Sankey Catchment Action Plan

Appendices

Appendix 1: Watercourse Profiles 1.1 Whittle Brook

Whittle Brook is an isolated river with no hydrological link to other water bodies in the Sankey Catchment and, as such, receives no from upstream sources. Whittle Brook rises in a natural channel in a semi-urban landscape close to Sutton Manor and Clock Face. This area is also known for its coal mining with the historic Sutton Manor and Clock Face collieries in close proximity. As the river traverses towards the Mersey it flows under the M62, A57 and through the urbanised area of Great. Many of the issues surrounding the water quality and physical form of Whittle Brook can be related to the urban environment. Whittle Brook joins Sankey Brook in an open channel immediately prior to confluence with the Mersey Estuary.

As the map above demonstrates, there are issues with phosphate in the headwaters of Whittle Brook. At the moment our understanding of the sources of the phosphate are limited, with potential for misconnections from urban areas such as Clock Face but also for recreational and agricultural land to be impacting on water quality. Modelling suggests that around 60% of phosphate in Whittle Brook can be attributed to arable farming. Further research is needed to identify the potential sources of pollution in and around the head waters but it would appear that a farm advice campaign, with the emphasis on pollution prevention and best practice of water management, would assist in reducing pollution to Whittle Brook.

At present it is not thought that the historic mining has resulted in any acute water quality issues but there is always the possibility of issues arising as changes in groundwater occur. Currently, Union Brook and Whittle Brook both receive drainage form the former colliery. This requires a watching brief.

Further down the catchment, the landscape becomes more urban and there is a greater risk of diffuse pollution from urban infrastructure but also greater scope for misconnections from domestic properties. Modelling suggests around 32% of phosphate is related to urban diffuse pollution. Major developments around Omega south have led to discharging to Whittle Brook and Barrow Brook. Much of , north , Lingley Mere and Whittle Hall areas are on separate sewer systems and in the past there have been several reports of misconnections causing water quality issues. These locations investigated for diffuse pollution and targeted as part of a misconnections campaign. Once the main sources of diffuse pollution are identified, the possibility of retro-fitting SUDs into existing green space should be investigated to reduce pollution entering Whittle Brook. There could also be opportunities to install street trees to help reduce pollution entering the brook as well as providing ecological, climate change and aesthetic benefits to local communities.

Whittle Brook has been physically changed and modified as the land around it has developed, particularly around Great Sankey. While some of these modifications are required for flood defence reasons, there are stretches of the brook where the removal of timber revetments and hard banks would improve the physical form of the river and improve ecology. These are indicated on the map by a green diamond. There are also issues with invasive species in and around the riparian environment, which require a catchment approach to management and eradication.

In terms of flood risk, the Whittle Brook Flood Risk Management Strategy (FRMS) flood cell extends from Lingley Green at its upstream end to Great Sankey, around 350m upstream of the railway culvert. The FRMS flood cell for Penketh Brook incorporates all of the flood risk area between Penketh Brook and Whittle Brook, including a length of the Whittle Brook upstream of the railway culvert. This reflects the primary risk of flooding from Penketh Brook in this area.

Penketh Brook also poses a risk of fluvial flooding to the local community. Penketh Brook is a small watercourse that has reaches of natural channel and other reaches that are maintained in a modified channel. It flows from the rural area upstream of the A562 Road through the more urbanised area of Penketh, passing under the St Helens Canal and railway line in culvert before discharging into the through an outfall culvert.

Recent local flooding at Hall Nook by, what are believed to be, low order events has highlighted a lack of capacity through the long culvert under the St Helens Canal and railway line and very limited storage capacity in the field adjacent to the right bank. There is also a culvert under the A562, which can restrict high flows. There is a tidal barrier (flap valve) at the confluence of Penketh Brook with the Mersey, with the only influence of the tide being the duration for which the watercourse is tide-locked. The FRMS notes that these problems are also exacerbated by lack of capacity in the surface water drainage system. However, works were undertaken in 2012 by United Utilities (UU) which will have significantly alleviated the surface water risks arising from more frequent events.

For Penketh Brook the FRMS preferred option was new linear defences; however economics have shown it would be difficult to secure central funding. This area is currently being reappraised by the Environment Agency, including the possible use of natural flood management.

The FRMS recommended a Do Nothing option for Whittle Brook, as the risk of flooding was considered to be low, however this will require close monitoring in future years because of the possible impacts of climate change. 1.2 Sutton Brook

Sutton Brook is the first of several rivers that feed into Sankey Brook. The water quality of Sutton Brook passes WFD standards but it has been physically altered over centuries of urban development.

While it is not possible to return the river back to a natural state, there are a number of these alterations that can be removed and changed in order to improve the physical form of the river. These changes include the removal of bank reinforcement, removal of obstructions in the river channel, the re-opening of culverts, improving the channel profile and the installation of fish and eel passes at several locations (where removal of a barrier to migration is not possible). Such changes will improve in-river and bankside ecology but also align the flow of Sutton Brook and reduce the potential for flooding from the river. The naturalisation of banks will also help mitigate climate change by cooling the river and reducing run off reaching the brook.

There are known issues with contaminated land near Watery Lane at the bottom of the Sutton Brook catchment. This contamination is unlikely to be resolved due to complex issues and as such the removal of hard banks in this section is unlikely as are further water quality improvements.

There could also be opportunity to remove culverts between Colliers Moss Common and Sutton brook, if there are no risks posed by contaminated land, and the culvert of a tributary and of Sutton brook that runs through Sherdley Park. Removing the culverts and naturalising the river in these areas would help filter and attenuate flows from these tributaries into Sutton Brook.

There is also the opportunity to initiate a ‘slow the flow’ natural flood management approach to water management in the upper reaches of this river to reduce flood risk to downstream communities.

1.3 Hardshaw (Windle) Brook

Hardshaw (Windle) Brook is typical of many water bodies; semi-urban and failing expected standards due to diffuse pollution from multiple sources.it is formed at the confluence of Windle Brook and Brook below Canal Street. The location of the water quality sample point on Hardshaw (Windle) Brook provides us with an indication of where the diffuse issues may be coming from.

Around 25% of phosphate in Hardshaw (Windle) Brook is attributed to agriculture. There is a need to carry out a rural pollution prevention/farm campaign offering land management advice and water management plans to land owners/manager. Installing buffer strips, shelterbelts and woody debris would also help slow the flow of water reducing flood risk downstream as well as improving water quality by reducing phosphate inputs and improving local habitat.

Approximately 60% of phosphate in this water body is believed to come from urban sources and phosphate is currently failing water quality standards. Any issues with combined sewers in the catchment would likely be identified and rectified by United Utilities (with many improvements already made in previous AMP schemes) and much of the combined sewer network is in the lower section of the catchment where housing stock is olders. Water quality in the river is already 'moderate' before it reaches the area served by the CSOs. The housing to the north of the sample point, around Denton’s Green, Eccleston and Windle, is on a separate sewer system and as such pose the greatest risk of misconnections to Windle and Mill Brooks. These locations would be ideal for a misconnections campaign. At the same time, there are opportunities to use existing green spaces to install online SUDs systems/wetlands to attenuate and filter the water body as it moves downstream or to filter surface water drainage before reaching the water body.

To undertake such measures requires partnerships with the local council, schools or other landowners who could benefit from a reduction in surface water charges if SUDs are used instead of traditional surface water discharges. Those parks, recreational grounds and schools close to the brooks include:

• Eccleston Road Park (Windle Brook);

• Windlebrook Crescent Open Space (Windle Brook);

• Bleak Hill primary School (Windle Brook);

• Lynton Way Play Area (Windle Brook);

• De La Salle School (Mill Brook);

• St Julies Catholic Primary School (Mill Brook);

• Mill Wood / Mill Brook Wildlife Site (Mill Brook);

• Dodd Avenue Playing Field (Mill Brook);

• Railway Wood (Windle Brook);

• Coleridge Avenue Open Space (Windle Brook);

• Derelict/Vacant land at WA10 6LW (Windle Brook); and

• Grassed land at the end of Windleshaw Road (Blocking access to Bishop Road) (Windle Brook). In future, there could also be the opportunity to install street trees as part of a street level activity to reduce pollutants in surface water and provide climate change resilience, air quality and aesthetic improvements.

Hardshaw Brook is a heavily modified water body requiring 32 mitigation measures and seven eel passes in order to improve the physical form of the river. Delivering these measures would help attenuate flow but also improve habitat and offer climate change resilience through provision of green and blue infrastructure. Beyond WFD required mitigation measures, there are some opportunities to the south of the catchment for ‘daylighting’ of the river where land use data indicates green or open space over a culverted section of water body, such as Ravenhead Greenway. Further investigation is required to identify historic and present day land contamination on the catchment and the full impact within the lower reaches of Hardshaw Brook.

