Publication - Consultation paper

Beavers in Scotland: consultation on the strategic environmental assessment

Published: 12 Dec 2017

A consultation on the policy to reintroduce beavers to Scotland and the strategic environmental assessment of this policy.

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Contents
Beavers in Scotland: consultation on the strategic environmental assessment
4.13 Beavers and Cultural Heritage

4.13 Beavers and Cultural Heritage

4.13.1 How Beaver activity affects the Cultural Heritage

Historically important monuments and structures

As detailed in section 4.1, beavers are burrowing animals that dig into banks along suitable water courses, lined with deciduous tree cover to create dens. They will also utilise suitable islands for shelter and foraging. They create scrapes, slides and bankside dens in particular areas of their territories and will therefore have an impact upon some banks of watercourses. They dive to shallow depths to dig up tubers of aquatic plants and use nearby bankside mud when building lodges and dams. In the course of constructing these, trees are felled and the timber floated to the required location. Accordingly, there is the potential for beaver activity, for example through burrowing causing subsidence, or dam-building causing localised floods, to affect historic sites.

There appear to be no documented cases of beavers damaging archaeological sites, but beavers' use of timber for construction material and underwater foraging could mean that any exposed timbers or archaeological deposits on, for example, crannog sites could be at risk from disturbance. In addition to potential direct impacts on submerged features from the above activity, the potential for changes in water levels which could affect the preservation of organic remains on such sites.

Gardens and Designed Landscapes

Ornamental gardens and ponds that connect to watercourses may be occupied by beavers. In most cases they may not be present for very long, but they can radically alter the aesthetic appearance by felling ornamental trees, burrowing or feeding on garden plants. Ornamental gardens and arboreta are relatively common features in Scottish, and the wider British, landscapes, with some being of international importance. Large specimen trees in the vicinity of watercourses can be readily protected, although this may be harder for multi-stemmed shrubs or other palatable vegetation. It is likely that they will feed on a range of plant species that do not occur in their natural habitats.

Other cultural benefits derived from the reintroduction of Beavers

The Beavers in Scotland ( BiS) report studied the interaction of beavers with the Human Environment. This considered the socio-economic implications of the reintroduction policy, the economic arguments of which are largely outwith the scope of the environmental assessment. However, it does illustrate the cultural value that people and local communities place on having beavers reintroduced into the environment. This was illustrated in the public support for the reintroduction which came out of the public consultation and survey work in particular. These benefits include recreational and educational value and a 'non-use' value attributed to the reintroduction of a charismatic species.

Table 4.13.1 Summary of positive and negative effects of beaver on cultural heritage interests

Activity

Mechanism

Positive effects

Negative effects

Notes

Felling

Change in riparian woodland: Opening of woodland canopy and increased patchiness

  • Increase in amount of light reaching watercourses and therefore stabilisation of banks and reduction in erosion due to binding effect of bank and riparian species, could help to protect historically important features within the riverine area
 

Felling

Change in riparian woodland: Change in relative abundance of different tree species

 
  • Possible reduction in deep-rooted species that bind bank material and therefore possible increase in erosion.
  • Felling of trees of commercial or ornamental value.

Felling and Constructions

Changes in amount/diversity of woody material in watercourses

  • Increased number of wood jams, resulting in attenuation of flow and lowering of downstream flood risk and improvements in water quality as fine sediments settle in areas of slower flow
  • Maintaining water levels which could help in the preservation of submerged organic remains.
  • Increased number of wood jams so a possibility of localised floodplain inundation and impacts on historic land use.

feeding

Feeding on specific terrestrial herbaceous and aquatic plant species

  • Underwater foraging could mean that any exposed timbers or archaeological deposits could be at risk from disturbance.
  • Feeding on specimen trees, shrubs and garden plants could impact on the quality of gardens and designed landscapes

Dams/pond creation

Change in hydrological processes on riparian and downstream habitat

  • Hydrological cycle and water flow maintenance:

- increased flood storage, and therefore a decrease in downstream flooding, maintaining water levels which could help in the preservation of submerged organic remains.

