SOMERSET HIGHWAYS BIODIVERSITY MANUAL October 2015 1 Somerset Highways Biodiversity Manual 2015-2020 Part of the Somerset County Council Highways Network Management Plan Version 2.2 2 Contents 1 Introduction ............................................................................................................ 5 1.1 Purpose ........................................................................................................... 5 1.2 Somerset’s Biodiversity .................................................................................... 5 1.3 Biodiversity Value of the County Network ........................................................ 6 1.4 What this Manual Covers ................................................................................. 7 2 Legislation & Policy ................................................................................................ 8 2.1 The Conservation of Habitats and Species Regulations, 2010 ......................... 8 2.2 Wildlife and Countryside Act, 1981 ................................................................ 10 2.3 Countryside and Rights of Way Act, 2000 ...................................................... 10 2.4 Natural Environment and Rural Communities Act 2006 ................................. 11 2.5 Hedgerow Regulations, 1997 ......................................................................... 11 2.6 Protection of Badgers Act, 1992 .................................................................... 11 2.7 Weeds Act, 1959 ........................................................................................... 12 2.8 Wild Mammals (Protection) Act, 1996 ............................................................ 12 2.9 Town and Country Planning (Trees) Regulations, 1999 ................................. 12 2.10 Salmon and Freshwater Fisheries Act, 1975 ................................................ 12 3 Effects of Road Works on Biodiversity .................................................................. 13 3.1 Disturbance ................................................................................................... 13 3.2 Street Lighting................................................................................................ 14 3.3 Habitat Loss ................................................................................................... 14 3.4 Habitat Fragmentation ................................................................................... 14 3.5 Barrier ............................................................................................................ 14 3.6 Pollution ......................................................................................................... 15 3.7 Hydrological changes..................................................................................... 15 3.8 Soil changes .................................................................................................. 15 3.9 Changes in numbers of predators and/or prey ............................................... 15 3.10 Introduction of new habitats ......................................................................... 16 4 General Issues Arising from Highways Maintenance Operations .......................... 16 5 Planning Work to Take Account of Biodiversity .................................................... 17 5.1 Establishing Known Constraints and Likely Impacts on Biodiversity ............... 17 5.2 Requirements for Works Affecting Designated Sites ...................................... 22 5.3 Consideration of Other Sites .......................................................................... 23 5.4 Important Habitats and Features .................................................................... 25 5.5 Important Species .......................................................................................... 27 6 Generic Methods to Take Account of Biodiversity ................................................ 33 6.1 General Matters ............................................................................................. 33 6.2 Finding Protected Species ............................................................................. 34 6.3 Grass Verges ................................................................................................. 34 6.4 Hedgerows .................................................................................................... 36 6.5 Trees ............................................................................................................. 39 6.6 Scrub and Saplings ........................................................................................ 41 6.7 Planting and Sowing ...................................................................................... 41 6.8 Visibility Splays .............................................................................................. 42 6.9 Drainage and Soil Movement ......................................................................... 42 (including verge excavation, the creation and maintenance of ditches, grips, gullies, balancing ponds, service tunnels, trenches and pits) ............................... 42 6.10 Pot-hole Repair, Patching and Minor Highway Subsidence .......................... 44 6.11 Kerbing ........................................................................................................ 44 6.12 Bridges and Structures ................................................................................ 45 6.13 Street Lighting .............................................................................................. 46 6.14 Surface Treatments ..................................................................................... 47 (including surface dressing and slurry sealing) .................................................... 47 6.15 Miscellaneous Highway Structures & Furniture ............................................ 47 3 (crash barriers, fences, signs, waymarks, stiles, gates and cattle grids) ............. 47 6.16 Storage and use of equipment and materials ............................................... 48 6.17 White Line and other Painting ...................................................................... 48 6.18 Gully emptying and Drain Jetting Operations ............................................... 49 6.19 Winter maintenance ..................................................................................... 49 6.20 Control of Injurious Weeds ........................................................................... 49 6.21 Eradication of non-native plants ................................................................... 51 6.22 Dealing with Emergencies............................................................................ 53 7. Planning for Species – Design, Working Method and Licensing .......................... 53 7.1 Introduction .................................................................................................... 53 7.2 Bats ............................................................................................................... 53 6.3 Common Dormouse ....................................................................................... 64 7.4 Otter .............................................................................................................. 68 7.5 Great Crested Newt ....................................................................................... 70 7.6 Water Vole ..................................................................................................... 73 7.7 Badger ........................................................................................................... 75 7.8 Nesting Birds ................................................................................................. 80 7.9 Barn Owl ........................................................................................................ 83 7.10 Reptiles ........................................................................................................ 85 7.11 Amphibians .................................................................................................. 88 7.12 Atlantic White-clawed Crayfish ..................................................................... 90 7.13 Lesser Silver Water Beetle (and other aquatic invertebrates) ....................... 93 8 Enhancement Measures for Biodiversity .............................................................. 95 8.1 Habitat Creation ............................................................................................. 96 8.2 Sustainable Drainage Systems (SUDS) ......................................................... 96 8.3 Bird Boxes ..................................................................................................... 97 8.4 Bat Boxes ...................................................................................................... 97 8.5 Bat Bricks and Crevices ................................................................................. 98 8.6 Common Dormouse ....................................................................................... 98 8.7 Otter .............................................................................................................. 99 8.8 Water Vole ..................................................................................................... 99 8.9 Amphibians and Reptiles ............................................................................... 99 8.10 Underpasses for Mammals/Amphibians/Reptiles