Alt 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 Knutsford 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 Alt Crossens Catchment Flood Management Plan (CFMP). This CFMP gives an overview of the flood risk in the Alt Crossens catchment and sets out our preferred plan for sustainable flood risk management over the next 50 to 100 years.

The Alt Crossens CFMP is one of 77 CFMPs for Approximately 300 properties in the catchment have a and Wales. Through the CFMPs, we have assessed 1% chance of flooding from rivers in any one year. The inland flood risk across all of England and Wales for catchment is heavily reliant on two pumping stations to the first time. The CFMP considers all types of inland drain it, failure of these could put over 6000 properties flooding, from rivers, groundwater, surface water at risk. The Alt Crossens catchment, being adjacent to and tidal flooding, but not flooding directly from the the Sefton coastline, is also at risk of coastal flooding. sea (coastal flooding), which is covered by Shoreline As a result of climate change, we estimate that by 2100 Management Plans (SMPs). Our coverage of surface approximately 405 properties will be at risk of fluvial and groundwater is however limited due to a lack of flooding alone. 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 many help us target our limited resources where the risks organisations. These include local authorities, United are greatest. Utilities, Natural England, Wildlife Trust, the RSPB and farming representatives. This CFMP identifies flood risk management policies to assist all key decision makers in the catchment. It was This is a summary of the main CFMP document, if you produced through a wide consultation and appraisal need to see the full document an electronic version process, however it is only the first step towards an can be obtained by emailing enquiries@environment- integrated approach to Flood Risk Management. As we agency.gov.uk or alternatively paper copies can be all work together to achieve our objectives, we must viewed at any of our offices in North West Region. monitor and listen to each others progress, discuss what has been achieved and consider where we may need to review parts of the CFMP.

The Alt Crossens catchment has a history of flooding with and most affected by past flood events. The main sources of risk are fluvial (from Tony Dean rivers), surface water, sewer flooding and from canals. Regional Director

Environment Agency Alt Crossens 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 Liverpool 12 2 Middle Urban Alt 14 3 Altcar and Ince 16 4 18 5 20 6 22 7 24 8 Banks Marsh 26

Map of CFMP policies 28

2 Environment Agency Alt Crossens 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 Alt Crossens Catchment Flood Management Plan 3 Catchment overview

The Alt Crossens area is low lying, Liverpool, and the coastal towns The CFMP area is also important with considerable areas of high of Formby and Southport. Further for nature conservation, and grade farmland, and approximately inland are the populated areas a number of nationally and 28% of the area is urbanised. The of Ormskirk, Maghull and . internationally protected sites are hydrology of the area is complex Agriculture within the study within the floodplain. Depending because much of the catchment is area has a significant role in the on the location and nature of the at or below sea level. Ultimately, social and economic well-being designation, flooding can have a heavy reliance is placed upon the of communities and to the region mixture of effects. For example, two main pumping stations of as a whole. Over 60% of all the Martin Mere Site of Special Altmouth and Crossens to evacuate Grade 1 and 2 agricultural land Scientific Interest (SSSI) is a water from the Alt and Crossens in the North West of England is managed wetland and changes to catchments respectively. There is no located in the catchment. There the current management regime capacity for gravity drainage from are approximately 300 properties may have positive or negative the Crossens catchment, although across the catchment at risk from effects. The Alt and Crossens within the Alt catchment, there is fluvial flooding during an event systems also flow into the Ribble some scope for gravity drainage with a 1% chance of flooding in and Alt Estuary Ramsar sites. during low tide at Altmouth. any one year. Approximately 50% However, the policies and actions of these properties are in Liverpool from this CFMP will not significantly The upper part of the Alt catchment and a further 25% in Maghull. Our affect the ecological features has a narrow floodplain, which approach to management in these of these protected sites. More widens significantly in the low lying high risk locations is focussed generally, the CFMP includes agricultural areas downstream of around sustainable development, actions to enhance the ecological Maghull, whilst the majority of flood warning, flood resilience and value of the catchment. the Crossens catchment has wide the idea of making space for water, floodplains. The Lower Alt and either locally or upstream. Crossens catchments have been extensively developed for agricultural use. As a result, a large network of modified watercourses and embanked rivers has been created to support agricultural production. The modified channels act as arterial flow routes to a network of 11 satellite pumping stations and the two main pumping stations. Across the catchment, we need to help safeguard the rural floodplains, improve management of flood risk in the urban areas, and mitigate the impacts of climate change.

