRA and it is available on the Council website, the SFRA was produced in close collaboration with Yorkshire Water, the Environment Agency and East Riding of Yorkshire Council, to enable a thorough and detailed understanding of flood risk to be presented, along with some recommendations to minimise these risks. East Riding of Yorkshire Council is currently reviewing its SFRA (2002) and it is expected to be published some time in 2010. Following the principles set out in PPS25, the Yorkshire and Humber RSS states its preferred approach for development to occur outside the Flood Zone (areas of flood risk defined by PPS25). As the RSS guides the formulation and development of the Local Plan in the study area the emerging LDFs will follow this philosophy. We have updated our Flood Zones for the River Hull using information from the assessment of flood risk carried out for this Strategy (see section 3.5) and for the Hull SFRA. Flood Zones are maps showing areas at risk from flooding, which are used by local authorities for development planning purposes. Opportunities and constraints – previously developed land in the floodplain The adopted statutory development plans, as well as the emerging LDF documents, identify a priority to develop land that has been previously developed on in order to create sustainable and unified central urban areas. New development will use the sequential approach to development in order to focus development away from areas at risk from flooding. This creates the opportunity to utilise existing Flood Zones, and to some extent open space and green infrastructure, for flood management purposes. This has the added benefit of preventing new building being placed at risk of flooding whilst providing more space for floodwater together with wildlife and recreation corridors. This may ultimately reduce flood levels elsewhere. Whilst the focus of development is within principal towns, urban centres and settlements, there is pressure for significant development in the region from the local and regional development strategies. This pressure for regeneration, particularly in terms of the economy, forms a significant constraint on the Strategy. For example, the Joint Structure Plan does not rule out the possibility for urban extensions which may require the release of green field land, which makes up a large amount of the Flood Zone. The Hull Local Plan provides particular focus for urban regeneration on the river corridor which is listed as a strategic regeneration site (and includes the Kingswood area). Where development in the Flood Zone is essential, we are encouraging planners and

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regeneration agencies to fully consider the implications of flood risk and design appropriately as well as leave a strip of land adjacent to the river. We also have powers under our land drainage bye-laws to prevent building within this strip. This provides space for flood flows or for construction and maintenance of flood defences. Such strips of land may have added benefits as a wildlife corridor or for walking and cycling along the waterfront. The recently adopted Hull SFRA and the review of East Riding’s SFRA is an opportunity to influence the expansion of areas designated as functional floodplain. We are also exploring the scope of negotiating planning contributions, as well as other means, with developers on brownfield sites in the floodplain. This would require the developer to contribute to investment in flood risk management at their sites or elsewhere in the catchment; this is particularly relevant with the recent publication of the Community Infrastructure Levy (CIL). Opportunities and constraints – environmental enhancement and protection Planning policy, particularly within Kingston-upon-Hull, places great emphasis on the River Hull corridor and the Humber estuary for the focus of environmental improvement and, particularly in the case of Hull city centre, the location of waterfront development. For example, the Hull Local Plan identifies the River Hull corridor as an ‘Area of Potential Change’ with the potential to develop the waterfront with emerging economic development such as office, residential and leisure development. This principle has been carried forward into the emerging City Centre AAP and Core Strategy for Hull. The potential to utilise flood management works for environmental improvements is recognised in the Joint Structure Plan, which states that environmental management methods will be promoted where possible to reduce the risk of flooding and enhance biodiversity by creating new habitat and protecting the integrity of existing watercourses, washlands and land drainage systems. It is also identified in the Hull Local Plan that the urban green space forming river corridors and other waterside areas will be protected from development and their improvement supported. The Strategy can help to protect and enhance existing green corridors along the River Hull (for example by creation of wildlife habitat and leisure facilities) by providing protection against flooding. Given the focus of Hull’s regeneration around the waterfront, the need to work in partnership with this regeneration is key; therefore there are potential opportunities to develop flood management schemes as part of the waterfront improvements in the study area. This approach should be taken throughout the catchment area, should the opportunity arise. Constraints – local planning policies and the historic environment Local development plans may restrict our options for flood risk management schemes through policies that protect designated nature conservation sites, Scheduled Ancient Monuments, Conservation Areas, and Historic Parks and Gardens. The development limits of local planning policy and proposed development, in the green belt and on the waterfront in particular, may restrict the flood risk management in the study area. Constraints – key transport movement The Joint Structure Plan designates strategic public transport corridor and multi-modal freight transport corridor which follows the River Hull. This designation may restrict a flood risk management scheme in that it will restrict the options which may impact upon the operation of these key transport corridors. 2.4.4 Environmental Issues There are many strategies and plans, both national and local, which consider environmental issues. There are both opportunities and constraints in linking these plans with flood risk management. The key strategic issues and opportunities identified for the Strategy study area are listed below, and these are the issues that have shaped our Strategic Environmental Assessment (SEA). • Safety, security and well-being of the population • Properties and material assets in the floodplain • Proximity of Humber Estuary, which is of international importance for nature conservation

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• Sites of Special Scientific Interest (SSSI) located close to the River Hull; and the opportunity to improve their condition • Opportunities to create new habitats, particularly wetlands or green corridors • Good quality agricultural land • Industry and port facilities in Kingston-upon-Hull, and the opportunity to improve Brownfield sites • Scheduled Monuments and Listed Buildings in the study area • Recreation and amenity facilities in the study area. Opportunities for better access to the riverside with footpaths and cycle ways, opportunities to create recreational corridors (“linear parks”) that link in to national networks • Maintaining water quality, and minimising pollution We have identified the following strategies and plans that are relevant to the key strategic issues, where there might be opportunities or constraints. However, the potential for any opportunities to be delivered is dependent on the combination of Strategy elements and the preferred Management Approach.

UK Biodiversity Action Plan (BAP), Hull Local BAP and East Riding local BAP - The UK BAP is the UK’s initiative to maintain and enhance biodiversity (the variety of flora and fauna). BAPs are also prepared at a local level. There could be opportunities associated with UK / local BAP habitats and species through the delivery of the River Hull FRM Strategy, or constraints where the Strategy may not assist with BAP targets. However, these opportunities or constraints have not been considered at the Strategy level, and would need to be considered as part of project level Environmental Impact Assessment (EIA).

Humber Eel Management Plan - Any improvements to habitats and water quality, and the naturalness of the river system are likely to contribute positively to the Eel Management Plan. There is a potential constraint for the River Hull FRM Strategy to hinder Eel management plan if migration of eel is in any way inhibited. The provision of eel passes at sluices and obstructions and screens at pumping stations will need to be considered either as stand- alone measures or when implementing the River Hull FRM Strategy.

Pulfin Bog Water Level Management Plan (WLMP) - opportunities could be sought to improve the SSSI by contributing to the WLMP. However, at present we have also identified the potential for negative effects, directly or indirectly, on the Pulfin Bog SSSI for a number of the Strategy elements being considered. At the Strategy level, we cannot be sure what change may result, therefore, we have had to assume a worst case, which is that long-term increased flooding of the SSSI has the potential to have a negative effect on the habitat types present. Further detailed work is needed by ourselves, with Natural England, to consider this and we will be actively pursuing alternative partnerships and funding sources for actions that could minimise the impacts.

Hull Headwaters SSSI WLMP - An objective of the River Hull FRM Strategy is to avoid damage to SSSIs, and so there should be no conflict with the Headwaters WLMP. Some River Hull FRM Strategy elements may also contribute, to some degree, to the objectives of the WLMP. In order to make an informed decision on whether certain Strategy elements could be implemented in the future, we would need to consider potential impacts on the River Hull Headwaters SSSI in more detail, as well as having more certainty on the role of other organisations and alternative funding

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sources. This could be achieved by linkages to the actions identified in the River Hull Headwaters Restoration Plan.

River Hull Headwaters Restoration project - Some River Hull FRM Strategy elements may also contribute, to some degree, to the objectives of the Restoration Plan.

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3. Flood risk

This section highlights the flood risk within the study area. It includes: • definitions of flood risk and probability; • a brief explanation of the causes of flooding in the River Hull catchment; • a summary of the history of flooding; • an overview of current flood risk management practices; • a summary of the Summer 2007 flood and the work we have carried out since then; • assessment of the current extent and frequency of flooding, and the level of flood risk; • the likely changes to flood risk in the future, including climate change and change in land use.

3.1 Definitions We frequently refer to flood risk and the probability of flood events, but what do we mean by these terms?

Flooding and risk As with all risk analyses, there are two elements that need to be considered, namely probability and consequence. 1. What is the probability that a flood event with a specified water level will occur? 2. What are the consequences of the flooding and what damage will result? When considering flood risk, and how best to manage it, we need to examine both of these elements.

Flooding and probability Historically, the likelihood of a flood event was described in terms of its ‘return period’. For example, a ‘1 in 100-year event’ could be expected to be equalled, on average, once every 100 years. However, there is a tendency for this definition to be misunderstood. There is a perception that if a ‘1 in 100- year flood’ occurs; a repeat of the event will not be experienced for another 100 years. This is not the case; the key words in this example are ‘on average’. To try to avoid this misunderstanding, we now express flood events as the chance of them occurring in any one year at a given location. This can be stated in two ways, either as a chance or as a probability. Taking the above example, we would say that this event has a 1 in 100 chance or a 1% probability of being equalled in any year. We refer to this as the 1 in 100 (1%) annual exceedence probability (AEP) flood.

3.2 Causes of flooding This section explains the causes of flooding and illustrates where these flooding processes occur within the study area.

Flooding processes When rain falls on land, it may either seep into the soil or run-off the surface. Generally speaking, when it flows over the surface or through the ground, it will eventually reach a drainage system, such as a ditch, stream or drain. These usually flow into larger drains or rivers downstream. If the quantity of water running off the land is greater than the capacity of the drainage system, flooding will occur. On a catchment scale, flooding of this nature from streams and rivers is known as fluvial flooding. It may affect widespread areas for periods of days or weeks. Generally the duration of flooding is shorter on small, steep tributary catchments and longer on larger, flatter rivers like the Hull and in places where floodwater

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ponds on areas of floodplain. At the other end of the scale, localised flooding from drains and sewers can occur in built-up areas or on roads. This type of flooding is known as urban drainage flooding and is often caused by short, very heavy rain storms where flooding usually lasts for a matter of hours. Sometimes these processes interact. Drains or sewers may be unable to discharge due to high water levels in the watercourse at their downstream end. In some cases, direct run-off from steep rural hill slopes or from urban ground surfaces can cause flooding of roads or properties before it reaches a drainage system. This is called surface water flooding. Again it is often caused by short, very heavy rain storms and lasts for a few hours. However, sometimes it can be caused by prolonged periods of rainfall and can last for several days like in June 2007. Often the processes of urban drainage flooding and surface water flooding are difficult to distinguish.

3.2.1 Fluvial (river) flooding Some flooding occurs when high flows in the river cause water to overtop low spots in the flood defences. This mainly occurs in the upper reaches of the River Hull between Driffield and Hempholme Weir and on Frodingham Beck, Driffield Canal and Old Howe near Brigham and North Frodingham. A significant number of defences here overtop relatively frequently, every few years on average. The defences overtop to a lesser extent at several locations further downstream, these include Watton Beck, Catchwater Drain and Monk Dike. Flooding due to the River Hull overtopping as a result of tidal surges no longer occurs as the Hull Tidal Surge Barrier is closed when a tidal surge is forecast.

Figure 3-1 Overtopping of River Hull at Wilfholme

Much of the flooding in the Hull valley is caused by the low level drainage system not being able to discharge floodwaters quickly enough, causing the surrounding land to flood. This is mostly due to the flatness of the catchment and the influence of the tide at the downstream end. Although there are pumping stations that can pump water from Beverley and Barmston Drain into the River Hull, these are turned off when the River Hull water levels get too high during a flood. Flooding occurs along some parts of Beverley and Barmston Drain and Holderness Drain relatively frequently, every 2 to 5 years in places.

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Figure 3-2 Flooding near Wilfholme caused by Beverley and Barmston Drain being unable to discharge

Generally, the worst fluvial flooding in the catchment is caused by long duration floods that have a large total volume of rainfall and resulting runoff instead of short more intense storms; this is due to the watercourses and ground having little or no gradient. We are currently developing techniques to improve the flood forecasting and warning service for flooding from the main rivers and drains in the River Hull catchment. 3.2.2 Tidal flooding Tidal flooding in the River Hull catchment is primarily from the Humber Estuary. Flooding from the Humber can occur either because the tide level in the estuary rises above the level of the defences along the estuary shoreline (including those along the various dock frontages within the city of Hull), or because water from the estuary flows up the river and causes water levels to rise above the river defences. The River Hull Strategy does not address either form of tidal flooding because: • A separate government approved Humber Strategy deals with the management of flood risk along the estuary shoreline and is now being implemented. • The Hull Barrier is closed when a tidal event that could overtop the river defences is predicted, preventing any flow from the estuary causing flooding further upstream. 3.2.3 Groundwater flooding Another source of flooding in the study area is groundwater flooding. This has occurred in areas to the west of the River Hull along the edge of the Wolds where the water table in the chalk aquifer is close to the ground level and where natural springs can occur (Figure 3-3). Flooding usually takes place a few days or weeks after the rainfall has occurred as it takes time for the rainwater to percolate through to the chalk and the water table to rise. As the water drains out so the water table will fall again and the flooding will stop, although this can take several weeks to happen. Areas at risk include Cottingham, Dunswell and south of Driffield.

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Figure 3-3 Location of natural springs

3.2.4 Surface water flooding Surface water run-off has led to flooding in towns and villages, particularly where they are located close to the Wolds to the west of the River Hull. In these areas, surface water can flow down from the Wolds and through and into the more built-up areas below. Surface water flooding has occurred in Cottingham, Willerby, Beverley, Leconfield, Beeford and the Orchard Park and Derringham areas of Kingston-upon-Hull. Local surface water flooding occurs relatively frequently and generally causes only minor disruption and little if any damage to property. Extreme and large scale surface water flooding, such as that which occurred in June 2007, can cause widespread property damage. This scale of flooding is much more unusual and is estimated to only occur once every 100 to 200 years, on average. Flooding of main road routes from surface water flooding can cause major traffic disruption and make access difficult for emergency services.

