Mersey Catchment Flood Management Plan Summary Report December 2009 managing flood risk We are the Environment Agency. It’s our job to look after your environment and make it a better place – for you, and for future generations. Your environment is the air you breathe, the water you drink and the ground you walk on. Working with business, Government and society as a whole, we are making your environment cleaner and healthier. The Environment Agency. Out there, making your environment a better place.

Published by:

Environment Agency Richard Fairclough House Road WA4 1HT Tel: 0870 8506506 Email: [email protected] www.environment-agency.gov.uk

© Environment Agency

All rights reserved. This document may be reproduced with prior permission of the Environment Agency. December 2009 Introduction

I am pleased to introduce our summary of the Mersey Estuary Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the Mersey Estuary catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years.

The Mersey Estuary CFMP is one of 77 CFMPs for have a 1% chance of flooding in any one year from rivers and . Through the CFMPs, we have (i.e. a 1% annual probability). We estimate that by 2100 assessed inland flood risk across all of England and approximately 25,000 properties will be at risk of river Wales for the first time. The CFMP considers all types of flooding. This is a 30% increase compared to the current inland flooding, from rivers, groundwater, surface water number at risk across the catchment. There is tidal flood and tidal flooding, but not flooding directly from the risk at several locations along the Mersey Estuary and sea (coastal flooding), which is covered by Shoreline around the , which can arise from high Management Plans (SMPs). Our coverage of surface water levels and from wave action, together with the and groundwater is however limited due to a lack of funnelling of water into the estuary from onshore winds. available information. We cannot reduce flood risk on our own, we will The role of CFMPs is to establish flood risk management therefore work closely with all our partners to improve policies which will deliver sustainable flood risk the co-ordination of flood risk activities and agree management for the long term. This is essential if we the most effective way to management flood risk in are to make the right investment decisions for the the future. To develop this plan and ensure social, future and to help prepare ourselves effectively for economic and environmental issues were taken the impact of climate change. We will use CFMPs to into account we worked with, and consulted help us target our limited resources where the risks many organisations. These included are greatest. Development Control Officers Group, Natural England, Defra, Warrington Borough Council, Wirral Borough This CFMP identifies flood risk management policies to Council, Ship Company, Natural assist all key decision makers in the catchment. It was England, NFU, English Heritage and United Utilities. produced through a wide consultation and appraisal process, however it is only the first step towards an This is a summary of the main CFMP document, if you integrated approach to Flood Risk Management. As we need to see the full document an electronic version all work together to achieve our objectives, we must can be obtained by emailing enquiries@environment- monitor and listen to each others progress, discuss agency.gov.uk or alternatively paper copies can be what has been achieved and consider where we may viewed at any of our offices in North West Region. need to review parts of the CFMP.

Urban areas at risk from significant river flooding in the Mersey Estuary catchment area include Warrington, , , St Helens and Hindley. In total Tony Dean across the catchment, approximately 19,000 properties Regional Director

Environment Agency Mersey Estuary Catchment Flood Management Plan 1 Contents

The purpose of a CFMP in managing flood risk 3

Catchment overview 4

Current and future flood risk 6

Future direction for flood risk management 10

Sub-areas 1 Glaze 12 2 Leigh (Atherton, Hindley, , and ) 13 3 St Helens (and Ashton-in-Makerfield) 14 4 Upper and Middle Sankey 15 5 Warrington (Lower Sankey, & Woolston) 16 6 and 18 7 Middle Mersey Estuary (Moss Side, Ince Banks, Knowsley) 20 8 Maritime Mersey (, Birkenhead) 22 9 () 24 10 ( & ) 26

Map of CFMP policies 28

2 Environment Agency Mersey Estuary Catchment Flood Management Plan The purpose of a CFMP in managing flood risk

CFMPs help us to understand the • Internal Drainage Board, water CFMPs aim to promote more scale and extent of flooding now companies and other utilities to sustainable approaches to managing and in the future, and set policies help plan their activities in the flood risk. The policies identified in for managing flood risk within the wider context of the catchment. the CFMP will be delivered through a catchment. CFMPs should be used combination of different approaches. • Transportation planners. to inform planning and decision Together with our partners, we making by key stakeholders such as: • Landowners, farmers and will implement these approaches land managers who manage through a range of delivery plans, • The Environment Agency, who will and operate land for projects and actions. use the plan to guide decisions agriculture, conservation on investment in further plans, The relationship between the CFMP, and amenity purposes. projects or actions. delivery plans, strategies, projects • The public and businesses to and actions is shown in figure 1. • Regional planning bodies and enhance their understanding local authorities who can use of flood risk and how it will the plan to inform spatial be managed. planning activities and emergency planning.

Figure 1 The relationship between CFMPs, delivery plans, projects and actions

Policy planning • CFMPs and Shoreline Management Plans. • Action plans define requirement for delivery plans, projects and actions.

Policy delivery plans (see note) Projects and actions • Influence spatial planning to reduce risk • Make sure our spending delivers the best and restore floodplains. possible outcomes. • Prepare for and manage floods • Focus on risk based targets, for example (including local Flood Warning plans). numbers of households at risk. • Managing assets. • Water level management plans. • Land management and habitat creation. Note: Some plans may not be led by us – we may • Surface water management plans. identify the need and encourage their development.

Environment Agency Mersey Estuary Catchment Flood Management Plan 3 Catchment overview

The Mersey Estuary CFMP area open areas of water and the end The catchment has been heavily covers the lowermost 800km² of of mining pumping has led to modified for industrial purposes, the Mersey catchment, including groundwater levels rising in some and this has affected the natural most of the Wirral, and tributaries locations, this could affect surface response of river flows. The north of the Manchester Ship runoff leading to increased flooding , which was Canal. The area extends from and a quicker response to rainfall. built for navigation, effectively in the east, through reduces fluvial flood risk through The major tributaries are the Warrington and St Helens, and Warrington. Rivers Birket and Glaze, Sankey, includes the Mersey Estuary at Ditton, Rivacre and Dibbinsdale The CFMP area includes 19 Sites Liverpool. Brooks. The flows of Special Scientific Interest Approximately 40% of the area is west through the area and enters (SSSIs) and the Mersey Estuary heavily urbanised. The catchment the at . Ramsar site. The CFMP considers is largely low lying with a few The Mersey is tidally influenced environmental opportunities and steeper areas in the headwaters of downstream from Howley Weir constraints with regards to future and Sankey Brook, and (Warrington). Sankey Brook, flood risk management. in parts of the Wirral. The response Ditton Brook and some smaller to rainfall is generally slow but watercourses have a tidal influence is much faster for some of the in their lower reaches. smaller tributaries flowing through urbanised areas. Over 19,000 properties are at 1% risk of fluvial flooding, these include locations in Warrington, Wallasey, Birkenhead, St Helens, Hindley and Leigh.

