Laleham Farm is a 45 hectare former sand and gravel extraction on the urban fringe near Staines in Surrey.
Case study date
Greenham Aggregates, Shepperton Aggregates
Sand & Gravel
Mineral Planning Authority
Surry County Council
Restoration / Priority Habitats
Protection of nesting birds
Market Gardening / arable
Safeguarding BMV soils
Drainage and water use
Best practice guidelines – Restoration SPD
An arable restoration on high-grade ‘best and most versatile’ agricultural soil (it was classified as grade 2), the site is delivering real biodiversity benefits and has won both the Cooper-Heyman Cup for mineral restoration and the English Nature Farming for Wildlife Award.
Laleham has been farmed by the Bransden family since the 1960’s and produces vegetables, herbs and flowers for wholesale markets and London restaurants.
A number of factors were instrumental in the restoration but the handling and placement of soils, drainage design and aftercare are of particular note. It lead to Surrey County Council drawing on the best practice demonstrated at the site when it developed the guidelines for agricultural restoration in its Restoration Supplementary Planning Document.
The site was progressively extracted, backfilled with inert waste, and then subsoils and topsoils placed and levelled to the correct depths (850mm of subsoil and 300mm of topsoil), in 6m wide strips, using an hydraulic excavator standing on the infill surface. This protected the soil profile by preventing machinery from continuously tracking over it, thereby avoiding compaction and damage to the structure. Phased working also allowed Laleham to continue being farmed during extraction, critical in assuring the site’s economic viability. No plant or vehicle traversed the soils until the farm cultivated and seeded with broad beans as a first overwinter cover crop. The first vegetable crop was planted the following spring.
Wildflower margins and hedgerows have been planted alongside the ditches, providing nesting habitat, shelter belts and wildlife corridors as well as enhancing the landscape quality of the area.
As farm managers, the Bransden family have been an important part of the site’s restoration success. In addition to being the tenant farmer, Barry Bransden was restoration manager for part of the site’s operational period and his affinity and long- term vision helped to ensure the restoration concept was fully realised.
The site supports a number of species including breeding lapwing and little ringed plover, both of which nest between and within the crops. Once nests are noted, farm workers are informed and a marker placed next to each to ensure the birds remain undisturbed for the duration of the breeding period.
The site was not clay capped but prior to each phase being restored with inert infill and soils laid, drainage pipes were installed linking to a network of ditches.
The site was engineered with a 1:300 slope from north to south with ditches created at approximately 300m intervals. 80mm plastic drainage pipes were laid in 12m intervals at right angles to the ditches, running at a 1:100 incline from the ditch to the ridge. These were covered with reject stone. The soils were then placed in 6m wide strips over the installed pipes, matching the 1:100 incline to form a corrugated ridge between the ditches. Drainage was effective immediately allowing the ditches to be used to control water levels on site.
The upfront drainage design, installed during the restoration process was crucial to enabling a high quality agricultural afteruse. It also allows the farm to draw water from an open water void on an adjacent gravel extraction site to irrigate the fields.
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