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Although the River Hull Strategy does not address surface water flooding, we are currently working with Local Authorities and other partner organisations to identify how best to manage it in the future. Hull City Council have been funded by Defra to prepare a Surface Water Management Plan and future actions and we have been involved in its development to ensure that our work is complementary. In the East Riding of Yorkshire the local authority have set up a Flood Liaison Panel which we are part of, along with other partner organisations such as Yorkshire Water. The purpose of this group is to look at all flooding issues across the area and to ensure we are joined up in our approach to reducing this risk

Figure 3-4 Surface water flooding in Hull

3.3 Flood history Agricultural land and urban areas have been flooded from the River Hull, Holderness Drain, the Beverley & Barmston Drain and their tributaries throughout recorded history as well as in recent years. Some of the recent significant flood events are listed in Table 3.1. Table 3.1 Recorded flood events in the River Hull catchment Date of Event Details January 1953 Weather and tidal conditions combined to produce an extreme storm surge that affected many parts of the east coast. This surge travelled up the Humber Estuary causing catastrophic flooding to coastal areas. 1969 A tidal surge caused widespread flooding to areas adjacent to River Hull and Holderness Drain through the City of Hull. This event resulted in flood damage to 855 houses. November Flooding occurred due to a long duration rainfall event, following one of the 2000 wettest autumns on record with twice the expected monthly rainfall in September resulting in ground saturation. An average rainfall of 250mm fell across areas of Yorkshire between the 26 th October and 8 th November resulting in widespread and prolonged flooding.

Flooding occurred on the River Hull when the raised high level system was full of water and could not drain fast enough into the Humber Estuary. When this happened, the pumps draining the low level system into the River Hull had to be turned down as the high level system was full. This meant that the low level system (Beverley and Barmston Drain, Holderness Drain etc.) filled up until the low lying areas along side these drains started to flood. The flood water was stationary and mostly of shallow depth but the duration of flooding was in excess of 10 days at some locations.

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Date of Event Details Flooding took place in Hull at Setting Dyke at Coronation Road and Western Drain at Astral Close. Flooding was experienced in the East Ridings area from the Beverley and Barmston Drain, the Holderness Drain, the River Hull and Burstwick Drain owing to water levels overtopping the embankments (particularly at low spots). The flooding seen during this period was the most recent fluvial event of a significant magnitude. June 2007 During June 2007, the River Hull catchment area was affected by a period of heavy and sustained rainfall causing some of its worst ever flooding with 8,657 houses, 1,300 businesses being inundated and 600 roads affected. Over 70mm of rain fell in part of the Hull area on the 15 th June and over 100mm of rain fell in parts of the Hull area on the 25 th June. The intensity of the rainfall overwhelmed ditches, drains and sewers and the low lying nature of the catchment exacerbated the problem. River levels on the River Hull reached 0.4 metres higher than previously recorded which would have led to some localised flooding, however, the severity of the surface water flooding caused the majority of problems within the Hull catchment.

The difference between the November 2000 floods and the June 2007 floods was that flooding in November 2000 was as a result of increased river levels and not surface water flooding. Prior to the floods in 2000 and 2007, the worst flooding has been associated with tidal flooding such as the east coast floods of 1953 and the 1969 Hull Flood which swamped 855 houses. Tidal flooding has since been prevented by the construction of the Hull Tidal Surge Barrier which was commissioned in April 1980 and is currently undergoing an extensive mechanical and electrical refurbishment. The flooding in the summer 2007 highlighted the threat of surface water and sewer flooding to Kingston-upon-Hull and the surrounding area. During this event Yorkshire experienced flooding in a total of 27,197 properties with 8,476 being from fluvial flooding and 18,472 estimated to have been from surface water flooding. Of these a total of 7,208 residential and 1,300 commercial properties were located in Hull and these were primarily affected by sewer flooding.

3.4 Flood management in the River Hull catchment

3.4.1 Responsibilities for flood management Several organisations are responsible for the management of watercourses and flood defences. We have legal powers to carry out works on designated main rivers, which are predominantly the larger rivers, although an increasing number of the smaller watercourses have recently been ‘enmained’. Main rivers are shown on a “main river map”. Our local Environment Agency office has a copy of this. All other rivers are referred to as ordinary watercourses. At present, other organisations with responsibilities and powers to manage watercourses and associated structures are: • Internal Drainage Boards (IDBs) have responsibility for ordinary watercourses identified as main drains, located in areas known as Internal Drainage Districts. The IDB within the River Hull study area is the Beverley and North Holderness IDB and Preston IDB. • In addition to the Environment Agency’s powers to carry out flood defence works, the Kingston-upon-Hull Act 1984 gives Hull City Council certain powers to serve notices on the owners of land adjoining the River Hull requiring them to carry out works to prevent the overflow of the River Hull. If the landowner does not carry out the works the Council has the power to do the works itself and recover its costs from the landowner • Maintenance of ordinary watercourses, which are not located in an Internal Drainage District, falls under the permissive powers of local authorities.

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• Water companies, such as Yorkshire Water, have responsibility for public sewerage systems. They have a statutory duty to ‘effectively sewer’ an area. • Highway authorities have responsibility for highway drainage. These will normally be the County Councils or Unitary Local Authorities, but in some cases it is the Highways Agency. Highway authorities and the Highways Agency are also responsible for some structures such as bridges and culverts. • Landowners have certain rights and responsibilities4 in relation to a watercourse flowing through or adjacent to their properties. These ‘riparian rights’ are based on common law and have been developed as a result of legal cases over many years. These rights are not absolute, and riverside landowners may, in any event, have to obtain consent from the Environment Agency, local authority, or another body for certain activities connected with the watercourse. • The Pitt Report recommends ‘that local authorities should lead on the management of surface water flooding and drainage at the local level with the support of all responsible organisations including the Environment Agency, water companies and internal drainage boards, the Highways Agency and British Waterways 5.’ The government reviewed these responsibilities and the Flood and Water Management Act 2010 was passed in April 2010. It is due to be commenced in October 2010, but in the interim, Defra are expecting the Environment Agency to undertake an overseeing role for all aspects of flood risk. Proposals were published by Defra in March 2005 6 for a more holistic approach to flood management. Defra has taken an integrated approach to drainage management in high-risk urban areas through Surface Water Management Plans. These cover flooding from fluvial, drainage, surface water and groundwater sources. This will enable the authorities responsible for different parts of the drainage system to work together to assess and manage flood risks, taking a long- term strategic approach. 3.4.2 Flood defences Figure 3-5 shows the extent of purpose-built, maintained flood defences in the study area. Details of these flood defences are given in Tables 3.2. Table 3.2 River Hull flood defence assets Asset Description Amount (km) or Average spend per year (£000) Capacity (m3/s) Main river channels River Hull 50 km 180 (Kingston-upon- Beverley & Barmston Drain 23 km Hull and urban area); Holderness Drain 23 km 180 (Kingston-upon- Others 136 km Hull to Hempholme Weir); Flood banks/walls 7 River Hull 75 km 80 (Upstream of Others 86 km Hempholme Weir) Main pumping Hempholme 1.9 m 3/s 20 stations Wilfhome 8.5 m 3/s 80 Tickton 2.5 m 3/s 20 Great Culvert 12 m 3/s 80 East Hull 7.5 m3/s 100 Outfall structures Hedon road outfall, 1 no

4 For further information refer to our free leaflet ‘Living on the Edge – An updated guide to the rights and responsibilities of a riverside owner’ available from our General Enquiry Line on 08708 506 506.

5 Cabinet Office (December 2007), The Pitt Review, Interim Report 6 Defra (March 2005), ‘Making Space for Water. Taking forward a new Government strategy for flood and coastal erosion risk management in England. First Government response to the autumn 2004 Making Space for Water consultation exercise’. http://www.defra.gov.uk/environment/flooding/documents/policy/strategy/strategy-response1.pdf 7 10km of the River Hull and 8km of other rivers are maintained by third parties

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Asset Description Amount (km) or Average spend per year (£000) Capacity (m3/s) Holderness Drain: Pointing doors 2 no Mickley Dike 2 no Watton Beck 1 no Scurf Dike 2 no High Flags outfall, Beverley and Barmston Drain: Pointing doors Other assets Hull Tidal Surge Barrier 100

In general, the River Hull catchment system can be split into three main sections: • The high level system, formed by the River Hull headwaters and the River Hull (the main river into which the headwaters flow). The river discharges to the Humber Estuary through the tidal surge barrier, except during high tides when the barrier is closed. • The low level system, which is formed predominantly by the artificial agricultural drainage network, including the Beverley and Barmston Drain. Flows are transferred from the low level system to the high level system via Wilfholme, Waterside and Hempholme pumping stations. This regulates water levels in the drains, whilst also influencing flow in the River Hull itself. The drain discharges to the River Hull by gravity at High Flags. • Holderness Drain is predominantly a low level carrier draining the catchment to the east of the River Hull, including Lambwath Stream, New Drain, Stream Dike and Monk Dike. Holderness Drain runs parallel to the River Hull from just north of Wilfholme to the Humber where it outfalls through pointing doors at Hedon Road. To increase flow and reduce water levels in the drain upstream of the city, the drain is pumped from upstream to downstream at Tickton and Great Culvert pumping stations. East Hull pumping station is operated to enable discharge to the estuary during high tides.

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Figure 3-5 Flood defences in the study area

It is the high level system where the channels have historically been embanked. They have developed as ‘perched’ systems in which the channel bed often now sits above the surrounding land. Through the urban area of Kingston-upon-Hull, the River Hull is highly engineered with hard bank protection. This high level system has the majority of the catchment’s formal flood defences. There are approximately 160km of formal flood defences in the Hull catchment. Along the reaches of the river in the East Riding of Yorkshire and in the northern parts of Kingston-upon-Hull, the flood defences largely comprise earth embankments (“soft” defences). Through the city a variety of steel sheet piling, concrete/timber wharves, stone walls, buildings and other structures form the “hard” defences along the river. The maintenance that we carry out varies between different watercourses and stretches of watercourses within the River Hull Strategy study area.

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We inspect pumping stations at least once a week and carry out various electrical and mechanical maintenance between once a month and once a year. We clear weed screens as necessary. We regularly inspect flood defence embankments, which includes an annual inspection for vermin damage. Routine works on rivers and drains includes grass cutting, aquatic weed control/spraying and clearing debris out of urban watercourses. In addition we cut back vegetation between mid October and mid March. We remove any obstructions such as cars, fallen trees and any rubbish that may have been dumped. We also repair embankments and channel slips when needed. 3.4.3 Flood warning and forecasting We issue flood warnings to give residents and businesses that are at risk time to take action and help minimise the impacts of flooding on their property. There are four levels of flood warning, which are given below, together with their meanings:

Flooding of low lying land and roads is expected. Be aware! Be prepared! Watch out!

Flooding of homes and businesses is expected. Act now!

Severe flooding is expected. There is extreme danger to life and property. Act now!

Previous flood watches or warnings are no longer in force for the area.

We issue flood warnings by a variety of means, including: Local media - We make extensive use of local media, including radio and television, to disseminate flood warnings. Floodline - Residents and businesses concerned about flood risk may telephone Floodline (0845 988 1188) to obtain current flood warning information and general advice. A ‘quick-dial’ number is available for each flood warning area, to allow callers to quickly access relevant information. Internet – All flood warnings are noted on our website (www.environment-agency.gov.uk). Floodline Warnings Direct (FWD) - This is the UK’s first integrated multi-channel warning system and provides flood warnings and information to the public, professional partners and media across England and Wales. In addition to phone and fax messages which the AVM provided, FWD can now warn via SMS text messages and email. Residents and businesses need to be registered with us to receive FWD; this can be done by contacting Floodline on 0845 9881188. At the moment we provide flood warnings to several communities along the River Hull, Beverley and Barmston Drain and Holderness Drain. The flood warning areas and associated trigger levels are currently under review. We have prepared local flood warning plans for Hull City Council and East Riding of Yorkshire Council. These provide local authorities and emergency services with information about flood risk and flood warning operations in their area. Hull City Council has prepared a Major Incident Plan for Kingston -upon-Hull. This describes the actions to take during a major flood. 3.4.4 Development control and flood mapping Through encouraging appropriate development, we use development control principally to minimise increases in future flood risk, rather than to tackle existing flood risk. Section 2.4 notes some of the links between planning, development and flood risk. Although we currently have no

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wider legal powers to control development in floodplains, we are consulted on planning applications as statutory consultees on any development in Flood Zone 3 and 2 (high and medium risk) and any development in Flood Zone 1 (low risk) over 1 hectare. A Flood Risk Assessment has to be submitted with all the applications and part of this is restricting the amount of surface water run-off from the development site. All new developments where we are consulted have to restrict the amount of surface water run-off as the existing drainage systems are at capacity, as you stated. Usually this can be done by using sustainable drainage techniques such as a balancing pond or underground storage tanks. This means that for any new developments where we are consulted there will be no extra pressure on the existing drainage infrastructure. For future land allocations we would ask the Local Planning Authority to look at the Flood Zones and to favour low risk areas as opposed to the high risk. We have also mapped Areas Susceptible to Surface Water Flooding. These are to be used by the LPA's when they are looking at sites for development allocations. We work with the planners on their allocations and policies in their Local Development Framework to ensure that future development does not add to the existing problem. We provide information on flood risk in the form of the Flood Map and the Flood Zones which are produced on a national scale by a flood mapping model. We provide them directly to local authorities for their planning work, and to individuals via our website. The Flood Zones show areas at risk from: i) A 1% AEP river flood event or 0.5% AEP tidal flood event (Flood Zone 3) ii) An extreme 0.1% AEP river or tidal flood (Flood Zone 2). iii) Land outside of the 0.1% AEP river or tidal flood (Flood Zone 1) The Flood Map is available on our website and provides additional information to the Flood Zones. The Flood Map classifies the likelihood of flooding into three categories (low, moderate or significant) taking flood defences into account, and it shows which areas benefit from flood defences. We update the national data based on more detailed local knowledge. The Flood Zones for the River Hull in the study area has been updated based on the detailed modelling and mapping work carried out for this Strategy (see section 3.5).