Eccleston/Denton’s Green is a community at risk of flooding. The flood risk mapping indicates fluvial flood risk is present from Mill Brook and Windle Brook. This area is relatively high up in the Sankey catchment, any ‘slow the flow’ or attenuation measures here could benefit downstream communities. There is also an embankment, which provides a standard of protection to playing fields just south of Wokefield Way.

1.4 Sankey Brook (Hardshaw Brook to Rainford Brook)

This section of river connects Sutton Brook and Hardshaw Brook and is the ‘start’ of Sankey Brook. The catchment is mainly urban, dominated by housing and industry.

Two mitigation measures have been identified on Sankey Brook to redress physical changes to the river to allow for urban development. These are required to improve the diversity of the river’s flow by removing hard banks and enhancing habitat surrounding the river. However, as there is a historic legacy of land contamination around St Helens, it is likely assessments of the hard banks need to be carried out in order to understand if there is any environmental risk associated with naturalising the riverbanks.

An eel pass is also required at Grove’s Dam.

From a water quality perspective, a sample point was established to specifically monitor for severe impact from contaminated land along this stretch of Sankey Brook. However, this river does not have any monitoring for WFD purposes and so there is no data to indicate what other chemicals are in the river. There are known issues of water quality where Sutton Brook and Sankey Brook meet due to contaminated land issues on Sutton Brook (see Sutton Brook).

There have also previously been reports of contaminated surface water near the allotments in Thatto Heath impacting upon the tributary that flows into Hardshaw Brook, rather than Sankey Brook (as illustrated on the map above). This suggests there could be potential for domestic misconnections and a need for a misconnections information scheme to reduce future risk.

1.5 Rainford Brook

Rainford Brook is a semi-rural river that passes through Rainford and St Helens before it reaches the confluence with Sankey Brook. The acute water quality issues are related to both rural and urban diffuse pollution. These result in increased levels of phosphate throughout the catchment. Modelling suggesting rural inputs account for around 32% of phosphate in Rainford Brook, while urban sources account for approximately 53% of phosphate.

There are opportunities in the upper section of the catchment to focus on reducing diffuse agricultural pollution. Agricultural land uses in this area tend to be arable and as such there are opportunities to work with local land owners to improve land management and working practices, such as the use of winter covering crop, and the installation of buffer strips near Rainford Brook and its tributaries. Rainford Brook is used for spray irrigation of arable crops, the brook is a valuable source of fresh water to mitigate the effects of contaminated land and over abstraction needs to be avoided in light of this information. Moreover, there could be opportunity to increase natural flood management techniques in the upper section of the catchment, above Rainford, holding water back to reduce peak flows and filtering water entering the brook, reducing both pollution and sediment.

The installation of shelter belts at strategic locations in river catchment above Rainford would also help counter the effects of the west-east orientation of the river catchment, which at present results in the prevailing wind ‘pushing’ water down the catchment, and would also help with surface water management by reducing run-off pathways.

Flooding occurred in September 2012 and December 2015 as a result of a debris blockage at a low footbridge with service crossings near Beech Gardens. A St Helens Council led scheme to raise the bridge and remove the service crossings has been completed, reducing the risk of blockage occurring in future. The Environment Agency also undertake de- weeding, de-silting and removal of in-channel debris along stretches of Rainford Brook.

Ecology is also failing the required standards in Rainford Brook. Further investigation is required to understand the pressures on ecology in Rainford Brook and whether there is an impact from point and diffuse pollution sources – whether chemical pressures or silt – or whether it is the heavily modified nature of Rainford Brook impacting on ecology. Rainford Brook has been physically altered from its natural state to benefit land drainage, urbanisation and to protect development from flooding. It is likely these alterations are preventing fish and eel migration and impacting plants and invertebrates in the river corridor. Although it is not possible to return the river to a natural state it is possible to remove and alter some modifications to benefit ecology and reduce flood risk without causing any adverse impacts. Further investigation is required to understand where such changes could be possible.

Urban diffuse pollution is believed to be a major cause of pollution in Rainford Brook. Unsurprisingly, this is focused around the urban centres of Rainford and St Helens. There is scope for misconnections around Rainford, with much of the housing connected to separate foul and surface water sewer systems, but also around Haresfinch, Sand Lodge and Laffak (on the catchment boundary of Rainford and Black brooks).

