The Challenge:

Stover Lake, lying at the heart of Stover Country Park on the edge of Dartmoor National Park, had once been known as a great place to find lilies and invertebrate diversity. However, over the last few decades that biodiversity has been in slow decline, in no small part due to the contaminated silt in the run-off from the adjacent A38.

The impacts of that contamination were evident from the water assessments carried out, but also visually from the disappearance of those famous lilies.

The Solution:

A number of works were undertaken to help with the remediation of this problem. Drainage was realigned, with the installation of line silt traps, oil interceptors, pollution control valves and reed beds that reduce silt, oil and soluble metals.

The work was done through extensive collaboration, including with; Highways England, Devon County Council, South West Highways, Natural England and Rangers at Stover Country Park.

The Impact:

This all helped to reduce the contamination from the A38 outfalls. The reed beds naturally slowed the water flow and removed contaminants. The installation of wetland provided some much-needed habitat for aquatic and bird species. Wildflower meadows were also created and have established with an obvious benefit to pollinating species. Several bird and bat boxes were also installed. All of the measures have ensured long-term biodiversity net gain.

The project was also recently a double winner at the ICE southwest awards, where it won Project Under £3m and the Judges Special Award

" Well done to everyone who has worked on this project. A great example of the wonderful work delivered through this contract. "
Dave Olorenshaw General Manager Southwest DSC

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