Water Resources Technical Stakeholder Meeting Update on … · 2017-02-28 · in 2012 (AMP5). •...
Transcript of Water Resources Technical Stakeholder Meeting Update on … · 2017-02-28 · in 2012 (AMP5). •...
Water Resources Technical Stakeholder Meeting
Update on demand management and resource options
07 February 2017
Overview of the water resource challenge. Historical droughts 1920 - 2010
London WRZ Growth: 530 Ml/d
Climate change: 200 Ml/d
SWOX WRZ Growth: 95 Ml/d
Climate change: 20 Ml/d
How we develop our next Water Resources Management Plan – WRMP19.
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Resilience assessments
Environmental performance
Bottom up risk and updated cost
WRMP19 rejection register
Pro
gra
mm
e a
pp
rais
al
Option feasibility
reports
System level assessment
Pre
ferr
ed p
rog
ram
me
Co
nc
ep
tua
l d
es
ign
rep
ort
fo
r c
on
str
ain
ed
lis
t
Co
nstr
ain
ed
lis
t o
f
optio
ns
Scre
en
ing
rep
ort
Ad
va
nc
ed
pro
gra
mm
e
inve
sti
ga
tio
ns
WRMP14
options
Option
investigation
needs
New options
3rd party
options
Methodology reports
Our approach.
October Technical Stakeholder Meeting – A recap.
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Demand management
• Overview of the process to develop and screen options, and the unconstrained options
considered.
• Outline of how programmes of options are developed and input to the programme
appraisal.
• Feedback sought on the approach and the draft constrained list of options.
Resource options
• Recap on the 4-phase programme, the engagement undertaken throughout this
process, and the documentation.
• The methodology to assess option types was accepted as robust.
• Overview of the options assessments, stakeholder discussion and comments (Meeting
minutes are available)
• Feedback sought on the feasibility reports and the draft constrained list of options.
Objectives of today.
• To present the comments received on the demand management and
resource options, our responses to them, and the revised draft constrained
lists of options.
• To provide an update on additional work to examine feasible options.
• To set out the next steps and reporting.
• To seek comments and feedback from stakeholders.
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Today
10:00 Welcome & introduction - Chris Lambert (Chair)
10:15 Demand management options – Anthony Owen
10:45 Resource options
10:50 Groundwater Feasibility Report – Victoria Price
11:20 Coffee Break
11:30 Raw Water Transfers – Alice Mortimore, Chris Lambert, Kieran Conlan
12:30 Reuse, Desalination, Direct River Abstraction – Bill Hume-Smith, Kieran Conlan
13:00 Lunch
13:45 Reservoir and Catchment Management – Chris Lambert
14:15 Screening Decisions and Updated Constrained List – Bill Hume-Smith
14:20 Update on the system work – Keith Banner
14:30 General discussion and Q&A
Anthony Owen, Thames Water
Demand Management Options
Outline
• Introduction to demand management
• Address stakeholder comments on…
• Screening process and investment terminology
• Metering programme
• Incentive scheme and innovative tariffs
• Next steps
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Every day we put ~2,600 Ml into supply – where does it go…
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Household usage is
> 50% of demand
Leakage is
~25%
Demand management to 2020
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106.5 Ml/d Demand Management
(>70% of the deficit)
2015 - 2020
London M
l/d
Area Previously AMP6
Leakage >300 Ml/d reduction
(32%) since 2004
Further 59 Ml/d
reduction (10%)
Metering Roll-out smart meters >441,000 progressive
meters to increase
coverage to 55%
Water efficiency 17 Ml/d savings in
AMP5
Double to 38 Ml/d
Stakeholder feedback
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Screening process & investment terminology
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Stakeholder comment Summary of response
What is ‘IDM’ and how
does it fit into the
screening process
• Integrated Demand Model (IDM).
• The model was used for WRMP14 and is being
updated for WRMP19.
• IDM is a DMA based model. IDM selects
feasible demand options for a DMA to reduce its
leakage & usage.
Is the IDM optimisation
process independent of
resource options
• IDM simply optimises for least cost demand
option interventions for DMAs.
• A range of optimised demand management
programmes from IDM are optimised against
supply options in EBSD+ and MCS.
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DMAs
Leakage (Ml/d)
Usage & Wastage (Ml/d)
Feasible Options
Costs (£)
Benefits (Ml/d)
Scenarios
Target Levels of
Demand Management
DM
A C
ost
Benefi
t O
pti
mis
ati
on
Output
Mix of Investment
Options
Investment Spend per
Option
Levels of Leakage,
Usage & Wastage
Ec
on
om
ic B
ala
nc
ing
of
Su
pp
ly &
De
ma
nd
mo
de
l
Range of
optimised
demand
programmes
EBSD
The screening process, IDM and EBSD models
IDM
MCS
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Programme Appraisal
EBSD+
IRAS/ MCS
• Range of Demand
Management
programmes
• Constrained list of
Resource options
• Future S/D forecast
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EBSD+
MCS
“Least cost”
Is an optimisation to
solve the deficit for
simply the lowest
financial long-term cost
“Best value”
Considers solutions beyond
simply least cost and appraises
them on, for example,
environmental and resilience
benefits/ dis-benefits
Stakeholder comment Summary of response
How does ‘best value’ get
considered
• EBSD+ and MCS determine ‘least cost’ and ‘best value’
supply/ demand programmes via the Programme
Appraisal process.
Metering programme
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Stakeholder comment Summary of response
Can the metering
programme be rolled out
faster
• Legal powers granted for compulsory metering
in 2012 (AMP5).
• WRMP14 (2014) made the case for installing >1
million smart meters in 15 years.
• Quality vs Quantity:
• i) Streetworks access
• ii) Work quality control
• iii) Customer engagement journey
• c140,000 Progressive meters since 2012…..
• Installing approx. 10,000 smart meters/month
TW metering penetration
should be higher than
industry average, not
below
• Access to install internal meters in flats is
challenging (10% success rate).
• Approx. 50% of London is flats & this is
increasing.
• The start of our programme has focussed on
improving London meter penetration.
Current levels of metering WRMP14 change in levels of metering in next 15 years
33% - 72%
53% - 91%
Incentive scheme and Innovative tariffs
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Stakeholder comment Summary of response
Update & progress on
the Incentive scheme
• Reward based scheme to incentivise customers
to use water efficiently.
• Trial underway in Reading, due to be expanded
into London in 2017
• Publish draft feasibility report in Spring’17.
