Final Water Resources Management Plan

Cambridge Water Company Final Water Resources Management Plan

January 2010

1 Cambridge Water Company Final Water Resources Management Plan

Contents

Page

Executive Summary 3

1.0 Overview

1. 1 Introduction 5 1. 2 Consultation 5 1. 3 Summary of Plan 6 1. 4 Cambridge Water Cycle Study 7 1. 5 Directions 7

2.0 Water Resources Plan

2. 1 Plan Content and Development 9 2. 2 Water Supply 12 2. 3 Water Demand 15 2. 4 Climate Change 25 2. 5 Greenhouse Gas Emissions 27 2. 6 Target Headroom 27 2. 7 Baseline Supply-Demand Balance 28 2. 8 Option Appraisal 28 2. 9 Final Water Resources Strategy 29

3.0 Tables 31

4.0 Appendices

1 - Consultation 32

2 - Strategic Environmental Assessment 36

3 - Economic Level of Leakage Assessment * 48

4 - Target Headroom Calculation * 49

5 - Effects of Climate Change on Supply 50

6 – Outage Assessment * 54

7 – 25 Year Appraisal of Metering Policies 55

* available on request

2 Cambridge Water Company Final Water Resources Management Plan

Executive Summary

Cambridge Water’s water resources management plan sets out how the Company will manage its resources to meet the needs of existing and future customers, and those of the environment, over the next 25 years.

The Company’s supply-demand balance (the amount of water available for use, compared with the quantity actually used) could be influenced by a range of factors: this plan describes those factors, and assesses their likelihood and impact. Using this assessment the Company’s supply-demand surplus (headroom) has been calculated over the planning period. An additional buffer (target headroom) has been included to cater for uncertainties.

The Board of Cambridge Water Company reviewed and endorsed the draft water resources management plan and its underlying policies at a Board Meeting held on 4th March 2008. Following publication, and a period of consultation, the draft plan was updated to take account of representations received during the consultation period and changes in the economic climate. Further information was requested by, and provided to, the Secretary of State, who subsequently agreed that this final plan should be published.

Baseline Water Resources Situation

Significant growth in housing numbers is planned for the Cambridge sub-region over the next 15 years. Cambridge Water has seen a rise in new housing connections over the past few years, and expects this trend to continue throughout the planning period. The Company has taken a view on the likely annual increase in housing numbers, based on the expectations set out in the East of England Plan, experience of the planning process, and historic build rates. Per property consumption for the new homes is forecast to be lower than traditionally assumed, as the principles set out in the Code for Sustainable Homes are incorporated into planning and building policy.

Modest growth in per capita consumption at existing properties is forecast: at this stage, the Company sees no significant savings arising from the retro-fitting of water-efficient devices on a large scale.

A percentage of existing unmeasured household customers is expected to opt to pay for their water on a measured basis, at a similar rate to that witnessed in recent years.

In line with published guidance, overall demand for water is expected to increase by up to 2% over the planning period as a result of climate change alone.

The Company expects to maintain total leakage at 14 megalitres per day (Ml/d), effectively reducing per property leakage by 35% by 2035, from 110 litres/property/day to 73 l/prop/d.

On the supply side, the planned refurbishment of one of the Company’s sources in 2009/10 will allow its full licensed quantity to be abstracted, providing a small increase in deployable output (DO) *. This increase is likely to be offset by a small loss of DO arising from a sustainability reduction applied by the Environment Agency. The reduction is the probable outcome of a series of investigations at a number of sources whose abstractions had been thought by the Agency, and Natural England, to have a possible detrimental effect on nearby environmental sites. However, the value of the likely reduction is not yet ascertained so, in accordance with the latest Agency guidance, no reduction in deployable output has been assumed at this stage. * deployable output is the amount that can be pumped from the Company’s sources, constrained by licence, geophysical features, or plant limitations.

3 Cambridge Water Company Final Water Resources Management Plan

Towards the end of the planning period, in order to preserve headroom, the Company will introduce measures to improve the security of supply at strategic single-borehole sites, as a means of reducing outage. These measures will not have a significant effect on the environment.

Recent studies show that climate change may also result in a small loss of deployable output, spread over a percentage of the Company’s sources. More work will be carried out in this area when the Environment Agency’s regional groundwater model is fully developed.

Under the baseline scenario headroom is expected to be maintained throughout the planning period. Figure 1 illustrates the projected supply-demand balance, under the baseline scenario, over the period.

Final Planning Solution

Over 70% of the water currently supplied by Cambridge Water is on a measured basis, and the benefits of this level of metering in curbing peak demand have been readily seen over recent years. There is no immediate threat to water resources in the Company’s area, and we do not propose to undertake an accelerated household metering programme during the planning period.

Given the Company’s current healthy supply-demand balance, there is no justification or benefit to be gained in the short-term from making significant investment in capital schemes designed to alter that balance.

Taking the above factors into account, the Company has not found it necessary to include a final planning solution in its final plan.

4 Fig.1 - Baseline Forecast

deployable output forecast total water available for use (TWAFU) TWAFU - target headroom dry year forecast (baseline) incl. climate change dry year demand forecast (baseline) normal year demand forecast (baseline) 120

115

110

105 outage 100

target headroom 95 Ml/d

90 supply demand balance

07-08 08-09 09-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 19-20 20-21 21-22 22-23 23-24 24-25 25-26 26-27 27-28 28-29 29-30 30-31 31-32 32-33 33-34 34-35 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 Cambridge Water Company Final Water Resources Management Plan

1.0 Overview

1.1 Introduction

This draft water resources management plan (WRMP) shows how Cambridge Water Company intends to maintain the balance between supply and demand over the next 25 years. The plan is complemented by the Company’s drought plan, published in early 2008, which sets out the short-term operational steps Cambridge Water will take if a drought occurs.

The Company published its first water resources plan in March 1999. This was later superseded by a second version, published in March 2004, after consultation with the Environment Agency.

The Water Act 2003, by amending the Water Industry Act 1991, introduced a statutory duty for water companies to prepare and maintain water resources plans. The Water Resources Management Plan Regulations 2007 prescribe how plans are to be prepared and published, and the latest guidance issued by the Environment Agency (EA) in April 2007 covers this process in detail. This plan has been prepared in line with Directions* from the Secretary of State, and the latest EA guidance. Responses received from consultees at the pre-draft stage have also been considered in the compilation of this document.

The updated draft plan, together with the Company’s statement of response to the representations received, were considered by the Secretary of State, who requested further information to enable a decision to be made regarding publication of Cambridge Water’s final plan: this was provided in October 2009. Having considered the further information provided, the Secretary of State agreed, in December 2009, that the final plan should be published.

* a summary of the Directions made by the Secretary of State, and assurance that this plan complies with those Directions, is set out in Section 1.5 below.

1.2 Consultation

The statutory process for the preparation of water resources management plans sets out defined stages for consultation. The three principal consultation stages are:

 Pre-draft consultation with statutory consultees and licensed water suppliers (see Note below)  Consultation with the Environment Agency’s regional planners, and with the Company’s Water Services Regulation Authority (Ofwat) Reporter during the preparation of this draft plan  Consultation with specified organisations, with the Company’s customers, and with anyone else who is likely to be affected, following publication of the draft plan. This is a 4-stage process: advising stakeholders of the plan’s publication; ensuring that it is available to those affected; allowing a reasonable time for interested parties to make representations; publishing a Statement of Response to show how the plan has been updated to take account of representations received

The consultation process that has been followed by the Company at all stages in the preparation of this draft plan is detailed in Appendix 1 to this document.

5 Cambridge Water Company Final Water Resources Management Plan

Note:- under the EA guidance companies are also required to consult with any licensed water supplier which supplies water to premises in the undertaker’s area via the undertaker’s supply system. There are currently no such licensed water suppliers operating in Cambridge Water’s area of supply.

1.3 Summary of Plan

The Company currently has an adequate surplus of deployable output, both against average daily demand and estimated peak week demand. Its strategy is to maintain the highest sustainable level of headroom throughout the planning period, thereby ensuring that all its customers continue to benefit from complete security of supply.

Given the Company’s current healthy supply-demand balance, and the actions planned under the baseline scenario, there are no plans for major investment in additional resources during the next 25 years.