Flood risk management is provided by channel maintenance, raised defences and other flood defence structures such as sluice gates and pumping stations, the Manchester Ship Canal and one flood storage basin.

Much of the CFMP area is underlain by the Permo-Triassic Sandstone aquifer which supports groundwater abstractions and is moderately unresponsive to rainfall events. Carboniferous coal measures underly the northern parts of the catchment. Mining River Mersey at Howley Weir, Warrington related subsidence has formed © Copyright Getmapping plc, supplied by Bluesky International Ltd

4 Environment Agency Mersey Estuary Catchment Flood Management Plan Map 1 Mersey Estuary CFMP - Main features

Environment Agency Mersey Estuary Catchment Flood Management Plan 5 Current and future flood risk

Overview of the current flood risk

Flood risk has two components: tributaries. Sankey Brook affects • Surface water flooding is caused the chance (probability) of a Warrington, St Helens, Ashton- by water collecting or flowing particular flood and the impact (or in-Makerfield and Rainford. over the surface before soaking consequence) that the flood would Leigh, Hindley Atherton and into the ground or entering have if it happened. The probability Westhoughton are affected by the a watercourse. This type of of a flood relates to the likelihood of River Glaze and its tributaries, flooding can occur throughout a flood of that size occurring within Birkenhead and Wallasey are the catchment but usually only a one year period, it is expressed affected by the River Birket/ causes a low level of risk. Our as a percentage. For example, Fender. Widnes and Prescott consultation showed that some a 1% flood has a 1% chance or are affected by Ditton Brook. of the urban areas of Liverpool, probability of occurring in any one There are a number of locations Warrington and Ashton in year, and a 0.5% flood has a 0.5% in the catchment where local Makerfield have high surface chance or probability of occurring in restrictions in the flow such as water flood risk, as do some any one year. The flood risks quoted a culvert or bridge or lack of areas on the Wirral. Further work in this report take account of flood channel capacity can lead to is required to investigate this defences, where they exist. flooding. Some flood events may type of flooding. be the result of the combined Historic flooding prompted flood • Sewer flooding is usually caused effects of different sources of risk management schemes at by inadequate sewer capacity or flooding. Warrington, Leigh and the Wirral. blockages within the network. Warrington was affected by tidal • Tidal flood risk exists at several Isolated sewer flooding affects flooding in 1990 (17 properties, locations along the Mersey various locations across the 8000m3 commercial floor space Estuary and around the Wirral catchment to some extent and a school) and to a lesser degree peninsula. The risk can arise but Hindley and are in 1998. Mining subsidence at from high water levels and understood to have a higher Leigh prompted the construction of from wave action, together incidence of sewer flooding Bedford Pumping station in 1943, with the funnelling of water problems. United Utilities have this has been upgraded in the into the estuary in certain an ongoing programme of work 1960s and 1980s. The Great Culvert wind directions. There are tidal to maintain and improve public and associated pumping station defences for many of the areas at sewers and are working with have historically reduced flood risk risk. There are areas where tidal the Environment Agency in from . Warrington has also flood risk combines with fluvial Warrington on this issue. benefited from the Manchester Ship flood risk on the lower reaches • A large proportion of the Mersey canal which, since its construction of the tributaries, and on the Estuary catchment lies upon a in the 1890s, has not suffered stretch of the Mersey between significant aquifer, which, in the fluvial flooding. Arpley Landfill Site and Woolston past, was pumped extensively for Weir in Warrington. Tidal flooding The main sources of flooding in the mining, water supply and other and coastal processes will be Mersey Estuary catchment are: industrial purposes. Groundwater assessed in the next Shoreline levels are rising in Liverpool • River flooding in this catchment Management Plan expected in and the Wirral and have caused is mainly from the Mersey’s 2010. problems for the underground

6 Environment Agency Mersey Estuary Catchment Flood Management Plan rail network, but in general, also been identified as an issue infrastructure items (substations, there is no known documented in several locations, including sewage and water treatment works, evidence of surface flooding Hindley, Prescot and Tyldesley. The schools, health centres, residential from groundwater in the Mersey risk from surface water and sewer homes, recreational assets, etc.) Estuary CFMP area. We consider sources is difficult to quantify, the The map overleaf illustrates where the current risk of flooding from CFMP includes recommendations the properties are at risk of flooding this source to be low compared to obtain a better understanding in a 1% annual probability event. to other sources of flooding. of these risks. In the CFMP area, We recognise the potential risk from significant assets at risk of flooding surface water and sewer flooding. (i.e., a 1% annual probability) Further studies, following on from What is at risk? include: 7km of motorways, 17km the CFMP, will be undertaken to of A roads and primary roads, quantify this potential risk. Using a broad-scale model and 18km of railways, and 256 other flood maps we estimate 19,000 properties in the catchment have a 1% chance of flooding in any one year from rivers (i.e., a 1% annual probability). There are six areas of Table 1. Locations of Towns and Villages with 100 or more properties SSSI, 28 local nature reserves and at risk in a 1% annual probability river flood 12 scheduled ancient monuments within the 1% annual probability Number of properties at risk Locations flood extent, some of which could be adversely affected by a flood. Over 5,000 Warrington and Sankey - In the Borough of Warrington

Where is the risk? 1,000 to 5,000 Hindley/Leigh - In the Metropolitan Borough of . Wallasey - In the A number of urban areas in the Metropolitan Borough of Wirral Mersey Estuary catchment are at potential risk from significant river 100 to 1,000 Padgate - In the Borough of flooding, including Warrington, Warrington. St Helens - In the Wallasey/ Birkenhead and Hindley/ Metropolitan Borough of St Helens. Leigh. Other areas where flooding is - In the Metropolitan considered to be an issue include: Borough of Knowsley. Widnes - In Tyldesley, Atherton, Westhoughton, the . - In Rainford, Ashton-in-Makerfield, St the Metropolitan Borough of Wirral. Helens, Widnes, Prescot, Netherley, Ellesmere Port - In the Borough Ellesmere Port and Bebington. of Ellesmere Port and Neston. There is also a tidal flood risk at - In the Metropolitan several locations along the Mersey Borough of Wirral. Liverpool - In the Estuary and around the Wirral City of Liverpool peninsula. Sewer flooding has

Environment Agency Mersey Estuary Catchment Flood Management Plan 7 Map 2 Risk to property across catchment for the 1% annual probability event

