Smallfield Flood Alleviation Scheme

Page Contents

Scheme overview

The Smallfield flood alleviation scheme has been in the planning and development process for a number of years. It aims to reduce the flood risk, from multiple sources, to people and property in Smallfield village, Tandridge.


The Weatherhill Stream flows in an open channel in a south-westerly direction through farmland towards Smallfield. The Weatherhill Stream is classified as an Environment Agency Main River just upstream of the Churchill Road culvert inlet (meaning water flows through and out faster than it can enter). Many ditches additionally drain surface water from the local farmland and roads into the Weatherhill Stream channel.

Flood risk in Smallfield occurs mainly due to the number of flow paths joining in the village from multiple directions and the limited capacity within the village to drain this water. This is due to environmental factors within the village alongside flow constrictions under the M23 which limit drainage. This leaves the village unable to effectively alleviate flood risks, particularly during high intensity rainfall.

Project progress

A wide range of flood risk management option types were considered, based on the work previously undertaken. The five short-listed options were the most technically, economically and environmentally viable options. Various sizes of flood storage options were assessed including both above and below 10,000m3, the expected future threshold for reservoirs falling under the amended Reservoirs Act (1975).

The individual options considered however, do not solve the whole flood risk problem for the village and if only a single option was implemented, a number of properties would remain at risk. The combined options currently being considered include flood storage of at least 10,000m3.

Next steps

The delivery will require detailed discussions with landowners and potential developers. These discussions may identify site aspirations which would need to be factored into the outline design.

Depending on the outcome of these conversations, we may take forward a different combination of options to those initially outlined. All these opportunities will require funding contributions in order to deliver the scheme.

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