The key urban areas within the catchment comprise the north east quadrant of the City of Altmouth Pumping Station

4 Environment Agency Alt Crossens Catchment Flood Management Plan Map 1

Altmouth Pumping Station

Environment Agency Alt Crossens Catchment Flood Management Plan 5 Current and future flood risk

Overview of the current flood risk

Flood risk has two components: The main sources of flooding in flat with low drainage gradients the chance (probability) of a the Alt Crossens catchment are as which can lead to ponding after particular flood and the impact (or follows: heavy rain. Wind blown sand in consequence) that the flood would the north west of the catchment • River flooding incidents in have if it happened. The probability can cause blockages in the recent times have been rare, of a flood relates to the likelihood of surface drains. Further work is and have mainly occurred a flood of that size occurring within required to better understand from watercourses prior to a one year period, it is expressed this type of flooding in the them becoming part of the as a percentage. For example, catchment. main river network and hence a 1% flood has a 1% chance or an Environment Agency • Sewer flooding has been probability of occurring in any one responsibility. There are over recorded in the urban areas year, and a 0.5% flood has a 0.5% 8km of culverted watercourses of Southport, Maghull and chance or probability of occurring in (main river in both the Alt and Liverpool. Discussions are any one year. The flood risks quoted Crossens sub-catchments) which underway with United Utilities in this report are those that take can potentially prove to be a and local authorities to identify account of flood defences already in significant source of flooding due and better understand this type place. to failure or blockage. of flooding. In the Alt and Crossens catchments, • There is tidal flood risk in the • Groundwater flooding is not since the installation of the Alt Crossens catchment. Flood thought to be a significant issue Altmouth (1971) and Crossens defences in the form of raised on its own. However groundwater (1961) pumping stations, reported embankments extend along the rise does occur within the lower flooding incidents are few and coast and provide a 1% standard Alt catchment. It is likely the localised. The most serious of protection. The main pumping groundwater table is near to the flooding to date concerned canal stations also provide protection surface in winter and therefore infrastructure, affecting over 200 against tidal ingress. Tidal the risk of local flooding may properties. Twenty newly developed flooding and coastal processes increase in probability during properties were affected by flooding will be assessed in the next stage prolonged wet periods. No north of Ormskirk in 2004 from an of the Shoreline Management information is available for ordinary watercourse although no Plan (SMP) process, expected in either the upper Alt or Crossens water entered the property. There summer 2010. catchments. has been localised flooding at Whinney Brook in Maghull due to • Surface water flooding does • Canal flooding occurred from culvert capacity being exceeded. occur in the Alt Crossens the Leeds and Liverpool canal lines brook breached catchment, but is very localised. in 1994 and flooded 200 to 300 twice in 2000 and once in 2008 and Based on information available it properties. There is a potential resulted in extensive flooding to is thought to be high in frequency risk of flooding where stretches farmland. but low in consequence and is of the canal are above ground likely to occur in the urban areas level and pass through the urban with high rates of run-off. Much areas of Burscough and Maghull. of the catchment is relatively

6 Environment Agency Alt Crossens Catchment Flood Management Plan What is at risk? Table 1. The areas with the highest concentration of properties at risk from river flooding are tabulated below: Using detailed hydraulic models we estimate 300 properties in the Number of properties at risk Locations catchment have a 1% chance of flooding in any one year from rivers, 51 to 150 Sefton Metropolitan Borough nearly half of which are in Liverpool. Council (Southport, Formby, There are 28,000 hectares of Maghull) Liverpool City Council agricultural land in the Alt Crossens (Liverpool) catchment, much of which is high grade, 2,100 hectares are at risk 25 to 50 None of flooding in a 1% event. There is one ecologically important site at 0 to 25 District Council flood risk in a 1% event and one (Ormskirk) scheduled ancient monument. Where is the risk? Table 2. Critical infrastructure at risk:

The catchment has a history of Liverpool Railway Lines, 3 A roads (A570, A59, A565), 4 B roads flooding with Liverpool and Maghull (including B5243, B5195, B5424) and 12 minor roads, 3 Electricity/gas most affected by past fluvial flood sub stations, 2 Waste Management sites, 2 Waste Water Treatment Works events. Formby and Ormskirk have experienced fluvial flooding to a lesser degree. The distribution of flood risk to properties across the catchment is illustrated on the map overleaf. If the pumping stations were to fail or be removed, it is estimated that in the region of 6,700 properties could be at risk, this is an increase of several thousand properties compared to the current number at risk. The majority of these properties affected would be in Southport.

We recognise the potential risk from surface water and sewer flooding. Further studies, following on from the CFMP, will be undertaken to help quantify this potential risk.

Agriculture in the catchment

Environment Agency Alt Crossens Catchment Flood Management Plan 7 Map 2 Risk to property within each sub-area for the 1% annual probability fluvial event

How we currently manage the risk in the catchment

Both the Alt and Crossens • Construction of the Crossens Activities that reduce the probability catchments have benefited, from pumping station in the early of flooding include: engineering schemes implemented 1960s, led to the abandonment • Maintaining and improving over the last 50 years or more. These of gravity outfall, in favour of existing flood defences, include: fully pumping the Crossens structures and water courses. catchment. Since construction • The construction of the Altmouth The Alt Crossens catchment has the station has been refurbished pumping station in the early 35km of raised defences and and electrified. 1970s overcame the problems 13 pumping stations. We spend of discharging into the sea In addition to these engineering over £2 million every year in this during high tides, and relieved schemes, other flood risk catchment on maintenance. the increased water levels management activities are carried • Enforcement, where riparian during high rainfall due to out in the catchment. These include owners and others carry out urban development. Channel activities, which help to reduce the work detrimental to flood risk, improvements were also made to probability of flooding, and those or need advice about riparian improve the flow of water to the that address the consequences of responsibilities. station. flooding.

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

• Identifying and promoting new In the future, flooding will be As a result of climate change, flood alleviation schemes where influenced by climate change, we estimate that by 2100 appropriate, such as major changes in land use (for example approximately 405 properties will refurbishment and improvement urban development) and rural land be at risk of fluvial flooding. This is the Altmouth pumping station management. In the Alt Crossens a 30% increase compared to the and development of a washland catchment, with current land current number of properties at with a storage volume in excess drainage practices, sensitivity risk. These properties are primarily of one million cubic metres in the testing revealed that climate change located in Liverpool, Maghull and Lower Alt. has the greatest impact on flood Ormskirk. Flood depths could risk. Land management change, and increase by as much as 0.25m in • Working with local authorities to urbanisation have a smaller effect. these areas. Climate change has influence the location, layout and Whilst we do not know exactly what little effect on river flooding in design of new and redeveloped will happen in the future the key Southport. property and ensuring that trends are: only appropriate development The extent of flooding on is allowed on the floodplain • more frequent and intense environmental sites will increase as through the application of storms causing more widespread a result of climate change and six Planning Policy Statement 25 flooding from drainage systems further sites are potentially at risk in (PPS25). and some rivers; a 1% event.

Activities that reduce the • wetter winters increasing the The effects of climate change consequences of flooding include: likelihood of large-scale flooding. were combined with pump failure scenarios and demonstrated • flood risk modelling and The future scenarios used in the Alt potentially large increases in flood mapping, understanding where Crossens CFMP were: risk at Formby and Southport (over flooding is likely to occur; • a 30% increase in peak flow in all 4000 properties). • operation of floodline and watercourses; The graph below shows the warning services to areas of • a total sea level rise of 670 mm difference between current and Southport and Crosby; by the year 2100; future flood risks from a 1% event at • providing flood incident key locations across the catchment. • increased urbanisation (by 8% in management; places). • promoting awareness of flooding so that organisations, Figure 2 Current and future (2100) flood risk to property from a 1% annual communities and individuals probability river flood, taking into account current flood defences. are aware of the risk and are prepared in case they need to 200 take action in time of flood;

• promoting resilience and 150 resistance measures for those

properties already in the 100 floodplain.