Have financial tariffs
being screened out
• No.
• We have completed technical investigations &
consulted customers.
• Will be considered in the future when meter
penetration is >60%.
• Will follow-on from Incentive scheme.
Consideration of wider
opportunities from the
Incentive scheme
• Effective tool to incentivise specific behaviours,
for example rewards during dry periods.
Provisional Feasible Options
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Next steps
Publish draft Non-potable options feasibility report in
Feb’17
Updated Demand Options screening reports in Mar’17
Undertake IDM modelling Mar – May’17
Update Screening report in May’17
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Questions
Resource Options
4 phase programme of work
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Phase 1
• Review WRMP14 options, consideration of new options.
• Development of an approach to review and refine the options taken forward for more detailed investigation.
Phase 2
• Complete detailed option review and feasibility assessment to inform a constrained list of options.
Phase 3 • Complete concept design work for the constrained options.
Phase 4
• Select preferred option(s) and take forward to outline design for planning submission.
September 2014
– July 2015
July 2015 - Now
November 2016 –
September 2017
Following approval
of WRMP19
Start
Finish
Bottom-Up Cost & Risk
Conceptual Design
Fine Screening Report Updates
Options Operating Philosophy
WLC/AIC Methodology
Raw Water Transfer Feasibility (incl. Cotswold Canal and 3rd party options)
Direct River Abstraction Feasibility (incl. DRA Teddington)
Water Reuse Feasibility
New Reservoir Feasibility
Environmental Assessment
Stakeholder Engagement
Network Reinforcement
Water Treatment
Cost & Carbon Methodology
Environmental Assessment Methodology
Desalination Feasibility
Groundwater Feasibility
Raw Water System
Inter-zonal Transfers
WRMP19 resource option development programme
Cross option study Methodology Feasibility Further development of options on constrained list
Catchment Management
Technical Stakeholder Meeting
V2 Final V1
May 2015
Update
Update
V3
So in this slot we will cover
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Groundwater Feasibility study Victoria Price
Break – 10 mins
Raw Water Transfers Chris, Alice Mortimore & Kieran Conlan
Reuse, Desalination, & DRA Bill Hume-Smith & Kieran Conlan
Lunch – 45 minutes
Reservoir and Catchment Management Chris Lambert
Screening and Updated Constrained List Bill Hume-Smith
Victoria Price, Mott MacDonald
Groundwater Feasibility study
Identification of options
Bottom-up identification of options
• Review of WRMP14 options and those passing Phase 1A screening
• Stakeholder engagement, including licence trading
• Removal of constraints to Deployable Output (DO)
• Groundwater development
• Artificial recharge/Aquifer storage recharge schemes
Top down identification of options
• CAMS groundwater body status
• WFD status and links to surface water
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48 groundwater options (<50 Ml/day) were assessed using the same approach as
the large options
Example screening outcomes
• Stage 1: Licensing not supported by EA, e.g. Epsom, Woods Farm
• Stage 2: Impact on river flows, low borehole yields e.g. AR Cricklade, R. Marden
• Stage 3: All options pass
Feasibility assessment
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Options discounted at Stage 1: Pass/Fail Criteria
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London Swindon and
Oxford
Slough,
Wycombe and
Aylesbury
Kennet Valley Guildford Henley
National/international nature
conservation sites 1 1 1 National/international nature heritage
sites
Areas of major built development
Water availability (CAMS/ALS status) 3 5 4 1 1 Realistic prospect of acceptable
abstraction licence 1 4 6 4 1 1
Drought resilience 1 4
Proximity of source water
Source quality (treatability)
Number of failed options 1 4 6 4 1 1
Options discounted at Stage 2
London
Shortlands Uncertainties about increased abstraction on
groundwater levels and other sources
London confined Chalk (north east) Unlikely to be sufficient yield within area to provide
any DO
SWOX
Artificial recharge - Cricklade
Risk of groundwater discharge, high recharge
pressure requirements during recharge and impact
on other sources.
River Marden Low yield and water quality concerns
Witheridge Hill borehole pumps Cost to complete investigation compared with
potential DO is too high
SWA Hampden Bottom-Wendover
Uncertainty regarding presence and thickness of the
Lower Greensand aquifer. Site may not be
hydrogeologically suitable.
Guildford
Aquifer storage and recovery - Guildford
(Abbotswood)
Risks regarding purchase of land, impacts on a local
nature reserve and location in flood plain
Removal of constraints - Sturt Road Spring capture
Uncertainties regarding water availability, potential
yield and resilience and high cost of investigation
required to remove uncertainties.
Kennet Valley Groundwater - Mortimer (transfer peak licence from
Arborfield)
Reassessment indicates that it is not possible to
achieve a DO equal to the licence transfer.
Therefore the site may not be hydrogeologically
suitable for this option.
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Stage 3 Assessment
Summary
• 21 options assessed and none failed at Stage 3.
• South Stoke 1 and Moulsford 1 are mutually exclusive. Moulsford 1 is being taken
forward as the preferred option.
• A number of options are interdependent:
− ASR South East London (Addington) is dependent on the delivery of the
upgraded WTW proposed for the GW – Addington option;
− Dapdune licence disaggregation is reliant on the delivery of the Dapdune
removal of constraints to DO option and the Ladymead WTW removal of
constraints to DO option;
− GW – Datchet and Eton removal of constraints to DO are reliant on the delivery
of the RC – Datchet main replacement option; and
− The SLARS options may be delivered separately but the sources are likely to be
operated in conjunction with one another and using an operating strategy
consistent with the existing available groundwater storage.
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Summary of potential DO benefits
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0
50
100
150
200
250
Average Peak Average Peak Average Peak Average Peak
All options Stage 1 Stage 2 Stage 3
DO
be
ne
fit (M
l/d
)
London SWOX SWA Kennet Valley Guildford Henley
Feasible options
WRZ Number of options Average DO benefit
(Ml/d) Peak DO benefit (Ml/d)
London 11 33.3 51.4
SWOX 2 2.2 6.0
SWA 3 4.8 9.3
KV 2 4.5 6.6
Guildford 3 0 7.8
Henley 0 0 0
Total 21 44.8 81.1
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Feasible options summary table
Key issues and further work
Key issues
• Uncertainty regarding yield and water quality of new sources
• Impacts on other sources/abstractions
• Network capacity for abstraction and recharge
• Operating strategy to be agreed with the EA for SLARS options
• Support from EA to use of River Thames during wet periods to provide recharge water
for ASR options
• Uncertainty on required borehole spacing and land issues for some ASR options
Further work
• Test pumping of boreholes to confirm yield, water quality, groundwater level and
recharge rates if applicable
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Questions
10 minute break
Alice Mortimore, Mott MacDonald
Chris Lambert, Thames Water
Kieran Conlan, Ricardo
Raw Water Transfers
Severn Thames Transfer (STT) - Canal and Pipeline Comparison
Activities
• Review of cost estimates for the Cotswold Canal and Deerhurst Pipeline
options (based on a 300 Ml/d transfer to Radcot)
• Further work on Water Quality and Ecology
(particularly Invasive Species)
• Review of feasibility assessment and comparison of options.