  • Increased flooding of riparian zone and beyond, so potential impacts on historic land uses such as historic gardens and designed landscape, encampments, settlements and field systems within riparian areas
  • Flooding of terrestrial land upstream/adjacent to lochs may result in deterioration of water quality through decay of vegetation and leaching of nutrients from soils

Dams/pond creation

Changes in water quality downstream

  • Bio-chemical remediation, e.g. beaver dams reduce the rate of erosion and sediment movement, and therefore the speed at which sediment leaves streams and rivers which could help protect submerged archaeological remains
  • Creation of ponds on inflow waters may lead to improvement in the quality of water in the receiving waterbody through attenuation of flow, sedimentation of solids and assimilation of nutrients within the ponds
  • Reduction in turbulence upstream of dam, and so a decrease in the rate of water oxygenation
  • Creation of ponds on inflow waters may lead to deterioration of water quality of loch inflows through changes in pH, a decrease in dissolved oxygen levels, a build-up of pollutants and disturbance within the ponds which could have an effect on submerged archaeological remains

Other constructions

Creation of lodges, burrows, canals etc.

  • Burrowing activity affects flood defences, sites of historical importance such as canals, crannogs, moats, earthworks etc.

Other

  • Various 'cultural ecosystem services' related to recreational, educational, aesthetic and symbolic aspects

These types of impacts are not connected to any single beaver activity per se, and may relate to the mere presence of beavers (e.g. as an 'iconic' animal). Also relates to socio-economic 'existence' values, and the bequest value for future generations.

Indirect habitat creation/restoration initiatives as result of beaver presence

Beaver used to promote opportunities for riparian and freshwater habitat creation /restoration

  • Restoration of riparian habitat, aquatic and wetland, for example by extending 'buffer zones' along the edges of watercourses, is likely to result in improvements to water quality of standing waters, restore natural connectivity in wetland-loch systems and benefit habitat and species (including those which may be otherwise adversely impacted, e.g. aspen), with consequent 'cultural ecosystem services' benefits

This may include positive impacts on tourism (e.g. for wildlife watching associated with riparian and freshwater habitats). Also relates to socio-economic 'existence' values, and the bequest value for future generations

4.13.2 Distribution of historically important monuments and structures within Policy Areas

4.13.2.1 Scheduled monuments in Knapdale and Tayside

Maps 20 and 21 and table 4.13.2 below detail the sites and locations of Scheduled Monuments within the Knapdale and Tayside potential core beaver woodland Policy Areas. Within this area beaver activity and impacts will be restricted to some freshwater features and the immediate riparian habitat. For ease of reading, larger maps are also included at A3 size in Appendix 1.

Map 20 Knapdale Scheduled Monuments, Battlefields and potential core beaver woodland

Map 20 Knapdale Scheduled Monuments, Battlefields and potential core beaver woodland

Map 21 Tayside Scheduled Monuments, Battlefields and potential core beaver woodland

Map 21 Tayside Scheduled Monuments, Battlefields and potential core beaver woodland

Table 4.13.2 Scheduled Monuments and potential core beaver woodland in the beaver policy areas