50 Number of Properties at Flood Risk at Properties Number of

0 Liverpool Maghull Formby Ormskirk

Current Future

Environment Agency Alt Crossens Catchment Flood Management Plan 9 Future direction for flood risk management

Approaches in each sub-area

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

Map 3 Sub-areas

10 Environment Agency Alt Crossens Catchment Flood Management Plan Table 3 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 Alt Crossens Catchment Flood Management Plan 11 Sub-area 1

Liverpool

Our key partners are: The issues in this with out of bank flow as well as flooding associated with conveyance Knowsley Metropolitan Borough sub-area problems on Tue Brook and Deys Council Within this sub-area, 139 residential Brook. Our vision is to sustain the current level of protection into the Liverpool City Council properties are at risk during a 1% annual probability flood event. future and to ensure no increase in Sefton Metropolitan Borough Some flooding from rivers does flood risk to people and property, Council occur, as a result of out of bank which under current conditions is flow and channel constrictions. In considered appropriate. In future St Helens Metropolitan Borough the future, by 2100, we estimate we would anticipate that current Council the number of properties at risk defences will be maintained, and to rise to 195 due to the effects of maintenance of the river corridors will United Utilities climate change. We are currently be continued. If we did not account Landowners managing this risk by carrying out for climate change in our adopted routine maintenance and by the policy, an additional 60 properties Natural England provision of limited raised flood could be affected in a 1% annual defences which provide a relatively probability event (APE). Localised low standard of protection to conveyance improvements to Tue approximately 20-40 properties Brook and Deys Brook will be sought during minor flood events. This to address the flood risk associated level of protection will become less with these watercourses. effective as the impacts of climate change occur in the future. Surface water flooding is reported to occur The key messages in this sub-area. Two railway lines, one electricity sub-station, a gas sub- • Proactive measures to mitigate station and three medical centres for climate change, such as are at risk during the 1% event. investigating options to improve defences and modify channels/ culverts and look into flood The vision and resistance and resilience of preferred policy property. • Support local planning Policy option 4: Areas of low, authorities to reduce moderate or high flood risk where inappropriate development we are already managing the flood within floodplain. risk effectively but where we may need to take further actions to keep • Work in partnership with United pace with climate change. Utilities and local authorities to produce a surface water The probability of flooding to the management plan identifying area of Liverpool covered by this the extent and potential sub-area is relatively high. Flooding management opportunities which occurs directly from the could be adopted to reduce the and its tributaries and is associated risk of surface water flooding.

12 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Investigate defences and conveyance capacity in Tue Brook and Deys Brook to identify options to mitigate flood risk on these watercourses.

• Establish policies within Local Development Frameworks that work towards long term protection and re-creation of watercourse corridors / floodplain through sustainable land use management.

• Encourage Sustainable Drainage Systems (SuDS) as a means of reducing overall flood risk and controlling pollution from urban run-off.