Ideally a misconnections campaign would be complimented with an ‘end of pipe’ solution to filter any remaining contaminates out of water entering Rainford Brook, such as retro- fitted SUDs, but there is limited green space for installing such a scheme and known issues with contaminated land towards the urbanised centre of St Helens. Further investigation would be required to identify a suitable site for a SUDs filtration system and there could be an opportunity to work with partners to install wet woodlands or street trees, providing air filtration, water filtration and climate change mitigation.

There are is also the opportunity to understand whether contaminated land in the lower section of the brook is impacting upon water quality and ecology. At present, it is believed there is likely to be an impact but the individual and cumulative impacts of contamination, and possible solutions, is not very well understood.

1.6 Black Brook

Black Brook is in the north east of the Sankey catchment and it faces a series of challenges related to water quantity, water quality, Carr Mill Dam and complex interactions with the .

From a water quality perspective, the main issue is from excessive phosphate, which causes excessive plant growth. Over 70% of the phosphate can be attributed to Billinge wastewater treatment works, which is due for closure before 2021. Once this has closed there will continue to be minor contributions from agriculture and urban diffuse sources. The agricultural improvements will be required in the north of the catchment and the catchment would benefit from the installation of shelterbelts, to counter the west-east orientation of the river, and the creation of buffer strips and attenuation ponds to reduce surface water runoff and filter pollution before entering the brook.

Even with improvements in water quality, it is likely that ecology will require improvements to the river’s physical form in order to offer a diverse and sustainable habitat. Black Brook is a heavily modified river, which has been altered by human activity to allow for changes to protect urban development from flooding and for industry. The latter has resulted in Carr Mill Dam, originally built to power a corn mill, but subsequently used to provide water for the Sankey Canal. It now has a number of recreational uses and stops the migration of fish and eels – this is unlikely to change as it would result in a significant impact on the use of the dam.

Despite this, there are likely to be changes to physical modifications in Black Brook that would result in improvements to bankside plants and invertebrates. Further investigation is required to understand what these changes might be.

Towards the confluence of Clipsley Brook with Black Brook there are two known mine water discharges, the discharge on Black Brook thought to be separate to the discharge on Clipsley Brook. Visually, the culverted stream at Arch Lane is often ochreous in dry weather conditions, which in turn has a high visual impact on Black Brook. Further investigation is required to determine the point source of the mine water, which is suspected to originate form a deep mine. Both of these discharges have potential to be treated via reed bed lagoons, which would lessen the impact of the discharges on local ecology but would need to be maintained to remain effective.

After the confluence of Clipsley Brook with Black Brook there is a community at risk of flooding, this includes 11 houses, two commercial properties and a busy highway route into St Helens. Internal flooding to properties has occurred here three times in the last 15 years. The flood risk is caused by water from the Black Brook catchment being forced through a long culvert immediately downstream of West End Road. Property-level protection measures were installed to the 11 properties on West End Road after flooding in 2012. These reduced the depth of internal flooding in December 2015 but did not prevent flooding entirely.

Environment Agency flood warnings are not viable here due to flashy response of the watercourses. There are also interactions with the river, canal and utility services that make a hard engineering solution to the flooding complex and disproportionately costly. As a result of this, a natural flood management approach has been taken to slowing the flow of water on tributaries of Black Brook, using woody debris to hold water back at peak flow. While this is cannot prevent flooding it can lessen the impact of low magnitude events. This natural flood management approach has also demonstrated a reduction in phosphate levels in after water passes through the woody debris.

1.7 Millingford (Newton) Brook

The Millingford (Newton) Brook catchment includes Millingford, Newton, Ellams, Garswood and Down Brooks. These brooks are believed to be impacted by pollution from mine water discharges, related to historic mine workings, and changes to the physical form of the river.

Mine water discharges have previously caused pollution on Down Brook and a mine-water treatment scheme is already in place, but there are still issues on Garswood Brook from the former Park Pit colliery. A solution could be the installation of a reed bed lagoon system to treat mine water discharges before entering Ellams and Garswood brooks if the problem is acute and requires remediation.

Millingford (Newton) Brook is designated as a heavily modified water body that has been altered for urbanisation and flood protection. There is a need to identify where it may be possible to mitigate these modifications and improve the physical form of the river, increasing its ecological value. Where possible, any measures to improve the physical form of the river could also offer improvements in water quality by adopting practices in the river corridor that could reduce pollution from diffuse sources, such as the installation of buffer strips and woody debris. Several eel passes are known to be required along the length of Newton and Millingford Brooks and at Dean Dam.

