The Environment Agency is working in partnership with Calderdale Metropolitan Borough Council, Ove Arup and Partners and BAM Nuttall Ltd to develop a Flood Alleviation Scheme (FAS) for Erringden Hillside.
The Erringden Hillside FAS will consist of highway drainage works to existing road and footpath networks, including gullies, drainage runs, kerbing and outfalls to the River Calder and the Rochdale Canal. The three main areas of work are above Stubbing Brink, at Hebble End and Fairfield.
Construction is due to commence early 2022.
BAM Nuttall commenced the ground investigation works on the 23rd August 2021. These investigations are now complete. The findings from this investigatory work will inform the detailed design and confirm constructability.
Submission of planning applications for Hebble End Rochdale Canal outfall and Shelf Road River Calder outfall are due to be submitted shortly. A public meeting was held on Monday 22nd November - please see Keeping You Informed document below for more information:
Erringden Hillside is located along the southern edge of Hebden Bridge in the Calder Valley. The upper slopes are primarily used for agriculture, with wooded areas on the mid slopes providing a buffer between the more developed lower slopes. The impacts of industrialisation associated with the milling industry are evident with the Rochdale Canal and the Calderdale railway flanking the River Calder within a narrow corridor along the valley bottom.
The catchment is characterised by steep slopes, with interconnected bridleways, footpaths and roads that traverse the hillside. The project area has been considered as three discrete elements, which are summarised as follows:
Located at the western end of Hebden Bridge, this straddles the Rochdale Canal and Calderdale railway cutting. The area is primarily residential.
The site is located between the River Calder and Rochdale Canal and contains a mix of residential and commercial properties. It provides an important access point to the Fairfield and Horsehold areas.
Located at the east of Hebden Bridge, it is bounded by the railway line. The area is primarily residential.
The network of footpaths and access tracks on the steep catchment provides efficient routes for surface water to flow down the hillside to the urbanised areas of Hebden Bridge. The three areas within the project have been flooded in recent years. The most notable event was June 2012 when existing drainage infrastructure was unable to cope with the volumes of surface water, resulting in flooding to a large number of properties.
Past flood incidents
The most notable flood event at Erringden Hillside was in June 2012 when existing drainage infrastructure was unable to cope with the volumes of surface water, resulting in flooding to a large number of properties.
In December 2015 flooding was widespread across Hebden Bridge. Whilst surface water runoff affected the key study areas, the intensity was generally less than in 2012.
In February 2020 during Storm Ciara, more than 100mm of rain fell in the upper Calder catchment between 11pm Saturday 8 February and 11am Sunday 9 February. This was the second highest flood event recorded in the Calder valley, second only to the Boxing Day flooding of 2015. Calderdale received more than a month’s rainfall over 48 hours during Storm Ciara (129.8mm). This led to many properties and communities been impacted by flooding again.
As part of the Erringden Hillside Flood Alleviation Scheme the Environment Agency have commissioned a suite of surveys to identify any potential environmental risks and identify opportunities for environmental enhancements which can be incorporated into the design of the project.
A Preliminary Ecological Appraisal Report which examined any ecological constraints, as well as any habitats for protected species has been undertaken. The recommendations from this report include appropriate timings to work in the river, any tree removal, and mitigation measures for any construction work.
As part of the Preliminary Ecological Appraisal Report it was identified that two bridge structures that may be affected by the proposed works had moderate to high bat roost potential. Two dusk emergence surveys were undertaken in the summer of 2021 to investigate whether any bat roosts were present in these structures. The surveys concluded there were no bat roost roosting in these structures.
The tree survey identified the location and condition of trees along the proposed scheme. An initial assessment aims to retain as many trees as possible. This will be developed and re reviewed as the design progresses. We will replant 5 trees for every mature tree removed and will work with stakeholders to identify where the replanting could take place around the Erringden Hillside area.
Water Framework Directive
A Water Framework Directive Screening Assessment has been undertaken. This assesses the biological elements (including fish and invertebrates), as well as hydro-morphological elements (flow quality or river width) and chemical quality elements (sediment or pollution). The proposed scheme is likely to result in minor localised impacts to the ‘Calder from Colden Water to Ryburn Confluence’ and ‘Rochdale Canal – Eastern Section’ WFD water bodies. However, the proposed scheme is not anticipated to cause any significant adverse effects on the quality elements of the water bodies, when considered against the embedded construction phase mitigation.
A Heritage Desk Based Assessment is being prepared for the Erringden Hillside Project. Initial findings have identified the risk of permanent adverse impacts associated with this package of works to be low. Works are primarily within the existing highway and therefore the likelihood of disturbing archaeological remains is low. Additionally, there is a small number of listed assets that may be affected by the works and given their nature, permanent impacts upon setting are unlikely.
Biodiversity Net Gain
Biodiversity Net Gain is an approach to development that leaves biodiversity in a better state than before. Where a project has an impact on biodiversity it encourages the project to provide an increase in appropriate natural habitat and ecological features over and above that being affected in such a way it is hoped that the current loss of biodiversity through development will be halted and ecological networks can be restored.
The initial Biodiversity Baseline has been calculated for the proposed project; the EA are aiming to provide 20% Biodiversity net gain on this project.
For any enquiries about the scheme please email HebdenBridgeFAS@environment-agency.gov.uk