How we currently manage the risk in the catchment

Watercourses in the Mersey Estuary In addition to these features and maintained by the Environment CFMP area have been modified over engineering schemes, other flood Agency. the years for flood risk management risk management activities are • Identifying and promoting new and other purposes including carried out in the catchment. These flood alleviation schemes where navigation. Notable features include include activities, which help to appropriate, such as the Gemini the Manchester Ship Canal, which reduce the probability of flooding, wash lands on Sankey Brook, also significantly reduces fluvial and those that address the Hay Brook river habitat scheme, flood risk through Warrington, consequences of flooding. Upper Moss Side Farm Salt Marsh underground drainage systems Activities that reduce the probability Scheme and the Warrington Flood discharging directly to the tidal of flooding include: Alleviation Scheme. reach of the Mersey, and a wide variety of flood defences, pumping • Maintaining and improving • Enforcement and maintenance stations and other flow control existing flood defences, structures where riparian owners and others measures (e.g. the flood alleviation and watercourses, the catchment carry out work detrimental to flood basin at Lilford on the Glaze) has raised defences, pumping risk or neglect their duties. stations and other assets that are

8 Environment Agency Mersey Estuary Catchment Flood Management Plan The impact of climate change and future flood risk

• Working with local authorities to In the future, flooding will be • Increased urbanisation, up to influence the location, layout and influenced by climate change, 25%. design of new and redeveloped changes in land use (for example We estimate that by 2100 property and ensuring that only urban development) and rural land approximately 25,000 properties appropriate development is management. In the Mersey Estuary will be at risk of river flooding. This allowed on the floodplain through catchment, sensitivity testing is a 30% increase compared to the application of Planning Policy revealed that climate change has the current number at risk across Statement 25 (PPS25). the greatest impact on flood risk, the catchment. In addition, the with urbanisation having a smaller Activities that reduce the depth of flooding is expected to effect and land management change consequences of flooding include: increase with many more properties having little effect. Whilst we do not experiencing flooding of depths • Flood risk mapping, know exactly what will happen in greater than 0.5m. There is also an understanding where flooding is the future the key trends are: increased risk of key infrastructure likely to occur. • More frequent and intense and emergency services • Operation of floodline and flood storms causing more widespread being affected. No additional warning services to nearly 600 flooding from drainage systems environmental or heritage sites are people in 12 areas of the Mersey and some rivers. in the future 1% annual probability Estuary Catchment. flood extent but the flood depth and • Wetter winters increasing the extent of flooding is expected to likelihood of large-scale flooding. • Providing flood incident increase slightly. management. The future scenarios used in the Figure 2 shows the difference Mersey Estuary CFMP were: • Promoting resilience and between current and future flood resistance measures for those • A 20% increase in peak flow in risk for a 1% annual probability properties already in the all watercourses. The predicted event at key areas in the catchment. floodplain. increase in flow can affect the Following on from the CFMP, frequency, timing, scale of • Promoting awareness of organisations need to work together flooding and the flood levels. flooding so that organisations, to investigate flood risk from other communities and individuals are • A total sea level rise of 817 mm sources (e.g. surface water and aware of the risk and are prepared by the year 2100. sewer flooding) in more detail. in case they need to take action in time of flood. Figure 2 Current and future (2100) flood risk to property from a 1% annual probability river flood, taking into account current flood defences.

8000

7000

6000

5000

4000

3000

2000

Number of Properties at Flood Risk at Properties Number of 1000

0 Huyton Padgate Hindley St Helens Widnes Wallasey Hoylake Warrington Other Areas Ellesmere PortBromborough Current Future

Environment Agency Mersey Estuary Catchment Flood Management Plan 9 Future direction for flood risk management

Approaches in each sub-area

For this summary document we to keep building and raising This document does set out our have divided the Mersey Estuary defences. This is why we have to policies for managing flood risk, CFMP area into ten distinct sub- look catchment wide at how we recognising the constraints that areas that have similar physical direct effort and resources to ensure do exist. Our future direction for characteristics, sources of flooding sustainable solutions. We have managing flood risk is expressed and levels of risk. These sub-areas assessed what will be the most by applying one of our six standard will allow the key stakeholders to sustainable approach to managing policy options to that sub area. To promote flood risk management flood risk in each sub-area. This is select the most appropriate policy, approaches, policies and actions presented in the following sections the plan has considered how social, that are most appropriate in and they outline: economic and environmental that area to deliver the various objectives are affected by flood risk Government and regional strategies, • The key issues in that area. management activities under each in particular “Making Space for • The vision and preferred policy. policy option. The six policy options Water”. In the face of increasing are explained on page 11. risk, it often is not sustainable • The proposed actions to implement the policy. Map 3 Sub-areas

10 Environment Agency Mersey Estuary Catchment Flood Management Plan Table 2 Policy options ➜ Policy 1 Areas of little or no flood risk where we will continue to monitor and advise This policy will tend to be applied in those areas where there are very few properties at risk of flooding. It reflects a commitment to work with the natural flood processes as far as possible.

➜ Policy 2 Areas of low to moderate flood risk where we can generally reduce existing flood risk management actions This policy will tend to be applied where the overall level of risk to people and property is low to moderate. It may no longer be value for money to focus on continuing current levels of maintenance of existing defences if we can use resources to reduce risk where there are more people at higher risk. We would therefore review the flood risk management actions being taken so that they are proportionate to the level of risk.

➜ Policy 3 Areas of low to moderate flood risk where we are generally managing existing flood risk effectively This policy will tend to be applied where the risks are currently appropriately managed and where the risk of flooding is not expected to increase significantly in the future. However, we keep our approach under review, looking for improvements and responding to new challenges or information as they emerge. We may review our approach to managing flood defences and other flood risk management actions, to ensure that we are managing efficiently and taking the best approach to managing flood risk in the longer term.

➜ Policy 4 Areas of low, moderate or high flood risk where we are already managing the flood risk effectively but where we may need to take further actions to keep pace with climate change This policy will tend to be applied where the risks are currently deemed to be appropriately-managed, but where the risk of flooding is expected to significantly rise in the future. In this case we would need to do more in the future to contain what would otherwise be increasing risk. Taking further action to reduce risk will require further appraisal to assess whether there are socially and environmentally sustainable, technically viable and economically justified options.

➜ Policy 5 Areas of moderate to high flood risk where we can generally take further action to reduce flood risk This policy will tend to be applied to those areas where the case for further action to reduce flood risk is most compelling, for example where there are many people at high risk, or where changes in the environment have already increased risk. Taking further action to reduce risk will require additional appraisal to assess whether there are socially and environmentally sustainable, technically viable and economically justified options.