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Severn Thames Transfer – conveyance options
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Oxford Canal and
Minworth STW to
Isis Lock Canal Routes
Kielder
Conveyance
Options
River route
Vyrnwy to
Gloucester
Deerhurst to Radcot,
Farmoor, Culham Deerhurst to Cricklade
Cotswold Canal
STT Canal and Pipeline Comparison
• Normalised cost:
• Normalised cost for ‘Do min’ Canal to Lechlade is 10% higher than the pipeline to
Radcot
• Rising to 19% when the canal outfall point is moved to Radcot
• Currently being updated for outfall at Culham
(expected to add similar additional cost to both options)
• Risk:
• Capex cost of ‘Do min’ canal is 22% higher than pipeline at feasibility
• Rises to 31% when bottom up risk is included
• Rising to 41% with canal outfall at Radcot and bottom up risk
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STT Canal and Pipeline Comparison– Water Quality and Ecology (WQ&E)
• Outfall location:
• Additional WQ&E work indicates releases >200Ml/d are not acceptable at Radcot
• Appropriate outfall point for 300 Ml/d discharge is Culham (more on this later)
• Invasive Species:
• Further information provided by the EA and review undertaken by Dr David Aldridge
• Focus is on minimising spread and controlling pathways
• Concluded that a pipeline with sand filtration in the Severn catchment presents lower risk
of spread than the Cotswold Canal option with treatment near the River Thames
• Restored canal would provide habitat for invasive species, increases opportunity for ‘jump
dispersal’ between areas of open water through angling etc
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STT Canal and Pipeline Comparison
The Cotswold Canal STT is rejected by comparison with the Deerhurst Pipeline STT
option for the following reasons:
• Normalised Cost -The necessary restoration of the canal including the Sapperton
Tunnel to allow navigation and transfer would be substantially more costly than the
Deerhurst pipeline
• Greater operational complexity of a canal involving 3rd parties and increased
number of pumping stations in series
• Greater construction complexity due to the need to construct assets of which
Thames Water has little experience, and the need to interface those assets with
existing historical assets and to the need for construction in urban areas.
• Cotswold canal option carries a higher risk of spread of non-native invasive
species than the pipeline
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44
Questions
Unsupported Severn Thames Transfer
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Unsupported Severn Thames Transfer - Background
Previous work on reliability of an unsupported transfer carried out on the basis
of analysis of twentieth century historic droughts. Not adequate for a complex
scheme such as the Severn Thames transfer due to:
• Differential nature of droughts that occur in the two catchments – spatial coherence
must be taken into account
• Hands off flow controls on the Lower Severn have a critical influence on the timing
and magnitude of the volume available for transfer
• Impacts of existing abstractions from the River Severn and the forecast impacts of
climate change
A more reliable and robust yield estimate of a 300 Ml/d transfer has been
derived through understanding performance based on analysis of:
• Historic droughts
• Future droughts (stochastic drought generation)
• Impacts of climate change
• Impacts of other abstractors
Flow Time series showing transfer availability from the Severn at Deerhurst under major historical droughts
Summary of Transfer Availability for the Major 20th Century Droughts
Critical Drought Year Percentage time that the Severn
Thames Transfer would have
been available if called for*.
1921 56%
1934 66%
1944 63%
1976 39%
* Some water is available but not necessarily the full 300 Ml/d
Historically based DO analysis 142 Ml/d
Future climate and more intense droughts than in the 20th century
• WRMP14 showed vulnerability to severe droughts not present in the historic
record
• Prolonged period of drought in the late 19th century (1890–1910) and intense
drought in mid 18th century
• Artificial drought data can be used to test robustness to droughts worse
than in the historical record.
Source: Major droughts in England and Wales, 1800–2006, Marsh et al. 2007
Collaborative working to ensure confidence in the approach
• Anglian Water, Southern Water, Severn Trent, Thames Water,
United Utilities and Dŵr Cymru are all undertaking work on
stochastic drought generation. There is regular company liaison to
share findings and ensure development of a robust approach
• UKWIR 2016 Risk based planning methods for WRMP19
• Water UK long term planning study used stochastic droughts to
understand the robustness of the existing water resources baseline
position in England and Wales
• This is complex and detailed technical work. We have engaged with
regulators and leading academic experts as the work has progressed
Development of stochastic “Drought Libraries” for analysis of wide variety of droughts in River Thames catchment
Each library contains 10 droughts, with 5 years warm up and 4 years cool down
Used to produce a yield-yield relationship between WARMs and IRAS
Actual droughts within each library shown in this graph
Drought Library A
Drought Library B
Drought Library C
Drought Library D
IRAS estimated
DO
Run
Number
Year
from that
1800 15 29 1941 2020
1815 25 16 1960 1975
1830 35 146 1961 2020
1845 45 138 1996 2035
1860 55 175 1927 1975
1875 65 32 1941 1960
1890 75 74 1955 2050
1905 85 53 1971 1990
1920 95 114 1951 2035
1935 105 38 1940 2165
1950 15 106 1977 2165
1965 25 67 1986 2240
1980 35 1 1942 2313
1995 45 7 1976 2225
2010 55 52 1952 2085
2025 65 11 1958 2085
2040 75 22 1950 2307
2055 85 47 1931 2313
2070 95 110 1991
2085 105 2 1946 2150
2100 15 128 1937 2265
2115 25 14 1986 2340
2130 35 147 1954 2295
2145 45 43 1925 2295
2160 55 9 1954 2325
2175 65 35 1957 2295
2190 75 133 1949 2380
2205 85 20 1948 2393
2220 95 180 1950 2355
2235 105 40 1970 2423
2250 15 121 1931 2560
2265 25 63 1927 2378
2280 35 76 1990 2555
2295 45 95 1979 2438
2310 55 165 1994 2453
2325 65 116 1993 2464
2340 75 45 1987 2481
2355 85 4 1924 2535
2370 95 178 1933 2453
2385 105 87 1977 2448
D
WaRMS
Yield
Drought
Library
Pro-
forma
Year
Location of that year
A
B
C
Stochastic Analysis of London’s Water Resources
Re
lati
ve
Yie
ld (
Ml/d
)
Stochastic analysis of rainfall and evaporation across the Severn and Thames basins
Expected yield is 80-90 Ml/d compared with 142 Ml/d historically based DO analysis
Evaluation of the impact of fully licensed Third Party Abstractions on flows at Deerhurst
Abstraction in spring and autumn periods is well below licensed volumes
Analysis of the Net Impact of Fully Licensed Abstraction by Other Users
Risk to reliable scheme yield from other abstractors operating within
their existing licences is up to 20 M/d
Summary
The following conclusions can be drawn about the benefits and
level of resilience of an unsupported transfer:
• Given low reliable yield, unsupported transfer in isolation is not a cost effective
option
• Scheme is very sensitive to the patterns and behaviour of drought across the two
catchments
• Expected yield is in the order of 80-90 Ml/d compared with 142 Ml/d from
historically based DO analysis
• Net yield of the scheme is not sensitive to climate change, even though absolute
flows in the Severn are notably lower under climate change futures
• Scheme is vulnerable to third party abstractions within the Severn. Overall this
places 20 Ml/d of the net yield benefit at risk when future conditions to 2040 are
considered
• Future reliable net yield is 60-70 Ml/d unless suitable licence or storage
arrangements can be negotiated with third parties
57
Questions
Partially supported STT
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Water Quality & Ecology of Outfall Locations and Potential Effects of Different Transfer Volumes
Detailed assessment of Lechlade to Culham reaches:
• Characterised hydrology within the reaches to understand how any
additional transferred flows may alter the hydrograph at sensitive
locations.
