Ecological impacts
The Stonehenge scheme would not just have archaeological and transport impacts; there would be a number of significant ecological impacts on habitats of international importance:
-
The Winterbourne Stoke bypass (to the west of the World Heritage Site) would
feature a damaging crossing of the River Till, designated a Site of Special Scientific Interest (SSSI) for its riparian habitats and
a possible candidate Special Area of Conservation (cSAC) because of its
Ranunculus (water crowfoot)
habitat and the protected species salmon, bullhead and Desmoulin's whorl snail
(the ice-age snail Vertigo moulinsiana that, famously, almost stopped the Newbury bypass and did help to
prevent construction of the
Sandford bypass near Wareham, Dorset).
The four-lane road would have to cross the River Till on a massive embankment, potentially causing
the same devastation as river crossings built into the M3 Twyford Down and A34 Newbury bypass schemes.
Ecological impacts would include direct habitat loss, habitat fragmentation, and pollution to both surface waters (i.e. the river) and groundwater (aquifers).
-
The proposed road would pass closer to Parsonage Down SSSI and cSAC (designated for its chalk grassland) than the current road.
Impacts uncertain.
- At Countess Roundabout, at the extreme east end of the Stonehenge scheme, a massive new flyover will be constructed immediately adjacent to the River Avon SSSI and cSAC. Ecological impacts would include direct habitat loss, habitat fragmentation, and pollution to both surface waters (i.e. the river) and groundwater (aquifers).
Newbury bypass campaigners set up a detailed scientific monitoring programme to study the effects of "runoff" (polluted water draining from the road into rivers and groundwater). This confirms that, even with "best-practice"pollution controls, toxic pollution does occur. Similar pollution would almost certainly affect the Till and Avon rivers if the Stonehenge scheme went ahead.
Mott Macdonald, the company now designing the Stonehenge scheme, also designed the notoriously damaging Twyford Down and Newbury schemes -- with their particularly badly designed river crossings. In fairness, I feel obliged to point out that the Newbury bypass did win an award... from the Concrete Society.