Scheduled Monument title

Policy area

Achnamara, clapper bridge, Knapdale

Knapdale

Barnluasgan, enclosures

Knapdale

Cnoc Mhic Eoghainn, motte 170m WSW of Ballimore

Knapdale

Crinan Canal, Cairnbaan - Ardrishaig

Knapdale

Crinan Canal, Crinan to Cairnbaan

Knapdale

Crinan Canal, Loch a' Bharain canal feeder

Knapdale

Loch Coille-Bharr, mill and lade, Knapdale

Knapdale

St Columba's Cave, cave and chapel, Knapdale

Knapdale

Ardblair Castle, earthwork

Tayside

Ardoch, Roman military complex 900m NNE of Ardoch Bridge

Tayside

Auchenlaich, fort

Tayside

Auchrannie, enclosure

Tayside

Balhomie, cup-marked stone

Tayside

Balintyre, homestead

Tayside

Ballownie, mound

Tayside

Balnaguard, settlements & field systems

Tayside

Bandirran, stone circle & standing stones

Tayside

Bertha, Roman fort

Tayside

Bochastle Roman fort, temporary camp and prehistoric enclosures

Tayside

Braclaich, deserted township & field system

Tayside

Broich, cursus, ring-ditch, barrow & palisade 600m SE of Duchlage

Tayside

Campsie Linn, grange site

Tayside

Cardean Roman Camp and pre-historic barrow, Wester Cardean

Tayside

Cardean, Roman fort 230m NW of Cardean Mill

Tayside

Carnbane Castle, Glen Lyon

Tayside

Castle Campbell

Tayside

Castle Hill, motte W of Mains of Cargill

Tayside

Clunie, Castle Hill and The Ward, motte,castle and settlement

Tayside

Colliston Castle, enclosure, souterrain, ring ditches & pit alignment

Tayside

Comrie Castle

Tayside

Cragganester, farmsteads, field systems, shielings and roadways

Tayside

Craig Hill, fort and broch

Tayside

Creag Eilid, settlements, field system and cairn

Tayside

Damside, fort

Tayside

David's Hill, enclosure

Tayside

Doune Castle

Tayside

Doune Roman Fort, fort 60m S of Doune Primary School

Tayside

Duncroisk, cup & ring marked rocks

Tayside

Dundurn Fort, fort St Fillan's Hill

Tayside

Dunkeld Cathedral

Tayside

Edinchip, chambered cairn

Tayside

Elcho Castle

Tayside

Finavon Castle

Tayside

Findynate, homestead

Tayside

Fisherhills, fort

Tayside

Foirche, settlement, Dalshian

Tayside

Friock Mains, pit alignment

Tayside

Glasclune Castle

Tayside

Glenbran, ring fort

Tayside

Gleneagles Castle, tower and earthwork

Tayside

Grassy Walls, Roman camp and prehistoric settlement, Sheriffton

Tayside

Haugh of Grandtully, fort

Tayside

Huntingtower Castle

Tayside

Hurly Hawkin, enclosure, broch and souterrain

Tayside

Inchbervis Castle

Tayside

Inchrye, motte

Tayside

Inchtuthil, Roman fortress

Tayside

Innerpeffray Wood, Roman camps

Tayside

Innes Bhuidhe, forts, NE of Bridge of Dochart

Tayside

Invercauld Bridge

Tayside

Invergighty Cottage, barrow cemetery N of Boysack

Tayside

Invermark Castle and township 220m SW of House of Mark

Tayside

Inverquharity, Roman fort, Roman camp and Iron Age settlement

Tayside

Invervar, shrunken township, Glen Lyon

Tayside

Kerrowmore, motte and settlement 590m S of Innerwick

Tayside

Kilspindie, unenclosed settlement N of Mill House

Tayside

Kinclaven Castle

Tayside

Kinnaird, settlements & field systems

Tayside

Lassintullich, St Blane's Chapel

Tayside

Loch of Kinnordy, crannog 500m NW of Balbrydie

Tayside

Lochleven Castle

Tayside

Lowbank, souterrain

Tayside

Lui Water, townships 800m to 2780m SE of Derry Lodge

Tayside

Lundin, dun

Tayside

Meikleour House, motte

Tayside

Millearnwood, Roman Road, 450m N of Raith

Tayside

Millhaugh, enclosures and other cropmarks

Tayside

Milton of Ogil ring ditch

Tayside

Moulinearn, military bridge, Mill Lands of Dalcapon

Tayside

Netherton, enclosure

Tayside

Newhall Bridge, two standing stones

Tayside

Old Faskally Farm, church

Tayside

Old Lawers Village, deserted settlement, Lawers Acres

Tayside

Orchill Fort, fort 450m NNE of Orchill

Tayside

Panmure Castle and Moat

Tayside

Parkhead, ring-ditch, souterrain and enclosure