• Reviewed the quality and availability of habitats sensitive to flow and
level change (inc. backwaters and weir pools) which could be affected
by a change in flow.
• Reviewed water quality at additional modelled locations to provide
greater spatial understanding of the water quality effect of various
transfer volumes.
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Evidence – Weir Pool Habitats
Weir Pool Habitat – Buscot Lock
Weir Pool Area (m2) Features
2 Buscot Lock 1 3,543
• Natural banks
• Varied depth
• Varied velocity
• Sediment/gravel bars
• Over hanging trees
Weir Pool Habitat - Sandford Lock
Weir Pool Area (m2) Features
16 Sandford Lock 9,545
• Natural banks
• Varied velocity
• Over hanging trees
Lechlade to Culham Outfall Location Assessment Findings
• Transfer >200Ml/d difficult to promote upstream of Farmoor:
− change flow regime from natural or semi-natural flow rate to a regulated river, causing adverse impacts on ecology within the main channel weir pool habitats.
• Large volume transfers between Farmoor and River Evenlode during low flow conditions would lead to the River Thames taking on the water quality characteristics of the River Severn, which could have consequential adverse ecological effects on fish communities in these upper reaches.
• Further downstream, supported or part supported options of ≥300Ml/d would be promotable, preferably downstream of the flow contribution from Sandford (Oxford) STW and the River Ock, which then also avoids the sensitive weir pool at Sandford Lock.
• River Thames at Culham (and downstream) is therefore considered the most suitable of the locations assessed for receipt of the River Severn transfers.
63
Comparison of transfer volumes at Culham - effects of supported and unsupported flows
Key environmental issues relate to a) transfer volume and b) proportion of “support” vs
“unsupported” volumes for the Culham outfall location. Linked to:
a) Raising the baseflow in the Thames d) Impacting rivers providing “supported” flows
b) Increasing the flow variability e) Reduced effectiveness of mitigation
c) Increasing low flows in River Severn
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Increasing volume
Incre
asin
g
su
pp
ort
ed
flo
w
Comparison of transfer volumes at Culham - effects of supported and unsupported flows
Unsupported transfer variants:
1. Flow variability in the River Thames increased
from that normally experienced
2. Increase in frequency of low flows in the River
Severn through unsupported components of
transfers
3. Increased complexity of mitigation package for
unsupported transfer components with variable
transfer rates.
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Transfer volume could raise base
flow in the River Thames to a level
that would remove current low flow
regime and, by 600Ml/d flows, be
more typical of wet years only
At high volumes of supported transfers river
systems beyond Thames may be affected
Partially Supported STT – Costs analysis
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0
40
80
120
160
200
240
280
320
360
0 100 200 300 400 500 600 700
AIC
(p
/m3
)
Transfer Capacity (Ml/d)
15 Ml/d support
75 Ml/d support
195 Ml/d support
308 Ml/d support
Partially supported Deerhurst pipeline AIC – Using indicative stochastic yield
Partially Supported STT – Costs analysis
67
• Little cost differentiation between the 300, 400, 500 and 600 Ml/d options –
none rejected on cost
• The 100 Ml/d capacity option performs poorly against other capacities
• The 15 Ml/d support option (effectively unsupported River Severn)
performs poorly against other support scenarios.
• 100 Ml/d capacity pipeline and unsupported River Severn rejected on cost
grounds
Water Quality and Ecology – Support Options
68
Deerhurst pipeline
London WRZ
Draycote
Reservoir
Minworth STW
Support options • Releases from Lake Vyrnwy of up to
180Ml/d (up to 60Ml/d without
replacement resources)
• 15 Ml/d licence transfer of the unused
element of the licence at Mythe WTW
• Minworth STW water reuse transfer to
the River Avon (88 Ml/d)
• Draycote Reservoir (25Ml/d):
‒ New intake at Warwick on the River
Avon and transfer via Willes Meadow
to support Draycote Reservoir
‒ Draycote expansion by 25%
‒ Augmentation transfer to the River
Leam at Warwick.
Willes Meadow
Contains Ordnance Survey data Crown copyright and database right © 2014
River Leam
Mythe WTW
Lake Vyrnwy
Draycote & Minworth screened out at Feasibility stage absent information from Severn Trent Water that:
• Transfer of Minworth effluent will not adversely impact downstream abstractors (in light of representations
from a large abstractor on the River Trent)
• New discharge of a significant volume of water to the River Avon under low flow conditions, required for both
the Minworth and Draycote options, would not have unacceptable environmental impacts in River Avon,
and that the necessary discharge permit applications are unlikely to be refused by the Environment Agency.