➜ Policy 6 Areas of low to moderate flood risk where we will take action with others to store water or manage run-off in locations that provide overall flood risk reduction or environmental benefits This policy will tend to be applied where there may be opportunities in some locations to reduce flood risk locally or more widely in a catchment by storing water or managing run-off. The policy has been applied to an area (where the potential to apply the policy exists), but would only be implemented in specific locations within the area, after more detailed appraisal and consultation.

Environment Agency Mersey Estuary Catchment Flood Management Plan 11 Sub-area 1

Glaze

Our key partners are: Approximately 190 properties The key messages are at risk of flooding in the 1% St Helens Metropolitan Borough annual probability event. Key • Future flood risk management Council infrastructure at risk includes will be targeted at areas that are one waste management site, one economically justifiable, this may Borough Council power station, two sewage and mean a reduction of maintenance Wigan Metropolitan Borough water treatment plants. There is in some low risk areas. Council also approximately 5.5km of rail • Future development should avoid and road network at risk. Parts of flood risk areas. Bolton Metropolitan Borough the Abram Flashes SSSI are also at Council risk of flooding, together with two • The nature of the Warrington Borough Council pollution inventory sites. Sewer environmentally designated sites flooding is an issue in and at Astley, Bedford, Risley and Natural England . Holcroft Mosses could withstand increased inundation which may United Utilities lead to enhancement / creation Network Rail The vision and of further Bio-diversity Action Plan (BAP) habitat. Highways Authority preferred policy

Landowners Policy option 2: Areas of low to moderate flood risk where we can Proposed actions to generally reduce existing flood risk implement the preferred management actions. The issues in this policy Overall flood risk is considered sub-area to be low in this sub-area. Future The essential actions to achieve our policy aim are listed below: This sub-area is one of the largest changes in flooding will be driven in the Mersey Estuary CFMP area. by climate change resulting in • To develop a maintenance plan It covers most of the lower reaches increases in properties at risk and for the area that will identify of the River Glaze catchment, and economic damages. Our vision locations where it is sensible to is connected to the uppermost is to reduce existing flood risk reduce our existing level of reaches by a narrow rural corridor management actions, accepting maintenance, this will include to the west of Abram. This area is that flood risk will increase with Jennets Lane Pumping Station. mainly low risk but includes the time. We estimate by 2100, 230 communities of Golborne, , properties will be at risk in a 1% • To investigate the potential for Worsley and Boothstown, which annual probability event (APE). flood storage in rural areas to generally have little or no flood reduce flood risk in the urban risk. It includes the environmentally area of Leigh. designated SSSI sites of Abram • To work with land managers Flashes, Astley and Bedford through the Entry and High Level Mosses, Risley Moss, Rixton Clay Environmental Stewardship Pits and Holcroft Moss. schemes to reduce run off in rural areas within the upper catchment.

12 Environment Agency Mersey Estuary Catchment Flood Management Plan Sub-area 2

Leigh (Atherton, Hindley, Tyldesley, and Westhoughton)

Our key partners are: Reservoir in Leigh. Bedford and • To investigate sewer flooding Pennington pumping stations help and implement improvement Wigan Metropolitan Borough to drain areas affected by mining schemes to deal with drainage Council subsidence. The key flood warning issues identified on the United areas are Bedford and Lilford in Utilities sewer flooding register. Bolton Metropolitan Borough Leigh. There are no environmentally Council designated sites in this area. Water and electricity Utilities Proposed actions to implement the preferred Network Rail The vision and policy Highways Authority preferred policy The essential actions to achieve our Policy option 5: Areas of moderate policy aim are listed below: to high flood risk where we can The issues in this generally take further action to • Develop a Flood Risk sub-area reduce flood risk. Management Strategy for the Glaze catchment. It is recognised that flood risk is This sub-area covers the largely • Encourage and assist the urbanised upper reaches of the currently very high in this sub- Regional Assembly and Local River Glaze and includes the towns area and is expected to rise due to Planning Authorities to produce of Hindley, Atherton, Tyldesley, increased urbanisation and climate Regional and Strategic Flood Risk Westhoughton, Leigh and Abram. change. By 2100 we estimate 2,300 Assessments to inform future Approximately 2000 properties are properties will be at risk of flooding development. Look to minimise currently at risk from a 1% annual in a 1% APE. Our vision is to take flood risk from all sources. probability event, which represents further action to reduce flood risk 9% of the total properties at risk now and into the future. • Seek to ensure that where, within the CFMP area. Notably 17 exceptionally, development must community assets, comprising of take place in flood risk areas, schools, colleges, surgeries, health The key messages flood resilience is incorporated centres, residential homes, and into buildings and safe access • Flood risk is currently very high. six recreational sites in the area of and evacuation can be provided Hindley, are at risk. Six kilometres Reducing the level of flood risk during flooding. of transport infrastructure is also will provide greater protection at risk. Sewer flooding is an issue to people and the economy. • Encourage the use of sustainable in Astley, Atherton, Leigh, Hindley, Hindley and Leigh will require drainage systems (SUDS) to Westhoughton and Abram. specific attention for actions. control run-off at source. • Investigate methods to provide Flood risk is currently managed • Future development should avoid protection or resilience to key through routine maintenance, and flood risk areas. the Lilford Park flood alleviation infrastructure. • To engage with Local Resilience basin and associated sluice gates Forums to improve our • Review and update the Sankey on Penleach Brook. In this sub- and Glaze Flood Warning understanding of flood risk, then area, mining has led to widespread Management Plan to consider the take appropriate action to reduce subsidence, most notably the impact of climate change and this risk. formation of Pennington Flash urban development.