3.5 Assessment of current flood risk We have developed a computer-based hydraulic model of the River Hull system, which includes the main rivers, drains and floodplains in the Hull and Holderness Drain systems as well as numerous structures (including the pumping stations) and some smaller drains and culverts to be able to model the movement of the water around the catchment. Data used in the hydraulic model includes river cross-section surveys, ground levels of all the floodplain areas, and embankment levels from high resolution surveys. We have also completed a detailed hydrological analysis of the catchment to calculate the flood flows and volumes of water entering the rivers and drains at various locations during different magnitude floods; these flows are then input into the hydraulic model. Some of the flows include a component to represent groundwater flow in the river. The model has been developed and tested by simulating flood levels recorded in several real past flood events, including summer 2007. We have also spent a significant amount of time working with people who live and work in the area to test that our model accurately reflects what happens on the ground. The model has then enabled us to: • Estimate flood levels for a range of events from the 1 in 2 (50%) AEP event to the 1 in 200 (0.5%) AEP event. • Investigate possible future flood risk due to climate change. • Test the effectiveness of possible flood risk management measures.

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We have overlaid the model’s predicted flood levels onto a ground elevation map of the River Hull catchment, to show the extent of land at risk from flooding. Figure 3-6 shows the predicted extent of flooding for a 1 in 2 (50%) AEP fluvial flood event and the 1 in 200 (0.5%) AEP fluvial flood event, for present day water levels taking into account the effect of the defences. More detail on the hydrology and hydraulic model are included in the Options Appraisal Report.

Onset of flooding and standard of protection It is important to understand the likelihood of flooding occurring in our communities. For example, is there a 1 in 10 (10%) chance or a 1 in 100 (1%) chance of flooding occurring in any given year? When averaged over the long term, this corresponds to the frequency of disruption and flood damage likely to be experienced by a community. We have used the modelled flood levels to estimate the frequency with which the flood defences and the banks of the main drains would be overtopped by flooding. We call this frequency the ‘onset of flooding’. In some locations in the catchment, flood water can overtop a defence and then flow behind the defence parallel to the river causing flooding adjacent to higher defences that are not overtopped. Also, in some locations flooding can be caused by overtopping from more than one river or drain. For this reason we have used flood extents in combination with the ‘onset of flooding’ of each watercourse to assess the flood risk to different parts of the catchment. The ‘onset of flooding’ is not the same as the term ‘standard of protection’ often used for a purpose-built flood defence, which refers to the event that the defence is designed to protect against. The height of designed defences includes an allowance for uncertainties in the estimated peak flood level, known as a ‘freeboard allowance’. This means that the standard of protection reported for a flood defence is usually lower than the onset of flooding due to overtopping.

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Figure 3-6 Predicted extent of flooding (present day)

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Table 3.3 Onset of fluvial flooding for River Hull catchment (taking into account the effect of the defences) Conversion of annual probability values to annual chance of flooding: 20% (1 in 5), 10% (1 in 10), 4% (1 in 25), 2% (1 in 50), 1.3% (1 in 75), 1% (1 in 100) & 0.5% (1 in 200)

Number of Properties Onset Location of flooding* / Key Locations Watercourses at risk* (AEP) comment Res Non Res Upper River Hull (West Beck) >50% Bell Mills plantation Driffield 0 0 Driffield Canal <0.5% n/a Upper River Hull (West Beck) 20% Limited rural flooding Wansford 0 0 Driffield Canal >50% n/a Frodingham Beck >50% Brigham Carr Brigham 0 0 Driffield Canal >50% Brigham Carr Rural land adjacent to Old Howe >50% Frodingham Bridge Frodingham Bridge 1 0 Frodingham Beck >50% Free landing place Into Frodingham Church River Hull >50% North Fordingham Drain 1 0 Carrs Frodingham Beck >50% Jarret’s Ings Roam Drain 20% North Frodingham Carrs Into top of Beverley & River Hull >50% Watton Carrs Barmston Drain 0 0 Beverley and Barmston Drain >50% Easingwold plantation Limited rural flooding near Aike Carrs and River Hull >50% Whitewater Drain 1 0 Arram Carrs Beverley and Barmston Drain >50% Aike Carrs, Arram Carrs Limited flooding between River Hull 20% River Hull and Drain Hull Bridge 0 1 Rural flooding south of Beverley and Barmston Drain >50% village Beverley Beverley and Barmston Drain <0.5% n/a 0 0 River Hull <0.5% n/a Thearne 0 0 Beverley and Barmston Drain 4% Limited rural flooding River Hull <0.5% n/a Dunswell Limited flooding adjacent 0 0 Beverley and Barmston Drain 20% to Dunswell Lane Orchard Park Beverley and Barmston Drain <0.5% n/a 0 0 Kingston-upon-Hull <0.5% (not incl. Orchard River Hull n/a 0 0 ** Park & Bransholme) Leven Carrs Holderness Drain 20% Leven Carrs 0 0 South Field / Leven Bridge Leven Catchwater Drain 20% 57*** 0 (The Orchards) Tickton Holderness Drain 2% Tickton Carrs 0 0 Bransholme Holderness Drain >50% Kestrel Avenue area ≈ 900 0 * within the 0.5% flood extent ** assumes statutory defence levels are maintained on the River Hull *** It is acknowledged that more properties experienced flooding in summer 2007 than is predicted by the model as local-scale flooding mechanisms in the area are complex and beyond the scale of the model. As we are very aware of the flooding issues in this area, we have included the numbers of properties believed to have flooded in summer 2007 in the table and not those predicted by the model. Assessing flood risk in detail here requires a seperate study which we are currently working with the residents to promote.

It is evident that the onset of flooding in the study area is very variable. There is also a high probability of flooding in many of the rural areas, most notably in the upper reaches between Frodingham Bridge, Brigham and Hempholme Weir and in the middle reaches in the Watton, Aike and Arram Carrs. These areas can expect to flood once every other year, on average. Larger

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floods, which have a smaller probability of occurring in any given year, cause more extensive flooding to rural areas and start to affect more properties. The 20% AEP flood event causes approximately 1km 2 of land in both Leven Carrs and North Frodingham Carrs to flood. Properties in the low lying area of Bransholme adjacent to Sutton Cross Drain are also at risk of flooding for the 20% AEP flood event due to high flows in Holderness Drain causing overtopping into the North Carr area. Through Kingston-upon-Hull, the onset of flooding is generally very high and the defences prevent overtopping for the 0.5% AEP flood event. The risk of flooding due to the River Hull overtopping as a result of tidal levels is reduced by the Hull Tidal Surge Barrier which is closed when a high tidal level is forecast.

3.6 Flood risk in the future In section 3.1 we outlined how flood risk involves both the likelihood of flooding and its potential consequences. Future flood risk will depend on how the likelihood and consequences of flooding change. This can be difficult to predict, so we need to ensure that the way we manage flood risk is flexible enough to deal with the uncertainties associated with future flooding. The Government’s Foresight programme was set up to identify visions of the future across a broad range of subjects. One of the projects considered is Flood and Coastal Defence. 8 The findings of this project were published in 2004. Nineteen areas involving future flood risk were evaluated by Foresight, including: • Climate change – sea level rise and changes in rainfall patterns; • Urbanisation – increased run-off from urban areas and the risk of failing to control new development appropriately; • Environmental regulations – which may be possible constraints on flood risk management and maintenance of river channels; • Rural land management – land management techniques can reduce run-off at a local scale, but further research is needed to determine whether catchment-wide effects can be demonstrated; • Increasing national wealth – increased value of property leading to increased economic impacts of flooding; • Social impacts – possible blight on sections of the population if risks are not managed. These impacts may be increased by difficulties of obtaining affordable insurance cover in areas prone to flooding. • Flood risk management responses – the measures that we take to manage flooding can affect both the likelihood and its consequences. This is discussed further at the end of this section. Below we describe some of the influences on future flooding that have been considered within this Strategy. 3.6.1 Climate change As we are increasingly aware, the global climate is changing. Sea levels are already rising and they are predicted to rise further due to thermal expansion of the oceans and melting glaciers and ice-caps. The lower and middle reaches of the River Hull (downstream of Hempholme) and parts of the drainage network are influenced by tidal levels in the Humber Estuary. We therefore need to include an allowance for sea level rise when considering the effects of climate change within this

8 Evans et al (2004) ‘Foresight Future Flooding. Scientific Summary: Vol1 – Future risks and their drivers’. Office of Science and Technology, see www.foresight.gov.uk/Flood and Coastal Defence/index.html

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Strategy. Research from Defra 9 recommends that sea level rise will accelerate from 4mm/year at present to 15mm/year after 2085. The total sea level rise over the next 100 years is predicted to be approximately 1m. Climate change may also produce altered weather patterns. This could mean changes to the frequency, duration and severity of rain storms across the UK. Winters are predicted to be wetter and summers drier. An increased frequency of heavy, intense rainfall also seems likely, both in winter and in summer thunderstorms. Research from Defra recommends that increases in peak river flows of 10 per cent may be expected by 2025 and an increase of flows of 20 per cent any time between 2026 and 2115 as a result of changing rainfall patterns. This Strategy covers a period of the next hundred years, and we have estimated an increase of up to 20 per cent in all inflows to the River Hull system by the early 2050s (further explanation can be found in the Options Appraisal Report in Appendix A). At this stage there is no clear agreement as to whether such increases are realistic for the Hull catchment. We have used the computer model of the River Hull system to test the effects of sea level rise and increased flows entering River Hull system. The model suggests that water levels are likely to increase most along the lower reaches of the River Hull and in the Beverley and Barmston and Holderness Drains. The greatest increase in River Hull water levels occurs during neap tidal conditions when the climate change water levels are still below the trigger level required to close the Hull Tidal Surge Barrier. In this situation, water levels through Kingston-upon-Hull will be up to about 1.0m higher with climate change. The increase in water level will reduce further upstream to about 0.5m at Hull Bridge and 0.4m at Hempholme Weir for winter flows. The increase in peak water levels during flood flows will be much smaller, typically of the order of 0.2m. These changes mean that existing river banks and walls, upstream of the city, could be overtopped more frequently than at present. Table 3.8 shows how the changes may affect the onset of flooding at selected locations in the study area. Table 3.4 Impact of climate change on onset of flooding Conversion of annual probability values to annual chance of flooding: 20% (1 in 5), 10% (1 in 10), 4% (1 in 25), 2% (1 in 50), 1.3% (1 in 75), 1% (1 in 100) & 0.5% (1 in 200)

Key Locations Baseline Climate No. of Onset (AEP) Change Onset Properties at (AEP) risk in future * Beverley <0.5% 4% 2 Thearne 4% >50% 10 Dunswell 20% >50% 25 Orchard Park <0.5% 4% 530 Kingston-upon-Hull (not <0.5%** <0.5%** 0 incl. Orchard Park & Bransholme) Leven Carrs 20% >50% 2 Leven 20% >50% 57*** Tickton 2% 4% 0 North Frodingham Carrs >50% >50% 1

* within the 0.5% future flood extent ** assumes statutory defence levels are maintained on the River Hull *** It is acknowledged that more properties experienced flooding in summer 2007 than is predicted by the model as local-scale flooding mechanisms in the area are complex and beyond the scale of the model. As we are very aware of the flooding issues in this area, we have included the numbers

9 Defra (October 2006) Flood and Coastal Defence Appraisal Guidance Supplementary Note to Operating Authorities – Climate Change Impacts

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of properties believed to have flooded in summer 2007 in the table and not those predicted by the model. Assessing flood risk in detail here requires a seperate study which we are currently working with the residents to promote.

Increased flood levels would also mean an increase in the area of land and property which is at risk from flooding. The model suggests that the locations with the greatest increase in area flooded from the River Hull system would be: • North Frodingham Carrs, Leven Carrs and the North Carr / Bransholme area for frequent floods (50% AEP flood) • Dunswell and the Orchard Park area of Kingston-upon-Hull for more extreme floods (1% AEP flood). The increase in flood risk to North Frodingham Carrs, Leven Carrs and the North Carr / Bransholme area is a function of both sea level rise and increase in fluvial flows. Sea level rise reduces the amount of water that can discharge from the drainage system during each tide, thereby increasing water levels upstream. The increase in flood risk to Dunswell and the Orchard Park area of Kingston-upon-Hull is mainly due to the effect of sea level rise, which causes the water levels in Beverley and Barmston Drain to increase as less water can discharge from the drain. Current research indicates that the frequency of intense rain storms is likely to increase under climate change. This means that more local ‘flash flooding’ may be experienced, from surface water run-off from the Wolds and urban areas, and from storm water drains. As we noted in section 3.4, at present the responsibility for managing flooding from surface water and sewers generally lies with other organisations, however we are currently working with other organisations to identify risks and solutions to surface water flooding. 3.6.2 Urban development Urban and rural development is driven by growth in population, housing demand, and investment in employment, leisure and retail facilities. This growth is grounded in planning policy and development management, guided by local, regional and national planning policy. Urban and rural development has two main implications for flood risk management: i. New urbanised areas increase the extent of impermeable surfaces (roads, roofs etc). Artificial stormwater drains and pipes carry run-off from hard surfaces into watercourses, and this happens much more rapidly than the natural process of water seeping through soils, if mitigation measures such as Sustainable Drainage Systems (SuDS) are not applied. These effects can increase flood peaks in watercourses downstream of new urbanised areas. There is also an increased risk of localised flash flooding in intense rainstorms. ii. To manage flood risk, it is important to locate new development outside flood risk areas whenever possible. Allowing development without considering flooding subjects additional people and property at risk. Where development within the Flood Zone is essential, it is vital that flood risk mitigation measures are included. The Yorkshire and Humber Regional Spatial Strategy (RSS) 10 guides development within the region up to 2026 and beyond. The RSS provides a broad and long term development strategy for the Region. Most of the Region’s Regional and Sub Regional Cities and Towns have suffered from population decline during the second half of the twentieth century. The Region’s economy, however, has grown in the years running up to the publication of the RSS, but dynamics of change in global, national and local economies means that growth and productivity gains remain key regional priorities.

10 Government Office for Yorkshire and the Humber (2008) ‘The Yorkshire and Humber Plan: Regional Spatial Strategy to 2026’ .

