Peatland Hydrological Restoration Project on Goss Moor National Nature Reserve

Tender description

Goss Moor National Nature Reserve (NNR), which comprises Goss and Tregoss Moors, is a large flat valley basin which forms the headwaters of the River Fal in Cornwall. The NNR is managed by Natural England's Devon, Cornwall and Isles of Scilly Area Team. The NNR is the largest remaining remnant of a once much greater area of wilderness stretching across mid- Cornwall. It contains areas of dry and wet heath, mire, fen and open water, and a diverse mix of wildlife habitats. The reserve's range of habitats and species has resulted in its being designated a Site of Special Scientific Interest, National Nature Reserve and a Special Area of Conservation. Past ditching works and the 'canalisation' of the eastern section of the River Fal accelerate the movement of water across the site resulting in a surface drawdown in some areas. In 2011 a project to restore a 500 metre stretch of the River Fal at Tregoss was completed, this saw the river diverted out of its canalised channel onto the flood plain into a channel which encompasses a newly constructed shallow channel and sections of historic meanders. Further hydrological restoration in the form of naturalising flows in ditches and canalised river channels, and blocking much smaller drains is desirable. Such restoration will raise water tables and increase wetland habitat, this work will also enhance Goss Moor's role in regulating river levels therefore managing flood events on the River Fal. The required works will take place on the main River Fal channel (non EA) and two tributary channels of the River Fal. The requirement is to: - Install current deflectors into the River Fal channel to encourage and speed up the creation of meanders to increase channel length and therefore retention time within the River Fal on Goss Moor. - Install leaky woody dams into the two tributary channels which will raise water levels to reduce the drawdown effect of the channels on the surrounding fen, while still allowing passage of wate