Environment Agency Mersey Estuary Catchment Flood Management Plan 13 Sub-area 3

St Helens (and Ashton-in-Makerfield)

Our key partners are: The vision and • Assess infrastructure and preferred policy community assets vulnerable to Knowsley Metropolitan Borough flooding and take appropriate Council Policy option 3: Areas of low to actions to reduce the flood risk. St Helens Metropolitan Borough moderate flood risk where we are Council generally managing existing flood risk effectively. Proposed actions to Wigan Metropolitan Borough implement the preferred Council Climate change and an increase in urbanisation are the key drivers for policy Flood Resilience Forum future changes in flooding; although The essential actions to achieve our this flood risk is not expected to Water and Electricity Utilities policy aim are listed below: increase significantly in the long Highways authority term, by 2100 we estimate 1,070 • To develop a System Asset properties will be at risk in a 1% Management Plan to identify APE. Our vision is to maintain opportunities to reduce existing the current level of flood risk level of maintenance and The issues in this management which is sufficient to implement alternative actions to sub-area cover the areas at greatest risk, and manage flood risk. to look at alternative actions. There This area is heavily urbanised and is potential to provide increased • Seek to ensure that where includes the major towns of St protection to Scheduled Ancient development must take place in Helens and Ashton-in-Makerfield, Monuments and recreational assets. flood risk areas it is appropriately and other smaller urban areas along designed. the East Lancs (A580) road. Flood • Investigate the feasibility of risk is currently managed through a The key messages providing a Flood Warning combination of maintaining existing Service to key flood risk areas, defences and the management • Maintaining the current level including St Helens and Ashton- of vegetation within channel. of flood risk management is in-Makerfield. Pumping Station also sufficient to cover the areas at falls within this area. Approximately greatest risk. However, areas • Continue to investigate causes of 1,000 properties are at risk for a 1% such as St Helens will need close sewer flooding and the standards annual probability event. Also at monitoring. of service in relation to problems. risk of flooding are 4km of transport • There are opportunities for network and some 17 community • Investigate fluvial, surface water United Utilities/Environment assets comprising schools, and sewer flooding issues in Agency to work in partnership to hospital, 12 power facilities and Ashton-in-Makerfield, Haydock identify areas at risk of flooding. two Scheduled Ancient Monuments. and Sutton Leach followed by There are no flood warning areas. • Encourage use of SuDS to reduce appropriate remedial works Sewer flooding is an issue in Ashton flood risk and control pollution. where necessary. in Makerfield, Haydock and Sutton • Encourage the use of Leach. There are no SSSIs or other • Future development should avoid appropriately designed SUDS to environmentally designated sites in flood risk areas. control run-off at source. this area.

14 Environment Agency Mersey Estuary Catchment Flood Management Plan Sub-area 4

Upper and Middle Sankey

Our key partners are: combination of channel and flood • To work closely with Natural defence maintenance. England and partners to look at Knowsley MBC the best ways of managing flood risk in the sub-area. Wigan MBC The vision and • To ensure that there is no increase St Helens MBC preferred policy in run-off within the catchment and look for opportunities to West District Council Policy option 6: Areas of low to reduce current run-off. (e.g. moderate flood risk where we will Warrington Borough Council sustainable drainage systems). take action with others to store Natural England water or manage run-off in such a • To carry out further investigations way as to provide overall flood risk to assess potential rise in National Farmers Union reduction or environmental benefits. groundwater levels, risks and consequences. North West Development Agency Future changes in flooding will be Water and Electricity Utilities driven by climate change resulting in small increases in properties at risk Network Rail and economic damages. By 2100 Proposed actions to we estimate 344 properties will be implement the preferred Highways Authority at risk in a 1% APE. Our vision is to policy Landowners take action with others to store water or manage run-off in locations that The essential actions to achieve our provide overall flood risk reduction policy aim are listed below: or environmental benefits, locally • To identify areas for reducing the The issues in this or elsewhere in the catchment. This flood flow, by storing excess will reduce the risk from flooding sub-area flood water in ponds/reservoirs to people and property, and in in the Sankey catchment. This sub-area covers the rural parts turn transfer it to locations where of the Sankey Brook catchment and it can be beneficial. There is a key • Work with local and national includes the towns of Rainford, opportunity to look at potential Government to create economic Newton-le-Willows and the storage areas to alleviate flood risk and social conditions that communities of Sutton Mill and downstream in Warrington. encourage appropriate land use Moss Bank. and land management. Approximately 315 properties The key messages • Consider appropriate detention and 2.2km of transport network times and maximum run-off rates are at risk of flooding for a 1% • There is the potential to decrease and produce a map to help annual probability event. There is annual maintenance expenditure, increase the take up of SUDS to a potential risk in the south west ensuring that Flood Risk mitigate flood risk downstream. parts of the sub-area from rising Management expenditure is risk groundwater levels; this is currently based. • Review the outcomes of the being investigated as part of a wider groundwater resource Environment Agency project. No • There are opportunities to create investigation in the Lower Mersey infrastructures or community assets storage areas to reduce local Basin and assess the effect on are vulnerable to flooding. Flood flood risk to the downstream flood risk. risk is currently managed through a catchment. Environment Agency Mersey Estuary Catchment Flood Management Plan 15 Sub-area 5

Warrington (Lower Sankey, Padgate & Woolston)

Our key partners are: probability flood event. The length The key messages of essential transport infrastructure Warrington Borough Council at flood risk is approximately • Reducing flood risk will reduce 25km. Other key assets at risk the impact from flooding on Manchester Ship Canal Company include schools, residential homes, people and property. Local Resilience Forum surgeries, recreational facilities, • Maintaining the Manchester Ship wastewater treatments works, Canal in an operational condition Emergency Services a small area of Woolston Eyes is very important in managing SSSI and one Scheduled Ancient Water and Electricity Utilities flood risk in this sub-area. Monument. Higham Avenue floods Network Rail regularly from sewer overflows. In • Some measures, and in particular the western part of this sub-area raising defences and creating Highways Authority there are potential areas at risk from new embankments, would need rising groundwater levels. careful consideration during the design and implementation Current response to flood risk is phases of any flood defence The issues in this through routine maintenance of schemes. sub-area channel and raised defences. Tidal flood forecasting and flood warning • Future development should avoid This sub-area covers the lower (both tidal and fluvial) is also flood risk areas. reaches of the Sankey Brook important in this unit. catchment between the M62 • To review existing urban drainage motorway and the River Mersey, issues and develop an integrated together with the main urbanised The vision and urban drainage strategy, taking areas in the Padgate Brook into account the effects of climate catchment. It includes the Lower preferred policy change and development. Sankey, Padgate and Woolston Policy option 5: Areas of moderate areas of the town of Warrington, and • To assess infrastructure and to high flood risk where we can areas in Warrington between the community assets vulnerable to generally take further action to River Mersey and the Manchester flooding and take appropriate reduce flood risk. Ship Canal. The Canal conveys actions to reduce vulnerability. approximately 70% of the peak It is recognised that flood risk • To improve the flood warning flow which by-passes central is considered very high in this service to properties where Warrington. The role of the Canal, sub-area. Climate change is the practical. its maintenance and operation is key driver for future changes in important in minimising fluvial flood flooding; this results in a further • To assess risks and risk in Warrington. 3,000 properties at risk. Our vision consequences of potential is to take further action to reduce groundwater rebound in the Approximately 9,800 properties are flood risk. western parts of this sub-area. currently at risk for a 1% annual

16 Environment Agency Mersey Estuary Catchment Flood Management Plan Proposed actions to implement the preferred policy

The essential actions to achieve our policy aim are listed below:

• To liaise with Peel Ports Group regarding flood risk and the maintenance of the Manchester Ship Canal (embankments, hydraulic structures, dredging, flow control).