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The Region is currently experiencing net inward migration and overall economic growth. This is fuelling demand for economic, service, leisure and residential development in the Region, which is to be focussed in the Regions service centres. Apart from York and Leeds, the larger towns and cities have lost population, and population has grown most within easily accessible rural areas. Development in rural areas, however, is minimal with rural areas making up 80% of the Region and housing only 20% of the Region’s population. In economic terms, the Leeds city region (including Bradford) is likely to remain the most significant economic driver of the Regions economy and will experience the most significant growth within Yorkshire and the Humber, with growth in office-based jobs, manufacturing and warehousing and distribution. The RSS notes the role of the government’s Northern Way strategy for increasing growth and the competitiveness of the north of England as a whole. The RSS seeks to re-use land and buildings, make the most of existing infrastructure and investment, maximise accessibility and reduce travel through focussing development, investment and activity in the region’s Regional (Bradford, Hull, Leeds and Sheffield) and Sub-Regional cities. The RSS sets a regional target of at least 50% for household development in the Regional and Sub-Regional cities over the plan period. The Regional and Sub-Regional cities will be complimented by Principal Towns (service, employment and transport hubs for surrounding area) which will provide a focal point for services, facilities and employment, supporting the role of the Regional and Sub-Regional cities. Rural areas will experience a slower pace and scale of growth, compared to urban areas, with development being focussed in Local Service Centres, i.e. towns and villages. The RSS seeks to prevent the dispersal of development to smaller settlements and open countryside. The above seeks to result in a more concentrated pattern of development across the region, with stronger control over the level of development coming forward in often small and relatively remote towns and villages. A sequential approach to development is set out in the RSS with significant focus on re-using ‘brownfield sites’. Recent economic performance in the Leeds City Region has helped growth in the urban parts if the city region leading to the encouragement of high levels of growth in households and jobs in sustainable locations, making best use of brownfield land and infrastructure. There continues to be pressures on the limited rural housing stock in the region, therefore minor housing development is required in the remote rural areas. However, this new development should be limited and restricted to Local Service Centres such as Sedbergh, Hawes, Leyburn, Pateley Bridge, Grassington Kirkbymoorside and Pickering. The economic sub area of the Humber Estuary is dominated by the three main urban areas of Hull, Grimsby and Scunthorpe, however recent economic indicators have shown falling performance in recent years. The importance of the Humber ports is recognised and the need to accommodate additional estuary related uses is identified as a priority. Housing development and demand is identified in Hull, in particular to the north of the Estuary.. 3.6.3 Rural land use and land management Ongoing research funded by Defra and the Environment Agency is evaluating the impacts of rural land use and land management on run-off and flood generation. 11 So far, it has concluded that impacts are evident at the local scale (individual fields and very small stream catchments). Further research is required, and is ongoing, to identify and understand impacts for larger catchments. It also appears that land management effects are more noticeable in small to medium flood events. In extreme floods the large amount of rainfall saturates soils throughout the catchment, and the overall volume of rainfall is more important than the influence of land management. Future changes in rural land use are difficult to predict. They will be strongly determined by future agricultural policy, particularly the role of subsidy payments and environmental stewardship schemes.

11 Defra / Environment Agency (2004), ‘R&D Project Record FD2114/TR Review of impacts of rural land use and management on flood generation’.

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3.6.4 Flood management responses Our review of influences on future flood risk has indicated that climate change could have a significant impact on the probability and consequences of flooding at many locations in the River Hull catchment, particularly in the flatter areas of land along the middle and lower reaches of the Hull (downstream of Hempholme Weir). Changes in urban and rural land use may have local impacts. We need to consider how best we can sustainably manage both current flood risk and future increases in flooding, particularly due to climate change. The measures that we take to manage flooding will affect both the likelihood and consequences of it occurring. The Government’s Foresight study for Flood and Coastal Defence examined the best responses to reduce future flood risk. These were grouped into the following five themes: • Managing the rural landscape – agricultural practices, afforestation, floodplain storage schemes including washlands; • Managing the urban fabric – urban design such as SuDS, managing drain and tributary interactions, appropriate design of buildings; • Managing flood events – flood forecasting, flood warning, use of temporary flood defences for individual properties; • Managing flood losses – development control to minimise exposure to flood risk, flood resilient building materials, insurance; • River and coastal engineering – ‘traditional’ methods such as channel works, raised defences, diversion channels. In section 4 we set out and assess options for flood risk management in the River Hull catchment. Although we have not grouped the options into the same themes, many of the measures being considered are very similar to the Foresight Responses. 3.6.5 Development control Controlling development in areas at risk of flooding is one particular response that can help to limit the consequences of future flooding. Allowing development without regard to flood risk endangers people’s lives, places property at risk of damage and can result in wasteful expenditure on managing flooding. A sustainable approach to flood risk would involve avoiding development completely in some areas. We have already referred in Section 2.4 to a greater awareness of flood risk among planners and developers, promoted by government Planning Policy Statement, 25, PPS25. We will continue to provide advice to planners on development control, both at the strategic level of Local Development Frameworks and when consulted on individual planning applications. However, we have no legal powers over planning decisions. It is therefore important that those who plan and occupy developments in areas of flood risk are aware of the hazards. Where it is impossible to avoid development in areas at risk from flooding, it is important to include measures to mitigate the impact. This may include planning evacuation routes, using building materials that are easy to clean up or renovate in the event of a flood, and measures to ensure that flooding is not increased elsewhere. Even where flood defences exist or are planned, people should be aware of the actions they should take in the event of a flood. Although defences can reduce the risk of flooding, they cannot eliminate it. Residents in flood risk areas can contact us via our Floodline service for further information and advice on flood risk and preparedness (see section 3.4 for further details). Emergency plans should be drawn up to deal with flooding in these areas, in consultation with ourselves and the emergency services.

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4. Appraisal of options

This section looks at the flood risk management options, highlighting: • how the options are appraised and prioritised; • the options considered; • the advantages and limitations of each option; • our recommended options; • the strategic risks.

4.1 Appraisal criteria for River Hull Strategy options In keeping with the strategy aims and objectives (refer to Section 1.3) we appraised the strategy options against the following criteria: • technical feasibility • strategic environmental assessment against set environmental objectives • economic viability • risk A brief summary of the appraisal criteria and process is provided in the following sections; detailed descriptions are included in the Options Appraisal Report in Appendix A. Our appraisal followed a staged approach, so that we could screen out unpromising options before spending a lot of time appraising them in detail. The options appraisal process is illustrated in Figure 4-1

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Initial Strategic Options Review

Ch. 4.1 Develop criteria to assess options against

Ch. 5 Outline Options Appraisal

Options rejected Ch. 6 Option development, refinement, modelling

Detailed Options Appraisal

Develop matrix of combinations Detailedmodelling

Ch. 7 Combinations Appraisal Options rejected

Option development, refinement, modelling

Short listed strategy solutions Options rejected

Ch. 8 Optimisation

Technical development: Refining modelling Ch. 9 and economic analysis Economicanalysis

Ch.10.1 Strategy elements

Develop combinations of Strategy elements

Ch.10.3 Appraisal of final Strategy options Options rejected

Relevant chapter in Options Appraisal Draft Strategy Report (Appendix A) Figure 4-1 Options appraisal process

4.1.1 Technical feasibility Technical feasibility relates to whether an option delivers flood risk management benefits and can be implemented from a practical perspective. To test this criteria we considered options against a wide range of technical issues including: • Catchment topography and the river and land drainage network, and how this affects the flooding processes; • Flood levels and their impact on developed areas and agricultural land; • The effectiveness of the options in managing flood levels, flood extents or the frequency of flooding. We used local knowledge of the drainage system and our computer model of the River Hull to assess this; • The effect of options on infrastructure such as roads, railways, canals and sewage treatment works; • Buildability issues of access, land availability and construction methods. (Can we build the option?); • Interactions with existing and proposed development; • Wider catchment impacts. Only options that are technically feasible will be included in the strategy plan.

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4.1.2 Strategic Environmental Assessment We have undertaken a Strategic Environmental Assessment (SEA) of the FRM Strategy elements to determine their strategic environmental impact. Through a process called scoping, we identified the key strategic environmental issues relevant to the Strategy study area and then set corresponding environmental objectives. We have assessed how the Strategy elements would achieve the environmental objectives as a measure of their strategic environmental performance, using professional judgement to reach our conclusions. These impacts have been considered while we developed our Strategy. Our assessment has also helped us to choose our proposed management in the short term (refer to Section 5), as well as potential risks and uncertainties that we will need to consider in more detail before we decide on any future change in the management approach. The key strategic environmental impacts are summarised below (see section 4.3), based on the assessments for each Strategy element. We also realise that there will be local impacts that we have not included in the SEA. These will be considered in more detail during project level Environmental Impact Assessment (EIA) process. We have developed a monitoring plan to compare the actual environmental impacts of implementing the Strategy against the impacts which we have predicted in our SEA. We will use existing data sources and established monitoring methods and report this through future reviews of the Strategy. Details of our SEA process, including the environmental objectives developed, are provided in the SEA Environmental Report in Appendix B. 4.1.3 Economic viability Economic viability relates to the business case for an option and we measure this by comparing the economic benefits of an option with the cost. An option has to be economically viable to allow us to promote it and to obtain funding. This process is briefly described below; details are provided in the Options Appraisal Report in Appendix A. (i) Benefits The economic benefits are the reduction in flood damages an option would achieve when compared to the base case Do Nothing option. This is normally referred to as the ‘benefits’ of an option. We used the computer model of the River Hull catchment to calculate flood levels and flood extents. We combined these results with detailed ground level data to give flood depths. These were used in combination with property databases to determine the area at risk from flooding and the number of properties within this area. Flood damage values for residential properties, commercial properties and agricultural land were obtained from published data. We also took into account the frequency of flood damage, using the onset of flooding shown in Table 3.4. (ii) Costs Information from various sources has been used to build up our estimates of construction and operating costs for the options. We have used a combination of our unit cost database and drawn on previous project experience. The year in which costs are expended can also vary for each option. Costs are therefore converted into a present value to allow accurate comparison. Current guidance from HM Treasury allows for ‘optimism bias’ to be added to preliminary cost estimates. Optimism bias allows for difficulties in estimating costs at such an early stage in a project and the tendency for scheme costs to be under-estimated. Optimism bias is initially set at 60% of the estimated costs. This figure can be changed as confidence in the data increases/decreases. We have described the process in more detail in Appendix A. (iii) Benefit cost ratio The benefit cost ratio is a measure used to assess the economic efficiency of an option. It is the ratio of the damages to the costs of the proposed works throughout their working life. A benefit cost ratio greater than unity (one) indicates that an option is beneficial; i.e. the benefits are greater than the costs. However, with our current levels of funding an option would not attract funding if the benefit/cost ratio is less than five to one.

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The incremental benefit cost ratio between different alternatives for a flood risk management scheme is used to indicate additional benefit relative to additional cost. An incremental benefit cost ratio of one shows that we are achieving an additional benefit to the same value as the additional cost. For example (not relating to this strategy), a scheme reducing flood damage by £40 million and costing £5 million would have a benefit cost ratio of 8. If a second option was also presented which would reduce flood damages by £42 million at a cost of £8 million it would have a cost benefit ratio of 5.25. Considering benefit cost ratio alone, both schemes would appear to qualify for funding. However, when comparing the options against each other the second option would only provide an additional benefit of £2 million for an additional cost of £3 million compared to the first option. The incremental cost benefit ratio between the two options would therefore be 0.67 (£2 million / £3 million). As this is less than 1, the second option would not be economically justifiable compared to the first option even though the second option had a benefit cost ratio of over 5 when considered in its own right. 4.1.4 Risks There are risks associated with the option appraisal process, as with all high-level studies. These risks primarily relate to the accuracy of the available data and the validity of the assumptions made. Sensitivity analyses are therefore used to determine the key parameters or assumptions. We have identified the following risks that we consider to be pertinent and have described the extent of the work carried out to date or the further work required to reduce these risks. (i) Modelling The predictions from any computer-based model are subject to confidence limits, typical factors include; • the input data, such as the nature of the catchment and inflows; • the accuracy of the ground levels; • the assumptions relating to the river channel, such as roughness; Our hydraulic model is very complex and was built in preparation for the Strategy over the period 2005 to 2009. The reliability of the model was tested by simulating three real flood events (including the major floods of summer 2007), and comparing the results with actual recorded river flows and flood levels. We have tested some of the uncertainties that may affect the flood risk management options. For example, we investigated the effectiveness of floodplain storage schemes for managing river flood peaks lasting for different lengths of time. (ii) Environmental Further project level environmental assessments will be undertaken as part of the promotion of any schemes recommended by this Strategy. There is, therefore, the potential for additional environmental issues to be identified, which could add new constraints or, indeed, may present new opportunities. An example of a risk highlighted by the SEA is the potential presence of contaminated land in areas where we are proposing to construct flood risk management options. Techniques that may be required to clean up the pollution or prevent it spreading could increase the costs of the option. Other project level environmental risks include the presence of protected species or discovery of unknown archaeology. (iii) Economics An increase in the estimated cost of an option reduces its benefit-cost ratio. The benefit-cost ratio is one of the indicators used to determine the priority of flood risk management schemes for funding, so an increase in costs could delay implementation. We have carried out sensitivity tests on the costs; details of which are provided in Appendix A.