On the supply side:-

i. the Company’s principal aim is to ensure that the full potential of its licensed abstraction sites is always available. It will achieve this through a proactive and considered approach to capital maintenance, applied to both infrastructure and non-infrastructure assets.

ii. timely capital maintenance programmes will help to ensure that planned outages are kept to a minimum

On the demand side:-

i. the build rate of new properties is expected to increase over historic levels, as the effects of the development of the Cambridge fringe areas, and the new town of Northstowe, are felt. It is assumed that, having increased, build rates will remain constant, both before and after the expiry of the current East of England Plan in 2021.

ii. it is expected that the demand for water in new dwellings will reduce, through a combination of:

. the adoption of the voluntary Code for Sustainable Homes, and proposed changes to the Building Regulations . the incorporation of grey water recycling at a percentage of new household properties. Note - there is a still a considerable amount of uncertainty surrounding this assumption, and no account has been taken of savings from grey water recycling in the preparation of this draft plan.

iii. a small increase in underlying growth for unmeasured households and non-households is anticipated, although zero growth is forecast for measured households, with a reduction assumed for measured non-households.

iv. the number of households opting to become measured is expected to continue at the same level as in recent years.

v. substantial investment has been made in the creation of district meter areas (DMAs) in and around Cambridge city. Comprehensive district metering will enable leakage to be monitored and controlled more effectively, thereby supporting the Company in meeting its leakage target in the future.

6 Cambridge Water Company Final Water Resources Management Plan

vi. the case for undertaking an increased level of mains renewal activity, identified by a network deterioration model as being necessary to maintain levels of serviceability, will be presented in the Company’s business plan. Using DMA information, mains renewal programmes will be targeted towards areas of high leakage.

1.4 Cambridge Water Cycle Study

The Company recognises that timely provision of water services infrastructure is essential to the success of the planned housing growth within the Cambridge sub-region. Cambridge Horizons, the body responsible for driving forward the planned development, has completed the first phase of a water cycle study to identify key water-related issues and possible obstacles to the planning process. Cambridge Water is represented on the Water Cycle Strategy Steering Group; has provided data and advice to Cambridgeshire Horizons and its consultants; and has pledged full support for the project.

1.5 Directions

The Secretary of State has made a series of Directions which underpin the Water Resources Management Plan Regulations 2007. A summary of the requirements of those Directions, and the corresponding sections of this plan which cover those requirements, is set out below: i) In the left-hand column of the table, references to a numbered section are to the section so numbered in the Water Industry Act 1991, unless otherwise stated. References to a numbered section in the right-hand column are to the section so numbered in this plan. ii) “the Regulations” means the Water Industry (Prescribed Conditions) Regulations 1999 (as amended by the Water Industry (Prescribed Conditions) (Amendment) Regulations 2007).

Regulation Covered in The Water Resources Management Plan Direction 2007 3. In accordance with section 37A(3)(d), a water resources management plan must include a description of the following matters— (a) how frequently the water undertaker expects it may need to impose prohibitions or restrictions on its customers in relation to the use of water under each of the following— (i) section 76; ) (ii) section 74(2)(b) of the Water Resources Act 1991(c); and ) Section 2.1.7 (iii) section 75 of the Water Resources Act 1991; )

(b) the appraisal methodologies which the water undertaker has used in choosing Section 2.8 the measures it intends to take or continue for the purpose set out in section

37A(2), and its reasons for choosing those measures; (c) the emissions of greenhouse gases which are likely to arise as a result of each Section 2.5 measure which the water undertaker has identified in accordance with section 37A(3)(b); (d) how the supply and demand forecasts contained in the water resources Section 2.4 management plan have taken into account the implications of climate change; and (e) except where the water undertaker does not supply, and will continue to not supply, water to premises in which, or in any part of which, a person has his Section 2.3 home, how the water undertaker has estimated future household demand in its area over the planning period, including the assumptions it has made in relation to population and housing numbers.

/cont’d over

7 Cambridge Water Company Final Water Resources Management Plan

Regulation Covered in The Water Resources Management Plan (No.2) Direction 2007 (as amended by The Water Resources Management Plan (No.2) (Amendment) Direction 2007) 2. In accordance with section 37A(3)(d), a water undertaker shall include in its water resources management plan a description of the following matters— (a) its estimate of the increase in the number of domestic premises in its area, over the planning period, in respect of which it will be required to fix charges by Section 2.3.11 reference to volume of water supplied to those premises under section 144A; (b) where the whole or part of its area has been determined by the Secretary of Section 2.9.1 State to be an area of serious water stress under regulation 4(1) of the

Regulations, its estimate of the number of domestic premises which are in that area and in respect of which it will fix charges by reference to volume of water supplied to those premises over the planning period; (c) its estimate of the increase in the number of domestic premises in its area Section 2.9.1 (excluding any domestic premises which are included in the estimate referred to in sub-paragraph (b)), over the planning period, in respect of which section 144B(2) will not apply because the conditions referred to in section 144B(1)(c) are not satisfied and in respect of which it will fix charges by reference to volume of water supplied to those premises; (d) full details of the likely effect of what is forecasted pursuant to sub-paragraphs Section 2.9.1 (a) to (c) on demand for water in its area; (e) the estimated cost to the water undertaker in relation to the installation and Section 2.9.1 operation of water meters to meet what is forecasted pursuant to sub-paragraphs (a) to (c) and a comparison of that cost with the other measures which it might take to manage demand for water, or increase supplies of water, in its area to meet its obligations under Part III of the Water Industry Act 1991; and (f) a programme for the implementation of what is forecasted pursuant to sub- Section 2.9.1 paragraphs (b) and (c).

Note : there is no Figure 2 in this document

8 CAMBRIDGE WATER COMPANY AREA OF SUPPLY, SHOWING IMPORTANT WETLAND SITES

LITTLE OUSE G THETFORD KEY TO SYMBOLS

47 PUMPING STATION

1 BOOSTER STATION 46 2 49 WATER TOWER/RESERVOIR 3 WETLAND AREA 48 4

E S U O 5 R E V I R

SCHEDULE OF RELEVANT WETLAND SITES OF SPECIAL SCIENTIFIC INTEREST (SSSIs) AND LOCAL NATURE RESERVES (LNRs)

M A C R E A. FOWLMERE WATERCRESS BEDS. I RV Relic fen habitat on low-lying chalk, with open shallow water and chalk grassland 12 8 9 11 F B. THRIPLOW MEADOWS. 10 CAMBRIDGE 27 Species-rich neutral pasture of variable drainage characteristics, with many uncommon plants 13 26 C. DERNFORD FEN. E 14 20 25 Relic of a much larger area of rough fen, ranging from dry grassland to reedbed and alder carr 21 22 15 I 28 17 R D. SAWSTON HALL MEADOWS. IV 16 E R Relic of wet pasture land, consisting of an area of meadows overlying spring-fed peat over chalk CA 23 M 24 R IV o E r R 29 18 G E. FULBOURN FEN . E HE R H R R A Species-rich neutral grassland on calcareous loam and peat, with fragments of 'fen’ woodland N GR VE C ANT 33 30 19 RI T A A D 37 36 F. WILBRAHAM FEN. 39 35 34 Large area of fen and neutral grassland with associated scrub and open water communities

A 40 B 32 G. EAST WRETHAM HEATH. 38 Area of Breckland grassland, with two fluctuating meres directly influenced by chalk groundwater 42 41 J H. ALDER CARR. 45 Rare example of wet valley alderwood on fen peat, of great value to invertebrates 44 43 I. NINE WELLS (LNR). Historically important site containing several chalk springs: the source of Hobson's Conduit

J. RIVER GRANTA AND CATCHMENT. Tributary of the River Cam. Much of its flow is made up of groundwater discharge from seepages and chalk springs. Supports a breeding trout population. 0 1 2 3 4 5 6 7 8 9 10 KILOMETRES

0 1 2 3 4 5 MILES SCALE Fig. 3 AREA OF SUPPLY CAMBRIDGE W A T E R SHOWING CIVIL PARISHES C O M P A N Y

RAMSEY

BURY WARBOYS WISTOW

PIDLEY M A H CUM S B N R R O FENTON E U M G O H S T OLD O N HURST COLNE WOOD HURST EARITH BLUNTISHAM

HOLYWELL ST IVES CUM NEEDINGWORTH OVER WILLINGHAM

N O N COTTENHAM T O N T WATERBEACH A FEN P ST M N DRAYTON A E R H F SWAVESEY C N A O E T B P N ON N D uyuuy T A G S A O NG N P T NI T R T IL CO S N A W H A A TH G O L V G O OR N T R W O G A E N OX L N HISTON E L E T B I E H P TH K S S E WOR N Y A LOL A G V BAR O O P ELSWORTH T MILTON IN E HILL W G N R Y IN R A O E P O R L N R GIRTON Y O IM H D R T R T E STOW H D Y D A CUM L R Y KNAPWELL I D FEN QUY E H MADINGLEY L C DITTON C IS T A RNE E LT BOU T K L X AM E C O IC T TEVERSHAM WILBRAHAM W CROXTON O C CAMBRIDGE E D N COTON N R D O L A H T A

C N

E GREAT

BOURN O GRANT

TOFT T CHESTER WILBRAHAM M R

O A

W FULBOURN C B W N C AR O O ES LT T T T ON T N S S O E T HASLINGFIELD G A N W N G D L LITTLE N E E N GREAT E C N I S E R D D S O V K R O R T L E O G S O V GRANSDEN E T W I R L R F L T V L H SHELFORD E R L (p O E A L A E a N E R U P T rt V X TA T

) E A T S IN N O

H N G GAMLINGAY O BABRAHAM

HATLEY T D BALSHAM

WIMPOLE L T R G HARSTON L O LT

L F

N L I E E ABING

BARRINGTON H SAWSTON M R S A

W N TON R O H

R T D A W R S O E W O

N H F R W ITT S

CROYDON S LE I E

O H SFO P

N E R M GT D L P FOXTON D A

R P L O

D ET ABING I LINTON HORSEHEATH

D H H T SHINGAY TON

D H HINXTON A T CUM WENDY E THRIPLOW H R F N D SHUDY CAMPS

W L O G O S E W T T DUXFORD BARTLOW U T M G L I O M L N I G E D B I BASSINGBOURN R A P CASTLE E CUM E N L CAMPS I KNEESWORTH SE T MELBOURN ICKLETON M T T L O I E N R P M G HEYDON D L O E T E O R GREAT N N D E & N LITTLE CHISHILL

0 1 2 3 4 5 6 7 8 9 10 KILOMETRES

0 1 2 3 4 5 MILES Fig. 4 SCALE Cambridge Water Company Final Water Resources Management Plan

2.0 Water Resources Plan

2.1 Plan Content and Development

This plan is a development of the Company’s current Water Resources Plan, published in 2004, and continues to embody the principles set out in that plan. Those principles are laid out in the summary of the plan under Section 1.3. The development of this plan has been based on the aim of maintaining secure supplies for customers through the twin track approach of: maximising the amount of water available for use, within current licensing and aquifer constraints; and regulating distribution input through a combination of active leakage control and demand management.

2.1.1 Planning Period The period of this plan is 25 years, running from 2010/11 to 2034/35. The ‘base year’ from which planning forecasts have been derived was originally 2006/07, but this updated draft plan has been re-based on 2007/08, using actual base year information.

2.1.2 Resource Zones The Company’s supply and distribution network is fully integrated, and forms a single resource zone. (A resource zone is defined within the EA guidance document as “the largest possible zone in which all resources, including external transfers, can be shared and hence the zone in which all customers experience the same risk of supply failure from a resource shortfall.”) An overall plan of the Company’s area of supply, showing key environmental sites, is shown in Figure 3. Figure 4 shows the parishes included within the area of supply.

2.1.3 Planning Scenarios This plan has been developed through the consideration of a number of different supply- demand scenarios. These are:

 Normal year annual average scenario: a normalised set of data for the 2007/08 base year has been developed from the actual base year figures, by making assumptions about the impacts of weather patterns and customer behaviour. These assumptions are explained more fully in Section 2.3.1.

 Dry year annual average scenario: the dry year, a period of low rainfall and unconstrained demand, forms the basis of this plan. An explanation of how the Company has derived its dry year figures from the normalised 2007/08 base year data is given in Section 2.3.2.

 Critical period scenario: the critical period for the Company is the ‘peak week’, i.e. the 7-day period in any year when the average daily distribution input figure is at its highest. Figure 5 shows the average day peak week (ADPW) distribution input forecast over the planning period.

Further discussion of the critical period scenario is included in Section 2.3.3.

2.1.4 Base Year Data The base year data used in this updated plan are those submitted to Ofwat by the Company as part of its 2008 June Return. The change of base year from 2005/06, on which the original draft plan was based, has had the effect of increasing base year distribution input by a mere 0.5%. There is no resultant material change to any of the plan’s assumptions or outputs.

9 Cambridge Water Company Final Water Resources Management Plan

2.1.5 Reconciliation of Data The Maximum Likelihood Estimation (MLE) method has been used to reconcile the base year water balance data in order to minimise uncertainty in base year estimates. When the sum of the individual water balance components for the base year was compared with distribution input a discrepancy of 0.41 Ml/d was identified, representing 0.6% of distribution input. This discrepancy was distributed among all the components, as shown in the following table:

Component Unadjusted Confidence Confidence % of Adjustment Adjusted Value plus or Range Total Value Value (Ml/d) minus (Ml/d) (Ml/d) (Ml/d) Mhh 20.64 3% 0.62 13.2% -0.05 20.59 Mnhh 20.43 3% 0.61 13.0% -0.05 20.38 Umhh 20.63 10% 2.06 43.9% -0.18 20.45 Umnhh 0.78 30% 0.23 5.0% -0.02 0.76 Dsou 0.15 50% 0.08 1.6% -0.01 0.14 Wtu 0.16 50% 0.08 1.7% -0.01 0.15 Dlosses 10.16 10% 1.02 21.6% -0.09 10.07 Total 72.95 4.70 100% -0.41 72.54

Base year distribution input = 72.54 Ml/d

Key to Abbreviations Mhh Water delivered billed measured household Mnhh Water delivered billed measured non-household Umhh Water delivered billed unmeasured household Umnhh Water delivered billed unmeasured non-household Dsou Distribution system operational use Wtu Water taken unbilled Dlosses Distribution losses

2.1.6 Sensitivity Analysis There are uncertainties in any supply-demand forecast. For Cambridge Water the biggest sources of uncertainty, i.e. those that are most difficult to predict, are the rate of build of planned new housing developments, and the amount of water consumed by the individual properties within those developments. Of the other components of the forecast, the long-term effects of climate change are still uncertain, but an allowance for this uncertainty has been made within the target headroom buffer. Most of the other components are either well- understood, from historic data, or have only a small effect on the overall forecast.

The following sensitivity analyses have been carried out to test the assumptions made in the supply-demand forecast against the two main variables mentioned above:

New household build rate +/- 20%: the Company considers that its forecast annual build rate, rising to 2500 dwellings per year by 2015, and 2650 per year thereafter, is realistic, given the rates that have been achieved in the past, and the current economic climate. Based on the per property water usage assumptions made in the baseline demand forecast (i.e. all new dwellings from 2010/11 to comply with the revised Building Regulation requirements) an increase of 20% in the annual build rate would increase demand by around 3.1 Ml/d by the end of the planning period. Thus, the target headroom buffer would start to be eroded by the end of 2033. The Company is confident that a trend towards greater housing numbers would be detected early, and that it would have ample time to take action, before the situation became critical.

10 Fig.5 - Average Day Peak Week (ADPW) Forecast

peak demand deployable output forecast ADPW water available for use (WAFU)

ADPW WAFU - target headroom ADPW demand forecast 140

130 outage

120 target headroom

110 supply demand balance Ml/d 100

Similarly, a 20% reduction in new build rates would see a demand reduction of around 3.1 Ml/d, resulting in a larger surplus at the end of the planning period.

Delay in implementation of revised Building Regulations: we have assumed that all new dwellings from 2010/11 will be subject to the requirements of the revised Building Regulations, and that water consumption at those properties will reduce to around 125 litres/head/day as a result. If the introduction of the revised Building regulations were delayed by 5 years, to 2014/15, demands at the end of the planning period could be up to 0.7 Ml/d higher than those currently forecast. This has no material effect on the overall supply demand balance.

Other variables have also been considered, but they also have only a small impact on the overall supply-demand balance, and are not discussed here.

The outcomes of the sensitivity analyses carried out are illustrated in Figures 6 and 7.

2.1.7 Reference Level of Service The Company’s reference level of service, set out in its Strategic Business Plan dated March 1994, is:-

. The need for a major publicity campaign requesting voluntary savings of water not more than once in 10 years

. A hosepipe ban on average not more than once in every 20 years

. A restriction on non-essential usage not more than once in every 50 years

. The risk of rota cuts or use of standpipes on average less than once in 100 years

This level of service is justified by the maintenance of a healthy supply-demand balance throughout the planning period.

2.1.8 Competition The Water Act 2003 amended the Water Industry Act 1991 to extend the opportunities for competition within England and Wales. However, as stated in Section 1.2 above, there are currently no licensed water suppliers operating within the Company’s area: neither does the Company see any opportunities, at this time, for selling water outside its statutory area of supply. Thus, competition has had no impact on the preparation of this plan.

