TIDEWAY BUILDING FOR 22ND CENTURY

The History and Delivery of a £5Billion Super Sewer

John Gullick 3rd April 2019 ’s Sewer System Lost Rivers of London

Stoke River Roding Newington

Islington Bow Barking Creek Black Notting Hill Ditch Erith

Waterloo Chelsea

Battersea

Eltham Roehampton Forest Hill Streatham

Beverley Brook

8383 Main Sewers - 1856

Stoke Newington Hampstead

Regents Park Bow Lake

Notting Hill Erith

Waterloo Chelsea Woolwich

Battersea

Roehampton Eltham Forest Hill Streatham

3 3288-05/127 Perception at the time

Source of Water Supply: for most of London, affordable water was extraction from the Thames Death’s Dispensary: but general belief was that disease was carried through the air and not water 4 4 The of 1858

London Cholera Deaths 16000

14000

12000

10000

8000

6000

4000

2000

0 1831 1833 1848 Bazalgette’s plan Early Major Sewer Works

Northern Outfall Sewer under construction at Wick Lane 1860s

7 7 The Fleet Sewer – deepening and today Embankment

9 Integrated Works

10 The Need for the Tideway Project

1860 2 million 1910 4 million

2018 Bazalgette 9 million design capacity

11 8-9 million people 50 million cubic meters Strained ecosystem London’s Sewerage System Today

13 THE PROBLEM: Overflow discharges

14 Combined & Separated Systems

15 Combined & Separated Systems

16 London’s sewerage network today

Percentage Connected

0-5 % Separate system 5-10 %

10-20 % Partially separate system 20-40%

40-70% Combined system 70-100%

17 Current situation

18 Intercepting the CSO’s

19 London Tideway Improvements

Beckton Riverside

Crossness

Long Reach Mogden

Sewage Works Upgrades Thames Tideway Tunnel

20 The Solution: Typical CSO Site

21 Impact of the Improvements

Typical Year CSOVolume Abbey Mills CSOvolume (cubic metres) Existing System –CSO volume (cubic metres)

5,000,000

19,418,500 4,000,000

3,000,000

2,000,000

1,000,000 Abbey Mills 0 (seeinset) Tideway CSO PS WesternPS

9

GreenwichPS

4

22 Impact of the Improvements

Typical Year CSO Volumes Abbey Mills CSOvolume (cubic metres) Thames Tideway Tunnel –CSO volume (cubic metres)

5,000,000

4,000,000

3,000,000

2,000,000

1,000,000 Abbey Mills 0 (seeinset) Tideway CSO

Hammersmith PS WesternPS No spill

9 GreenwichPS

4

23 Route Map and Geology Length: 25 kilometres Diameter: 7.2 metres

Depth: 30 metres to 66 metres Volume: 1.6 million cubic metres (include Lee Tunnel) Gradient: Falls one metre every 790 metres for self-cleansing 25 Existing sewerage network New reclaimed area

Air Treatment

Existing CSO

Vortex Shaft

Main Tunnel

Connection

Image: CSO interception TBM Drive Strategy

27 TBM drive site: Tunnelling set-up

28 Main Drive Site – Kirtling Street

29 Tunnel Boring Machines

30 Main Tunnel Blackfriars Albert Embankment Falconbrook Questions ?