Partially Supported STT – Conclusions
69
• 600 Ml/d rejected in respect of water quality and ecology analysis
• 100 Ml/d capacity pipeline rejected by cost analysis
• Transfer of 300 Ml/d and greater, to outfall at Culham
• Unsupported River Severn transfer provisionally rejected by cost analysis
in favour of partially supported options
• Draycote & Minworth rejected as support options due to lack of information
on environmental acceptability or impact on other abstractors
• Options expected to be taken forward to fine screening:
‒ Partially supported 300, 400 and 500Ml/d Deerhurst Pipeline to Culham
‒ Support from Vyrnwy and Mythe
70
Questions
Other Transfers
71
Other Transfers – Status
• Welsh Water resource options – no information received.
• Oxford Canal options – Continued dialogue with the Canal and River Trust relating to
resource yield and operating cost.
• Minworth to Isis Lock option - Severn Trent Water has declined to offer Minworth
effluent for transfer by canal following environmental assessment; therefore, the option will
be rejected.
• Farmoor options:
1. To replace Farmoor abstractions with STT discharging at Farmoor – to be rejected as
provides no appreciable Deployable Output benefit due to different timing of London and
SWOX critical droughts
2. To provide supply to Farmoor off Deerhurst-Culham pipeline allowing reduction of
abstraction at Farmoor – to be considered separately by TW and EA in Farmoor WFD
discussions
• Combined TW reservoir and STT pipeline – Rejected as WARMS2 modelling indicated
only very limited additional Deployable Output benefit from the combined option
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Other Transfers – Next Steps
• Review feasibility assessment for all options that have changed, or been
introduced
• Update cost analysis set out above once results from stochastic modelling
has been received for other Severn-Thames Transfer size and support
combinations
• Finalise rejection text /reasons for options that are not taken forward to fine
screening
• Finalise and re-issue the Raw Water Transfer Feasibility Report
73
74
Questions
Bill Hume-Smith, Mott MacDonald
Kieran Conlan, Ricardo
Reuse, Desalination, Direct
River Transfers
Cumulative Environmental Effects in the Middle Tideway
76
High level review of potential cumulative tidal level and salinity effects of combinations of options in the Mid-
Tideway:
• Beckton Reuse (300Ml/d) ● Crossness Desalination (300Ml/d)
• Beckton Desalination (150Ml/d) ● Lower Lee DRA (150Ml/d)
• Teddington Direct River Abstraction (DRA) (300Ml/d)
1. Long-term salinity effects:
a) Baseline local mid-Tideway inputs play a significant role in maintaining the salinity regime locally (range
and pattern) . If freshwater input reduces the local salinity regime could change.
b) Risk under prolonged low River Thames flows (potentially exacerbated by Teddington DRA) of gradual
saline ingress up the Tideway until flushed out by high river flows.
c) Initial studies, requiring validation, suggest that more than a 20% reduction in freshwater inputs (taken
up by options) could result in salinity regime modification. All combinations of options listed below
include >20% reduction:
2. Tidal level effects:
a) High rates of abstraction for desalination (31Ml/h Beckton; 62Ml/h Crossness) at low tides are likely to
lower tidal levels, increasing habitats exposure and creating local eddies.
b) Beckton and Crossness desalination options unlikely to result in a combined effect.
77
Desalination Feasible List
Thames Water Intakes Thames Water Pumping Stations
Datchet Intake
Surbiton
intake
Ashford
Common
WTW
Hampton
Intake &
WTW
River Wey
River Mole
Hogsmill
River
Laleham Intake
Wraysbury Intake Teddington
Weir
Wraysbury
River, River
Colne &
Colne Brook
Staines PS
Old Windsor Weir
Bell Weir
Penton Hook Weir
Chertsey
Weir
Shepperton
Weirs
Molesey
Weirs
River Brent
Beverley
Brook
River
Wandle
River
Lee
Ravensbourne
River
Abbey Mills PS
Hogsmill
STW
Beckton STW &
Gateway WTW
Thames
Barrier
River
Roding
Richmond Half-Tide
Sluice
London Ring Main
Lee Valley
Reservoirs
London Ring Main Shaft
Mogden STW
Kempton
Park
WTW
Honor Oak
Barrow Hill
William Girling
King
George’s
Banbury
Deephams STW
Sunbury Weirs
Walton
Intake,
PS &
WTW
Crossness
STW
Riverside STW
Longreach
STW
Beddington
STW
Chingford South
WTW
Sewage treatment works Water treatment works
Raw water storage
Luxbrough Lane
Proposed new site
Coppermills WTW
Northumberland
Heath SR
Honor Oak
SR
Feasible List
Plant Location Distribution Location Maximum
DO
Fine
screening
Beckton STW Coppermills WTW (blending) 142 ✔
Crossness (blended)
[previously Thamesmead]
Coppermills WTW (blending) 268 ✔
Crossness (direct supply) Northumberland Heath SR
(direct supply)
69 ✖
Contains Ordnance Survey data Crown copyright and database right © 2014
Desalination
78
Stakeholder comment Summary of response
Impacts of reducing
freshwater flows in
Tideway and localised
impacts of brine
discharges
TW commissioned Ricardo to consider cumulative
impacts of desalination, reuse and DRA options on
salinity in Tideway and on localised impacts of brine
discharges
Additional option
proposed of small
desalination plant at
Heathwall site in
Battersea
Insufficient land on TW sites and initial review of
sizeable brownfield sites in vicinity has found them
to be consented for development.