Surface water drainage enters Ellams Brook at its source and also enters Dean Brook which feeds Dean Dam. Discharges can have a significant impact in terms of silt, sediment build up and an increase in hydrocarbons. A reduction in settlement and attenuation flows would be beneficial, also helping to address the protection of the downstream catchment form spillages form road traffic on highways.

At present, monitoring suggests urban diffuse pollution is not causing the river to fail water quality standards but there have previously been reports of contaminated surface waters related to domestic misconnections in this catchment. It is often difficult to apportion the pollution to its source, with inputs from possible contaminated land and industrial estate as well as domestic sources. The presence of culverts under urban development further complicates matters but, at this moment in time, diffuse pollution is not a priority unless the cumulative impact of the pollution is found to be impacting upon ecology.

1.8 Sankey Brook (Rainford Brook to Mersey) and Sankey Canal

Sankey Brook (Rainford Brook to Mersey) flows from St Helens to the Mersey at , passing through urban, semi-rural and green belt land on its way. It is the point of discharge for most the Sankey Catchment and there is a tidal influence on Sankey Brook in Warrington which, as the map above demonstrates, results in a number of communities at risk of both tidal and fluvial flooding. The areas of greatest significance for flooding include Gemini, Dallam, Orford and .

The main sources of water pollution in Sankey brook are varied but the wastewater treatment works is the primary source of phosphate, which is the main water pollution issue and is believed to cause excessive plant growth (eutrophication) in the brook. At present, the technology required to reduce the amount of phosphate from the waste water treatment works is not considered technically feasible, but this could change in future.

Work undertaken at Bridges Sewerage Pumping Station has seen a reduction in the frequency of overflows and a reduction of sewage litter entering the brook between Bewsey and Sankey Bridges.

As the brook travels towards Warrington there are tributaries with potential for pollution to enter the brook and it is believed that Dallam and Longford brooks are impacted by urban diffuse pollution from industrial and urban sources. Further investigation into the presence of sewerage litter in Longford and Dallam Brook is needed to identify the problem , with a possible solution of sewer overflows.

There is further potential for pollution from industrial and trading estates in the catchment, including Gemini and Warrington Business Park. These have been identified by University’s National Trading Estates report and represents perceived risk based on the types of businesses and associated processes, rather than actual environmental harm. Further investigation is required to identify those areas where urban diffuse pollution is causing water pollution, the scale of the problem and whether there is an impact on ecology.

Sankey Brook is not classified as a heavily modified water body but analysis of historic mapping suggests the course of the river has altered to accommodate urban development, particularly around Warrington.This mapping also suggests there have been physical changes to the water body, such as the installation of hard banks, and there is a need to understand where these modifications have occurred, if these have affected ecology and whether these modifications can be removed or altered, to improve riverine habitats and flow.

There is also likely to be a need to address invasive species in the river catchment (along both the brook and canal) and a number of eel passes are required in the upper section of the brook to allow migration through the brook and its tributaries.

Sankey Canal is the oldest canal in , originally opened in 1757 and closed in 1963. Sankey Brook and Sankey Canal are hydrologically linked between St Helens and Warrington before splitting into two separate entities in Warrington. Historic mapping shows the extent of changes to the hydrology over time. The issue of a lack of water in the Sankey Canal between Fiddler’s Ferry and Spike Island, an extension of the original canal, is exacerbated by problems with leakage and connectivity, with barriers reducing flow between sections of the canal. There is current a feasibility study ongoing to try and identify potential sources of water for this section of canal that could provide water now and in the future. Mitigation measures could benefit major fish mortality rates, as well as addressing significant algal blooms and low dissolved oxygen levels, which is believed to be attributed to high nutrient levels from the Mersey Estuary used to top up the canal during low flow and summer months.

A number of mitigation measures have been identified as required to improve the ecology of the canal. Some of these measures, such as removing hard banks, could have a significant impact on the use of the canal for navigation in future and should be discounted. However, there are many measures that would benefit fish passage in the canal that should be undertaken where feasible. The Sankey Brook catchment contains a number of locations at risk of flooding. The CFMP for this area is the Mersey Estuary CFMP, and is covered by sub-area 5, Warrington. The designated policy for the residential areas at risk is ‘Policy Option 5: areas of moderate to high flood risk where we can generally take further action to reduce flood risk’. There are three main areas at risk of flooding – Longford Brook, Sankey/Dallam and Sankey Bridges.