Tayside

Pitcarmick Estate, settlements, field systems and cairns

Tayside

Pitmiddle, deserted village

Tayside

Pitroddie Farm, souterrain and unenclosed settlement

Tayside

Powmouth, settlement 400m E of Haughs of Kinnaird

Tayside

Prince Charlie's Bridge, military bridge, Dalcapon Wood

Tayside

Rait Hill, fort

Tayside

Restenneth Priory

Tayside

Ryehill, unenclosed settlement

Tayside

St Blane's Chapel

Tayside

Stormont Loch, crannog

Tayside

Stracathro, Roman fort and camp

Tayside

Strageath Mains, Roman fort, annexe and field system

Tayside

Strowan Church, church and burial ground

Tayside

Tirai, settlement and standing stone

Tayside

Tom na Croiche, castle

Tayside

Tyndrum, lead mines and associated remains

Tayside

Vayne Castle, castle 290m SSW of Vayne

Tayside

Wester Tullich, sulphuric acid works

Tayside

Whiteloch, ring-ditch

Tayside

4.13.2.2 Battlefield sites

The table 14.13.3 below and maps 20 and 21 above and in Appendix 1 detail the location of the Battlefield sites within the Tayside beaver policy area. Within this area beaver activity and impacts will be restricted to some freshwater features and the immediate riparian habitat.

There are no battlefield sites in Knapdale which overlap with potential core beaver woodland.

Table 4.13.3: Battlefield sites and potential core beaver woodland in the beaver policy area

Battle of Dunkeld

Tayside

Battle of Dupplin Moor

"

Battle of Killiecrankie

"

Battle of Sheriffmuir

"

Battle of Tippermuir

"

4.13.2.3 Gardens and Designed Landscapes

Table 4.14.4 and maps 22 and 23 below (see also Appendix 1) detail the location of the Gardens and Designed Landscapes within the Knapdale and Tayside beaver policy areas and overlap with potential core beaver woodland. Within this area beaver activity and impacts will be restricted to some freshwater features and the immediate riparian habitat.

Map 22 Knapdale Gardens and Designed Landscapes and potential core beaver woodland

Map 22 Knapdale Gardens and Designed Landscapes and potential core beaver woodland

Map 23 Tayside Gardens and Designed Landscapes and potential core beaver woodland

Map 23 Tayside Gardens and Designed Landscapes and potential core beaver woodland

Table 4.13.4: Gardens and Designed Landscapes and potential core beaver woodland in the beaver policy areas

GDL title PA code
Knapdale Ballimore 8779
Tayside Abercairny 8742
Tayside Aberuchill Castle 8744
Tayside Airlie Castle 8749
Tayside Balmanno 8782
Tayside Blair Castle 8796
Tayside Blair Drummond 8797
Tayside Bolfracks 8800
Tayside Braco 9212
Tayside Brechin Castle 8804
Tayside Castle Campbell 9216
Tayside Castle Menzies 8823
Tayside Cleish Castle 9219
Tayside Cluny House 8830
Tayside Corrour Lodge 8832
Tayside Cortachy Castle 8833
Tayside Cowden Japanese-Style Garden 10439
Tayside Craighall Rattray 8835
Tayside Doune Park 8863
Tayside Drummond Castle 8867
Tayside Dunira 8877
Tayside Dunkeld House 8878
Tayside Dupplin Castle 9226
Tayside Falls of Bruar 9229
Tayside Fingask Castle 8894
Tayside Glamis Castle 8904
Tayside Glendoick 8911
Tayside Grantully Castle 8915
Tayside Guthrie Castle 8918
Tayside House of Dun 8928
Tayside House of Pitmuies 8930
Tayside Invercauld 8938
Tayside Invermay 9233
Tayside Keillour Castle 8942
Tayside Keir 8943
Tayside Kinfauns Castle 8950
Tayside Kinnaird Castle 8955
Tayside Kinross House 8957
Tayside Meggernie Castle 8984
Tayside Megginch Castle 8985
Tayside Meikleour 8986
Tayside Melville House 8990
Tayside Methven Castle 8992
Tayside Monzie Castle 9238
Tayside Murthly Castle 8998
Tayside Ochtertyre 9010
Tayside Rossie Priory 9032
Tayside Scone Palace 9038
Tayside Stobhall 9046
Tayside Taymouth Castle 9051
Tayside The Burn 9052
Tayside The Gleneagles Hotel 9056
Tayside The Guynd 9057
Tayside The Hermitage 9059
Tayside The Roman Camp 9248