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There are also risks associated with the construction and operation of the flood risk management options. Some options have a higher level of associated risk than others. The risk issues associated with individual options are described in the option assessments in section 4.3 below. 4.2 Options for consideration This section summarises the findings of the options appraisal process. More detailed descriptions of the options and the assessment process are included in the Options Appraisal Report in Appendix A and the SEA Environmental Report in Appendix B. 4.2.1 Initial strategic options Options appraisal started with twelve existing options from a Preliminary Strategic Review carried out in 2004. From an Options Workshop in May 2006, we generated 19 options to be considered in each of the three catchment areas, listed in Table 4.1 below. Table 4.1 Summary of initial flood risk management options

Number Option Name Option Description All maintenance would stop with this option and any defence 1 Do Nothing failure would not be repaired. Reinforcement of Strengthening or replacing existing defences. Maintain 2 Defences- maintain existing/statutory height of existing defences. The height of existing defences would be increased to allow for Raising of Defences- 3 climate change and, therefore, the existing Standard of sustain Protection would be maintained. Raising of Defences- The existing defences would have a further height increase to 4 improve improve the Standard of Protection & allow for climate change. Defences would be realigned to sustain or improve the 5 Defence Realignment Standard of Protection, and the defences would be set back to help create habitat. 6 Flood Storage Flood storage areas will be created in specific locations. Low lying land will be used as washlands and spill locations 7 Floodplain Utilisation will be controlled. Storage using Holderness The Holderness Drain channel and adjacent land will be used 8 Drain and adjacent area to store flood water. Storage using Beverley & The Beverley & Barmston Drain channel and adjacent land will 9 Barmston Drain and be used to store flood water. adjacent area The channel bed will be re-graded to provide additional 10 In Channel Regrading capacity. The width of the channel will be increased, dredging will occur 11 In Channel Improvements and obstructions removed. Removing silt from the channel (dredging), and land 12 Silt Management management practices to reduce silt entering the channel. This includes a diversion of the River Hull to the east of the city (original course filled in or retained) and/or a new channel from 13 Channel Diversion the Humber up to Hempholme Weir, following the course of the River Hull and Beverley & Barmston Drain. A further barrier will be installed in the river to maintain water 14 Barrage/Impoundment levels in the River Hull through the city and prevent the tide entering the River Hull. Use the existing barrier to prevent high tides entering the River 15 Barrier Rules Amended Hull.

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Number Option Name Option Description

Localised flood alleviation measures where there are specific 16 Minor Schemes properties, low spots and bad condition defences. There will be liaison with planning authorities to prevent inappropriate development in the floodplain in the future. Also 17 Development Control areas suitable for strategic flood risk management will be identified. Improved forecasting & warning to allow communities and 18 Flood Warning landowners to be prepared for flooding, & take appropriate action. Old Howe diversion to Using the Old Howe channel & extending it to the North Sea to 19 North Sea divert the flow from the headwaters away from the River Hull.

4.3 Options appraisal

4.3.1 Outline options appraisal We carried out an initial appraisal to get a shorter list of options to take forward to the next stage. We used an evaluation matrix (refer to the Options Appraisal Report in Appendix A) to score options against technical, economic, environmental and social criteria. We rejected the following options and took the remaining options forward for further investigation. • In Channel Regrading, In Channel Improvements and Silt Management: this option was rejected as coarse modelling showed that only a small reduction in flood levels could be achieved and the cost of this option would be very high. (approximately £14.6 million each time the river is dredged - see Options Appraisal Report in Appendix A for more details). The main reason for dredging having little impact on the River Hull is that the gradient of the river is set by an outcrop of rock at Stoneferry in Hull. This means that digging silt out upstream has the effect of creating a pond, rather than improving flow. In addition, this option would have adverse environmental impacts (see SEA Report in Appendix B). There is currently a study into the effects of dredging underway. It is recognised that the findings of this study will be important and will need to be considered in the development of the Strategy. • Flood Storage and Floodplain Utilisation (lower catchment area): this option was rejected as there is very little storage available adjacent to the River Hull in the lower catchment area through the city. • Storage using the Beverley & Barmston Drain and adjacent land (lower catchment area): this option was rejected as there is very little storage available adjacent to the River Hull in the lower catchment area through the city. • Barrier Rules amended: this option was rejected as the current Barrier rules are sufficient to prevent tidal surges propagating up the River Hull. • Old Howe diversion to North Sea (upper catchment area): this option was rejected as only a relatively small proportion of the total flow in the River Hull could be diverted along this course and only a small reduction in water levels could be achieved. • Minor Schemes, Development Control and Flood Warning: these will be taken forward alongside the final Strategy option and so are no longer included in the list of Strategy options. 4.3.2 Detailed options appraisal We investigated the options taken forward from the Outline Options Appraisal in more detail for each of the three catchment areas, using modelling to determine changes in flood extents and

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river water levels. Further options we rejected at this stage and those taken forward are listed below. Options rejected • Defence Realignment (all catchment areas): this option was rejected as only a small reduction in flood levels could be achieved and the cost of this option would be very high. • Channel Diversion (lower and middle catchment areas): this option was rejected in the lower catchment area as it would have very little impact on water levels upstream of the city and there is only a small residual flood risk with the existing flood defences from the River Hull through the city so it would not be possible to justify a new diversion channel. This option was rejected in the middle catchment because there is not sufficient gradient to enable a ‘non- embanked’ channel to effectively convey flows to the Humber. Options taken forward • Do Nothing (all catchment areas): this has to be included to assess the benefits of doing something above this baseline. • Defences -maintain, sustain and improve (all catchment areas) • Flood Storage (middle and upper catchment areas) • Storage using Holderness Drain and the adjacent land (lower and middle catchment areas) • Channel diversion to Holderness Drain • Storage using Beverley & Barmston Drain and the adjacent land (middle catchment area) • Impoundment/Tidal Exclusion (lower catchment area) 4.3.3 Combinations appraisal We considered the options taken forward for the three catchment areas in combination (for example, maintain defences in the upper catchment area, storage in the middle catchment area and sustain defences in the lower catchment area), to investigate possible Strategy solutions, using modelling to look at flood extents and river water levels. Some combinations were rejected and others taken forward as possible Strategy solutions. Combinations rejected • Storage using Holderness Drain via by-pass channel (middle catchment area): this option was rejected as it would be expensive to construct and would not provide significant additional benefit compared to other options. • Storage combinations (middle catchment area): this option was rejected as combining storage options in the middle area has little flood risk benefit over just one storage option in the middle area. • Storage using Holderness Drain (lower catchment area) with Storage options (middle catchment area): the main benefit of the Storage using Holderness Drain (lower catchment area) option is an assumed defence that protects the Bransholme area from flooding. However, the necessity or size of any defence in this location to reduce the risk of flooding to Bransholme is linked to the pumping capacity of East Hull Pumping Station. As we are currently progressing a scheme which looks at the long term pumping facility at East Hull, this element of the strategy is being developed in conjunction with this work. Combinations taken forward • Solution 1- Do Nothing • Solution 2- Flood Defences (maintain/sustain/improve) in all catchment areas • Solution 3- Flood Defences and Floodplain Storage in the middle catchment area

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• Solution 4- Flood Defences and Storage using the Beverley and Barmston Drain in the middle catchment area • Solution 5- Flood Defences and Floodplain Storage in the upper catchment area Following these combinations taken forward, storage using the Beverley and Barmston Drain and storage in the upper catchment (solutions 4 and 5) were rejected in favour of the potential flood storage area at Leven Carrs in the middle catchment (solution 3). The potential flood storage area at Leven Carrs in the middle catchment (solution 3) was selected for the following reasons and potential benefits: • It provides the largest volume of flood storage and the land is currently low lying and floods regularly (even in small floods). • As it is the largest area it provides the greatest flood risk benefit by reducing water levels in the River Hull. This would have the benefit of reducing the pressure on the defences and therefore a reduced maintenance regime would be anticipated. This is difficult to quantify and has not been included in the economics. • Reduced water levels in the River Hull during floods increases the standard of protection of the existing defences, allowing for climate change and therefore risk of overtopping of the River Hull defences is reduced. • Across the catchment as a whole, there would be a reduction in flooded agricultural land. • There are opportunities for biodiversity enhancements, which would contribute to local biodiversity action plan targets. For example, carr land could be restored to the site and environmental benefits could be included within the economic case. • There is potential for improved recreational facilities on the site, including foot and cycle paths. The options appraisal progressed concentrating on solutions 1, 2 and 3 (Do Nothing, Flood Defences and Flood Defences with Flood Storage in the middle catchment). We reviewed costs against flood risk benefits of other assets (not just flood banks), which highlighted the high costs associated with maintaining and refurbishing our pumping stations. As a result, we further investigated the pumping stations detailed in section 4.3.5. Refer to the Options Appraisal Report (Appendix A) for further information and the economic assessment of these solutions. 4.3.4 Optimisation Optimisation is a process that is carried out to determine the most cost-effective standard of protection and hence defence height to build or maintain a defence. We carried out optimisation on the height of the flood defences for the two short listed solutions taken forward, i.e. Solutions 2: Flood Defences and Solution 3: Flood Defences with Flood Storage in the middle catchment. Optimisation was carried in each of the three catchment areas individually with varying Standards of Defence (SoP) in each of the areas. For the lower catchment area the SoPs considered were: • 1%, 0.5% 0.33%. For the middle catchment area the SoPs considered were: • 50%, 20%, 10%, 5%, 2%, 1.33%, 1% and 0.5%. For the upper catchment area the Do Nothing and Maintain options were considered. Results showed that the SoP considered in the lower catchment has minimal impact on river water levels and flood extents as there is very little variation in maximum water level between return periods and therefore very little variation in defence levels between SoPs in the lower catchment.

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The benefit cost ratio for continued maintenance of the lower catchment area defences was 143 and therefore clearly justifiable. In the middle catchment area results showed that the SoP had a large impact on river water levels but very little impact on flood extents as most flooding comes from the low level drainage system in this area. As the SoP in the middle catchment has virtually no impact on flooding, and because the costs of raising defences was significant, the optimum SoP for the middle catchment for both types of Strategy option is low. Maintaining the existing low SoP in the middle catchment area returned the highest benefit cost ratio of 5. A higher standard of protection did not have an incremental benefit cost ratio above 1. Due to the lack of flood risk benefits in the upper catchment, only routine or reduced maintenance of the defences can be economically justified. Optimisation showed that the cost of routine maintenance would be almost equal to the benefits, i.e. have a unity cost benefit ratio. This highlighted that it would be difficult to obtain future funding to repair or rebuild these defences. 4.3.5 Pumping station appraisal We considered the optimum combination of pumping arrangements for the catchment. This involved assessing the flood risk and economic impacts of maintaining, deactivating or removing individual pumping stations as well as combinations of pumping stations. The impact of maintaining, deactivating or removing individual pumping stations was assessed for both the existing situation, taken to be Strategy Option 2: Maintain, and Strategy Option 3: Flood Defences and Storage in the middle catchment area. The following pumping stations were assessed: • Hempholme (pumps Roam Drain & Mickley Dike) • Wilfholme (pumps Beverley & Barmston Drain into River Hull) • Tickton (in-line pump on Holderness Drain) • Great Culvert (in-line pump on Holderness Drain) • East Hull (overpumps Holderness Drain into the Humber) In addition to individual pumping stations’ deactivation or removal, the impact of deactivating combinations of pumping stations was also assessed. The combinations assessed were as follows: • Combination 1: deactivate Hempholme and Wilfholme, maintain Tickton and Great Culvert. • Combination 2: remove Tickton and Great Culvert, maintain Hempholme and Wilfholme. • Combination 3: deactivate Hempholme and Wilfholme and remove Tickton and Great Culvert. The economic analysis of this appraisal showed that the benefit cost ratio for most of the pumps was less than unity. This can be seen in Table 4.2 and Table 4.3. The only pumping station that was shown to be economically justifiable was East Hull. Table 4.2 Benefit cost ratio for pumping station appraisal in the maintain option

Pumping Great Hempholme Wilfholme Tickton East Hull Station Culvert BCR 0.32 0.02 0.47 0.00 25.62

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Table 4.3 Benefit cost ratio for pumping station combinations appraisal in the maintain option

Pumping Combo 1 Combo 2 Combo 3 Station BCR 0.10 0.00 0.00

Further development of the strategy (as discussed in the following sections) further investigated operation of these pumping stations. It was identified that there would be justification for the continued operation of Great Culvert pumping station because of the way in which Great Culvert was designed. Holderness Drain and Monk Dike have been modified to operate with Great Culvert pumping station. Removing the pumping station would cause the raised water level of Monk Dike to cause reverse flow up Holderness Drain during flood events, thereby increasing flood risk upstream of Great Culvert. The continued operation of the other three pumping stations (Hempholme, Wilfholme and Tickton) continues to remain uneconomically justifiable with a cost benefit ratio of only 0.1 in the maintain scenario. This is explained further in Section 4.5 and the Options Appraisal Report in Appendix A. 4.3.6 Further consultation and technical development At this point in our assessment we held a series of drop-ins and presented our findings to the public. There was a high level of concern in our draft findings and we have subsequently been carrying out the following work: • Refining agricultural damages – the methodology was revised to consider the effects of the reduced land drainage. This included consideration of reduced agricultural productivity and updated agricultural land value. The land value used was taken from the Royal Institution of Chartered Surveyors (RICS) farmland market survey H1 2008 for farmland in Yorkshire and Humberside with arable land valued at £14,827/ha and pasture land valued at £12,356/ha. These values have been reviewed thoroughout this period and land values for H2 2009 have fallen with arable land valued at £13,591/ha and pasture land valued at £9,884/ha. Owing to current the economic climate and the likelihood that the prices will return to the 2008 values in the short term the values were not reduced in the economic assessment. • Sensitivity checks on damages to make sure our findings are correct. For pumping stations to reach a unity cost benefit ratio (i.e. the cost of keeping the pumps would be equal to the benefits they provide) overall damages would need to increase by a factor of 9 (i.e. nine times the calculated damage). • Assessment of drainage margins to ensure full effects of reduced pumping are considered. This included identifying the areas of land that would be affected if pumps were removed and / or reducing or stopping maintenance on upper catchment area defences. • Sophisticated analysis of land drainage benefits to inform our work and future discussions with others • Raised the profile of the issues we have found internally within the organisation to ensure that our policies are correct. • Gained additional information regarding extra flow paths (e.g. culverts under roads) during consultation and follow up work with IDBs and flood action groups. • Refined the model to increase linkages across the catchment areas • Updated economic analysis with the latest model results

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• Carried out a further, more detailed analysis of the impact of the flood banks breaching on the Hull Headwaters SSSI. • Held more detailed discussions with our professional partners • Held various meetings with local flood action groups to understand their concerns and share our technical work. • Carried out a detailed assessment of various combinations of our current maintenance activities across the upper and middle catchment areas to enable us to identify the best way to target our funding in these areas to maximise the flood risk benefit to the communities. Following technical development of the Strategy and work carried out between the project team and various local groups a number of negative impacts of storage at Leven Carrs (solution 3) were identified. • Locally there would be an increased risk of flooding to some properties. • Access to flooded properties would be affected. • We would either have to compulsory purchase the properties in the storage area where flooding was increased, or pay out compensation. • The option was hugely unpopular in the local area. • Locally there would be an increase in flooded agricultural land. This is mostly grade 3 with some grade 2 and 4 land. • The storage area effectively moves water from the Beverley and Barmston drain catchment to the Holderness drain catchment and changes the implications of flood risk accordingly. • The storage area would fall under the Reservoirs Act so the costs of it’s design and construction would increase. It’s potential failure may also increase the risk to life or property. Whilst it would be possible to mitigate against the local increase in flood risk it would be at an increased cost. Due to the combination of an increased local flood risk, a reduced economic case and the level of public opposition it was decided not to develop this option further and it was rejected as a Strategy option. 4.3.7 What does this mean for the Hull Catchment? This means that almost all the people and property and a significant amount of land will continue to have the risk of flooding much reduced from the River Hull system, now and in the future. However, we are also faced with some challenges. In the longer term we will be unable to use our funding to manage the defences in the upper catchment and several of the pumping stations in the middle catchment. This means there is a need to secure alternative funding to continue their operation. Without this there would be a major impact on the farmers whose land will be affected, on the small number of people whose property will be affected, and as a result on the wider local community. This is an issue we cannot address on our own, so we are proposing to set up a group with partner organisations and local communities to examine the implications and explore possible ways of dealing with it. The group will be able to draw on the experience of a similar group we have set up to look at flood risk to the east of Hull (the East of Hull Liaison Panel), where we have similar problems and are working with others to resolve them. We will take the lead in establishing the group and support it during its lifetime. We expect the group to review the operation and importance of the assets in question and explore alternative funding or ownership options if appropriate. This will be a clearly defined action from our strategy and we are already starting work on it. We will accept the groups findings provided they are consistent with our national and regional obligations (including the flood defence funding criteria), and will do all we can to ensure they are implemented satisfactorily. In order to allow time for this important planning exercise, we will commit to all necessary maintenance up to five years to keep our assets operational.