The River Alt near Sefton

Environment Agency Alt Crossens Catchment Flood Management Plan 13 Sub-area 2

Middle Urban Alt

Our key partners are: In the future we estimate the currently at risk. To achieve this, number of properties at risk we will continue with the current Sefton Metropolitan Borough could increase to 132 by 2100 maintenance programme on the Council in a 1% APE due to the effects existing flood defences and river of climate change. Flood risk is corridors. Although we do not West Lancashire District Council currently managed through routine anticipate improvements being United Utilities maintenance of the river corridors, made to existing defences, future raised defences which provide works will be considered to remove Natural England protection to and surrounding channel constrictions to improve agricultural land, and by operations conveyance. at the Altmouth Pumping Station The issues in this which reduces the risk of the River Alt backing up to Maghull. This level The key messages sub-area of protection will gradually reduce • The current level of flood risk This policy unit is largely rural and as river flows increase in the future. will be maintained by continuing contains the town of Maghull and with the current level of flood risk the villages of Aughton and Lunt. management. To mitigate against It covers the transition between The vision and increasing risk, and to cater for the naturally draining upper Alt preferred policy climate change related increases through Liverpool and the heavily in water levels, targetted flood managed, lowland areas of the Policy option 3: Areas of low to resilience and resistance Lower Alt catchment. There is flood moderate flood risk where we are measures will be encouraged and risk to an estimated 84 residential generally managing existing flood promoted. properties and ten commercial risk effectively. properties in Maghull during a 1% The residential community of • Work with local planning APE. This is mainly due to out of Maghull is frequently exposed authorities to avoid inappropriate bank flow from the River Alt and to river flooding from the River development within the blockage and conveyance issues Alt tributaries as a result of floodplain. associated with Whinney Brook conveyance restrictions. This is • Reduce risk at the most flood and Dovers Brook. Approximately expected to increase as climate 100 hectares of Grade 1 and 2 prone places by influencing change occurs, resulting in higher planning to ensure that agricultural land is also at risk of flood damages and hazards to flooding from the river during this development takes account of people. Our vision is to continue the level of flood risk. event as well as the B5244 road and our flood risk management actions a waste management site. There are but balanced with the fact that: • Work in partnership with United reported incidents of surface water some specific higher risk locations Utilities to and local authorities flooding to property in this sub- may require improvement, to identify extent and potential area. and others less management management opportunities which actions. Flood resistance and could be adopted to reduce the resilience opportunities should risk of surface water flooding. be encouraged for properties

14 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Undertake a pre-feasibility study for conveyance improvements to Whinney Brook Culvert and Dovers Brook.

• Undertake investigations to determine the feasibility of flood storage on Brook to reduce the impact of flooding downstream.

• Establish policies within Local Development Frameworks that work towards long term protection and re-creation of wetland corridors/floodplain through sustainable land use management.

• Encourage SuDS as a means of reducing urban run-off and surface water flood risk, whilst benefiting water quality.

• Encourage the use of flood resistance and resilience measures to mitigate flood risk.

The River Alt and surrounding agriculture downstream of Maghull © Copyright Getmapping plc, supplied by Bluesky International Ltd

Environment Agency Alt Crossens Catchment Flood Management Plan 15 Sub-area 3

Altcar and Ince

Our key partners are: The vision and The key messages

Sefton Metropolitan Borough preferred policy • High grade agricultural land has Council Policy option 6: Areas of low to major economic importance locally and regionally, and West Lancashire District Council moderate flood risk where we will take action with others to contributes significantly to UK Land Managers store water or manage run-off in food production. This makes it locations that provide overall flood necessary to pursue this policy Natural England risk reduction or environmental ensuring minimal effects on benefits. agricultural food production.

The agricultural land at risk • Agricultural practice and land The issues in this of flooding has economic management must consider soft sub-area importance locally and regionally approaches to the environment, and continued protection is habitat creation and soil The Altcar and Ince sub-area is considered appropriate. Altmouth management to contribute predominantly rural with a number Pumping Station provides this to wider sustainability of of small villages. The main flood level of protection and also agriculture. For example, agri- risk is from the River Alt, either as provides benefits to upstream and environment schemes and a result of overtopping of defences downstream locations such as improved soil management. or surface water ponding as a Maghull and Formby. Our vision is result of the land drainage system • There are opportunities to continue operating the pumping backing up from high water in the for habitat enhancement station, and over the whole river. However, only one property through ‘wetting up’ of land Alt catchment carry on routine is at risk during a 1% APE. The and promotion of ecological maintenance of the River Alt and main economic risk of flooding is to networks. the arterial drainage ditches. The approximately 200 hectares of high effects of climate change will lead to grade agricultural land. Flood risk increased risk to agricultural areas management is heavily reliant upon without increased operational time the Altmouth Pumping Station to or capacity at the pumping station. provide land drainage and, without We also envisage a reduction in this, there would be an extensive management of smaller watercourse risk to agricultural land. Within this and tributaries within this policy sub-area, two minor roads and the unit. We believe this will result Hill House Waste Water Treatment in localised re-naturalisation and Works are at risk of flooding. The ‘wetting up’ of land, delivering Downholland Moss SSSI and part localised flood storage and of the Sefton Coast SSSI are located environmental benefits. In within this sub-area. No further particular, flood storage options are properties are at risk due to the being considered at Lunt Meadows. effects of climate change.

