Farnham quarry is adjacent to Aldershot on the Surrey/Hampshire border, surrounded by major roads and housing. Hanson Aggregates inherited the 50 ha site from Pioneer who began extracting sand and gravel here in the late 1990s. Extraction ceased in 2010, allowing Hanson to commence the final phases of restoration.

Case study date







Hanson Aggregates

Mineral Planning Authority

Surrey County Council

Mineral Type

Sand and gravel

Habitat(s) Created

Lowland Meadows, Wet Grassland, Standing Open Water

Restoration / Priority Habitats

Lowland Meadows
Standing Open Water
Lowland Mined Deciduous Woodland
River reprofiling

Partnership Working

Surrey County Council
Blackwater Valley Countryside Partnership
Surrey Wildlife Trust

Key Issues

Hydrology and hydrogeology
Limited overburden for landforming

Public Benefits

Accesible greenspace
Defined access routes to afford good views of wildlife without compromising nature conservation interest
Flood alleviation potential


Farnham quarry is adjacent to Aldershot on the Surrey/Hampshire border, surrounded by major roads and housing. Hanson Aggregates inherited the 50 ha site from Pioneer who began extracting sand and gravel here in the late 1990s. Extraction ceased in 2010, allowing Hanson to commence the final phases of restoration.

The River Blackwater rises further north-west of Aldershot and flows through the site. The Blackwater Valley Countryside Partnership works along the river to provide a continuous greenspace attractive to wildlife and the community. Being close to Farnham and Aldershot, and within the Blackwater Valley area, means Farnham quarry is ideally placed to provide greenspace as well as much-needed wildlife habitat.

Planning history

Prior to extraction the site was intensively farmed arable land (the soil is classified as grade 3b). Under Pioneer, the approved restoration was to lakes and a country park with public access. When Hanson took on the site they realised the original scheme was not feasible due to issues with the underlying geology and hydrogeology but that this provided the opportunity to focus on nature conservation as the afteruse. The restoration scheme was revised, with the aspiration to deliver greater biodiversity benefits through habitat creation, whilst retaining the community benefits.

Restoration details for the site have continued to be subject to revision over time due to a number of factors. For example, limited overburden material has resulted in the site being a lot ‘wetter’ than anticipated and provided a slightly different composition and ratio of habitats than planned. Some silt lagoons outlined in the original plan have not been required, but elsewhere others have been added due to operational needs. In addition, the Environment Agency took the opportunity on to realign the adjoining River Blackwater on non-operational land as an integral part of the revised restoration (see below for further details).  The weather has also affected progress on the restoration. An unseasonally wet summer in 2012 has resulted in the final earthworks being put on hold until 2013.

Habitat creation details

The site is being restored to open water and a variety of semi-natural, species-rich grasslands with some woodland planting on silt lagoons aiming to create wet woodland. In addition, a belt of native broadleaved floodplain woodland is being planted alongside the River Blackwater, and oak/ash/hazel woodland around the drier perimeters of the site.

Limited overburden for use in restoring the worked out voids, has resulted in a larger area of open water being created in the south east (where the base of the extraction rests on the underlying chalk) and an area of grassland that is likely to remain flooded for prolonged periods. Only the previously restored ‘meadow’ area (neutral grassland) in the north west part of the site is expected to remain dry throughout the year. However, as the habitats develop, this transition from open water, to flooded grassland to seasonally wet grassland through to dry meadow should create a series of ecotones that are valuable for biodiversity.

Before extraction, the topsoil and sub-soil from initial phases were stripped and stored in perimeter bunds. Once working was complete in each phase, the topsoil, subsoil and overburden from the next working area were stripped and direct placed using best practice soil handling methodology. The final phases of restoration are utilising soils stored in perimeter bunds.

Woodland areas

A band of trees was planted in the early stages of extraction to screen the workings from the nearby residential area. This initial belt was extended when members of the community helped to plant the ‘Jubilee Wood’ in 2002. Local people already enjoy walking in this woodland of native deciduous trees, and planted stock, supplemented by natural regeneration, is establishing well despite some early vandalism problems.

Wet woodland is being created in the complex of silt lagoons across the northern half of the site. Once the lagoons have been filled, lagoon bund walls will be pushed in to partially cap off the drying silt. Pioneer species typical of wet woodland will be planted directly into the silt substrate in lagoon centres, with other more demanding native broadleaved species on drier soiled edges. The lagoon woodlands will tend to form a gradation from birch woodland on the drier sandy substrates at the upper end of lagoons, grading down to wetter alder/willow National Vegetation Classification types at the lower ends on clay substrates.