2.1.9 Strategic Environmental Assessment The Company has followed published guidance in reaching the conclusion that a full Strategic Environmental Assessment (SEA) is not required for this plan. However, the screening stage of the SEA process has been undertaken, in consultation with the three statutory consultees – the Environment Agency, Natural England, and English Heritage. The process that has been followed is detailed in full in Appendix 2 to this document, together with supporting data and analysis.

11 Fig.6 - Sensitivity Analysis: +/- 20% New Households

total water available for use (TWAFU) - target headroom dry year forecast (baseline) incl. climate change

dry year forecast (baseline) incl. climate change + 20% dry year forecast (baseline) incl. climate change - 20% 120

110

100 Ml/d

90 supply demand balance

07-08 08-09 09-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 19-20 20-21 21-22 22-23 23-24 24-25 25-26 26-27 27-28 28-29 29-30 30-31 31-32 32-33 33-34 34-35 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 Fig.7 - Sensitivity Analysis: Building Regs Delayed to 2015

total water available for use (TWAFU) - target headroom dry year forecast (baseline) incl. climate change (Building Regs Delayed to 2015) dry year forecast (baseline) incl. climate change 120

110

100 Ml/d

90 supply demand balance

2.2 Water Supply

2.2.1 Deployable Output Deployable output totals are generally in line with the audited output from the Company’s Source Reliable Output (SRO) study, undertaken in 1997, and updated in February 1998. This study determined the quantity of water available from each of the Company’s sources to satisfy average and peak demands, under drought conditions. Borehole level data used in the study were those recorded during the 1991/92 drought, which was the most severe drought of recent times. There have been no serious droughts since the study was undertaken that would suggest a need to change deployable output; however, the Company proposes to undertake a comprehensive review of the 1997 SRO study during the AMP5 (2010/11 to 2014/15) period.

Total deployable output for the 2007/08 base year was 110.06 Ml/d. This figure differs from that quoted in the Company’s 2004 Water Resources Plan, for a number of reasons:

. SRO 1998 updated table used to determine DO, not 1997 original table . licence renewals at Brettenham PS, Euston PS, Fowlmere PS (these are the Company’s only time-limited licences) . pumping test at Westley PS (confirming an increase in SRO) . pump upgrade at Brettenham PS . recommissioning of Sawston PS

The changes to deployable output that have taken place since the 2004 WRP are tabulated below:

1997 SRO, Brettenham added 2004 Water Resources Plan 2007 June Return 2008 draft WRMP, based on 1998 SRO figures Source DO Average Demand Ml/d DO Average Demand Ml/d DO Average Demand Ml/d DO Average Demand Ml/d Limit Constraint Limit Constraint Limit Constraint Limit Constraint Abington Park 1.00 annual licence 1.00 annual licence 1.00 annual licence 1.00 annual licence Babraham 9.09 annual licence 9.09 annual licence 9.09 annual licence 9.09 annual licence Brettenham 5.00 environmental 5.00 environmental 7.38 pump rating 11.34 annual licence Croydon 1.99 annual licence 1.99 annual licence 1.99 annual licence 1.99 annual licence Dullingham 3.60 DAPWL 3.60 DAPWL 3.60 DAPWL 3.60 DAPWL Duxford Airfield 4.56 annual licence 4.56 annual licence 4.56 annual licence 4.56 annual licence Duxford Grange 3.41 annual licence 3.41 annual licence 3.41 annual licence 3.41 annual licence Euston 8.00 annual licence 8.00 annual licence 8.00 annual licence 8.00 annual licence Fleam Dyke 12" (3.27 annual licence) (3.27 annual licence) (3.27 annual licence) (3.27 annual licence) Fleam Dyke 36" 15.57 (12.30 DAPWL) 15.57 (12.30 DAPWL) 15.57 (12.30 DAPWL) 15.57 (12.30 DAPWL) Fowlmere 9.09 annual licence 9.09 annual licence 3.60 annual licence 3.60 annual licence Fulbourn (1.49 annual licence) (1.49 annual licence) (1.49 annual licence) (1.49 annual licence) Great Chishill 1.15 annual licence/DAPWL 1.15 annual licence/DAPWL 1.15 annual licence/DAPWL 1.15 annual licence/DAPWL Great Wilbraham 4.58 pump rating for Bhs1/2 4.58 pump rating for Bhs1/2 4.58 pump rating for Bhs1/2 4.58 pump rating for Bhs1/2 Heydon 1.13 annual licence 1.13 annual licence 1.13 annual licence 1.13 annual licence Hinxton Grange 5.77 annual licence 5.77 annual licence 5.77 annual licence 5.77 annual licence Horseheath 2.30 annual licence temporarily out of use Kingston (0.00 treatment) 1.00 (1.00 treatment) 1.00 (1.00 treatment) 1.00 (1.00 treatment) Linton 1.93 annual licence 1.93 annual licence 1.93 annual licence 1.93 annual licence Lords Bridge 0.00 (0.00 treatment) (0.00 treatment) (0.00 treatment) (0.00 treatment) Lowerfield 3.41 annual licence 3.41 annual licence 3.41 annual licence 3.41 annual licence Melbourn 7.94 annual licence 7.94 annual licence 7.94 annual licence 7.94 annual licence Morden Grange 2.27 annual licence 2.27 annual licence 2.27 annual licence 1.60 * pump capacity Bhs 2+3 Rivey 2.20 annual licence 2.20 annual licence 2.20 annual licence 2.20 annual licence Rushford Sawston 1.49 annual licence 1.49 annual licence St Ives 1.20 pump rating temporarily out of use Westley 8.90 DAPWL 11.39 annual licence 11.39 annual licence 11.39 annual licence Weston Colville 4.59 (3.10 DAPWL) 4.59 (3.10 DAPWL) 4.59 (3.10 DAPWL) 4.31 (2.82 DAPWL) 108.68 108.67 107.05 110.06

* SRO gives 1.50, but higher outputs regularly achieved

12 Cambridge Water Company Final Water Resources Management Plan

Deployable outputs for each of the individual sources within the Company’s single resource zone are also listed in Table WRP5. Two sources, Horseheath and St Ives, are temporarily out of use because of a Cryptosporidium risk; nevertheless, they feature as supply side options in the Company’s drought plan, and are thus included in the table.

An increase of 1.09 Ml/d is forecast in 2009/10 as the opportunity is taken, during capital maintenance work at Great Wilbraham Pumping Station, to increase its pumping efficiency to achieve its full licensed capability.

2.2.2 Reductions in Deployable Output The latest indications of possible sustainability reductions were advised by the Environment Agency in October 2008. This advice follows investigation work undertaken by the Company during the AMP3 (2000/01 to 2004/05) and AMP4 (2005/06 to 2009/10) periods at a number of its sources to determine the effects of its abstractions on nearby environmental sites. A list of the latest indicative sustainability reductions (other than zero) is given below:

Site Designation Licence Indicative Reduction Alder Carr SSSI * Linton 1.0 Ml/d (summer only) Granta River BAP ** Linton, Rivey 1.0 Ml/d (total) * Site of Special Scientific Interest ** Biodiversity Action Plan

Further investigation, in the form of options identification and appraisal, has been identified by the Agency for inclusion in the Company’s AMP5 (2010/11 to 2014/15) programme of work.

In accordance with Agency guidance, we have not reduced our deployable output figure to take account of sustainability changes, as none of the above reductions are definite.

The Company recently commissioned a study to look at future nitrate trends at its sources, based on historical data. The results of this work show that, based on historical data, nitrate levels across the aquifer continue to rise. The implications of this for the Company’s operations and its customers, and possible engineering solutions, are the subject of ongoing studies: however, there are no anticipated threats to deployable output.

Some elements of the Company’s licensed deployable output, notably those from its Thetford and Fowlmere sources, are time-limited, and expire in 2015. Ministers have instructed the Environment Agency to ensure that time-limited licences do not present a risk to security of supply, and that any “notice of change” will provide sufficient time to restore the supply-demand balance: accordingly, this plan assumes the probability that they will be renewed without amendment. The assumption is reinforced by the Agency’s latest guidance, Managing Water Abstraction: Interim Update - June 2008. In this document the Agency confirms that it applies a ‘presumption of renewal’ when licences reach the end of their time limit, provided the three tests of environmental sustainability, continued justification of need, and efficient use of water, can be demonstrated. We have already undertaken considerable work to prove that our Thetford abstractions have no significant effect on nearby environmental sites, and this conclusion was accepted by the Agency when agreeing the current licence extension. There is no reason to believe that the outcome will be any different when the licences are next considered for renewal, in 2015.