16 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Refurbishment of Altmouth Pumping Station is critical to the continued management of flood risk over the whole catchment and this sub-area, it plays a significant role in existing agricultural practice.

• Develop the Lower Alt with Crossens Pumped Drainage Strategy involving key catchment stakeholders.

• Review the Environment Agency obligations for land drainage and satellite pumping station operation throughout this sub-area.

• Identify opportunities for wetting up, and linking areas of ecological value.

• Investigate and promote a partnership approach for the Lunt Meadows Washland development.

Hightown and the mouth of the River Alt- Courtesy of the and North Wales Coastal Group

Environment Agency Alt Crossens Catchment Flood Management Plan 17 Sub-area 4

Formby

Our key partners are: The issues in this The vision and

Sefton Metropolitan Borough sub-area preferred policy Council This sub-area contains the coastal Policy option 4: Areas of low, West Lancashire District Council town of Formby and the surrounding moderate or high flood risk where agricultural area. The River Alt we are already managing the flood United Utilities runs through in the south of the risk effectively but where we may sub-area and is discharged via need to take further actions to keep Developers Altmouth Pumping Station which pace with climate change. maintains water levels in the Alt The current flood risk management low enough to allow free discharge measures deliver an appropriate of the drainage network in Formby. level of risk to the people and Flooding occurs to approximately property in Formby. The impact of 60 properties in Formby during the climate change will primarily be an 1% APE due to backing up of the earlier onset of flooding. Our vision drainage infrastructure, conveyance for this sub-area is to continue to issues and blockages. The B5195 maintain the current standard of and B5424, two minor roads, two flood risk protection into the future. gas and electricity sub-stations, one Local businesses and property waste management site and Formby owners will be encouraged to Waste Water Treatment Works are adopt flood protection measures at risk during the 1% APE. There to help plan for and manage risk to are limited reports of surface water property. flooding. The risk of flooding is currently managed by undertaking channel maintenance in conjunction with continued operation of The key messages Altmouth Pumping Station. By 2100 • It is our intention to refurbish and the effects of climate change do not continue to operate Altmouth put any further properties at risk. Pumping Station to provide the The environmentally designated current standard of service. sites of Ribble and Alt Estuaries • Continue to work with local and the Sefton Coast are located authorities in order to prevent partially in this sub-area. inappropriate new development in areas at flood risk.

• Encourage properties currently at risk to consider flood resistance and resilience measures.

18 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Identify potential local hotspots for surface water flooding and develop a Surface Water Management Plan in conjunction with United Utilities and local authorities.

• Promote individual business flood resilience management plans.

• Identify potential sites and investigate the potential role of minor booster pumping stations to assist conveyance within urban watercourses.

• Establish policies within Local Development Frameworks that work towards long term protection and re-creation of watercourse corridors/floodplain through sustainable land use management.

Formby Point- Courtesy of the North West England and North Wales Coastal Group

Environment Agency Alt Crossens Catchment Flood Management Plan 19 Sub-area 5

Ormskirk

Our key partners are: The issues in this maintained into the future through sub-area continued maintenance of the river West Lancashire District Council corridor. This will mitigate the impacts of climate change which, Developers This sub-area contains the rural market town of Ormskirk which is if left unmanaged, would result in Natural England set amidst high grade agricultural an additional six properties at risk. land. Ormskirk is located at the Our vision is to focus on reducing upper reach of the main gravity the risk of flooding that occurs as a draining watercourse in the result of conveyance and blockage Crossens catchment. Flooding issues and to promote the adoption through Ormskirk is associated of flood resilience techniques. with capacity issues and blockage We also believe that there could of the culverts within Ormskirk, in be opportunities to provide flood particular the A59 culvert, which storage higher in the catchment on can result in 15 properties being Hurlston Brook and Sandy Brook affected by flood water in a 1% which may reduce downstream event. The A59 and A570, along flood risk. with three minor roads are at risk during the 1% APE. Out of bank flow occurs in rural areas downstream The key messages of Ormskirk potentially causing • Agriculture contributes flood risk to 30 hectares of grade 1 significantly to the local and 2 agricultural land. Flood risk economy and productivity of the management is focussed on river land needs to be considered. asset and channel maintenance Current flood-related impacts to activities. agriculture are considered to be at an appropriate level.

