the challenge of keeping london supplied with water
DESCRIPTION
The challenge of keeping London supplied with water. Piers Clark Commercial Director Thames Water. We are the UK’s largest water and sewerage company. 8.9 million water customers 14.3 million wastewater customers 19,400 miles of water mains 67,400 miles of sewer network. - PowerPoint PPT PresentationTRANSCRIPT
The challenge of keeping London supplied with water
Piers Clark Commercial DirectorThames Water
2
RiverCherwell
Banbury
Swindon
Oxford
Reading
Slough
HighWycombe
Guildford
We are the UK’s largest water and sewerage company
8.9 million water customers 14.3 million wastewater customers 19,400 miles of water mains 67,400 miles of sewer network
Biggest capital delivery programme in the industry, worth £5bn over five years
3
Rainfall March 2010 – September 2012
Thames Rainfall Deficit 2010-2012
Thames Area Rainfall Deficit 2010 to 2012(Cumulative surpluses & deficicencies carried forward month by month.
Thames Area Annual Rainfall is 739mm, based on Historical Long Term Average)
1
28 27
-2
-24
-50
-82
-34-49 -57
-77
-119-107 -107
-149
-195-215
-201 -209 -204-227
-272
-307 -303-328
-400
-350
-300
-250
-200
-150
-100
-50
0
50
100
mm
Cumulative surpluses and deficiencies. Thames Area Average Annual rainfall is 739mm based on historical long term average.
5
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Level 4 Risks
Level 4 restrictions represent the point at which London’s reservoir storage has declined to its emergency reserve (equivalent to approximately 30 days storage)
Demand must be drastically reduced so that London does not run out of water
Level 4 has major customer, economic, reputational and regulatory consequences
The company must be able to demonstrate that it has done everything in its power to prevent reaching Level 4
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Forecast London reservoir storage to determine drought management measures
Over Last 16 months Rainfall in the South East of England has been Notably low or Exceptionally Low.
Cumulative rainfall for Jan to Jan 2011/2012 has been lower than 1975/76 and 2005/06
Cumulative monthly rainfall data for 1975 to 1976, 2005 to 2006 and 2011 to Jan 2012 with Long Term Average (LTA) Rainfall since 1883
0
200
400
600
800
1000
1200
1400
1600
Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov
Month
Cum
ulat
ive
Rai
nfal
l (m
m/m
onth
)
LTA 1975-76 2005-06 2011-12
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Surface water (SW) flows – forecast at Teddington Weir
Drought severity as a function of flow at Teddington (May-Aug)1991-2011 with 4 driest years – 60% long term average rainfall
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
Mean natural daily flow Thames at Teddington (m 3/s)
4 driest years 1991-2011 London Predictive Flows 01/02/2012 - 60% of Long Term Average Rainfall
Drought Severity
2012 Predicted
19441976
2003
20092006
1991
19921995
1996
2005
199719211934 2011
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Rainfall March 2010 – September 2012