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HS2 – Impacts on historic and natural environment

Map 5: Potter Row
In this section the HS2 route will run along to top of the hills to the east of Great Missenden through a farmland landscape, though
the line will be in a cutting for most of this section

• The line cuts through Sibley’s Coppice (ancient woodland), arable fields, hedgerows and properties beside Frith Hill Lane in a
cut and fill ‘green tunnel’ before entering open cutting. • The cutting then travels along the top of the valley side for the remainder of this section. • Issues to consider in this section include: o Changes in hydrology (particularly relevant to the remaining trees and ground flora in Sibley’s Coppice. o Vibrations from trains in tunnels o Risk of subsidence o Noise disturbance ,dust and air pollution during the construction phase o Visual intrusion of the cuttings, tunnel portal and new bridges. o Congestion and other traffic related impacts resulting from construction traffic, materials movement, spoil removal. o Loss of ancient woodland. o Fragmentation of habitats and habitat corridors. o Severance of ancient routeways. Impacts on historic and natural environment – section summary

Potential direct impacts:
 3 pre-18th century routeways, including Leather Lane (sunken) and Thrift Hill Lane
 Sibley’s Coppice, an ancient woodland will be partially destroyed  1.15 km pre-1840s species rich hedgerow destroyed  13 ‘truly ancient’ or ‘valuable’ trees destroyed Potential indirect impacts:
 2 Scheduled ancient monuments - Redding Wick Moated site and moated site at Chalk Dell Wood near Frith Hill.
 Potter Row Historic Core Archaeological Notification Area adjacent to the construction corridor, and 3 further ANAs lie within 1km (including Missenden Abbey and Great Missenden Historic Core).  2 Conservation areas (Great Missenden and Missenden Abbey Parkland).  Registered Common – Hundridge Wood  Listed buildings –Grade 1 (Church of St Peter and St Paul), 11 x Grade 2  Indirect impacts on 7 other woodlands, one of which is an ancient woodland Local Wildlife Site, three other ancient woodlands and three further woodland Biological Notification Sites (one of which is also ancient). These woods are all less than 1km from the construction corridor.  Indirect impacts on a Biological Notification Site designated for its basic grassland.  Indirect impacts to a site supporting BAP priority wood-pasture and parkland habitat.
For further details see tables below.
Records are recorded with reference to the profile maps.


NATURAL ENVIRONMENT
Description
Distance from
Nature of impact
Aspects of the
construction
development
corridor
to consider

Within Distance
The south-west corner of the wood will be there will ultimately be a green tunnel here, the construction of the cut and cover tunnel could cause a wide corridor of damage and a Indirect impacts to the rest of the wood are  Noise disturbance, dust and air pollution  Changes in air flows (due to passing of trains and structural change in woodland beech trees are large rowan, cherry and downy birch with natural regeneration of all species. The understorey on the western side is dominated by holly, and it is along the western margin that a relic hedgerow contains old sessile oak stools with hornbeam and beech. Wetter corners of the wood have sallow with a ground flora including wavy bittercress and soft rush.  Noise disturbance, dust and air pollution route is the  Changes in hydrology (see entry below  Noise disturbance, dust and air pollution ‘green tunnel’. construction. Construction traffic is likely to pass along the northern boundary with spoil removal lorries from cuttings to the  Contamination of groundwater sources  Noise disturbance, dust and air pollution route is the – particularly from construction traffic globally rare and vulnerable habitat supporting some of our most threatened species.  Noise disturbance, dust and air pollution valley side the canopy. Beneath this is a mixed understorey including whitebeam, rowan, holly, maple, dogwood and even occasional yew. Despite being a fairly small wood, this wood has a very rich flora with 29 plants particularly indicative of ancient woodlands, including moschatel (Adoxa moschatellina) which is rare to Bucks.  Noise disturbance, dust and air pollution valley side  Noise disturbance, dust and air pollution west.  Visual intrusion on setting of wood.  Fragmentation of wildlife corridors to and  Noise disturbance, dust and air pollution 60m long) will  Visual intrusion on setting of wood.  Fragmentation of wildlife corridors to and wildlife sheltered corridor runs from the wood to Potter Row.  Noise disturbance, dust and air pollution valley side  Fragmentation of some of the wildlife  Noise disturbance, dust and air pollution valley side  Fragmentation of some of the wildlife  Noise disturbance, dust and air pollution west. Over 2.25km within the construction corridor
would be destroyed. These include 1.15km
Hedgerows form important wildlife corridors invertebrates though to mammals – large and small; butterflies to bats). Each hedge that is
sliced through links to other hedges crossing
the wider landscape (49 within this section).
Severing this network will have a significant
impact on wildlife movement, important for
feeding and breeding.
13 truly ancient and/or
Within the construction corridor and would be destroyed.
32 Potentially interesting
HISTORIC ENVIRONMENT
Description
Distance from
Nature of impact
Aspects of the
construction
development
corridor
to consider
pollution from the cutting, particularly pollution from the cutting, particularly lorries from cuttings to the south, likely pollution from the cutting, particularly cuttings to the south) is likely to pass pollution from the cutting, particularly  Vibration –construction & trains. pollution from the cutting, particularly  Vibration –construction & trains. pollution from the cutting, particularly  Vibration –construction & trains.

Source: http://www.chilternsaonb.org/uploads/files/high_speed_2/historic-and-natural-environment-description-map-5.pdf