Longford has been identified as a particularly difficult area in which to manage flood risk. Much of the existing flood risk is due to combined sewer overflows and surface water drains that discharge into the brook upstream of the pumping station. Outfalls are susceptible to surcharging and blockage when river levels are high and run-off from the catchment could also generate enough fluvial flow to cause flooding. The area is effectively a shallow basin. Channel bed levels are lower at the upstream end of Longford Brook than downstream on Dallam Brook, so when water levels on Sankey Brook are high, water tends to flow upstream and flood the Orford area.

A barrage was constructed on Longford Brook to prevent water backing up along the channel. This asset is owned and operated by United Utilities (UU). The existing UU owned and operated barrier and pumping station were designed to prevent tidal water flowing upstream and restricting sewer discharges, and to allow surface and fluvial water to be removed when water levels are high on Sankey Brook. With climate change, tidal levels and surge levels will change, leading to a likely increase in the operation of the pumping station. The FRMS preferred option for this area was construction of a new pumping station and sluice gate to a 1 in 100 (1%) standard of protection. This is currently being reappraised by the Environment Agency. It might be possible to identify areas suitable for the information attenuation of surface water drain discharges in the Longford Brook catchment to reduce the amount of discharge reaching the brook during rainfall events. Any such areas could also help filter pollution via SUDs.

The Sankey/Dallam flood risk area includes the Sankey Brook from north of the M62, through the Gemini Business Park and Callands areas, down to Bewsey (it also includes all of Dallam Brook). From north of the M62 downstream to some distance north of Sankey Bridges, on Sankey Brook, and on the tributary, Dallam Brook, the main flood risks are fluvial and surface water flooding or overflowing of drainage ditches. There are tidal influences within the Dallam Brook and Sankey Brook but flows and flood risk are mainly fluvial.

An embankment exists to manage flood risk around the Gemini Business Park area south of the M62. However, the channel is natural in this area and as a result of its meanders, the embankment is significantly eroded in some places, giving it a high likelihood of failing in an extreme event. It might be possible to reconnect Sankey Brook with its flood plain at this location, with a lower embankment set back from the river edge. This would also provide a number of water quality improvements by filtering discharges from the motorway.

South of the A574, Sankey Brook flows through a predominantly residential area, past the confluence with Dallam Brook towards Bewsey Old Hall. There have been frequent low-level flood events to several properties at Higham Avenue. There is also flood risk nearby to Southworth Avenue. Further south in the Dallam area the flood extent mapping suggests that there is very little fluvial flood risk in the commercial area to the east of the railway line. However, to the west of the line a number of residential properties are at risk. High flows in Sankey Brook can cause flows in Dallam Brook to back up. The most recent assessment in the Dallam area was presented in the Dallam Flood Alleviation Scheme Project Appraisal Report produced by Atkins and submitted to the EA (September 2013). This notes that the only existing defence in the area is an embankment on the left bank of Dallam Brook, adjacent to Charter Avenue. These defences were assessed to be in a poor condition, with seepage through the embankment having been witnessed.

Further downstream a bridge crosses Sankey Brook which is designed to limit the flow under high flow conditions and push water over the low area into an overspill channel (normally dry) which feeds into Sankey/St Helens Canal.

With reference to the surface water flood risk, United Utilities undertook major works to Bewsey Pumping Station to improve its capacity and standard of protection provided in the Sankey Brook area. Overall, surface water risk appears to be significantly lower than fluvial flood risk. Towards Sankey Bridges, Sankey Brook flows broadly parallel to Sankey Canal to the west, which varies in distance from Sankey Brook between 100m to 200m. After flowing under the A57, Sankey Brook flows adjacent to Sankey Valley Park. To the south and east there are significant numbers of residential and non-residential properties, including two schools. Immediately downstream of Road Bridge the flood risk areas adjacent to both banks contain mainly commercial properties. South of the railway line the extent of flooding is significantly less.