79
Water Reuse Feasible List
Thames Water Intakes
Datchet Intake
Surbiton
intake
Ashford
Common
WTW
Hampton
Intake &
WTW
River Wey
River Mole
Hogsmill
River
Laleham Intake
Wraysbury Intake Teddington
Weir
Wraysbury
River, River
Colne &
Colne Brook
Staines PS
Old Windsor Weir
Bell Weir
Penton Hook Weir
Chertsey
Weir
Shepperton
Weirs
Molesey
Weirs
River Brent
Beverley
Brook
River
Wandle
River
Lee
Ravensbourne
River
Hogsmill
STW
Thames Barrier
River
Roding
Richmond Half-Tide
Sluice
Lee Valley
Reservoirs
Mogden STW
Kempton
Park
WTW
William
Girling
King
George V
Banbury
Coppermills
WTW
Deephams STW
Sunbury Weirs
Walton
Intake,
PS &
WTW
Crossness STW
Riverside
STW
Longreach
STW
Beddington
STW
Chingford South
WTW
Sewage treatment works
Water treatment works
Raw water storage
Contains Ordnance Survey data Crown copyright and database right © 2014
Beckton STW
& Gateway
WTW
Millbrook Rd PS
Proposed new site
Greenwich PS
Hydes
Field
Abbey Mills PS
Wandle
Valley
PS
Luxborough Lane STW Lower Hall
Armada Way
Feasible list
Source Treatment Discharge Maximum
DO
Fine
screening
Beckton STW Beckton Lower Lee 336 Ml/d ✔
Crossness STW Crossness Lower Lee 174 Ml/d ✖
Deephams STW Deephams Lower Lee 58 Ml/d ✔
Mogden STW Kempton River Thames 180 Ml/d ✖
Mogden South Sewer Hydes Field River Thames 49 Ml/d ✖
Reuse
80
Stakeholder comment Summary of response
Deephams reuse:
dependency with existing
investigations into
abstractions on Lower Lee
and with new Lower Lee DRA
option
Retaining 60Ml/d Deephams Reuse options
pending implications of:
• investigations into existing Lower Lee
abstractions
• work to assess potential yield from new
Lower Lee DRA
Rejection of Crossness
Reuse: potential lower
average cost of shared
conveyance with Beckton
Reuse
Continues to be rejected at Fine Screening
due to:
• cumulative impact on salinity in Tideway
• resilience concerns around excessive
reliance on membrane technology
81
Direct River Abstraction Feasible List
Thames Water Intakes
Datchet Intake
Surbiton
intake
Ashford
Common
WTW
Hampton
Intake &
WTW
River Wey
River Mole
Hogsmill
River
Laleham Intake
Wraysbury Intake Teddington
Weir
Wraysbury
River, River
Colne &
Colne Brook
Staines PS
Old Windsor Weir
Bell Weir
Penton Hook Weir
Chertsey
Weir
Shepperton
Weirs
Molesey
Weirs
River Brent
Beverley
Brook
River
Wandle
River
Lee
Ravensbourne
River
Thames Barrier
River
Roding
Richmond Half-Tide
Sluice
Lee Valley
Reservoirs
Mogden STW
Kempton
Park
WTW
William
Girling
King
George V
Banbury
Coppermills
WTW
Deephams STW
Sunbury Weirs
Walton
Intake,
PS &
WTW
Longreach
STW
Beddington
STW
Chingford South
WTW
Sewage treatment works
Water treatment works
Raw water storage
Contains Ordnance Survey data Crown copyright and database right © 2014
Proposed new site
Options on Feasible List
Beckton
STW New WTW
Culham Direct to
Supply
Beyond map extents
Source Discharge Maximum
DO
Fine
screening
River Lee at 3
Mills Lock
Treat and transfer to King George V
reservoir [replaces direct option]
TBC TBC
River Thames
at Teddington
Transfer effluent from Mogden to
Teddington. New intake upstream of
Teddington Weir with direct transfer to
Thames Lee Tunnel
268 Ml/d ✔
River Thames
at Culham
Treatment and direct supply to SWOX 4.5 Ml/d TBC
Lower Lee Direct River Abstraction
82
Stakeholder comment Summary of response
Screening out of indirect
option at feasibility stage
challenged
• Direct option would need bank-side storage for
water quality risk so expected to be screened
out at feasibility stage.
• Indirect option to King George V being taken
forward
Challenge to potential
DO of Lower Lee option
• Sensitivity analysis confirms that economic
viability of option is heavily dependent on DO.
• Atkins is modelling a range of maximum
abstraction volumes available under
drought/normal and tidal conditions.
Teddington Direct River Abstraction
83
Stakeholder comment Summary of response
Challenge around
whether a larger scheme
is possible
Mogden flows based upon domestic sewage
volume not infiltration or trade flows because:
• Extent of infiltration in severe drought
unpredictable
• Domestic and some commercial flows expected
to be reduced by non-essential use ban.
EA requested that some discharge continue at
existing location to avoid on/off leading to first flush
of pollutants
Environmental impact of
reducing freshwater
flows to Tideway
HR Wallingford commissioned to assess impacts
on water quality upstream and downstream of
Teddington
Hydrodynamic modelling and assessment for Teddington DRA
Further, ongoing, work to quantify the fluvial and tidal environmental effects and tidal
navigational effects of a Teddington DRA scheme through modelling (by HR
Wallingford) and assessment (by HR Wallingford and Cascade)
Scope developed with Environment Agency and Port of London Authority to assess:
• Likely operational pattern of use of the option
• Freshwater River Thames:
Hydrodynamics, water temperature, fisheries ecology
• Estuarine Upper Thames Tideway:
Water level, navigation restrictions, velocity/sedimentation, saline intrusion, water
temperature, oxygen, STW effluent dispersion, WFD water quality status risk, plant
nutrients, ecology (fisheries, aquatic macroinvertebrates and invasive non-native
species) and WFD status risk.
• In the wider Thames Estuary:
Overall estuarine sediment budget and integrity of mudflat.
84
85
Questions
Land
Competing development interests for land. Work is underway to look at land
availability and alternative sites. For example:
Beckton STW:
• Water resource desalination option
• Water resource water reuse option
• Future wastewater growth
• Land reserved for Thames bridge crossing
Mogden
• Land has pressures on it related to future wastewater growth due to
predicted population increase in the catchment.
86
Enjoy your lunch…please be back at 13:45
Chris Lambert, Thames Water
Reservoir and Catchment
Management
89
Location Capacity (Mm3) / Deployable Output (Ml/d)
30 Mm3 50Mm3 75 Mm3 100 Mm3 125 Mm3 150 Mm3
Abingdon 59 Ml/d 103 Ml/d 153 Ml/d 204 Ml/d 247 Ml/d 287 Ml/d
Chinnor 59 Ml/d 103 Ml/d
Marsh Gibbon 59 Ml/d 103 Ml/d 153 Ml/d
Reservoir - Feasible List
Reservoir
90
Stakeholder comment Summary of response
Challenge that Abingdon Reservoir is less
resilient to severe drought than the STT
Further work has been completed to consider the resilience of
the Abingdon using stochastic assessment of yield under future
drought scenarios.
Challenge that Marsh Gibbon and
Chinnor sites should be retained if smaller
reservoir options are retained
Marsh Gibbon and Chinnor reservoir sites screened out as
they perform significantly worse than the Abingdon reservoir,
desalination and reuse options on cost across the options
sizes.