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4.4 Strategy elements and final options

Whilst we are committed to work with others to find an alternative funding solutions where we are unable to attract flood risk funding for all of our existing operations, we have had to carry out a further, more detailed assessment to clarify where it is possible for us to attract funding. This section details our approach to this and it has enabled us to maximise our investment and target it where we understand the affects on flood risk are greatest. In order to do this we have had to assess the implications of some of our assets being deactivated or removed. However, it must be re-emphasised that this is not our intention or strategy.

Through the development of the Strategy, it has become clear that no single option provides acceptable flood risk management. The reality is that a number of Strategy elements, which may change over time, will be combined to provide a Strategy option. These Strategy elements are described in the Options Appraisal Report in Appendix A. Although discrete Strategy elements have been identified, these need to be assessed in likely combination, due to the linkages present in the catchment, to properly identify the effects. The technical appraisal of Strategy elements was carried out on both a catchment area basis and for the whole catchment. The SEA considered individual Strategy elements within the upper, middle and lower areas of the catchment. Economic appraisal was carried out on the whole catchment and further split between the lower catchment area and the middle and upper catchment areas combined. The catchment was spilt this way because the Strategy elements in the middle and upper catchment areas have a direct affect in other parts of this wider catchment although not necessarily on the catchment area in which they are implemented. For example, reducing or stopping maintenance in the upper catchment can result in increased flooding in the Orchard Park area in Hull for certain combinations of the strategy elements. For this reason, the area around Orchard Park was included in the middle and upper catchment area. The following sections present information for each of the Strategy element combinations, i.e. Strategy options. The information in the following sections further describes the options, the effect they have on flood risk and recommendations / risk of implementing them as options. A summary of the economic analysis is included in Section 4.5 and a summary of the environmental impact is included in Section 4.6. For a more detailed description, including the technical viability, of the options refer to the Options Appraisal Report in Appendix A.

Table 4.4 Summary of Strategy options (combinations of Strategy elements)

Option Number Option Description

1 Do Nothing

Maintain defences in middle and upper catchment, sustain defences in lower 2 catchment and reduce or stop pumping station operation in the middle catchment.

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Option Number Option Description

Maintain defences in middle and upper catchment, sustain defences in lower 3 catchment and maintain pumping station operation in the middle catchment.

Reduce or stop maintenance of defences in upper catchment, maintain defences 4 in middle catchment, sustain defences in lower catchment, reduce or stop pumping station operation in the middle catchment.

Reduce or stop maintenance of defences in upper catchment, maintain defences in middle catchment, sustain defences in lower catchment and part reduce or 5 stop pumping station operation in the middle catchment (maintaining Great Culvert and Wilfholme).

Reduce or stop maintenance of defences in upper catchment, maintain defences 6 in middle catchment, sustain defences in lower catchment and maintain pumping station operation in the middle catchment.

4.4.1 Option 1 – Do Nothing Description By ‘Do Nothing’ in the whole catchment we mean that no further flood defence works would be carried out anywhere. We would not build any new defences and maintenance of our existing flood defences and the river corridor would cease. We would not give flood warnings. No work would be undertaken to address the impacts of flooding, including increased flooding due to future climate change. Option assessment There would be a major increase in flood risk resulting in the majority of the City of Hull becoming uninhabitable. Over 94,000 existing properties would be flooded from a 1 in 100 year (1% AEP) flood in future climate conditions (i.e. in 100 years time). ‘Do Nothing’ is not an acceptable option to manage the flood risk across the study area. However, we are required to compare the benefits and costs of the other options against it. In view of this we did not assess risks for this option

4.4.2 Option 2 – Maintain defences in middle and upper catchment, sustain defences in lower catchment and reduce or stop pumping station operation in the middle catchment Description Existing routine maintenance activities such as grass cutting, weed cutting & vermin control would continue into the future for all defences throughout the catchment. A programme of capital works would also be developed, repairing and replacing existing defences into the future. This programme of capital works would ensure the integrity of the defences in the middle and upper catchment, maintaining the existing defence height. In addition to maintaining the integrity of the defences in the lower catchment, the defence level would be periodically increased to ensure the standard of protection is maintained to accommodate the effects of climate change. Pumping stations in the middle catchment, i.e. Hempholme, Wilfholme and Tickton, would continue to be operated and maintained for a 5 year period whilst discussions into their future funding and

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operation take place. We will not continue to operate and fund these pumping stations after 5 years. Great Culvert pumping station, which is in the lower catchment, would continue to be operated into the future. This will include replacement of electrical and mechanical components within the initial years and an extensive refurbishment or rebuild at the end of the stations estimated 60 year design life, (year 2027). Option assessment This scenario substantially reduces flood risk when compared to the Do Nothing scenario. The vast majority of residential and commercial properties are protected from flooding as are large areas of agricultural land. Refer to Figure A9 in Appendix A showing the flood extent for this option. There would still be flooding in the North Frodingham Carrs area and in the low lying areas adjacent to Beverley and Barmston Drain and around the River Hull headwaters. The Leven Carrs area would also flood naturally and more frequently because it is such a low lying area. All of this flooding would occur from a low order event, e.g. 50% flood. During a high order event, e.g. 1% flood, there would be increased flooding to agricultural land. Areas downstream of Tickton, around Dunswell and Orchard Park and near Bransholme would also be at flood risk. The flooding around Bransholme will be alleviated by the East Hull Pumping Station project. This project may either increase pumping into the estuary thereby reducing water levels in Holderness Drain or provide an embankment protecting the houses at Bransholme (or a combination of these factors). The pumping stations largely have land drainage rather than flood risk benefit. If operation of the pumping stations cease there will be an increase in agricultural flooding. The overall area affected is largely already prone to flooding, but flooding would be seen more frequently and the duration would be for longer. The area of agricultural land affected by poor drainage will also increase because some areas of low lying land will be unable to drain adequately to support agricultural production. Refer to the Options Appraisal Report in Appendix A for further information. Maintaining the defences in the middle and upper catchment to their existing defence height will provide a flood defence into the future. The current standard of defence will, however, reduce owing to the effect climate change will have on increasing sea levels and river flows. This option allows an initial period of 5 years in which the pumping stations will be run. During this period discussions with land owners, IDBs and other concerned parties would take place to discuss the long term future of the pumping stations.

4.4.3 Option 3 – Maintain defences in middle and upper catchment, sustain defences in lower catchment and maintain pumping station operation in the middle catchment Description Maintenance to the defences both routine and capital works would continue the same as Option 2. All existing pumping stations, Hempholme, Wilfholme, Tickton and Great Culvert would continue to operate into the future. This would include replacement and refurbishment of electrical and mechanical components within the initial years of the strategy. At the end of the pumping station’s design life of 60 years they would be extensively refurbished or replaced. The year this would be necessary varies with pumping station as follows; Hempholme reaches its 60 year design life in 2030, Wilfholme in 2039, Tickton in 2030 and Great Culvert in 2027. Option assessment The flood risk for this option is similar to Option 2 and also substantially reduces flood risk when compared to the Do Nothing option. With reference to Figure A10, Appendix A it can be seen that

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the continued operation of Tickton pumping station would provide a small additional reduction of agricultural flooding in the Leven Carrs area (compared to Option 2) although would increase the flood risk downstream of Tickton as a result. The continued operation of Hempholme pumping station would reduce flooding in the North Frodingham Carrs area during the lower order flood events and high winter baseflow conditions. During higher order flood events the additional pumps provide little flood risk benefit. This is currently not an acceptable long term management approach for us, as the artificially pumped drainage is not cost beneficial and offers little flood risk benefit. This would not enable us to qualify for flood risk funding for future operation and maintenance of all of these assets.

4.4.4 Option 4 – Reduce or stop maintenance of defences in upper catchment, maintain defences in middle catchment, sustain defences in lower catchment, reduce or stop pumping station operation in the middle catchment Description This option is the same as Option 2 in relation to the regime on the lower and middle catchment. The upper catchment would see all existing routine maintenance such as grass cutting, weed cutting & vermin control as well as higher cost capital expenditure of periodic repairs to defences reduced or stopped. Reducing or stoppping maintenance in the upper catchment would result in the defences deteriorating over time and flow reducing in the channel owing to increased weed growth during the summer months. Eventually breaches would form in existing defences which would result in out of channel flows into the adjacent low lying areas. Any breaches of the defences would not be repaired. Flows from breaches would form an alternative flow path into the existing low lying Beverley and Barmston Drain. The increased flow in this drain would result in an increased downstream flood risk in the Dunswell and Orchard Park area. The management of the pumping stations would be the same as Option 2. Option assessment This option increases the downstream flood risk which would affect a significant number of properties in the Orchard Park / Dunswell areas, as can be seen in Figure A11, Appendix A. There are, however, a number of possible localised sub-options that would reduce this flood risk and would need to be further considered if this option were to be implemented. There would be additional flooding around the headwaters in the upper catchment, around North Frodingham Carrs, Watton Carrs and Arram Carrs when breaches form in the upper catchment area embankments. Simply stopping maintenance of all of the banks in the upper catchment is not practical due to the local impact. However, as there is relatively small amount of flood risk benefit associated with many of the banks, we will not be able to qualify for flood risk funding for all of these defences into the future. We would need to work with affected parties to determine a more efficient approach to the management of the defences in the upper catchment area.

4.4.5 Option 5 - Reduce or stop maintenance of defences in upper catchment, maintain defences in middle catchment, sustain defences in lower catchment and part reduce or stop pumping station operation in the middle catchment (maintaining Great Culvert and Wilfholme) Description This option is a development of Option 4 with the addition of continued long-term operation of Wilfholme pumping station in the middle catchment. Wilfholme would provide continued pumping

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of the Beverley and Barmstom drain into the River Hull and Great Culvert would continue to lift the low level Holderness Drain at the confluence with Monk Dike thus maintaining a continued downstream flow. Option assessment Wilfholme pumping station would reduce the downstream flood risk, though due to the increased flows in the Beverley and Barmston drain it would be required to work more frequently than it currently does. This would result in increased operational costs such as electricity and would also increase the maintenance demand on the asset. The impacts of climate change will increase water levels in the River Hull which will reduce the frequency that Wilfholme can operate. This is because Wilfholme cuts out when the River Hull levels reach a predetermined ‘cut out’ level to prevent the pumped flows from overtopping the River Hull defences. This will mean that in the future the effectiveness of Wilfholme to reduce downstream flooding whilst located at its current position will be reduced and future flooding of the Dunswell and Orchard park area will increase. This can be seen in Figure A12, Appendix A. Future sub-options would therefore be required to reduce the downstream flood risk to Orchard Park before the effects of climate change are realised. The upper catchment defences are not cost beneficial when the additional cost of maintaining them is compared against the additional benefit they provide. We would need to work with affected parties to determine a more efficient approach to the management of the defences in the upper catchment area.

4.4.6 Option 6 – Reduce or stop maintenance of defences in upper catchment, maintain defences in middle catchment, sustain defences in lower catchment and maintain pumping station operation in the middle catchment Description This option will apply the same proposed management to the river defences as in Options 4 and 5, however, all the existing pumping stations, Hempholme, Wilfholme, Tickton and Great Culvert would continue to operate into the future. This will include replacement and refurbishment of electrical and mechanical components in the initial years of the strategy (within 5 years). Additionally, as would be the case in Option 3 the pumping stations would be removed and replaced at the end of their 60 year design life. Option assessment The continued operation of Hempholme and Tickton pumping stations has the effect of reducing the extent of flooding during high winter baseflow around the North Frodingham area (when compared to Options 4 and 5). The extent of flooding in Leven Carrs would be reduced, however there would be increased flooding south of Tickton compared to Option 5, as can be seen in Figure A13, Appendix A. These effects are more pronounced when the effects of climate change are considered. The extent of flooding in Frodingham Carrs during day to day average flows and low order events is reduced slightly owing to the effect of Hempholme operating. During higher order flood events the additional pumps provide little, if any, flood risk benefit. This option is not viable for us as the additional pumps and the associated cost when compared to Option 5 do not provide the additional benefit necessary for us to obtain funding.