The vision and • Flood risk to property within the preferred policy sub-area is primarily related to the conveyance, capacity Policy option 4: Areas of low, and blockage of culverts and moderate or high flood risk where therefore concentrated works will we are already managing the flood alleviate the risk to property. risk effectively but where we may need to take further actions to keep pace with climate change.

The current level of flood risk is considered appropriate for the sub-area of Ormskirk and the current level of flood risk will be

20 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Pre-feasibility studies into the flood storage potential for Hurlston Brook and Sandy Brook and identification of downstream and environmental benefits.

• Investigate the capacity of problem culverts, including the A59 culvert, and assess the potential benefits of installing CCTV monitoring of the upstream debris screens.

• Establish policies within Local Development Frameworks that work towards long term protection and re-creation of watercourse corridors/floodplain through sustainable land use management and integration with green space agenda.

Culvert under A59, Ormskirk

Environment Agency Alt Crossens Catchment Flood Management Plan 21 Sub-area 6

Martin Mere

Our key partners are: The issues in this Extensive areas of high grade agricultural land and one property Sefton Metropolitan Borough sub-area are at risk during the 1% APE. Council This sub-area is situated in the Without the current level of flood risk management, as many as West Lancashire District Council heart of the Crossens catchment, and is a low lying area which 1,500 properties could be affected Environmental groups is reliant on pumping for land by flood waters. Our vision for this drainage. The area is predominantly sub-area is to continue the current National Farmers Union used for high grade agriculture, and level of flood risk management Local agricultural groups is environmentally rich, with several activity, thus enabling the drainage designated sites including Martin system to function. This will also Natural England Mere SSSI/Ramsar and Mere Sands maintain water levels at the sites Wood SSSI. Under the current, of environmental importance and heavily managed regime, only two therefore reduce potential impacts properties are at risk during a 1% associated with water level change. APE, but there are 1500 hectares of We do not plan to increase our high grade agricultural land at risk. management activities to adapt to Three kilometers of raised defences the impacts of climate change, as a provide a 2% standard of protection result there will be greater wetting to Martin Mere SSSI. The Southport up of land during periods of high to Wigan and the Preston to rainfall. Liverpool railway lines, the B5243 and 7 minor roads are at risk during the 1% event. By 2100 no further The key messages properties are at risk in a 1% APE due to climate change. • Martin Mere sub-area contains significant areas of high grade Surface water ponding and agricultural land which has insufficient capacities of the local economic importance and satellite pumping stations during wider regional and national food periods of heavy rainfall contribute production importance. to the main source of flood risk. • Various national and international sites of environmental value are The vision and located within this sub-area and we are obliged to protect these preferred policy sites under legislation. Policy option 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.

22 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Review the status of some of the main river watercourses.

• Review the use of satellite pumping station operation throughout this sub-area and use the findings to help identify opportunities for wetting up and linking areas of ecological value to create ecological networks.

• Develop the Lower Alt with Crossens Pumped Drainage Strategy involving key catchment stakeholders.

• Review the potential for rationalisation of pumping station capacity.