• Develop a Flood Risk Management Strategy for Warrington.

• Encourage the Regional Assembly and Local Planning Authorities to produce Regional and Strategic Flood Risk Assessments to minimise future flood risk from all sources. Seek to ensure that where exceptionally, development must take place in flood risk areas, that it is adequately designed.

• Encourage the use of appropriately designed SUDS to control run-off.

• Review and update the Warrington Flood Warning Management Plan and review the Multi Agency Flood Response Plan for Warrington to ensure safe access and evacuation can be provided during flood events.

• Review the outcomes of the groundwater resource investigation in the Lower Mersey Basin with regard to the effect on flood risk.

The Mersey at Warrington - Courtesy of the and Coastal Group

Environment Agency Mersey Estuary Catchment Flood Management Plan 17 Sub-area 6

Widnes and Penketh

Our key partners are: waste management sites. There The key messages are reports of sewer flooding in St Helens Metropolitan Borough the Penketh and Widnes areas • Flood risk is considered to be Council and, in the majority of this area, low and maintaining the current there is a potential risk from rising level of risk is sufficient to Halton Borough Council groundwater levels, this is being cover the areas at greatest risk. Warrington Borough Council investigated as part of a wider Flooding issues in Great Sankey Environment Agency project. and Penketh, Stewards Brook in Knowsley Metropolitan Borough Widnes and Widnes Warth will Council Current flood risk is managed need close monitoring however. through routine maintenance of the Flood Resilience Forum river channels and raised defences. • To investigate opportunities to manage flood water. Emergency services Bank is a tidal flood warning area. • To assess infrastructure and Electricity and Water Utilities community assets vulnerable to Landowners flooding and take appropriate The vision and actions to reduce risk of flooding. Network Rail preferred policy • To look at feasibility and Highways Authority Policy option 4: Areas of low, seek implementation of local moderate or high flood risk where improvement schemes to deal we are already managing the flood with specific drainage issues. The issues in this risk effectively but where we may need to take further actions to keep • To assess risks and sub-area pace with climate change. consequences of potential groundwater rebound in the This sub-area is in two parts, one The overall flood risk in this sub- western parts of this sub area. falls within the Whittle Brook area is considered low, and current catchment and includes Lingley risks are managed to an appropriate • United Utilities to implement Mere, Great Sankey and Penketh level, which is thought to be their recent proposals for areas in the western parts of adequate to cope with any increase remedial works to reduce sewer Warrington. The other area covers in tidal levels. Future changes in flooding issues in this sub-area. the lower reaches of the Ditton flooding will be driven by climate • Flood risk management Brook catchment and includes the change and urbanisation, the risk expenditure will be cost-efficient heavily urbanised area of Widnes. from fluvial flooding may increase in and risk-based. Approximately 324 properties are the future. By 2100 we estimate 740 at risk for a 1% annual probability properties may be at risk of flooding fluvial flood event. Also at risk in a 1% APE. are 3.2km of transport network Our vision is to take further action and 13 vulnerable infrastructures to sustain the current level of flood including three power stations and risk into the future.

18 Environment Agency Mersey Estuary Catchment Flood Management Plan Proposed actions to implement the preferred policy

The essential actions to achieve our policy aim are listed below:

• Deliver the Flood Risk Management Strategy for Warrington. This includes the Penketh Brook catchment and will consider the justification for reducing flood risk in Great Sankey and Penketh and look at appropriate ways of doing it, this includes environmental benefits, for example promotion of green corridors where feasible.

• Develop System Asset Management Plans for key systems, (focussing on the current maintenance expenditure versus flood risk) in order to identify opportunities to mitigate for future increase in flood risk, particularly fluvial flooding.

• United Utilities to implement their recent proposals for remedial works to reduce sewer flooding issues in this sub-area.

• Look to encourage the use of flood resilience and flood-proofing to existing properties in Penketh through the provision of information and advice and seek appropriate opportunities for funding these measures.

• Encourage the use of appropriately designed Sustainable Urban Drainage Systems (SUDS) to control run-off at source.

• Produce a hydraulic model for Stewards Brook to provide key Environment Agency data and deliver accurate flood outlines for updating the Flood Map.

• Review outcomes of groundwater resource investigation and look to enhance the monitoring network in areas susceptible to groundwater emergence.

• Develop a Multi Agency Flood Plan for Widnes to ensure safe access and evacuation can be provided during flood events.

River Mersey at Widnes - Courtesy of the North West England and North Wales Coastal Group

Environment Agency Mersey Estuary Catchment Flood Management Plan 19 Sub-area 7

Middle Mersey Estuary (Moss Side, Ince Banks, Knowsley)

Our key partners are: Approximately 570 properties are Overall flood risk is considered at risk of flooding for a 1% annual to be low in this sub-area. Our Warrington Borough Council probability event. Seven of these intention is to reduce existing flood are on Moss Side. This includes risk management actions, accepting Halton Borough Council 6km of transport network at risk. that flood risk will increase with West and Some 0.6km2 of the Mersey Estuary time. We estimate by 2100 590 RAMSAR, SPA, SSSI designations properties may be at risk of flooding Knowsley MBC are also exposed. in a 1% event. The wetland nature of the environmentally designated Liverpool City Council Moss Side has 2km of maintained sites in the south of the sub-area embankment and channel that St Helens MBC would also withstand increased provide localised protection to this flooding which may also lead to Manchester Ship Canal Company area. There is also a toxic waste creation of wetland habitat. disposal site at Randle Island (also Water and Electricity Utilities known as ). At Ince Natural England Banks, the current maintenance comprises of two pumping stations The key messages and vegetation management within • Reduce existing flood risk the channel. management where economically The issues in this North of the Estuary, flood risk justified. However, care must sub-area is currently managed through be taken over the toxic waste maintenance of both channel disposal site at Randle Island This sub-area consists of the areas and raised defences. Dog Clog and around the lower reaches of that border the middle part of the Pumping Station is used for land Rams Brook. Mersey Estuary on the north and drainage purposes. Sewer flooding south banks and extends north • To assess risks and is an issue in Huyton, Whiston and into the Knowsley area. It includes consequences of potential and in southern parts of Moss Side and Ince Banks, which groundwater rebound in the this sub-area, there is a risk from are areas of environmental value eastern parts of this sub-area. rising groundwater levels, this is between the River Mersey and currently being investigated as part the Manchester Ship Canal. Ince • Future development should avoid of a wider Environment Agency Banks is a mud flat that forms flood risk areas. project. There is a flood warning part of the Mersey Estuary Site of area at Fiddler’s . • To investigate how environmental Special Scientific Interest (SSSI) value can be improved and gaps and Special Protected Area (SPA). in knowledge addressed. North of the River, this sub-area covers predominantly rural reaches The vision and • To implement flood awareness of Ditton Brook and Rams Brook preferred policy and resilience measures. and includes the following areas: Halewood, Childwall, Whiston, Policy option 2: Areas of low to • To investigate effects of Prescot, Huyton-with-Roby and moderate flood risk where we can withdrawal of maintenance on the Fiddler’s Ferry. generally reduce existing flood risk pumping stations and channel management actions. maintenance on Ince Banks.