From the Sankey Bridges area downstream, the flood risk is from tidal, fluvial and surface water. Sankey Brook discharges into the Mersey and is tidal up to some distance north of Sankey Bridges. Liverpool Road Bridge constricts the flow on both the brook and the adjacent canal and contributes to backing up of fluvial flows on Sankey Brook. However, it also helps to restrict entry of the tide, thus limiting potential tidal flooding upstream on the brook. Over time, climate change will increase both fluvial flows and tidal flows within Sankey Brook. A further issue is the condition of the current defences, some of which have been classified as failing.

The properties at risk of flooding at Sankey Bridges include residential, commercial and industrial properties and public buildings. Critical public buildings include Evelyn Street Community Primary School, Little Treasures Day Nursery on Evelyn Street and a leisure centre on Hood Lane. In addition, infrastructure is at risk.

The FRMS preferred option for this flood cell was new linear defences with a standard of protection of 1 in 200 years and whole life cost estimated at £8m. As a result of the FRMS appraisal a linear defence scheme was taken forward for Business Case development. However further economic assessment showed that there was a significant funding gap, which needed to be addressed before it could proceed; this is currently being reappraised through NCPMS.

The groundwater around Winwick is a Safeguard Zone due to rising levels of nitrate. Issues that require resolving include diffuse non-agricultural pollution, permitted non-mains drainage and diffuse agricultural pollution. For the latter, there is a need to utilise advice and incentives to reduce agricultural leaching through alternation of management practices.

An investigation is also required to understand the actual contribution of sewage effluent to contamination within the Safeguard Zone.

Appendix 2: Environment Agency Climate Change Risk Assessment for the Sankey Catchment

Data from the latest CAMS ledgers, Range of projections for the 2050s. Calculations are based on Change in amount of water available calculated for the 1990-2007 climatic period the National Climate Change Risk Assessment 2012 for dilution of pollutants

River Name 1990-07 EFI Recent Current Wet Climate Dry Climate % chance of Baseline Wet Climate Dry Climate Naturalised Actual Surplus/ flows below Deficit EFI (today) threshold

Sankey Brook (at 24.6 20.9 23.9 3.0 1.2 Surplus -4.9 Low 80% 100% 93% 67% Causey Bridges GS)

Newton Brook 5.0 4.3 4.4 0.2 -0.2 Low -1.4 V. Low 100% 100% 92% 64%

Black Brook 4.6 3.9 6.0 2.1 1.8 Surplus 0.6 Surplus 0% 100% 95% 75%

Sutton Brook 5.8 4.9 4.4 -0.5 -0.9 Low -2.4 V. Low 100% 100% 91% 58%

Rainford Brook 8.7 7.4 8.6 1.1 0.5 Surplus -1.6 Low 76% 100% 93% 67%

Whittle Brook 1.4 1.2 1.4 0.2 0.1 Surplus -0.2 Low 68% 100% 93% 68%

 All flow data in Ml/d

 EFI = Environmental Flow Indicator

 CMS = Catchment Abstraction Management Strategy

Appendix 3: Local Wildlife Sites

Site O/S Grid Reference O/S Grid Reference Site (start) (finish)

Rainford Brook SD463025, SJ514969 A stretch of Rainford brook which supports a population of Water voles

Bawdy Brook SD474030 SD463025 A stretch of Bawdy Brook which provides habitat for Water voles

Randles Brook SD490021 SD472011 A stretch of Randles Brook which provides habitat for Water voles

Holiday Moss SD496014 - A restored landfill site with relict lowland raised mire. Restoration has included the creation of a variety of woodland, grassland and wetland habitats.

Black Brook (Kings Moss) SJ504010 SJ519992 A stretch of Black Brook which provides habitat for Water voles

Goyt Hey Wood SJ538994 SJ529983 Ancient semi natural woodland on the steep banks of a stream. The woodland is dominated by oak and supports a rich ground and bryophyte flora including a large number of locally rare species and extensive carpets of Bluebells. The woodland is an important breeding bird site.

Carr Mill Dam SJ526981 - Originally a mill dam but enlarged in the 1820s to provide water to the St. Helens Canal system. The dam supports a range of aquatic and marginal habitats and species as well as acid grassland and woodland.

Windle Brook SJ475972 SJ4899965 A section of Windle Brook, which provides habitat for Water voles.

Ellams Brook SJ595974 SJ591967 A stretch of Ellams Brook which provides habitat for Water voles

St Helens Canal SJ532901 SJ970045 A disused stretch of the St. Helens canal at the end of the Blackbrook branch. This section of the canal has extensive emergent vegetation and aquatic vegetation dominated by common reed and reedmace.

