River Test – Bossington Test reborn, Feature 3

Project Details

Location: Bossington estate, Houghton, Stockbridge. SO20 6LT Length: 800 metres River: Main river Test (Middle Test) Clients: Bossington Estate / Environment Agency Project sponsors: Environment Agency / Natural England Nature of Contract: Design / build / project supervision (Principle designer/Principle contractor) Installation date: 18th October to 15th December 2017

Related Projects

Gravel extraction site

Please use the following links below to discover more about the Bossington Test reborn project.

  1. ‘House beat’ – R/H branch (Bossington mill race d/s to Wallop brook confluence)
  2. ‘House beat’ L/H branch – (Upper reach to top boundary)
  3. Gravel extraction site
  4. ‘House beat’ L/H branch (bottom reach to confluence)
  5. Pipe bridge crossing – Upper ‘House Beat’
  6. ‘House beat’ Central
  7. ‘Home beat’ U/S Weir pool & Fishing hut
  8. ‘Home Beat’ weir structures
  9. ‘Home beat’ D/S Weir pool & Riffle
  10. Nursery side stream
  11. ‘Home beat’ to Bailey bridge
  12. Ecological monitoring
  13. Native planting of margins and in-stream macrophytes

The estate extracted an estimated 5,500 tonnes of gravel from a site close to the upper and middle sections of ‘House beat’. This enabled a full-scale bed raising and channel re-meandering exercise over 800m of main river Test plus the restoration of a 200m salmonid-spawning and nursery side stream.

Having access to high-quality floodplain gravel close to point of use is the holy grail of chalk stream restoration.

Photo 14 – Having access to high-quality floodplain gravel close to point of use is the holy grail of chalk stream restoration.

Before –

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Photo 15 & 16 – A small parcel of gravel-bearing land adjacent to the upper and middle House beats was identified through geological mapping as the preferential site for extraction.

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Photos 17 & 18 Several trial pits were dug to establish the presence and feasibility of extracting gravel.

During – The deep seam of gravel was extracted by a 13t machine sitting on the upper surface of the seam and working back over the excavated area and down to a depth of 5metres. Gravel was washed in situ and loaded onto 10 tonne dumpers for transport across temporary pipe bridges, to point of use.

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Photos 19 & 20 – Gravel was located approximately 1m to 1.5m below vegetation level. The overlying top soil and sub soil layers were graded off and stored in a bund seen rear of image.

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Photos 21 & 22 – The thick gravel seam was extracted using a 13t machine set back on the upper surface of the seam and working back over the excavated area and down to a depth of 5 metres. Gravel was washed in situ and loaded onto 10 tonne dumpers for transport across two temporary pipe bridges, to point of use.

After –

Photo 23

Photo 23 – On completion the gravel pit was sculpted into an attractive still-water floodplain feature with a shallower inter-connected marginal wetland pond favourable to amphibians and Southern Damsel fly.

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