20 Environment Agency Mersey Estuary Catchment Flood Management Plan Proposed actions to implement the preferred policy

The essential actions to achieve our policy aim are listed below:

• Assess the level of flood risk to Randle Island waste disposal site.

• We are currently undertaking a groundwater resource investigation in the North Merseyside and Lower Mersey Basin. We will review outcomes of this study and look to enhance existing groundwater monitoring network targeting areas susceptible to groundwater emergence.

• To develop a System Asset Management Plan for key systems, including Dog Clog Pumping Station in order to ensure investment in flood risk management is appropriate to the level of flood risk.

• Investigate how the environmental value within the Inner Mersey Estuary can be preserved and improved within this sub-area.

• Consider the programme and findings of the Shoreline Management Plan review process (SMP2).

• Encourage the use of flood resilience and flood-proofing to existing properties by providing information and advice, and looking for appropriate opportunities for funding these measures within the community.

• Promote and work with land managers through the environmental stewardship schemes to reduce run-off in rural areas within the upper catchment reaches.

• Investigate how environmental sites such as Mersey Estuary RAMSAR, SPA, SSSI designations could withstand increased flooding to enhance or create further wetland habitat.

Manchester Ship Canal and the Mersey at Wigg Island- Courtesy of the North West England and North Wales Coastal Group

Environment Agency Mersey Estuary Catchment Flood Management Plan 21 Sub-area 8

Maritime Mersey (Liverpool, Birkenhead)

Our key partners are: The current number of properties out by the local authority, Mersey at risk for a 1% annual probability Docks and Harbour Company and Liverpool City Council event is approximately 4,850. United Utilities (for sewer flooding There are 12km of transport risk and the Birket pumping station). Halton Borough Council network, 7 recreational assets and On the Wirral, the environmentally Sefton MBC an additional 34 infrastructures and community assets including designated sites at and Metropolitan Borough of Wirral schools, that are vulnerable to Meadows are at flood risk. flooding. Current flood risk is managed Water and Electricity Utilities through channel and flood defence Network Rail There is flood risk from tidal flooding maintenance and flood warning. at some locations within Liverpool Flood warning areas (fluvial and Highways Authority city centre and on the waterfront. tidal) include Meols, Moreton, Approximately 510 properties , , Pacific Road, Natural England are at risk from tidal flooding for Shore Road and Upton Bridge. Mersey Docks & Harbour Co a 1% annual probability event. This includes 0.4km of railway network and three infrastructure The vision and and community assets vulnerable The issues in this to flooding. The risk associated with preferred policy sub-area fluvial and surface water flooding is Policy option 4: Areas of low, unknown and needs investigating. moderate or high flood risk where This sub-area extends along the This sub-area has areas potentially we are already managing the flood northern banks of the Mersey at risk from rising groundwater risk effectively but where we may Estuary to the Irish Sea and includes levels that could have a significant need to take further actions to keep much of the city of Liverpool, impact on development that has pace with climate change. including the city centre. On the taken place since abstraction western side of the estuary, it covers Future changes in flooding will started. Rising groundwater could the main urbanised area in the River be driven by climate change and affect both the Mersey and Birket catchment in the northern urbanisation resulting in significant railway underground infrastructure. parts of the Wirral and includes increases in properties at risk and Network Rail had to install a series the towns of Birkenhead, Wallasey, economic damages. of dewatering boreholes that are Hoylake, New Brighton and Meols. A effectively controlling groundwater This could increase the number of narrow urban corridor also extends levels and inflows. Sewer properties at risk by about 1450 west to the town of Irby. flooding is an issue in , properties for a 1% event by the In Liverpool, fluvial flooding is Brighton Le Sands and Litherland year 2100. Our vision is to take from more than ten ordinary and on the Wirral in Leasowe and further action to ensure no increase watercourses, which are largely Arrowe Hill/Upton. in flood risk into the future. culverted and flow through urban We have flood defence assets in areas of Liverpool into the Mersey this area, including raised defences Estuary. In the north of the Wirral, along the Birket and the Great fluvial flooding is mainly due to the Culvert Pumping Station. Current River Birket. management of flood risk is carried

22 Environment Agency Mersey Estuary Catchment Flood Management Plan The key messages • Tourism is important within this unit, especially along the waterfront. Maintaining a low risk of flooding to these sites will ensure that this is maintained.

• Tidal flooding issues are being addressed by the Liverpool Bay Shoreline Management Plan (SMP).

• This area is heavily urbanised and so there may be little opportunity for environmental enhancement through the creation or enhancement of Biodiversity Action Plan (BAP) habitats.

• Future development should avoid flood risk areas.

• Rising groundwater levels will need to be monitored in the future and appropriate actions (resilience, dewatering) should be implemented according to the risk and consequences (to be identified).

• There are opportunities for United Utilities and the Environment Agency to work in partnership to identify areas at risk of flooding from complex sources.

• SUDS should be encouraged as a means of reducing overall flood risk and controlling pollution from urban run- off.

Proposed actions to implement the preferred policy The essential actions to achieve our policy aim are listed below:

• Engage with key stakeholders to develop maintenance plan for existing flood defence assets within this sub- area to take account of future changes being driven by sea level rise, climate change and regeneration within Liverpool. Review tidal flood forecasting and flood warning procedures within this sub-area to take account of future changes.

• We are currently undertaking a groundwater resource investigation in the North Merseyside and Lower Mersey Basin. We will review outcomes of this study and look to enhance existing groundwater monitoring network targeting areas susceptible to groundwater emergence.

• Identify and map the watercourses in Liverpool using a combination of desk top studies and site investigation to improve understanding and to help prioritise flood management issues.

• Look to encourage the use of flood resilience and flood-proofing to existing properties in Liverpool by providing information and advice.