The effects of climate change on deployable output are discussed in detail in Section 2.4.1.

13 Cambridge Water Company Final Water Resources Management Plan

2.2.3 Outage The Company’s policy is to minimise planned outages at sources, through an effective capital maintenance strategy. Nevertheless, the amount of water available for use remains vulnerable to unplanned outages, such as extraordinary plant failures, power interruptions, pollution incidents, and delivery main failures. Standby generation is in place at strategic sites to mitigate the effects of mains power failures; however, pollution incidents and other occurrences are outside the Company’s control.

A record of planned and unplanned outages is kept for each site. In recent years a number of third party pollution events and unplanned plant failures have resulted in some sites being unavailable for prolonged periods.

Sourceworks which are particularly vulnerable to outages are those which have only a single borehole. The Company possesses two major single-borehole sources, Fleam Dyke and Brettenham. During the summer of 1990, in the middle of a serious drought, the Company suffered a major outage at Fleam Dyke, which lasted for several days, as a result of two successive failures of the downstream delivery main. It proved impossible to maintain storage reservoir levels by increased pumping from other sources, and appeals had to be made to customers through the local press to use water for only emergency purposes until repairs had been effected. More recently, in early 2007, Brettenham was subject to a planned outage lasting for several months, while pumping equipment was upgraded. At the end of the year, the new pump suffered an unexplained failure, resulting in a further, unplanned, outage.

The Board of Cambridge Water acknowledges the risk-based approach to outage that is set out in the water resources planning guideline. Nevertheless, it remains the Company’s view that outage is currently defined by the real loss of its strategically most important source, namely, Fleam Dyke Pumping Station: accordingly, the outage figure included in our draft WRMP was based on the loss of this strategic site. The Company was criticised for this and, following the Minister’s review of our Statement of Response, we engaged consultants to reassess our outage figure, using a probabilistic approach. This reassessment took account of the design and operation of our production and supply network; records of historic outage events; and the potential for future events. A proprietary software programme was used to model the outage probability distribution for the Company’s single resource zone. This approach is the one recommended by UKWIR, and referred to in the WRMP planning guideline. The full text of the consultants’ report, which forms Appendix 6 of this final plan, is available on request.

Our outage figure will be reviewed as circumstances change: in particular, as plans to install nitrate removal plants come to fruition, the interdependence of sources for nitrate blending will reduce, and this should lead to a reduction in outage. Similarly, our plan also includes a proposal to sink an additional borehole at Fleam Dyke during the AMP8 period (2025/26 to 2029/30): this will improve security of supply, and provide a means of maintaining headroom, by reducing outage, towards the end of the planning period. The sinking of additional boreholes at other single-borehole sources will also be investigated - but these measures will not help to prevent a repeat of the 1990 Fleam Dyke incident referred to above.

2.2.4 Raw and Potable Water Transfers and Bulk Supplies The Company currently operates no raw water transfers. There are a number of cross-border metered supplies with neighbouring companies, Anglian Water (AW) and Three Valleys Water (TVW), both into and out of the Company’s area, but these serve small numbers of properties only, and are not the subject of formal agreement.

Two future supply/transfer schemes have been built into the baseline demand forecast: the first is an agreement to supply Natural Mineral Water to a local bottled water facility; and the second is for a bulk supply of potable water to Anglian Water from the Company’s Thetford delivery main. There is also an existing emergency supply arrangement with Three Valleys

14 Cambridge Water Company Final Water Resources Management Plan

Water: as this is a non-drought arrangement, it has no effect on deployable output. At present this is a one-way transfer to TVW, but both companies are investigating ways of improving the arrangement to their mutual advantage.

2.2.5 Distribution and Treatment Works Operational Use and Losses A small allowance has been made within this plan for distribution system operational use. No treatment works operational use or losses are forecast.

2.3 Water Demand

2.3.1 Normalisation of Base Year Demands observed during the base year of 2007/08 were not those of a typical year. The cool, wet summer effectively curbed peak demands, with peak week demand occurring at the beginning of May. The poor weather, combined with a continuation of an active leakage control strategy, resulted in a distribution input which was slightly lower than the previous year – in itself a year of low demands.

In order to normalise the actual base year distribution input (DI) figure, the following adjustments were made:

Unmeasured households – 2005-06 per unmeasured household demand used Measured households – 2005-06 per measured household demand used Unmeasured non-households – as 2007-08 actual Measured non-households – as 2005-06 actual

This resulted in an overall uplift in 2007/08 DI of around 4.2%

2.3.2 Derivation of Dry Year Multiplier To derive its dry year baseline estimates, the Company has continued with the methodology employed in its previous water resources plans, i.e. to compare summer and winter distribution input. Analysis of water usage data during the period considered, 1974 to 2007, showed that, in a normal year, an average 5% more water was used during the summer months than during the preceding winter period. However the analysis also highlighted three maximum years when 11.15% more water was used during the summer than during the preceding winter. These findings led to the determination of a ‘dry weather multiplier’, which was used to forecast dry year distribution input. Derivation of the dry weather multiplier is explained below:

Normal Year Let average daily DI for winter months = x So, average daily DI for summer months = 1.05x

Thus, annual average daily DI = x + 1.05x 2 Dry Year Average daily DI for winter months = x Average daily DI for summer months = 1.1115x Thus, annual average daily DI = x + 1.1115x 2

Therefore, dry year multiplier = 2.1115 x 2 = 1.03 2.05 x 2

15 Cambridge Water Company Final Water Resources Management Plan

This uplift of 3% has been applied to the ‘normal’ year predicted demands to derive dry year baseline forecasts, and each of the “water delivered” components of the water balance has then been increased by an appropriate amount (but assuming no increase in total leakage) to achieve an overall balance. The percentage increases applied to individual components, to give an overall 3% increase, were: measured household constant 3.5% measured non-household constant 3.5% unmeasured household from 3.5% in 2006/07 to 2.8% in 2034/35 unmeasured non-household constant 3.5% leakage zero

These percentages were derived using experience gained from previous water balance calculations. The effect of the increases is shown in the WRP tables that form part of this plan.

2.3.3 Critical Period Scenario The critical period for the Company is the ‘peak week’, i.e. the 7-day period in any year when the average daily distribution input figure is at its highest. An analysis of distribution input (DI) for the years 1995 to 2008 concluded that, in general, average day peak week (ADPW) DI was 18% higher than average daily DI. However, there were four high years when ADPW DI was around 25% higher than average daily DI. The results of this analysis are shown in the following table.

Average Day Peak Week Distribution Input 1995 - 2008 compared with average daily DI ave daily DI ADPW DI 120

100

60 Ml/d

0 4 96 07 999 003 1995 19 1997 1998 1 200 2001 2002 2 200 2005 2006 20 2008

Only one of these four highest years constituted a ‘dry year’, using the methodology described in 2.3.2 above. Thus, for this critical period analysis, a factor of 1.25 has been applied to the normal year baseline forecast to produce an average day peak week forecast: this has been plotted against peak deployable output, and included as Figure 5. The plot shows that, under average day peak week conditions, headroom is maintained throughout the planning period. (Note: for this scenario, the outage figure (see Section 2.2.3.) has maintained at its full value, to stress the importance the Company attaches to its approach to outage.)

16 Cambridge Water Company Final Water Resources Management Plan

Peak week demands can be comfortably met without breaking daily licence limits, and without causing supply problems: a separate critical period forecast has therefore not been included with this plan.

2.3.4 Base Year Population and Properties Unmeasured and Measured Household Population: the Company’s methodology for deriving population uses figures provided by Cambridgeshire County Council (without alteration), on a parish-by-parish basis. As a first step, the population of all non-households, such as residential homes, is assessed. Subtracting non-household population from the area total leaves total household population.

Prior to 1989, virtually all of the Company’s household customers were unmeasured. 1989 saw the introduction of universal metering of all new households. During the 1990s the Company had various domestic metering policies, for example: 1993 – all sprinkler uses to be metered; 1995 – free meters for lone pensioners plus those customers affected by mains renewals schemes; 1997 – free meters to pensioner couples; 2000 onwards – free meters for optants. On an annual basis, since 1989, an assessment has been made of the additional population attributable to the newly metered properties, for example, lone pensioner households – occupancy one; pensioner couples – occupancy two; new build households – occupancy two etc. On this basis, a total population for measured is obtained, with unmeasured households making up the remainder of the household population.