4.13.3 Assessment of effects on cultural heritage interests within the beaver policy areas

Knapdale

At Knapdale, Historic Scotland monitored potential beaver impacts on a crannog on Loch Coille-Bharr, in particular to assess whether foraging on aquatic plants might affect the scheduled monument. Loch Coille-Bharr crannog (Scheduled Monument Index No. 10131) is a submerged artificial island presumed to be the site of a late prehistoric - early historic period lake dwelling. The recovery of timber artefacts from the site in 1867 suggests that the lake silts around the site have preserved organic deposits relating to the occupation and use of the crannog. No impact was observed and the likelihood of impact was thought to be low. The Crinan Canal (Scheduled Monument Index Nos. 6500 and 6501) is an historic and well used waterway, mostly consisting of clay-lined earthen banks with intermittent areas of stone pitching revetting the banks. The canal is fed by a system of streams and lochs, mostly unscheduled. No impact was observed during the trial period on the Canal.

The Knapdale beaver population would be expected to expand, with some likely further impacts on forestry infrastructure. This might include some flooding of tracks and other infrastructure resulting from beaver dam-building activity (including attempts to block culverts) and some occasional felling of trees onto tracks and footpaths. Animals will eventually start to move outside the forest itself, with increasing incidences of the types of impacts described above in the wider area. Continued monitoring would be required along the Crinan Canal, in particular to look for any burrowing into the canal embankments and for any beaver activity in the feeder lochs above the canal.

There is only one Garden and Designed Landscape which overlaps with core beaver woodland at Ballimore. There are no known Battlefield sites within the Knapdale Beaver Policy Area.

Tayside

The effects on the cultural heritage interests in Tayside have not been analysed to the same degree as the study at Knapdale. However, there have been nine records of beaver impacts on ornamental and amenity value trees in private gardens in Tayside. There was also a record of a fish pond being flooded.

The overall findings and recommended mitigation and monitoring measures from the study in Knapdale could be applied similarly to both submerged features and archaeological interests with riverine areas in Tayside. Table 4.13.1 above details the range of positive and negative effects with consequent implications for cultural ecosystem services. There are 97 scheduled ancient monuments coincide with the core beaver woodland within the Tayside Policy area, 5 Battlefield sites and 54 Gardens and Designed Landscapes.

4 .13.4. Mitigation Measures

There are a number of methods that can be used to protect cultural heritage interests and in some cases it may be prudent to protect especially sensitive interests before problems arise. This is more achievable for small-scale structures, such as individual features. The pre-emptive protection of larger scale structures that may be vulnerable to beaver activity, such as canals and settlements and earthworks, would be more challenging. The scale and costs involved for revetment or reinforcement to prevent burrowing would be high. There would therefore be a need to identify and prioritise those structures that may be most vulnerable. Scotland could draw on European approaches to targeting sites for management, and GIS-based tools to identify areas where beaver activity is predicted to be more likely.

There are other issues that might affect small numbers of individuals, for example damage to ornamental trees and gardens. For these, and the more complex infrastructure issues described above, the development of an appropriate management framework will be required. This will need to include guidance on management techniques (for both pre-emptive and reactive actions) and information on sources of advice and support. The effectiveness of beaver management in Scotland will increase over time as experience is gained and methods refined.

Section 5 also details the hierarchy of mitigation techniques that can be used to address impacts from beaver activities, including generic management and licencing approaches to more practical measures including those addressing:

  • Dam building activities
  • Burrowing activities and
  • Foraging activities

These mitigation measures apply to the potential negative effects identified in relation to beaver activity and the cultural heritage.


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