• To develop a System Asset Management Plan for the Birket system in order to identify opportunities to mitigate for future increase in flood risk.

• Seek to ensure that, where development must take place in flood risk areas, measures such as, raising floors to an appropriate level and flood resilience is incorporated into buildings. It must also be demonstrated that safe access and evacuation can be provided during flooding.

• Encourage the use of appropriately designed SUDS to control run-off.

• Work with United Utilities to look at operation and maintenance of the Great Culvert Pumping Stations, to address current flood risk and future increases in flood risk.

Environment Agency Mersey Estuary Catchment Flood Management Plan 23 Sub-area 9

Bebington (Bromborough & Ellesmere Port)

Our key partners are: The issues in this will be at risk in a 1% event. Our sub-area vision is to maintain the current Wirral Metropolitan Borough level of flood risk management Council This sub-area covers the main acknowledging that the flood risk at these locations may rise in the Cheshire West and Chester Council urbanised areas in the Dibbinsdale Brook and Rivacre Brook long-term. We intend to review our Water and Electricity Utilities catchments on the Wirral, and approaches in the future to manage includes the towns of Bebington, changes in flood risk due to climate Network Rail Bromborough and Ellesmere Port. change. Highways Authority The current number of properties at risk for a 1% annual probability event is approximately 124. This The key messages includes 3km of transport network. • This area is heavily urbanised New Ferry, Meols Meadows, Mersey and so there may be little Estuary and Dibbinsdale SSSIs opportunity for environmental are also at risk. Sewer flooding enhancement through creation / is an issue in . In a enhancement of BAP habitats. large part of this sub-area, there are areas potentially at risk from • Any future rise in flood risk would rising groundwater levels. We are affect northern parts of the sub- currently carrying out a groundwater area. study within the Lower Mersey Basin. Current flood risk is managed • There are opportunities for through channel maintenance. United Utilities/Environment There are no Flood Warning Areas in Agency to work in partnership this sub-area. to identify areas at risk of flooding from complex sources through combined integrated The vision and drainage strategies, with a review of receiving watercourses/ preferred policy catchments, foul and surface Policy option 3: Areas of low to water sources, and considering moderate flood risk where we are the effects of climate change. generally managing existing flood • SuDS should be encouraged as a risk effectively. means of reducing overall flood Future changes in flooding will risk and controlling pollution be driven by climate change from urban run-off. (particularly for sea levels) and urbanisation, resulting in some increase in properties at risk. By 2100 we estimate 149 properties

24 Environment Agency Mersey Estuary Catchment Flood Management Plan Proposed actions to implement the preferred policy

The essential actions to achieve our policy aim are listed below:

• To develop a System Asset Management Plan to identify opportunities to reduce existing level of maintenance, where it can no longer be justified.

• Seek to ensure that, where development must exceptionally take place, in areas at risk of flooding, measures such as, raising floor levels to an appropriate level and flood resilience is incorporated into buildings and it is demonstrated that safe access and evacuation can be provided during flooding.

• Produce hydraulic model for Dibbinsdale Brook and Rivacre Brook to provide Agency data and deliver accurate flood outlines for updating the Flood Map.

• Continue to investigate causes of sewer flooding (including links to river processes) in Great Sutton and Ellesmere Port, followed by appropriate remedial works where necessary. United Utilities will lead this action.

• Review the groundwater resource investigation report for the North Merseyside and Lower Mersey Basin. This will investigate the feasibility of Identification of areas at risk from groundwater rebound.

• Encourage the use of appropriately designed SUDS to control run-off at source.

Eastham Ferry and Country Park - Courtesy of the North West England and North Wales Coastal Group

Environment Agency Mersey Estuary Catchment Flood Management Plan 25 Sub-area 10

Greasby (Heswall & Neston)

Our key partners are: The issues in this estimate 180 properties may be at risk of flooding in a 1% event. Cheshire West and Chester Council sub-area Our vision is to take action with This sub-area covers rural areas in Metropolitan Borough of Wirral others to store water or manage the western part of the Wirral and run-off in locations that provide North West Development Agency includes the upper reaches of the overall flood risk reduction or Rivers Birket and Fender, and of Water and Electricity Utilities environmental benefits, locally or Dibbinsdale and Rivacre Brooks. elsewhere in the catchment This The northern and southern parts of Network Rail supports sustainability by reducing the sub-area are joined by a narrow the risk from flooding to people and Highways Authority rural corridor to the west of the town property, and in turn transferring of Irby. The main communities are Natural England the risk to locations where it can be Heswall, Neston, and beneficial. There are opportunities National Farmers Union Willaston. The current number of to create storage areas on the properties at risk for a 1% annual Wirral (both on and off line) in order probability event is approximately to reduce flood risk in sub-areas 119. This includes 3km of the located downstream. transport network. There are four infrastructures and community assets vulnerable to flooding including wastewater treatment The key messages works. Sewer flooding is an issue in • Flood risk is considered to be Grange (). Current flood low and maintaining the current risk is managed through channel level of flood risk management maintenance. is sufficient to cover the areas at greatest risk. The vision and • There is the potential to decrease annual maintenance expenditure, preferred policy ensuring that FRM expenditure is Policy option 6: Areas of low to risk based. moderate flood risk where we will take action with others to store water or manage run-off in locations that provide overall flood risk reduction or environmental benefits.

Future changes in flooding will be driven by climate change, resulting in some increase in the number of properties at risk. By 2100 we

26 Environment Agency Mersey Estuary Catchment Flood Management Plan Proposed actions to implement the preferred policy

The essential actions to achieve our policy aim are listed below:

• To develop a System Asset Management Plan for key systems in order to identify opportunities to reduce existing level of maintenance, where it can no longer be justified.

• Work with local and national government to create economic and social conditions that encourage appropriate land use and land management.

• Encourage the use of appropriately designed SUDS to control run-off at source.

• Produce a hydraulic model for Dibbinsdale Brook and Rivacre Brook to provide key Agency data and deliver accurate flood outlines for updating the Flood Map.

Parkgate near Neston - Courtesy of the North West England and North Wales Coastal Group

Environment Agency Mersey Estuary Catchment Flood Management Plan 27 Map of CFMP policies

28 Environment Agency Mersey Estuary Catchment Flood Management Plan

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

* Approximate call costs: 8p plus 6p per minute (standard landline). Please note charges will vary across telephone providers.

Environment first: Viewing this on-screen? Please consider the environment and only print if absolutely necessary.

If you're reading a paper copy, please don't forget to reuse and recycle.

GENW0309BPKS-E-E