The Sluice and Middle Drain Watercourses

Environment Agency Alt Crossens Catchment Flood Management Plan 23 Sub-area 7

Southport

Our key partners are: The issues in this practices result in no flood risk to sub-area property and only seven hectares Sefton Metropolitan Borough of agricultural land at risk during Council This sub-area is predominantly a 1% APE. Our vision is to sustain the current level of flood risk West Lancashire District Council urban and contains the seaside town of Southport. Under the management into the future, this United Utilities current pumped and heavily will include keeping an appropriate maintained flood management level of maintenance and the Environmental groups regime, there are no properties at continued operation of the Crossens risk during a 1% APE. There is a Pumping Station located in the 200m length of raised embankment Martin Mere sub-area. To ensure no providing the Cop Retail increase in flood risk to Southport with a 2% standard of protection. from the effects of climate change, Decreased maintenance activities increased operating effectiveness or a reduction in the pumping of Crossens Pumping Station, in regime could potentially lead to conjunction with a potential flood increased flood risk to as many as warning area at , will 4,000 properties. Parts of Southport contribute to the management of town are at risk from surface water these increased risks. flooding and also from coastal flooding, the latter is currently being assessed as part of the production The key messages of the shoreline management • Surface water flooding does plans (SMP). There are a number of present a flood risk to people and environmentally designated sites in property although information on this sub-area including the Sefton the scale or location of this risk is Coast, Hesketh Golf Links and the incomplete. Ribble and Alt Estuaries. • Properties in the low lying areas of Southport rely solely on the The vision and operation of Crossens and preferred policy satellite pumping stations to manage flood risk. Reduction of Policy option 4: Areas of low, capacity, failure or removal of moderate or high flood risk where these pumping stations could we are already managing the flood lead to a significant increase in risk effectively but where we may the number of properties at risk. need to take further actions to keep pace with climate change.

This sub-area is largely urban and current flood management

24 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Investigate extension of the existing Flood Warning Area in the locality of Meols Park.

• Promote individual business flood resilience management plans.

• Identify potential local hotspots for surface water and sewer flooding and develop a Surface Water Management Plan in conjunction with United Utilities and local authorities. Part of this plan should consider opportunities for the implementation and encouragement of SuDS as a means of reducing overall flood risk and controlling pollution and urban run-off.

Marsh Side SSSI

Environment Agency Alt Crossens Catchment Flood Management Plan 25 Sub-area 8

Banks Marsh

Our key partners are: The issues in this climate change occur, increased sub-area wetting up and ponding of Sefton Metropolitan Borough agricultural land will occur. Our Council The majority of this sub-area is vision is to continue the current level of flood risk management to West Lancashire District Council high grade agricultural land with a few isolated properties and maintain the current standard of National Farmers Union farms. Under the current, heavily protection accepting that the risk maintained, flood management of flooding may increase into the Natural England regime there is no risk to future. As part of this management, Environmental groups property and only a limited risk Banks Marsh Pumping Station will to agriculture; this is largely due be appraised for refurbishment. to Banks Marsh and Crossens Pumping Stations. There are no raised defences providing The key messages protection from river flooding, but • High grade agricultural land is there are raised coastal defences the predominant feature in this running the entire length of this sub-area and plays an important sub-area’s boundary with the role in the economy of local Ribble Estuary. Within this sub-area communities. We will continue are a number of environmentally our land drainage activities to designated sites including the enable agricultural practice to Ribble Estuary SSSI and Ramsar site continue where it is justifyable to and the River Alt Estuary SPA and do so. Ramsar site. No further properties are at risk in this sub-area due to • Due to the effects of climate climate change. change flood risk will increase over time. However, we envisage that with the current flood risk The vision and management measures, the preferred policy impacts of these increased risks to agricultural production will be Policy option 4: Areas of low, limited. 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.

Within this sub-area, flood risk to people, property and agricultural land is limited. It is recognised however that as the impacts of

26 Environment Agency Alt Crossens Catchment Flood Management Plan Proposed actions to implement the preferred policy

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

• Review the status of some of the main river watercourses.

• Review the operation of the Environment Agency's satellite pumping stations throughout this sub-area and use the findings to help identify opportunities for wetting up and linking areas of ecological value to create ecological networks.

• Promote agri-environment schemes and encourage take up to support improved soil management, minimise flood risk and encourage the improvement and creation of ecological networks.

Banks Marsh and the mouth of the River Crossens- Courtesy of the North West England and North Wales Coastal Group

Environment Agency Alt Crossens Catchment Flood Management Plan 27 Map of CFMP policies

28 Environment Agency Alt Crossens 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.

GENW0309BPTO-E-E