Parr Hall Millennium Green and Canal SJ522963 SJ529959 An exceptionally rich and varied marsh and grassland, which has existed for at least 200 years. The site consists of both marsh and grassland and the site contains a number of regionally and locally important species. Water voles are also present on this stretch of the St. Helens canal.

Cloghe Wood and Grassland SJ562936 SJ553953 Ancient semi-natural woodland and associated grassland which runs along the steep banks of Cloghe Brook. The woodland is highly diverse with a stream and associated wetland habitats, including marsh and sallow / alder carr woodland. The woodland and grassland contains a number of regionally and locally rare species

St. Helens Canal, Broad Oak Basin and Frog Hall SJ542958 - This site includes St. Helens canal and a series of three ponds which support a good range of marginal and aquatic plants. Diverse acid grassland surrounds the canal. Both the canal and grassland support a number of regionally and locally important plant species

Havannah Flash SJ548957 - A subsidence flash formed in the second half of the nineteenth century. The water quality is good and the flash has developed rich aquatic and marginal vegetation, with regionally and locally rare species including Rigid hornwort, Spiked water-milfoil and Small sweet-grass.

Newton Lake and Southern Woodland SJ594957 - A large lake within Willow Park with associated swamp habitats and a sandstone outcrop on the eastern shore. The woodland contains one of two known rookery sites within St Helens.

Mill Brook SJ487956 SJ484956 Fast flowing watercourse in Eccleston, which also provides habitat for Water voles.

Mill Wood SJ487955 - One of the few wet broadleaf woodland sites in St. Helens. Carex riparia present in its only urban site in the borough. Drainage ditches were dug to enable woodland planting to take place possibly in the early 20th century.

Mesnes Park and Stream SJ588954 - This site includes the stream area within Mesnes Park. This site contains a range of habitats including, scrub, neutral grassland and small areas of developing wet woodland beside the stream providing habitat for locally rare species

Sankey Brook SJ535961 SJ584932 A stretch of Sankey Brook that provides habitat for Water voles.

Newton Brook 05 SJ591949 SJ951943 A section of Newton Brook with adjacent flood plain habitat. This section of the brook is diverse and includes stream, marginal vegetation, and scrub and sandstone bank habitats. The site supports a number of nationally, regionally and locally important species.

Stanley Bank Meadow, Ponds and Wood SJ534971 - This site forms part of Stanley Bank Local Nature Reserve. The site comprises Stanley Bank Meadow SSSI, the largest area of lowland damp neutral grassland in , and Stanley Bank Wood ancient semi- natural woodland. This is a diverse range of habitats and over 200 plant species are supported, a number of which are nationally, regionally and locally important

Windle Brook SJ475972 SJ489962 A section of Windle Brook that provides habitat for water voles.

Grassland South of Towpath, Sankey Valley Park SJ567948 - An extensive grassland area within Sankey Valley Park which provides important butterfly habitat. Other habitats include swamp and woodland adding to the diversity of the site

Rough Grassland around Sutton Dam Stream SJ527925 - This site contains a mosaic of habitats including neutral grassland, scrub, broadleaf woodland and wetland and marsh areas around Sutton Mill Brook that runs through the centre of the site. The site contains a number of nationally and regionally important species.

Sutton Mill Dam SJ523923 - A water body created by the damming of Sutton Mill Brook. The site contains a number of nationally and regionally important habitats and plant species including the nationally scarce species Tasteless water- pepper (Persicaria mitis).

Pendlebury Brook SJ493920 SJ515914 A stretch of Pendlebury Brook, which supports a population of Water voles.

Whittle Brook SJ521902 SJ53589 A stretch of Whittle Brook which provides habitat for Water voles

Gemini Washlands SJ491413 - An area of inundated grassland

Sankey Brook SJ953913 SJ596901 A stretch of Sankey Brook that provides habitat for Water voles.

Bewsey Meadows SJ595898 - A former landfill providing wet grassland habitat.

Sankey (St Helens Canal) SJ591894 SJ584876 A reach of canal providing habitat to water voles and containing a wetland nature reserve with extensive reedbed. Gatewarth Phase 3 SJ5718869 - Former landfill by the river Mersey providing habitat for Brown Hare and Short Eared Owl.

Sankey Canal SJ573872 SJ531852 A reach of canal providing habitat with reed fringe providing habitat for water voles

Appendix 4: Nature Improvement Area