Grassland areas

A number of methods were used to establish vegetation in the lowland meadow. The first phase was cultivated and seeded with a Countryside Stewardship approved “re-creating grasslands” mixture with a small proportion of wildflower mix added. Subsequent phases have generally incorporated natural regeneration from the soil seed bank. Hay strewing was also used as a source of propagules in the second and third phases when conservation volunteers from the Blackwater Valley Countryside Partnership spread green hay collected from nearby species-rich meadows.

A third phase was also over-seeded using a stewardship grass seed mix but with alternate strips seeded with a more expensive MG5(MG5 = Species-rich lowland Mesotrophic Grassland under Rodwell’s National Vegetation Classification) grass/wildflower mix. The hay-strewing has been the most successful method to date, though composition of the sward is expected to change as it matures.

To increase species-richness, all areas have been mown just once or twice per year in late summer, though no cropping or removal of vegetation has yet been possible, and a hay-cutting and/or a grazing regime is being considered if a suitable tenant can be found. Grazing began on the site in 2009 using ponies but has since ceased due to overstocking by the tenant. Overstocking led to problems with poaching, although this may have been beneficial for the strewn hay. The restored meadow is now be cut in late summer after flower seed has set. Grassland surveys were undertaken in 2007 and 2011 and found that the species richness of the meadow continues to improve over time, with certain parts now well established.

An “accidental” wet area has been left in the meadow due to soil compaction and shallow gradient, which has been accepted and left without further remedial treatment. Such action would have been taken if the focus of after-use had been towards agriculture rather than nature conservation. This wet area attracts a number of birds, adding further interest to the meadow.

Advice from the local authority ecologist helped in drawing up the design, in particular to make the grasslands more attractive to key bird species by removal of previously proposed hedgerows/trees that could harbour predators.

In late 2011, on the recommendation of Surrey County Council’s Restoration Manager, one of the silt lagoon bunds was breached and the silt allowed to slump and flow out in the direction of the open water area. It is hoped this material will settle and dry out but remain wet enough to enable a wet grassland sward to develop.

River re-profiling

In 2006, the Environment Agency took the opportunity to re-profile the heavily canalised River Blackwater where it runs along the northern boundary of the ‘Jubilee Wood’ in a straightened artificial channel. The Environment Agency dug a new channel, with a number of large meanders that reflect the river’s historical flow path. The canalised channel was then filled in but maintaining connections from storm drains to the new channel.

The new channel has been designed to accommodate the river’s very low summer flow, but potential high winter flow – the main channel is narrow and deeper than before, but with gently sloping banks that provide a wide channel for winter. The wide, sloping banks also encourage marginal vegetation. A wader scrape and small pool have also been created. The primary function of this restructuring is flood defence, but landscape and wildlife will benefit significantly.

Bat roost

A non-operational conveyer belt tunnel has been retained on the former plant area and will be converted into a bat roost, using a series of boards fitted to the interior. Tree planting in this area will provide flight lines as a way of encouraging bats to use the roost. As well as hopefully developing into an important ecological niche, it recognises the site’s operational past.


Farnham Quarry is fortunate to have a 20-year aftercare agreement with Surrey County Council and benefits from a Management Plan and site BAP that help inform and guide aspects of the long-term management. In addition, a Management Group has been formed and meet regularly to discuss progress on the restoration and aftercare. The Group includes Hanson’s Principle Landscape Manager, the County Council’s Restoration Manager, local ornithologists and the Blackwater Valley Countryside Partnership (BVCP). It is hoped BVCP will remain closely involved in the site’s management in the long term. Good access for grazing animals and vehicles used for management will be key to ensuring high quality habitat develops across the site, particularly on areas that may remain wet for prolonged periods.

Public benefits

When the site has been completely restored, permissive footpaths will run through the northern woodland areas. Viewing points over the southern meadows and wet grassland will be available at intervals, allowing visitors to enjoy excellent views of birds and other wildlife but preventing disturbance of nesting birds.

The information set out within this advisory sheet in no way constitutes legal or regulatory advice and is based on circumstances and facts as they existed at the time Nature After Minerals compiled this document. Should there be a change in circumstances or facts, then this may adversely affect any  recommendations, opinions or findings contained within this document