Challenge that the proposed
embankments at Abingdon have
exceptionally flat slopes due to geological
conditions. Costs at Marsh Gibbon and
Chinnor may have been overestimated in
the event that geotechnical conditions are
better at these sites.
Slope angles have been used at feasibility stage of between
1:4.5 and 1:6, which are not unusual for embankments formed
of clay, on clay foundations due to risk of very slow rates of
strength gain due to consolidation. This issue is present for any
dam with a clay foundation - the clay present at the Abingdon
site (Kimmeridge and Gault Clay) is broadly the same as at
Marsh Gibbon and Chinnor.
Challenge that options for phased
development should be dropped as they
do not make full use of the site potential
and would cause excessive disruption
and property blight
Strategic Environmental Assessment and Environmental Metric
will take account of environmental impact of phased options.
As there is reduced deployable output and increased cost they
would only be selected if second phase could be substantially
deferred beyond construction of the first phase.
Yield and expected performance of the Upper Thames Reservoir under
future major droughts
91
92
Upper Thames Reservoir – yield of 150 Mm3 scheme across a range of possible future droughts
Previous work on yield of the Upper Thames Reservoir (UTR) carried out on the
basis of analysis of 20th Century droughts:
• Scheme estimated to provide 287 Ml/d of additional yield during the critical 1921 and 1934
drought events
• Historic record shows scheme is resilient to droughts with a critical duration of 20 months
or less
• Relationship between intensity and duration needs to be accounted for when resilience of
London system acting conjunctively with UTR to different drought durations is considered
Expected performance under major future droughts
• Stochastic analysis of expected yield undertaken using weather generator emulating 20th
Century droughts to generate rainfall and evaporation data. Large number of droughts of
known severities generated
• Droughts were ranked using IRAS model and a statistically representative sample of 30
events were identified for detailed investigation
• Analysis of UTR yield performance for these droughts carried out using WARMS
Stochastic Analysis of London’s Water Resources
Re
lati
ve
Yie
ld (
Ml/d
)
• Each library contains 10 droughts, with 5 years warm up and 4 years cool down
• Used to produce a yield-yield relationship between WARMs and IRAS
• Actual droughts within each library shown in this graph
Drought Library A
Drought Library B
Drought Library C
Drought Library D
Single very high outlier removed from library B – unusual winter type event, not able to estimate in WARMS
Development of stochastic “Drought Libraries” for analysis of Upper Thames Reservoir yield
Yield of 150 Mm3 UTR scheme across a range of future droughts
95
Droughts were formed into 3 libraries (A-C) containing a continuous 100 year
time series of rainfall and evaporation for each of the 10 Thames sub-
catchments in WARMS. 3 advantages of this drought set:
• Droughts represented good range of events from 1 in 100 to 1 in 1000
year return period. They covered 1/6th of the available events from
the full stochastic data set so provided a good test of performance
• Droughts previously run through WARMS so their yield and severity
already known
• Events all randomly selected based on their relative yield alone
Analysis of likely yield during each drought was estimated based on storage
performance of the London system with and without the UTR at various
demand levels
Summary of Yield Analysis Libraries A-C
96
Start Finish Duration (Days) 287 242 220 Difference Est Yield
Drought 1 06/08/2024 02/11/2025 453 10000 22 309
Drought 2 Minimal Diff 0 287
Drought 3 Minimal Diff 0 242
Drought 4 20/06/1954 20/10/1955 487 4500 9 296
Drought 5 Minimal Diff 0 220
Drought 6 Approx. half way between 242 and 287 no calc 265
Drought 7 Approx. half way between 242 and 287 no calc 265
Drought 8 Minimal Diff 0 287
Drought 9 03/06/2004 18/11/2005 533 7000 13 300
Drought 10 29/03/2014 10/01/2015 287 7000 24 311
Average yield across all 10 droughts 278
Not used
Drought
Number
Not used
Not used
Not used
Not used
Storage Change when Additional
Demand Placed on System with UTR (Ml) Timing of Recession
Estimated UTR Yield
(Ml/d)
Not used
Start Finish Duration (Days) 287 230 95 Difference Est Yield
Drought 1 Not Used Minimal Diff 95
Drought 2 23/06/1934 18/11/1935 513 4500 9 296
Drought 3 Approx. half way between 230 and 287 259
Drought 4 05/03/1954 01/12/1957 1367 5000 4 291
Drought 5 16/08/1964 06/12/1965 477 10000 21 308
Drought 6 Minimal Diff 287
Drought 7 1000 4 291
Drought 8 8000 17 304
Drought 9 Not Used Minimal Diff 230
Drought 10 05/07/2014 05/11/2015 488 -1000 -2 285
Average 264
Timing of Recession Storage Change when Additional Demand Estimated UTR Yield Drought
Number
Not Used
Not Used
13/04/1985
14/08/1994
Average expected yield of UTR 282 Ml/d
Library A Library B
Library C
Analysis of performance across a range of future droughts
97
The following conclusions can be drawn from the analysis:
• Yield of UTR is expected to be robust for all droughts with a similar
critical period to the major historic events. This covered 27 of the 30
sampled events and the UTR had a yield benefit within 20% of the
287 Ml/d figure
• Some longer 24 to 36 month events were contained in the libraries
and under these droughts there was insufficient winter recharge to
offset this longer duration
• There was no noticeable trend of resilience versus severity
Summary of Scheme Resilience The following conclusions can be drawn about the benefits and
level of resilience of the Upper Thames Reservoir:
• Scheme yield is resilient for all major droughts where critical
duration is similar to that seen in the worst historic events
• 3 of the 30 drought events (10%) contained longer critical durations
with low enough winter recharge to reduce yield of the scheme.
Probability of encountering a drought that is both severe enough to
test the existing London system and cause a failure of the UTR
scheme is extremely small – less than once every 1000 years
• 90% of the major drought events within the Thames catchment are
expected to have a critical duration of less than 24 months
• UTR shows relatively little variability in yield across the majority of
the major drought events that are expected to occur in the future,
with an average expected reliable yield of 282 Ml/d
Catchment management: Further work identified
• Develop the pilot investigations programme in consultation with stakeholders
• Review potential for catchment and/or in-river improvement measures to
reduce the scale of “sustainability reductions” proposed by the EA
• Review the potential for development of strategic water supply schemes to
reduce abstraction from existing Thames Water sources in sensitive
environments where adverse effects of abstraction have been identified
• Consider whether the benefits of options included in the Constrained List could
be enhanced through the inclusion of catchment management approaches
• Additionally, Thames Water will be continuing its water quality focused
catchment management activities over the coming years
99
Seeking a wider perspective
100
TW hosted a catchment management workshop (October 2016).
