Smallfield Flood Alleviation Scheme

Surrey County Council, in partnership with Tandridge District Council, the Environment Agency and Thames Water, is delivering the Smallfield Flood Alleviation Scheme to reduce the risk of flooding to homes and infrastructure in Smallfield.

Smallfield has been subject to several flooding incidents, including the significant event in November 2022. The scheme aims to reduce the likelihood and severity of future flooding in Smallfield and protect the community from the impacts of flooding through a combination of a Flood Storage Area and Property Flood Resilience.

This work is supported by a combination of funding sources, including Flood Defence Grant in Aid from Defra, contributions from us, and support from local partners. The funding enables the delivery of long-term, sustainable flood risk management solutions for the community.

What the scheme involves

1. Plough Road Flood Storage Area

The project proposes a flood storage area (FSA) at Plough Road Recreation Ground to capture and store flood water to reduce flood risk in the south-eastern and central part of Smallfield.

The FSA is designed to temporarily capture and store water within the recreation ground during periods of heavy rainfall, helping to prevent the local drainage systems from being overwhelmed and flooding nearby homes.

The proposed design includes a low wall along the northern and western edges of the recreation ground, which will gradually taper into the existing ground levels. An outfall will connect to the highway drainage network, allowing water to be released in a slow and controlled manner – a significant improvement to the rapid runoff currently experienced during storms.

The recreation ground will retain its primary use as a sports field after construction, except when temporarily storing flood water in extreme weather events, when the pitches would typically be inundated with surface water. The project team is also exploring opportunities to improve field drainage which would improve utilisation of the recreation ground year-round.

The scheme is currently in the detailed design stage meaning the final design is still being refined in consultation with partners and through the planning process.

2.Property Flood Resilience

The Property Flood Resilience (PFR) project focuses on making individual homes more resilient to flooding. This includes installing measures such as flood doors, air brick covers, and non-return valves. These adaptations help to reduce the impact of flooding and enable residents to recover more quickly after a flood event.

The work will be completed in two phases:

• Phase one involves a pre-design survey that assesses the property, evaluates the flood risk, and provides a list of recommended measures to improve the home’s flood resilience.
• Phase two covers the detailed design survey, installation, and handover of the PFR measures to the homeowner. The installation contractor will carry out their own survey, guided by the recommendations from the pre-design phase. Based on this, they will prepare the final design, taking into account any construction constraints. Once agreed upon, the measures will be installed. The pre-design surveyor will then conduct a post-installation audit to confirm that the measures have been installed correctly, and that the homeowner has received proper guidance on how to deploy them. Some wet testing will also be carried out to validate the installed measures.

Next steps

• Design and planning are ongoing for the Plough Road FSA, with construction expected to be completed by early 2027. Public consultation will be available with the planning application.
• The delivery of PFR scheme is expected to begin delivery in summer 2025.

What has already been achieved in Smallfield

Surrey County Council and its partners have already taken several important steps to address flooding in Smallfield including:

Drainage Improvements

• Blockages in the surface water drainage network, particularly along Wheelers Lane and Broadbridge Road, have been cleared. Defective sections have been repaired or replaced.
• Maintenance of the M23 balancing ponds and drainage network to restore them to good working condition.
• Installation of a 600mm diameter pipe between Wheelers Lane and Weatherhill Road to improve water flow.
• Numerous upgrades to the Wheelers Lane drainage network to increase capacity and reliability.
• Installation of Wheelers Lane rain garden to address a localised surface water flooding issue.

Surveys and Investigations

• An extensive survey of local ditches identified key issues, and landowners were engaged to help remove obstructions.
• Forgotten third-party pipe systems were rediscovered and brought back into serviceable condition.

Flood Risk Assessments

• A comprehensive flood risk assessment was completed. This supported identification of key areas to implement flood risk measures.
• These assessments have been incorporated into planning conditions of local housing development sites.

Community Engagement

• Engaging with the community via a Flood Action Group with our partners.

Funding Secured

• Grant in Aid funding has been approved to support the development and delivery of the scheme.