4.5 Summary of economics The options have been analysed against a range of flood events with varying probability of occurrence, i.e. 1 in 2 years (50%), 1 in 5 years (20%), 1 in 10 years (10%), 1 in 25 years (4%), 1 in 50 years (2%), 1 in 75 years (1.33%), 1 in 100 years (1%) and 1 in 200 years (0.5%). The flood

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damages for all of these flood events have been analysed for each option under both the present climate and in the future climate in 100 years time where increased river flows and sea level rise have been taken into consideration. Economic analysis has been used to assess the economic viability of improving flood defence in the strategy area in accordance with Defra guidance in FCDPAG3 and subsequent updates. Flood damages have been presented as present value (PV) damages in accordance with this guidance (refer to Appendix A – Options Appraisal Report for further information). Key facts

• Maintenance and sustaining the lower catchment area defences returns a high benefit cost ratio of 105. • WIlfholme, Hempholme and Tickton pumping stations cost £12 million to operate and maintain and only return £1.2 million of benefits if defences are maintained (over the next 100 years). This is a benefit cost ratio of 0.1. • Maintenance of the defences in the upper catchment area would cost over £62 million and return approximately £11.6 million of benefits if the pumping stations were maintained. This is a benefit cost ratio of 0.2.

• Parts of the upper catchment area river corridor are protected by a SSSI designation.

Table 4.5 presents the flood damages for all options for the catchment when considered as a whole. It can be seen that there are substantial damages from the baseline Do Nothing scenario (i.e. Option 1) of almost £8.5 billion. This high damage value would be reduced to approximately £62 million under Option 2. The PV cost of implementing this option over the whole catchment is approximately £217 million. Residual damages would be further reduced in Option 3 to approximately £61 million, i.e. a further reduction of £1.2 million compared to Option 1. However, in order to achieve this £1.2 million reduction an additional cost of almost £12 million would need to be spent. It can be seen that the £1.2 million relates primarily to agricultural damage. From these figures it can be clearly seen it would not be justifiable to spend £12 million of public funds to protect an additional £1.2 million of agricultural land. Table 4.5 Summary of economic damages (Whole Catchment) 12 Total Damages Residential Commercial Agricultural Option (PV £) Damages (PV £) Damages (PV £) Damages (PV £)

1 8,453,020,216 7,410,375,267 909,050,865 133,594,084

2 62,227,248 49,309,948 43,739 12,873,560

3 60,985,563 49,328,313 34,317 11,622,932

4 358,008,767 310,937,694 4,388,897 42,682,176

5 78,515,872 55,657,457 539,328 22,319,086

12 Flood damages shown do not include social equity weighting factors. Social equity weighting factors increase damages for the upper and middle catchment by 1% and damages in the lower catchment by 10%.

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Total Damages Residential Commercial Agricultural Option (PV £) Damages (PV £) Damages (PV £) Damages (PV £)

6 71,981,734 50,996,572 542,184 20,422,978

When the catchment areas are considered separately the difference in flood damages between the options can be seen more clearly. The reduction in agricultural damage between Option 2 and Option 3 is primarily experienced in the upper and middle catchment areas. This can be seen in Error! Reference source not found. . It is worth noting that because the catchment is so flat and interconnected the catchment areas have to remain very large to reflect how flooding mechanisms occur. This means that the benefits are high given that such large areas have to be considered together. This is why our assessment work moves towards a review of incremental cost benefit ratios, rather than the consideration of benefit cost ratios of individual elements of the catchment. This is in accordance with Appraisal Guidance. The economic case for the three pumping stations can be demonstrated by comparing Options 2 and 3 and is summarised as follows: • The PV cost of Option 2 in the middle and upper catchment areas would be approximately £146 million, • The PV cost of Option 3 in the middle and upper catchment areas would be approximately £158 million. • The additional £12 million cost between the two options is for the continued operation of the three pumping stations (Hempholme, Wilfholme and Tickton). The cost includes refurbishment in the first 5 years, replacement at the end of their asset life (in approximately 20 years time) and annual operation and maintenance costs over 100 years. • The pumping stations would provide an additional £1.2 million of benefit compared to Option 2. • The Benefit Cost Ratio (BCR) for Option 2 is 11 and Option 3 has a BCR of 10. • The incremental cost benefit ratio between Option 2 and Option 3 is 0.1. As explained in Section 4.1.3 this means Option 3 is not economically justifiable above Option 2, i.e. a £12 million cost is not justifiable for a benefit of £1.2 million. Whilst the pumping stations are not likely to attract flood risk funding in the future, we are committed to maintaining them for a five year period whilst we lead a group, made up of our professional partners and members of the community, to review alternative ways of managing or funding these assets. Similarly, the economic case for the defences in the upper catchment area only can be demonstrated by comparing Option 3 against Option 6. This is summarised as follows: • Option 3 would see continued maintenance of defences in the upper and middle catchment areas. The PV cost of this option would be approximately £158 million. • Option 6 would see only the continued maintenance of defences in the middle catchment area. The PV cost of this option would be approximately £96 million. • Both options would have all pumping stations operational. • The BCR of Option 6 is 17 • The incremental BCR of Option 3 above Option 6 would be only 0.2. • On the basis of the low incremental BCR (i.e. less than unity) Option 6 would be the preferred of the two options, however, this option would result in a significant and unacceptable increase in residual damages (particularly residential damage).

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• Parts of the River Hull in the upper catchment area are designated as a Site of Specialist Scientific Interest (SSSI). There is a statutory requirement on the Environment Agency not to worsen a site with such a designation. Reducing or stopping maintenance on the defences could worsen this site. • Due to the economic case it is the long term aim to move away from the long term demands of maintaining the upper catchment defences. This will involve working with others (such as land owners and Natural England) and establish a reduced maintenance requirement whilst not increasing flood risk or adversely affecting the SSSI. From economic analysis it has been established that neither operating the three pumping stations nor the defences in the upper catchment are incrementally cost beneficial. The next logical step is therefore to compare a combination of these options, i.e. reducing or stopping maintenance of the upper defences and removing the three pumping stations. This is done in Option 4. It can, however, be seen that the combination of reduced or stopped pumping and reduced or stopped maintenance of the upper defences has a worse effect than just the sum of the damage increase from reducing or stopping maintenance of the upper defences or removing the three pumping stations (i.e. the damages from Option 4 is significantly worse than adding the residual damages of both Options 2 and 5). Option 4 would: • Result in a residual damage of approximately £309 million an increase of almost £300 million compared to Option 2. • The cost of this option is £83 million, • The BCR is 16. • The incremental BCR for Option 2 compared to Option 4 is almost 5. The BCR is high because of the large reduction in damages compared to the Do Nothing option (Option 1) at a low cost, however, with such a high residual damage this option is not acceptable at managing flood risk.

Table 4.6 Summary of economic damages (upper and middle catchment areas only) 12 Total Damages Residential Commercial Agricultural Option (PV £) Damages (PV £) Damages (PV £) Damages (PV £)

1 1,632,588,138 1,446,194,426 83,646,511 102,747,200

2 13,304,772 1,165,220 43,739 12,095,813

3 11,937,273 1,052,065 34,006 10,851,201

4 308,606,544 263,323,025 4,388,897 40,894,623

5 28,823,860 6,758,926 539,328 21,525,606

6 23,444,750 3,224,661 542,184 19,677,905

It can be seen in Table 4.7 that the flood damages in the lower catchment area are very similar for all options (except the Do Nothing option). This is because all options have the same preferred management in the lower catchment, i.e. sustain defences. Consequently the cost of approximately £71 million is the same for all options in the lower catchment area. The BCR is high at 105 and means that the preferred option in this catchment area is economically justifiable. The difference in damages that do occur as are agricultural damages as a result of the option in the middle and upper catchment area, most noticeable in Option 4. The increase in damages for

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this option compared to the others (except Option 1) is because of the combination of reduce or stop maintenance in the upper catchment and removing Wilfholme pumping station which results in an increased downstream flow. The residual residential damages of approximately £48 million for Options 2 to 6 are in the Bransholme area and will be prevented by the East Hull Pumping Station project. Table 4.7 Summary of economic damages (lower catchment area only) 12 Opti Total Damages Residential Commercial Agricultural on (PV £) Damages (PV £) Damages (PV £) Damages (PV £) 1 6,820,432,078 5,964,180,841 825,404,354 30,846,884

2 48,922,475 48,144,728 0 777,747

3 49,048,290 48,276,248 311 771,731

4 49,402,223 47,614,669 0 1,787,553

5 49,692,012 48,898,532 0 793,480

6 48,536,984 47,771,911 0 765,073

4.6 Summary of Strategic Environmental Assessment We have assessed the strategic environmental impacts that the Strategy elements are likely to have on the environmental objectives we set, using professional judgement to reach our conclusions. This assessment is summarised here. SE1 - Reduce or stop Maintenance of Defences in the Upper Catchment If we stopped all maintenance, eventually existing defences would fail. This could allow water to flow from the river and flood surrounding land and enter the low level drains in the middle catchment. This might increase flood risk to properties (minor adverse impact); damage the River Hull Headwaters Site of Special Scientific interest (SSSI); and lead to increased flooding of larger areas of agricultural land than are currently affected (both major adverse impact). The negative impact on the SSSI reflects the potential effect on the objective to protect its condition, which is based on keeping the current SSSI designation (as an artificial system). However, in the longer term, this Strategy element could result in significant benefits for the SSSI, if it is closely linked with other management issues, such as putting into place the river restoration plan. Although our SEA reflects the worst case position in relation to agricultural land use, we will be actively pursuing alternative partnerships and funding sources for actions that could minimise the impact. This Strategy element has neutral effects on most of our other environmental objectives but could have a beneficial impact on sustainable land use (through the use of land for flood management and the creation of wetland), and in terms of helping to achieve the Water Framework Directive targets. This will only be applied where risks of not maintaining the defences are low. SE2 - Maintain Defences in Upper Catchment This Strategy element would mean that no additional properties would be at risk in the short-term, although a few could be affected in the long-term due to the effects of climate change. It also protects the current status of the River Hull Headwaters SSSI but does not help to improve its condition. However, overall, we have had to assess this element as having a moderate adverse impact on SSSIs due to the potential negative effects, directly or indirectly, on the Pulfin Bog SSSI. At this Strategy level, we cannot be sure what change may result, therefore, we have had to assume a worst case, which is that increased flooding has the potential to have a negative effect on the habitat types present. We have assessed the impacts of this element as neutral to all our other environmental objectives.

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SE3 - Maintain Defences in Middle Catchment with Pumping Stations Operating As this maintains the present conditions in the catchment, we have assessed this as being generally environmentally neutral. The only exception to this is the moderate adverse impact on the wetland habitats objective. Overall, we have had to conclude this due to the potential negative effects, directly or indirectly, on the Pulfin Bog SSSI, as explained for Strategy element 2 above. This Strategy element does not lead to any environmental improvements. Maintenance of the pumping stations can only be assured for the short-term. SE4 - Maintain Defences in Middle Catchment without Operation of Pumping Stations This Strategy element will prevent wide scale flooding from the river Hull (major benefit) in the short-term but without pumping stations there will be increased seasonal or permanent flooding of low lying areas (major adverse impact on agricultural land use objective due to larger areas being affected than at present) and additional properties would be at risk in the long-term due to the effects of climate change (moderate adverse impact on flood protection objective). It will have a moderate adverse impact on the wetland habitats objective due to the potential negative effects, directly or indirectly, on the Pulfin Bog SSSI, as explained for Strategy element 2 above. Although our SEA reflects the worst case position we will be actively pursuing alternative partnerships and funding sources for actions that could minimise the impacts. This Strategy element may provide minor benefit for sustainable land use (through creation of natural habitats), and will be largely neutral to Water framework Directive (WFD) objectives but may contribute to some actions needed to improve the condition of the pumped waterbodies. SE5 - Sustain Defences in Lower Catchment This approach keeps the existing level of protection from flooding to people, property and heritage features from increased flooding into the future. Defences will be repaired to improve their existing condition and will be improved as needed in the future so that flood risk to the city of Kingston upon Hull will not increase due to climate change (major benefit). However, in our assessment we have had to identify a moderate adverse impact for the flood protection objective as a result of the continued risk of flooding in the Bransholme area of Hull. We have recognised the need for a separate project at the East Hull Pumping Station (starting shortly), which will consider this impact. Depending on the preferred option chosen, there may be an improvement in flood protection for the whole of the Lower catchment, but we cannot reflect this at present as part the SEA for the Strategy. The effects on all other environmental objectives is neutral although we will look for benefits for recreation and natural habitats during the design of individual schemes arising from this Strategy element.

4.7 Impact of climate change The analysis involved assessing the performance of the preferred long-term Strategy option under the affects of a climate change scenario to better understand how flood risk could change in the future. For the purposes of this analysis we have looked at the scenario of being unable to find alternative sources of funding to continue maintaining the defences in the upper catchment, in which case Option 5 would be implemented in the long-term. Climate change is predicted to increase river flows and sea levels, which will increase the frequency and extent of flooding in the future. The recommended allowances for the increase in flows and sea level rise is given in Section 3.6.1. The result of these increases for the preferred long-term Strategy option are summarised below: Lower catchment area: The height of the River Hull defences will be sustained to prevent overtopping in the city both now and in the future. The Hull Tidal Surge Barrier will close more frequently in the future to prevent high tides and tidal surges from propagating up the River Hull thereby preventing the defences from being overtopped. Climate change will therefore not increase the flood risk from the River Hull to the city. Another project looking at the best way of providing pumping capacity at East Hull pumping station into the future will aim to mitigate any increase in flood risk from Holderness Drain in the lower catchment.

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Middle catchment area: Water levels in the River Hull will increase and overtopping will occur more frequently at some locations, though the main source of flooding in this area will still be from the drainage system backing up and not the river overtopping. The greatest increase in flood risk in the long-term will be in the Orchard Park and Dunswell areas, which will flood due to Beverley and Barmston Drain not being able to discharge as effectively due to the higher tidal level. In the future, we may develop local schemes in these areas or possibly relocate Wilfholme PS further downstream to reduce this predicted flood risk, though we predict that this won’t be needed until approximately 2055. The current and future flood risk to this area will be reviewed at regular intervals, particularly if updated climate change guidance is published. Upper catchment area: Climate change is predicted to increase river flows, thereby increasing water levels and the extent of flooding in the upper catchment. Increasing sea level will also have an impact during floods in the long-term as this will reduce the rate at which water can drain from parts of the upper catchment area. Climate change will cause the extent of flooding to increase in the North Frodingham Carrs area and adjacent to Roam Drain but will have much less impact elsewhere in the upper catchment area.