Between 1995 and 1999 the Company fitted over 8,000 free meters for single elderly customers living alone. For properties metered in that way, an occupancy rate of 1.0 was assumed. Since that time it is likely that many of those properties have changed hands, and are now occupied by a mix of single customers, couples and families. It is therefore reasonable to assume a current average occupancy rate for those properties of 1.5: for that reason a one- off transfer of 4,000 population has been made between unmeasured households and measured households. This has resulted in a discrepancy between actual measured and unmeasured household populations and those forecast in the Company’s Water Resources Plan for the report year.

Properties: with the introduction of the Company’s new billing system, Basis2, in February 2006, reports have been developed that enable the billing system to report on property counts consistent with Ofwat’s June Return reporting requirements. Robust property counts are therefore obtained for: unmeasured and measured billed household properties; unmeasured and measured billed non-household properties; and corresponding categories of void properties.

Occupancy rate for new build properties: the Company has assumed an occupancy rate of 2.1 for metered households as a whole – the same as the national average. In the absence of more robust information from customer surveys, we have reasoned that a slightly lower figure of 2.0 is appropriate for new build households: this reflects the trend to wards more social housing, changes in family structure, and increased life expectancy. For these reasons, it is also likely to follow that new build occupancy will decrease in the coming years, although we have not built this into our per capita consumption (pcc) forecast. We conclude, therefore, that our chosen occupancy rate for new build properties is realistic.

2.3.5 Forecasting the Potable Water Customer Base New households – notwithstanding the effects of the current economic downturn, the build rate of new households in the medium- to long-term is expected to be greater than historic rates, as the effects of the Cambridge fringe area developments, and the new town of Northstowe, are felt. It is assumed that, having increased, build rates will remain constant, both before and after the expiry of the current East of England Regional Spatial Strategy (RSS) in 2021.

17 Cambridge Water Company Final Water Resources Management Plan

To inform our assumptions about new household build rates, two sources of published information were considered: Sub Regional Housing Trajectory for the Cambridge Sub Region, prepared by Deloitte on behalf of Cambridgeshire Horizons, Cambridgeshire County Council, Cambridge City Council, Cambridgeshire District Authorities and the East of England Development Agency (EEDA), May 2007; and EEDA (new housing forecasts for 2006 – 2021). Both these sources indicated that, to the year 2021 at least, average annual new build rates within the Company’s area would be in the region of 2,500 – 2,600. The basis for these figures was the Regional Spatial Strategy for the East of England (RSS14), first published in draft form in 2004.

RSS14 was updated in May 2008, under the title ‘East of England Plan’ (accessed via www.gos.gov.uk/goee/docs/193657/193668/Regional_Spacial_Strategy/EE_ Plan1.pdf ) This document reviewed progress to date, identified a shortfall, and assumed that the shortfall would be made up over the remaining period of the plan. The following edited extract from the East of England Plan sets out the assumptions made on future housing numbers in the Company’s area, based on the original RSS14 targets, and numbers achieved to March 2006. (Note – as our area of supply covers only around 35% of the Huntingdonshire District Council area, we have made a corresponding adjustment to the HDC numbers.)

Area / Minimum Dwelling Provision 2001 to 2021 District (net increase, with average annual rates in brackets) Minimum to build, Of which already built Minimum still to build Apr 2001-Mar 2021 Apr 2001-Mar 2006 Apr 2006 to Mar 2021 Cambridge 19,000 2,300 (460) 16,700 (1,110) Hunts (part) 4,000 1,030 (206) 2,970 (198) South Cambs 23,500 3,520 (700) 19,980 (1,330) Total 46,500 6,850 1,366 39,650 (2,638)

The above table shows that the rate of housebuilding over the next 15 years would need to be double that of the first 5 years of the plan, in order to make up the shortfall and achieve the overall target. The Company took the view in its original draft plan that these rates were unrealistic and unachievable, and based its demand forecast on a build rate of 2,000 new dwellings per year over the planning period. This gave a total new build of 50,000 dwellings over the life of the plan (i.e. to 2035), compared with the outstanding figure of 39,650 (to 2021) in the table.

In this final plan, we have not only taken account of representations received, but also the effect of the current economic downturn, which has depressed the housing market. The table below summarises our assumption on new housing numbers over the planning period.

2010-11 2011-12 2012-13 2013-14 2014-15 2015 on Total 1,300 1,600 1,900 2,200 2,500 2,650 62,500

This latest forecast, whilst predicting modest numbers during the AMP5 period, predicts an average of 2,500 new connections per year over the life of the plan, and an increase of 12,500 in the total of new dwellings, compared with the original draft plan forecast. The result is that the assumed average new build rate is now more closely aligned with the RSS14 forecast. The total numbers predicted in our updated draft plan exceed the RSS target by nearly 60%, although it is acknowledged that the end dates are quite different.

New non-households – in line with recent trends, the Company has assumed an annual new build rate of 100 non-households.

18 Cambridge Water Company Final Water Resources Management Plan

2.3.6 Actual Base Year Household Demand Unmeasured household demand: the current methodology (first adopted in 2002/03) no longer relies on the Company’s former domestic consumption monitors. Because of the significant take-up of household meters, particularly during recent years, the information provided by these monitors was felt to be no longer reliable. (The problem faced by companies in maintaining property numbers within their consumption monitors, to ensure robust consumption estimates are maintained, is acknowledged by Ofwat in its Security of Supply, Leakage and the Efficient Use of Water, 2003/04 Report, which states that “…this is proving a significant difficulty for many companies as more properties become metered.”)

The basis of the current methodology is to use the Company’s measured households (which, during the base year 2007/08, accounted for over 59% of billed households) as a surrogate consumption monitor. The Company’s new billing system, Basis2, is capable of producing robust reports on consumption per measured household and, coupled with ancillary information (weather information, trends in unmeasured household per capita consumption nationally and at adjacent water companies etc), the Company believes that an appropriate, and realistic, assessment of unmeasured household consumption can be made.

As part of its business plan submission to Ofwat the Company proposes to actively explore the possibility of creating a new joint household consumption monitor with one or more of our neighbouring water companies.

Measured household demand: this is derived from the Company’s billing records. For internally metered households, an assessment of underground supply pipe leakage is added since this leakage does not pass through the customer’s meter. Meter under-registration is also taken into account.

2.3.7 Normalisation of Base Year Household Demand As discussed in 2.3.1, for both unmeasured and measured households the respective 2005/06 per property demands were used.

2.3.8 Forecast Household Demand Existing unmeasured households – annual underlying growth in demand is assumed to be 0.25%. Where an unmeasured household opts to be metered, a 10% reduction in its demand has been assumed. For unmeasured households subject to compulsorily metering, a 5% reduction in their demand is assumed.

New build and existing measured households – annual underlying growth in demand is assumed to be zero.

New build households – in accordance with the latest guidance, it has been assumed that all new dwellings from 2010/11 onwards will comply with the requirements of the revised Building Regulations, due to come into force in Spring 2009. The new Regulations will require all new homes to comply with a water use standard of no more than 125 litres per head per day (including external usage).

Although the Code for Sustainable Homes aspires to a more stringent per capita consumption (pcc) target for new dwellings, this is not mandatory, and the Company considers that it would be imprudent to assume a lower figure at this stage.

It is acknowledged that the above assumptions differ from those set out in the Company’s Strategic Direction Statement (SDS), published at the end of 2007. The dry year demand forecast contained in our SDS illustrated the influence that appropriate water re-use technologies could have on water demand over the next 25 years, assuming they were implemented from the outset. Clearly, those technologies are not yet available on a wide scale, and this plan takes a pragmatic view of the current situation. The effect of delaying the introduction of grey water recycling (but also taking account of predicted water efficiencies at

19 Cambridge Water Company Final Water Resources Management Plan new and existing properties), and of making an explicit allowance for climate change in the demand forecast, is to increase by 0.4 Ml/d the headroom available at the end of the planning period, compared with the SDS.

2.3.9 Non-household Demand – Base Year and Forecast Measured non-household demand (base year) - this is derived from the Company’s billing records, with the additional impact of meter under-registration taken into account. To normalise measured non-household demand, the actual 2005/06 total demand has been used.

Measured non-household demand (forecast) – in recent years, there has been no real increase in water delivered to our measured non-households despite a gradual increase in the number supplied. This suggests that the demand being created from our new non-households is being offset by existing metered non-households reducing their demand through water efficiency measures. We have assumed that the amount of water delivered to our existing and future new non-households will remain constant, with a small increase in the water delivered to all measured non-households resulting from those switching to a meter.