The workshop concluded that:
- TW had completed a comprehensive review of options.
- Catchment approaches have potential, but there is currently a lack of evidence.
- Pilots are required in different catchments, using different forms of governance to
identify the model(s) that has the greatest benefits and can be rolled out.
- TW is currently examining opportunities for a whole catchment pilot and the
format this may take.
There are many ‘small p’
political considerations within a
catchment – right down to the
individual housing association.
There is no unified catchment
theory for us to find and no
silver bullet. It is inherently
complicated
Rob Cunningham,
RSPB
101
Questions
Bill Hume-Smith, Mott MacDonald
Screening Decisions and
Updated Constrained List
103
Network Element
Water
Reuse
Desalination
New
Reservoir
Severn-
Thames
Transfer
Reuse
plant
WTW London
Ring Main
Desal
plant London
Ring Main
Resource
Element
Raw Water Conveyance
Element
Raw Water
System Element
Treatment
Element
WTW London
Ring Main
WTW London
Ring Main
River regulation
London raw
water storage
London raw
water storage
London raw
water storage
Separating options into system elements
Updated Constrained List - London
104
Option Resource Element Raw Water Conveyance Raw Treatment Network
Type Location Nominal
Capacity
Ml/d
Indirect water
reuse
Deephams 60 Deephams to King George
V Intake - 60Ml/d
TBC East London
Treatment
See network
reinforcement
Beckton 3*100
2*150
Beckton to King George V
Intake - 300Ml/d
matrix
Raw Water Vyrnwy 180 Deerhurst-Culham TBC Kempton See matrix
Transfer Mythe 15 300/400/500Ml/d
Desalination Beckton (blended) 150
N/A N/A N/A
See matrix, plus
Beckton to Coppermills
Crossness (blended) 3*100 Crossness to Beckton
New Abingdon 75Mm3 153 N/A TBC Kempton See network
Reservoir Abingdon 100Mm3 204 reinforcement matrix
Abingdon 125Mm3 247
Abingdon 150Mm3 287
Abingdon 30+ approx 90Mm3 59+179
Abingdon 70+ approx 50Mm3 145+93
Direct River
Abstraction
Teddington Weir (Mogden effluent transfer) 300 Teddington to Thames-Lee
tunnel shaft - 300Ml/d
TBC Kempton /
East London
See network
reinforcement matrix
Aquifer AR - Kidbrooke 3 N/A N/A N/A N/A
Recharge AR Merton (SLARS3) 5
AR Streatham (SLARS2) 4
Ground- GW - Addington 1 N/A N/A N/A N/A
water GW - London confined Chalk (north) 2
GW - Southfleet/Greenhithe (new WTW) 8
Licence
Trading
GW licence trade
2
N/A N/A N/A N/A
ElementElement Water
System
Element
Element
Updated Constrained List – Thames Valley
105
Option Resource Element Raw Water Treatment Network Element
Type Location Nominal Nominal
Capacity
Ml/d
Capacity
Ml/d
Raw Vyrnwy 20 Deerhurst-Culham Radcot Included in treatment element
Water Transfer 300/400/500Ml/d WTW
New Abingdon 75/100/125/150 Mm3 20 N/A Abingdon Included in treatment element
Reservoir Abingdon 30+ approx 90Mm3 WTW
Abingdon 70+ approx 50Mm3
Groundwater Moulsford 1 3.5 (ADPW) N/A N/A N/A
Removal of constraints
to DO
Ashton Keynes borehole pumps 2.5 (ADPW) N/A N/A N/A
Inter-zonal Mortimer disused source N/A Kennet Valley to SWOX 8.3 / 12.8
transfers Henley to SWOX 2.5
Inter-company transfersN/A N/A Wessex Water to SWOX
(Flaxlands)
2.9
Groundwater Datchet N/A N/A N/A
Datchet main replacement 9.3 N/A N/A N/A
Eton removal of constraints (ADPW) N/A N/A
Inter-zonal transfers N/A N/A Henley to SWA 4.1
Groundwater Mortimer recommissioning 4.5 (ADPW) N/A N/A N/A
Removal of constraints
to DO
East Woodhay borehole pumps 2.1 (ADPW) N/A N/A N/A
Groundwater Dapdune licence disaggregation N/A N/A N/A
Dapdune removal of constraints 7.8 (ADPW) N/A N/A N/A
Ladymead WTW N/A Included in treatment element
Inter-co. transfers N/A N/A SouthEast Water to Guildford 5 / 10
KV
Gu
ild
ford
Removal of constraints
to DO
Element LocationConveyance
Element
SW
OX
SW
A Removal of constraints
to DO
Keith Banner, Thames Water
Update on System work
Environmental assessment
Review of the capacity and capability of the current infrastructure
Strategic resources Treatment capability
Network constraints
Demand
WARMs
Monthly WTW capability profiles
WTW Capability & Resilience Model
Strategic Network Model 1.8
Hazard scenario 1
Hazard scenario 2
Hazard scenario 3
Abstraction 1.1 1.2 1.3
Storage 1.4 1.5 1.6
WTW Capability 1.7
Network Storage
2 3 4
1
Service levels
Options
Development of system resilience
1.8 Motts
1.1 CH2M Voyage
1.2 WRA – INCA met ,
doc
1.3 Motts – Op
Strategy
1.4 Atkins – deterioration
1.5 CEH – Treatable volumes
1.6 CEH – Algal Speciation
1.7 Innovation – Mecana
Trial
System Strategy
System Strategy
Jan Feb Mar 2017
Operating Philosophy
Raw Water
Systems
Water
Treatment
Works
Network
Reinforcement
O
P
T
I
O
N
S
Network Blueprint
Element
CDR’s
Assumptions: DYAA/Drought Demand Location
Risks:
Element
CDR’s
110
General discussion
Demand management options
Non-potable reuse feasibility report February 2017
Incentive scheme update report March 2017
Updated screening report March 2017
Resource options
Updated screening report March 2017
Bottom up cost and risk methodology March 2017
Inter-zonal transfers March 2017
Updated option feasibility reports March 2017
Conceptual Design Reports (Summary) January 2018
• rr
Publication of reports
Thank you for your time and contributions today.
Dates for future meetings
• 16 March 2017: Water Resources Forum, Reading
• (tbc) April 2017: Technical meeting on options
113