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5. Our Plan

This section states: • our proposed plan, including flood risk management measures, further studies and policy recommendations; and, • how we intend to implement our findings.

5.1 Introduction We have identified the extent of flood risk within the study area and appraised flood risk management measures for the River Hull catchment against technical, environmental and economic factors. This chapter sets out our proposed plan to manage flood risk in the River Hull catchment for the next 100 years. We aim to implement a number of projects, undertake further studies, engage with our external partners and commence construction of some of the options identified in the Strategy. It also covers our day to day activities of asset management, development control and the provision of flood warning. Overall, the Strategy will allow us to implement flood risk management for the River Hull catchment in a planned and holistic way. It will also help us make the most of opportunities for working with others, to achieve improvements for local people, economic regeneration and wildlife.

Our proposed Strategy We will continue to maintain and, in some areas, improve those flood banks, walls and other structures for which we are responsible and can obtain funding. This will involve an investment of £109 million over the next 20 years. We will continue to maintain the flood banks in the upper catchment for a period of up to five years while we work with East Riding of Yorkshire Council, Internal Drainage Boards, Natural England, landowners and others to develop a longer term plan for water level management in this area.

We will continue to operate and maintain the Hull Barrier and our pumping stations at East Hull and Great Culvert. This will include work such as the £10 million investment currently underway at the Hull Barrier.

We will work with Hull City Council and the owners of riverside land to develop a plan for repairing and improving the private defences beside the River Hull through the city. We will continue to maintain and operate our other pumping stations, Tickton, Hempholme and Wilfholme, for a period of up to five years while we work with the local authority, Internal Drainage Boards, landowners and others to find a longer term funding solution.

We will continue to maintain the flod banks in the upper catchments for a period of up to five yesrs while we work with East Riding of Yorkshire Council, Internal Drainage Boards, Natural England, landowners and other to develop a longer term plan for water level management in this area.

5.2 Proposed flood risk management measures Our Strategy recommends both strategic and local flood risk management measures. Strategic measures include the proposed management of the defences and pumping stations throughout the catchment, whereas an example of a local measure would be an embankment, or increased

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pumping at East Hull, to locally protect properties at Bransholme. Strategic measures benefit a wider flood risk area than local measures which reduce flood risk to people and property in the immediate area. 5.2.1 Strategic flood risk management measures We have identified non-structural measures which will provide strategic benefit for flood risk management in the River Hull catchment. These measures will contribute to an overall reduction in flood risk in addition to the preferred options identified during the options appraisal process. These measures could also provide opportunities for significant environmental and recreational enhancements of the catchment. • Control Development – we will continue liaison with local planning authorities to ensure that Planning Policy Statement 25 (Development and flood risk) is properly implemented. • Flood warning and flood forecasting improvements – we will continue to improve flood forecasting and the dissemination of warnings in the River Hull catchment to allow communities and landowners to be prepared for flooding and take appropriate action. We have identified a number of structural measures which will provide strategic benefit for flood risk management in the River Hull catchment into the future. These measures will ensure that 99,000 residential and commercial properties and 5,500 hectares of agricultural land will continue to be protected to a high standard against flooding from the River Hull System. • Existing flood defences – we will continue to maintain existing flood defences within the lower and middle catchment areas and in short term the upper catchment whilst we work with the local authority, Internal Drainage Coards, landowners and others to find a longer term solution. • The Hull Tidal Surge Barrier is currently undergoing a £10million investment which will ensure its continued reliability. We will continue to operate the barrier into the future and it will be operated more frequently as the effects of climate change are realised. • Pumping stations - We will continue to operate and maintain our pumping stations at East Hull and Great Culvert. We will continue to operate and maintain our other pumping stations for the first 5 years whilst we work with the local authority, Internal Drainage Boards, landowners and others to find a longer term funding solution. 5.2.2 Local flood risk management measures The risk of flooding from the Holderness Drain to properties in the Bransholme area is being reduced by the East Hull Pumping Station project. This project is already underway with an initial £ 0.9 million investment to refurbish the existing facility. The project will then look at the most efficient option of pumping and / or raised flood defences to further reduce risk for the future. We will consider the possibility of increasing the pumping capacity and of providing additional embankments.

5.3 Strategy action plan The principal findings of the River Hull Strategy are summarised below: • Lower Catchment – the number of people and properties at risk in Hull mean there is an overwhelming case for continuing to maintain and improve the flood defences in the lower catchment (including the Hull Barrier). Many of the defences beside the River Hull which are in private ownership are in poor condition. • Middle Catchment – we can definitely continue to maintain the flood banks and similar defences beside the River Hull. It is difficult, however, to justify funding to continue to operate and maintain all our land drainage pumping stations in this part of the system for flood risk management benefit, though we recognise that they are needed for land drainage purposes.

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• Upper Catchment – although we can continue to provide ongoing maintenance for the flood defences in the upper catchment, we will not be able to use our funding to carry out much needed improvements. Our plans for managing flood risk within the study area have been separated into the short term (i.e. the first five years) and the long term. 5.3.1 Short term (Years 1-5) Our proposed strategy is to implement Option 2, this would mean: • We will continue to maintain and, in some areas, improve those flood banks, walls and other structures for which we are responsible and can obtain funding. This will involve an investment of £109 million over the next 20 years. This will mean, by catchment area, we will: o Lower – continue to maintain, sustain and repair the existing defences ensuring the standard of protection continues into the future. o Middle catchment area – continue to maintain and repair existing defences to their existing standard of protection. o Upper catchment area – continue to maintain existing defences for a period of up to five years while we work with others (East Riding of Yorkshire Council, Internal Drainage Boards, Natural England, landowners and others) to find alternative sources of funding or identify an alternative and more economically viable maintenance programme for water level management in this area. • We will continue to operate and maintain the Hull Barrier and our pumping stations at East Hull and Great Culvert. This will include work such as the £10 million investment currently underway at the Hull Barrier • We will work with Hull City Council and the owners of riverside land to develop a plan for repairing and improving the private defences beside the River Hull through the city. In addition to the Agency’s powers to carry out flood defence works, the Kingston-upon-Hull Act 1984 gives Hull City Council certain powers to serve notices on the owners of land adjoining the River Hull requiring them to carry out works to prevent the overflow of the River Hull. If the landowner does not carry out the works the Council has the power to do the works itself and recover its costs from the landowner. As the management of this flood risk into the future is so important to us we will work closely with Hull City Council and the landowners so that collectively we can identify the works that are needed and draw up a plan for undertaking them. Where it is not possible to identify landowners or where the funds needed for the repairs are not available, we will work with the Council to ensure the city continues to be properly defended by identifying partnerships and funding sources to enable the necessary works to be carried out. • We will continue to maintain and operate our other pumping stations, Tickton, Hempholme and Wilfholme, for a period of up to five years while we work with the local authority, Internal Drainage Boards, landowners and others to find a longer term funding solution. • We will continue to maintain the flood banks in the upper catchment for a period of up to five years while we work with East Riding of Yorkshire Council, Internal Drainage Boards, Natural England, landowners and others to develop a longer term plan for water level management in this area. This will mean that almost all the people and property (99,000 properties) and around 5,500 ha of land will continue to be protected to a high standard against flooding from the River Hull system, now and in the future. The action plan for implementing this is summarised in table 5.1.

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Table 5.1 Short term action plan

Key actions Target completion date 1. We will continue to maintain and, in some areas, improve all flood banks, walls and other structures for which we are responsible and can obtain government funding.
Carry out regular maintenance as at present. Ongoing
Review findings of current national study on dredging, assess Autumn 2010 applicability to the River Hull system and implement as appropriate.
In the lower catchment area repair and improve defences, raising low Ongoing spots as necessary to continue to provide appropriate standard of protection now and in the future 2. We will continue to operate and maintain the Hull Barrier and our pumping stations at East Hull and Great Culvert.
Carry out regular operation and maintenance as at present. Ongoing
Complete current £10 million improvements to Hull Barrier. October 2010
Complete planned improvements to East Hull pumping station. Ongoing 3. We will establish and support a group representing the community and other local interests to review the future management of the remaining flood defences and pumping stations for which we are responsible and will continue to operate and maintain these assets until the review is completed.
Carry out regular operation and maintenance as at present. Up to Apr 2015
Establish community representative group (River Hull Liaison Panel). Dec 2010
Provide support to the RHLP as necessary for the review to be completed. Throughout 4. We will accept the findings of the review provided they are consistent with our national and regional funding and other policies, and will do all we can to help implement them.
Confirm we can accept the review findings. On completion of
Assist implementing the findings. review As necessary 5. We will work with Hull City Council and the owners of riverside land to develop a plan for repairing and improving the defences beside the River Hull through the city.
Strengthen relationships with Hull City Council and owners of riverside Dec 2010 land.
Develop detailed action plan for improving defences beside the River Apr 2011 Hull, identifying where works are needed urgently and setting out a programme for remaining works.
Determine who is responsible for undertaking the urgent works and Oct 2011 identifying sources of funding.
Start implementing the urgent works.
Start implementing the remainder of the plan, assigning responsibilities Apr 2012 and identifying sources of sources as necessary. Apr 2012 6. We will continue to improve our development control and flood warning
Continue to improve our development control to ensure that new Ongoing developments are not placed inappropriately
Continue to improve our flood warning within the catchment area, to Ongoing provide more accurate flood warning to people and property

5.3.2 Long term (Years 5-100) In the longer term we will be unable to use our funding to manage the all of the defences in the upper catchment and three of the pumping stations in the middle catchment. This means there is a need to secure alternative funding to continue their maintenance and operation. Without this there will be a major impact on the farmers whose land will be affected, on the small number of people whose property will be affected, and as a result on the wider local community. It is our long term aim to move away from the large long term maintenance demands of all of the upper catchment defences. We aim to work with other parties and identify how the current demand can be reduced. This may mean discontinuing the existing maintenance and allow defences to naturally deteriorate over time. Alternatively we may find a reduced maintenance regime on a reduced length of defences (compared to what is currently maintained) or works to

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alter the existing defences may prevent the downstream flood risk by keeping flows within the upper catchment defences. This is an issue we cannot address on our own, so we are proposing to set up a group with partner organisations and local communities to examine the implications and explore possible ways of dealing with it. The group will be able to draw on the experience of a similar group we have set up to look at flood risk to the east of Hull (the East of Hull Liaison Panel), where we have similar problems and are working with others to resolve them. We will take the lead in establishing the group and support it during its lifetime. We expect the group to review the operation and importance of the assets in question and explore alternative funding or ownership options if appropriate. This will be a clearly defined action from our strategy and we are already starting work on it. We will accept the group’s findings provided they are consistent with our national and regional obligations (including the flood defence funding criteria), and will do all we can to ensure they are implemented satisfactorily.

5.4 Procurement Strategy Funding requirements for our Strategy in the short term over the next 20 years are estimated to be £109 million. This figure assumes we will be able to work with Hull City Council and the riverside landowners to get funding for the third party defences through Kingston-upon-Hull. Repairs to these city defences may cost a further £60 million. Over the next 100 years, the costs are estimated to be £495 million. It is anticipated that the schemes would be funded by Defra Grant in Aid. However, external contributions should also be actively sought in the future. As the approval sum is in excess of £50M, this Strategy will require both Defra and Treasury approval. Once the Strategy is approved, it is recommended that the spend profile is incorporated in the national and regional long term plan for Flood Risk Management.

5.5 Strategy risks There are a number of risks associated with our preferred Strategy. We have identified these and summarised them in Table 5.2. Table 5.2 Strategy risks Risks associated with implementing the Strategy Health & Safety A residual flood risk to life always remains as flooding cannot be entirely eliminated in the catchment. Health & Safety risks during maintenance and repair activities. Technical Climate change effects are underestimated or overestimated. A cost-effective standard of protection cannot be maintained / sustained. Pumping stations failing before expected. Affects on agriculture are worse than predicted. Economic Availability of funds, and constraints on funding delaying implementation of the Strategy No alternative sources of funding found, preventing maintenance of defences in the upper catchment area and pumping stations. Residual damage to properties and land is greater than predicted. Difficulty of Hull CC in recovering costs through Kingston-upon- Hull Act. Environmental Uncertainty over impacts on Pulfin Bog and the Hull Headwaters SSSIs as a result of implementing the Strategy

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Risks associated with implementing the Strategy Local scale impacts identified through project EIA, which were not considered at strategy level. For example (but not limited to) impacts on protected species and listed buildings. Public/ Public expectations are not met through the Strategy Stakeholder Our relationship and reputation with the public and other organisations is damaged.

The implementation of detailed appraisals and strategic reviews coupled with our procedures and processes will ensure that these risks can be mitigated. Undertaking detailed appraisals will help us to obtain a better level of site specific information to ensure that the preferred measures are environmentally, technically and economic feasible. Regular strategic reviews will ensure that the Strategy can be updated as more information is obtained or as circumstances change.

5.6 Strategy review The Strategy is a live document and will be reviewed to take account of future changes in flood risk, national policy, legislation, funding availability and environmental issues. The review will be undertaken every 5 years, unless significant changes make it necessary to do the review sooner, or delay it. As part of a review, the priorities and timescales for our flood risk management measures will be re-evaluated, based on recently acquired information for example. As a result, our preferred programme of works will also be updated. In future reviews, we may need to extend the scope of the Strategy to include non-main river tributaries, local drainage and surface water flooding in response to Defra’s proposals for integrated urban drainage management and the possibility that we will oversee all forms of flooding in the future.

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Environment Agency – River Hull Flood Risk Management Strategy

Appendices

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Environment Agency – River Hull Flood Risk Management Strategy

Appendix A: Options Appraisal Report

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Environment Agency – River Hull Flood Risk Management Strategy

Appendix B: Environmental Report

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Would you like to find out more about us, or about your environment?

Then call us on 08708 506 506 (Mon-Fri 8-6) email [email protected] or visit our website www.environment-agency.gov.uk incident hotline 0800 80 70 60 (24hrs) floodline 0845 988 1188