Unmeasured Non-household demand (base year) – the Company assumes 800 litres per property per day. In practice, little is known about unmeasured non-household consumption, but it is a very small component of distribution input (<2%) and has no significant impact on the other components. Whether 400 or 1,200 l/prop/d were assumed, unmeasured non-household consumption would remain an insignificant component of the overall water balance.

Unmeasured Non-household demand (forecast) – annual underlying growth in demand is assumed to be 0.25%.

2.3.10 Household Micro-component Consumption The collection of company-specific household micro-component data is a complex and costly process and, at present, Cambridge Water holds no Company-specific data. Table WRP7 has been completed using published micro-component data (WRc; Environment Agency; Anglian Water (Sodcon)) as the basis for the base year, with pragmatic assumptions made to complete the forecasts.

2.3.11 Metering, Leakage and Water Efficiency Our long term vision is that all customers are metered, and pay for what they use. Customer research indicates that our customers believe this is the fairest method of charging. We are keen as a Company to investigate the benefits of alternative tariff options with both resource and social objectives.

Further our customers have expressed their view that leakage is a key issue for the Company to address. There is clear evidence that “customers” are willing to play their role in “using water wisely” as long as they can see that the Company is taking the issue seriously. In this context customers expect the Company to promote water efficiency activities. This will not only fulfil their desire to play their part, but also reduce their bill.

Our strategy to promote, inform and involve all our customers on the issue of water efficiency is embedded into our water resources plan. Thus our approach to demand management is as follows:-

 to encourage the transfer of customers to a metered supply. By the end of the base year 2007/08 over 59% of our domestic customers were metered.  to continue to operate at one of the lowest levels of leakage in the industry through the use of advanced leakage technology and the provision of a free leak repair service for domestic customers.  to promote water efficiency to all customers through information, practical assistance and, where appropriate, site-specific advice.

20 Cambridge Water Company Final Water Resources Management Plan

Looking at each issue in turn:

Metering: the stabilising effect of metering on distribution input can readily be seen, especially as a result of two big initiatives in the 1990s, first to meter sprinkler users, and subsequently to meter registered hosepipe users. The proportion of total billed households which are metered has been growing at almost 2% per year recently, firstly due to the effect of new households, which are all metered, and secondly due to those existing customers who have opted to transfer from unmeasured to measured charging.

It has been assumed in the baseline forecast that the historic pattern of meter transfers will continue, i.e. in any year approximately 3% of the previous year’s total unmeasured households will opt to have a meter installed. We expect to see a reduction of 10% in water usage from customers who have switched to a meter in this way, and this reduction has been built into our demand forecasting model.

In addition all new properties will continue to metered. We expect by 2035 that 88% of all billed households will be paying for their water in relation to the volume they use.

We confirm that our baseline forecast only includes the impact of meter optants and meters installed in new properties.

Our Water-Care scheme offers assistance to metered customers who may face financial difficulty. Further details of the scheme are contained in our “Special Needs” leaflet, which is available on request, or may be downloaded from our website www.cambridge-water.co.uk

The Minister’s review of our Statement of Response asked us to provide evidence of all the metering options we had appraised, together with associated costs and benefits, and assumptions made. The report we presented to the Minister forms Appendix 7 of this plan.

Leakage: the Company has historically relied on traditional waste metering as a means of leakage control. However, in 2004/05 the Company failed its target for the first time, and this prompted a review of leakage practices. As a result a leakage action plan was prepared and instigated, which adopted a more proactive approach to leakage control. The plan has proved successful and, in the two ensuing years since it was implemented, the Company has achieved its leakage target.

District Metering At the core of the Company’s leakage action plan is a commitment to the creation of a comprehensive network of district meter areas (DMAs) in and around Cambridge. The project has required a significant financial investment by the Company, and the benefits have already been seen in the villages around Cambridge, where DMAs were set up in 2006. A second stage has extended the coverage into Cambridge itself, where 36 new DMAs were commissioned at the end of 2008.

Completion of this project sees approximately 85% of the Company’s area covered by DMAs, and this will radically change the way in which we detect and report leakage. Our annual leakage calculation has in the past been derived from bi-annual bulk waste tests but, following concerns expressed by Ofwat, we have agreed that, from 2010, our reported leakage figure will be based on DMA data. A transition programme is currently being implemented.

Not only will DMAs provide a more robust leakage figure; they will also provide early warning of the occurrence and location of leaks, enabling us to direct our leakage effort more effectively, and helping to achieve our leakage target in the future, despite the anticipated growth in our network. As a further aid in this regard, DMAs will help us to target our mains refurbishment programme at the worst-performing areas of our infrastructure.

21 Cambridge Water Company Final Water Resources Management Plan

Sustainable Economic Level of Leakage (SELL): the Company’s SELL assessment, which forms Appendix 3 to this document was updated at the end of 2008. It is based on data up to and including 2007-08. The latest study concluded that the Company’s sustainable economic level of leakage was 14 Ml/d, both for the short- and long-term, confirming that the Company’s current and proposed future level of leakage activity was appropriate.

Water Efficiency: our current water efficiency initiatives with indicative volumes saved and implied unit costs are as follows:-

Savings Number Cost (£) Unit cost (Ml/d) (£m/Ml/d) Supply pipe repairs 0.008 191 46,576 5.822 Cistern devices 0.014 1,454 2,378 0.170 Tap re-washering service 0.014 1,114 6,500 0.464 Water audits and literature 0.006 N/A N/A N/A Regulation inspections 0.075 3,392 184,863 2.465 Total 0.117 6,151 240,317 2.054

Source June Return 2008 Table 1

These explicit initiatives are supported by articles in our customer literature and specific leaflets and advice which are available to all on request. These general information initiatives have been supported by one off exercises, when the Company has been concerned about the short term water resource situation. For example, in September 2006, following two successive dry winters and the possibility of a third, we wrote to every one of our customers to forewarn them that, should there be low winter rainfall during the coming winter, a hosepipe ban was highly likely.

Further, Cambridge Water has been running a series of environmental roadshows. These are designed to educate the general public (both adults and children) regarding ways to save water, sustainability within the home and garden and other environmentally friendly messages. Boards have been displayed in various public locations, such as, central libraries, garden centres, churches and park & ride facilities. The roadshows are to continue being rolled out across locations in Cambridgeshire, including schools.

In order to support World Water Day 2007, Cambridge Water, in conjunction with Cambridge City Council, held a stand in Cambridge market square. The aim was to educate the general public regarding World Water Day and ways in which to save water. Visitors to the stand were asked to estimate the quantities of water used in various daily activities like cleaning the car or washing up and these were compared to the quantities of water available to people in the third world.

Stickers have been produced and handed out freely at shows and charity events encouraging people to use water wisely. Two versions have been created, one for adults and one for children. These stickers form one of the planks in Cambridge Water’s 2008 Water Efficiency programme. Companies and schools are encouraged to place them near taps in cloakrooms and kitchens.

Finally Cambridge Water has a discretionary fund to support local initiatives for water conservation projects. For example, the River Mel Restoration Group has received a grant of £500 from the Company towards a community project to restore the River Mel at Meldreth by installing soft revetments, which will be planted with native plants to increase biodiversity.

The Company will continue to undertake such initiatives, and quantify the benefits in terms of water saved in the context of our duty to promote water efficiency.

22 Cambridge Water Company Final Water Resources Management Plan

External organisations: in addition to the above initiatives, the Company part-funds Waterwise, an independent non-governmental organisation (NGO) established by the UK water industry in September 2005. Waterwise has produced a “Best Practice Register” that identifies a wide variety of initiatives, and establishes costs and benefits of each. Further, Cambridge Water is part of Waterwise East, a new initiative established in 2007 which aims to reduce demand for water in the East of England by influencing planners, developers and the public and by acting as an authoritative focal point for water efficiency in the region.

Water Efficiency Target: from 1 April 2008, Cambridge Water has adopted a water efficiency target, set by the government-led Water Savings Group. The target builds on our duty to promote the efficient use of water, and reflects the Environment Agency’s assessment that Cambridge Water is in an area of serious water stress. For the years 2008/09 and 2009/10 the target is voluntary, but for the AMP5 period (2010/11 to 2014/15) the target is imposed as part of the price-setting process. Our target is 1 litre/property/day, which translates to a saving of 0.125 Ml/d, year on year. This reduction has been built into our demand forecast.

