1. Biodiversity and the Thames Tunnel Stephanie McGibbon, EIA Manager 12 May 2011

2. Contents Overview of the Thames Tunnel project Thames Tunnel EIA and Biodiversity –Data gathering –Initial findings –Engaging with stakeholders Questions

3. Project overview

4. Victorian infrastructure

5. Combined sewer system

6. 57 Combined sewer overflows (CSOs)

7. Headline news

8. Thames Tunnel to intercept combined sewer overflows

9. Capturing the overflows

10. Environmental Impact Assessment (EIA) and Biodiversity

11. Baseline Baseline Survey Reports Scoping Scoping Report (March 2011) Preliminary Environmental Information Preliminary Environmental Information Report (Autumn 2011) Environmental Statement Stakeholder Consultation EIA & reporting stages

12. Terrestrial ecology data gathering Desk Study: GIGL data search and consultation Use of Satellite/Geo-viewer Imagery Phase 1 Habitat Surveys and Plans (completed) Detailed Surveys for Protected/Notable Species (underway)

13. Terrestrial ecology: protected / notable species surveys Bats Birds (Breeding & Wintering) Reptiles Amphibians Invertebrates Otter and water vole Botanical

14. Phase 1 terrestrial ecology surveys - extract SiteHabitatsSpecies Potential Abbey MillsMature trees Scrub Semi-improved grassland Disused buildings Birds Bats Reptiles Invertebrates Water Voles and otter Invasive Plants Acton Storm TanksAmenity grassland Tall ruderal vegetation Scattered trees Wintering birds Bats Reptiles Barn ElmsAmenity grassland Semi-improved grassland Tall ruderal vegetation Scrub Scattered trees Running water Breeding and wintering birds Badgers Bats Reptiles Invertebrates Water Voles and otter Beckton STWScrub Scattered trees Plantation woodland Standing water Breeding and wintering birds Black redstart Bats Reptiles

15. Aquatic ecology data gathering Desk study –Environment Agency fish and invertebrate databases –Mammal data –Local Habitat Action Plan’s (HAPs) Field surveys –Construction and ‘Improvement’ sites –Range of sites and spatial scope of survey

16. Fish surveys (autumn 2010)

17. Total fish

18. Invertebrates surveys (Autumn 2010)

19. Invertebrate diversity

21. Mitigation hierarchy REDUCE IMPACT ABATE IMPACTS AT SOURCE ABATE IMPACTS ELSEWHERE (as close to impact as possible) COMPENSATE IN KIND COMPENSATE BY OTHER MEANS ENHANCE Enhancement Compensation Mitigation AVOID IMPACT

22. Balance sheet ABCDEFG Habitat Permanent landtake for built footprint Mitigation landtake Total landtakeHabitat creation Habitat enhancement Total creation/ enhancement Net loss/gain WoodlandHa Scattered TreesNo. HedgerowM ScrubHa Tall RuderalHa Ornamental Planting/Introduced Shrub Ha Semi-improved Grassland Ha Amenity GrasslandHa Short Perennial/DisusedHa Standing Water/WetlandHa TOTAL (Semi-natural habitats) Hard-standing (buildings and roads/tracks) Ha TOTAL (All habitats)

23. Engaging with stakeholders A Thames Tunnel Biodiversity Forum has been established –November 2010 –March 2011 Stakeholders –14 local planning authorities –Environment Agency –Natural England –London Biodiversity Partnership –Thames21

25. Background Information Slides For reference

26. Bazalgette’s intercepting sewers

27. Thames Tideway Strategic Study Two problems: Overloaded sewage treatment works; discharging directly into the river after heavy rainfall Overloaded sewer network; discharging into the river via CSOs. Three solutions:

28. River Brent River Lee River Roding River Beam River Ingrebourne Sewage treatment works discharging to the tidal River Thames Thames Estuary Southend Gravesend Long Reach Riverside Crossness Mogden Beckton

29. The Lee Tunnel Four mile tunnel from Abbey Mills to Beckton. To start and end on land we already own; requires no intermediate construction sites. To intercept 16 million cubic metres of untreated sewage currently discharged into the River Thames each year on average, via the River Lee. Planning consent granted, subject to planning conditions. £600 million project – largest contract TWUL has ever awarded. Construction started in June 2010 and is scheduled to finish in 2014.

30. Birds Objectives: To obtain survey data on wintering birds and breeding birds at and adjacent to preferred work sites. Approach: A huge amount of data and local knowledge already exists on bird populations across London. Proposed work sites will first be screened for inclusion in the survey. Sites will then be further screened on the basis of current knowledge. Methodology: Survey methodologies would be developed. Methodologies will be agreed in consultation with statutory agencies.

31. Bats Objectives: To obtain information on the following, which could be affected by development works i)roost sites, and ii)any significant foraging or commuting routes Gather and collate existing data Phase 1 surveys will include a site evaluation Initial use of remote monitoring equipment Site surveys. Surveys methodologies Approach/Methodology: There is a large pool of existing data on sites used by bats. The approach will be to: