Water Resources Technical Stakeholder Meeting Update on … · 2017-02-28 · in 2012 (AMP5). •...

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Water Resources Technical Stakeholder Meeting Update on demand management and resource options 07 February 2017

Transcript of Water Resources Technical Stakeholder Meeting Update on … · 2017-02-28 · in 2012 (AMP5). •...

Page 1: Water Resources Technical Stakeholder Meeting Update on … · 2017-02-28 · in 2012 (AMP5). • WRMP14 (2014) made the case for installing >1 ... Undertake IDM modelling Mar –

Water Resources Technical Stakeholder Meeting

Update on demand management and resource options

07 February 2017

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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

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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.

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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.

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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

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Anthony Owen, Thames Water

Demand Management Options

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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%

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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

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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.

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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.

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Current levels of metering WRMP14 change in levels of metering in next 15 years

33% - 72%

53% - 91%

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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.

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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

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Resource Options

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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

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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

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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

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Victoria Price, Mott MacDonald

Groundwater Feasibility study

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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

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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

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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

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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

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10 minute break

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Alice Mortimore, Mott MacDonald

Chris Lambert, Thames Water

Kieran Conlan, Ricardo

Raw Water Transfers

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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

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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

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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

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Flow Time series showing transfer availability from the Severn at Deerhurst under major historical droughts

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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

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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

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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

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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

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Stochastic Analysis of London’s Water Resources

Re

lati

ve

Yie

ld (

Ml/d

)

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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

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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

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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

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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

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57

Questions

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Partially supported STT

58

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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.

59

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Evidence – Weir Pool Habitats

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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

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Weir Pool Habitat - Sandford Lock

Weir Pool Area (m2) Features

16 Sandford Lock 9,545

• Natural banks

• Varied velocity

• Over hanging trees

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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

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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

64

Increasing volume

Incre

asin

g

su

pp

ort

ed

flo

w

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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.

65

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

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Partially Supported STT – Costs analysis

66

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

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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

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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.

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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

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70

Questions

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Other Transfers

71

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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

72

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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

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74

Questions

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Bill Hume-Smith, Mott MacDonald

Kieran Conlan, Ricardo

Reuse, Desalination, Direct

River Transfers

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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.

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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

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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.

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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 ✖

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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

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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

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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.

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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

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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

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85

Questions

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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

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Enjoy your lunch…please be back at 13:45

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Chris Lambert, Thames Water

Reservoir and Catchment

Management

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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

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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.

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Yield and expected performance of the Upper Thames Reservoir under

future major droughts

91

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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

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Stochastic Analysis of London’s Water Resources

Re

lati

ve

Yie

ld (

Ml/d

)

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• 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

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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

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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

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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

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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

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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

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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

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101

Questions

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Bill Hume-Smith, Mott MacDonald

Screening Decisions and

Updated Constrained List

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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

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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

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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

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Keith Banner, Thames Water

Update on System work

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Environmental assessment

Review of the capacity and capability of the current infrastructure

Strategic resources Treatment capability

Network constraints

Demand

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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

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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

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110

General discussion

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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

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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

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113