We plan to achieve our target using a twin-track approach – by continuing existing water efficiency measures, as set out in our June Return, but also through an increase in activity, particularly with regard to the supply of Hippos and by means of a new welcome pack, which will contain a water audit for customers to complete.

In addition to the above the Company will continue to proactively raise awareness of water efficiency via its website, literature, display stands, education talks, and a new online shop it has launched with the retailer Save Water Save Money.

The table below summarises how we propose to meet the year on year target of 0.125 Ml/d:

Initiative Volume Efficiency Ml/d Saving Hippos 2000 hippos 2.5 l/d 0.042 Tap re-washering 1100 taps 12.0 l/d 0.013 Metering (Selective) 14 60.3 l/d 0.001 Metering (Optants) 1367 11.3 l/d 0.015 Self audits 200 (140 acted upon) 30.0 l/d 0.004 Water regs inspections (non-household) 225 0.026 Water regs inspections (household) 3167 0.049 Welcome packs 1440 (288 acted on) 10.0l/d 0.002 TOTAL 0.152

In calculating the Ml/d savings outlined in the table above, the company has taken into consideration the guidelines outlined in “Future Water Efficiency Targets: A Consultation,” published by Ofwat in June 2008.

Potential initiatives: we have reviewed the Water Saving Group Best Practice Register published in 2007 and have identified ten areas of initiatives which build on the work we are currently undertaking. These are set out in the following table.

We are investigating each area further as part of our Business Plan preparation.

23 Cambridge Water Company Final Water Resources Management Plan

Initiative Description

1 Cistern Displacement Continue to distribute hippos and hogs on customer request Device Promote hippos and hogs on customer contact in our call centre Install hippos and hogs when our tap rewasherer visits customer homes 2 Household water audit Expand the remit of the re-washering to include basic audit in the home 3 Commercial water Project currently being undertaken to reduce water usage at audit Cambridge University. 4 Customer education Continue to provide literature and promotional activities as described above 5 Miscellaneous In response to customer feedback, continue with subsidised tap activities rewashering service 6 Metering Continue to promote free meter optants in all literature and in debt counselling process Promote water efficient homes, by working with local authorities and developers Trial latest meter technology including smart meters in appropriate new developments in area. Install data loggers on large users of water to allow both parties to understand usage on a timely basis. 7 Tariffs Establish the benefit of sophisticated tariff structures, to deliver resource and social objectives 8 Water butts etc. Promote water collection devices including water butts on request / via our website and at external events 9 Toilet retrofit Undertake a trial to understand the costs and benefits of retrofitting existing toilet cisterns 10 Free supply pipe Continue to repair domestic supply pipes free of charge in a repairs timely manner.

Water Neutrality We have assessed the concept of water neutrality, as set out in the Environmental Agency’s report Towards Water Neutrality in the Thames Gateway (November 2007). The concept is that “for every new development, total water use in the region after the development must be equal to or less than total water use in the region before development”. The report concluded that it was possible to achieve water neutrality in the Thames Gateway by 2016, through a combination of water efficiency and metering measures, but found that compulsory metering of existing households was a fundamental requirement to achieve neutrality. We have noted that the baseline characteristics of the study zone (only 10% of total demand from measured households) were quite different from those in the Cambridge Water area (around 27% of demand from metered households) so the potential for achieving savings from further metering within the study zone was greater.

In the study, around 10% of the total required savings were attributed to compulsory metering with, typically, around 15% resulting from new dwellings built to the Code for Sustainable Homes. Around 45% of savings were attributed to retrofitting and the report recognised that, for every new home built to the new sustainable standard, between 4 and 8 existing homes would need to be retrofitted to achieve neutrality. This means that between 200,000 and 400,000 existing homes would need to be retrofitted in the Cambridge area (assuming 50,000 new homes were to be built), whereas our existing housing stock amounts to less than 115,000 homes. Finally, 30% of the total was attributed to non-specific, non-household savings, and therein lay a considerable uncertainty.

We acknowledge water neutrality as a worthwhile concept, and will continue to work towards greater savings through appropriate demand management measures.

24 Cambridge Water Company Final Water Resources Management Plan

2.4 Climate Change

2.4.1 Supply The Company has followed the supplementary guidance issued by the Environment Agency in November 2007 to assess the likely effects of climate change on deployable output (DO). Consultants have used the results of the Source Reliable Output Study, completed in 1997, to determine at which sites the potential yield could be limited by a decline in drought pumping water levels towards or below the deepest advisable pumping water level (DAPWL). Two global climate change models (GCMs) were used: the ECHAM4-OPYC3 model, which produced the greatest negative impacts on recharge and groundwater levels; and the HadCM3 model, which was considered more applicable to UK conditions. (Impacts on recharge and hence groundwater levels were much less severe using this model.) The choice of GCM is one of the main sources of uncertainty in predicting future climate change impacts: indeed, some of the models predicted increased recharge, and hence a rise in groundwater levels.

Both models that were used indicated reductions in groundwater levels in future drought conditions greater than had been seen during historical droughts. Climate change impacts were added to the summary diagrams used to determine critical levels during the 1997 Source Reliable Output Study: where the additional decline due to climate change reduced the drought groundwater level below the deepest advisable pumping water level (DAPWL) for the source, its reduction in deployable output was calculated.

The decline in groundwater levels indicated by the ECHAM4-OPYC3 model was used to assess which sources’ deployable outputs might be affected by climate change: the reductions in DO were also calculated using this model. The reduction in overall DO was then assessed for the HadCM3 model to give a more representative indication, based on UK conditions.

The results of the studies indicated six current operational sources where there was a “probable” impact on DO from climate change. The HadCM3 model suggested an overall reduction of 1 Ml/d (although this figure rose to around 5 Ml/d if the results from the ECHAM4- OPYC3 modelling were used).

The full content of our consultants’ work is included as Appendix 5.

2.4.2 Demand In considering the impact of climate change on baseline demand the Company has referred to the 2003 report Climate Change and the Demand for Water (CCDeW) as recommended in the Environment Agency’s planning guideline. For the Anglian region the report suggests a growth in household demand due to climate change of 1.8% by 2030, and a growth of 2.6% in non- household demand over the same period. Other components of the water balance are not affected by climate change. The effect of climate change on distribution input as a whole has been assessed at 1.8% at 2030 (and extrapolated to 2.25% by 2035), by applying a weighted average to all water balance components, as shown below:

Baseline water delivered 2029/30 Climate change uplift Households 54.80 Ml/d 1.80% Non-households 21.40 Ml/d 2.60% Distribution losses + misc 9.71 Ml/d 0.00% Distribution input 85.91 Ml/d 1.80% weighted ave

25 Cambridge Water Company Final Water Resources Management Plan

A linear increase of 0.09% per year has been applied to the baseline dry year distribution input figure throughout the planning period to take account of climate change impacts on demand.

2.4.3 Impact on Supply-Demand Balance The demand-related impacts of climate change have been explicitly built into the Company’s demand forecast, and have the effect of reducing available headroom at the end of the planning period.

The effects of climate change on supply availability are more difficult to quantify: the predicted loss of deployable output amounts to only 1% of total deployable output, but there is some uncertainty associated with this prediction. The Company expects supply-related climate change impacts to make little or no difference to its activities before 2035: therefore, as suggested in the planning guidance, it has not adjusted its deployable output figure to account for climate change effects.

In accordance with the published guidance, the uncertainty associated with the climate change assumptions has been included in the target headroom calculation (see Section 2.5 below). Although the guidance permits the incorporation of a greater allowance for uncertainty in the headroom calculation where no explicit allowance is included (as is the case for supply-related impacts, above), the uncertainty for supply-related impacts has been kept deliberately to a minimum, so as not to be seen to have an undue influence on the target headroom figure.

2.4.4 Future Work The guidance and methodology for assessing the impacts of climate change on DO values for groundwater sources provide a framework for assessing the impacts of climate change on groundwater recharge using three different methodologies. However, in the case of the

Company’s sources, it is unlikely that application of two of the suggested methods would produce a significantly improved assessment of the potential loss in DO than has already been established (the two methods are only very approximate).

The Environment Agency is currently developing regional groundwater models covering all the locations of the Company’s sources. The models should be available for use as predictive tools by 2010. In addition, new climate change models should be available in early 2009 from the UK Climate Impacts Programme.

The Company proposes to wait until the Agency’s regional groundwater models are available, together with the new climate change models, and use them to develop more accurate predictions of the impacts of climate change on deployable output. The assessment will be done for the six sources already identified as being at risk. A review of the need for carrying out the assessment for other sources will be done once the results of the initial assessment are available.

26 Cambridge Water Company Final Water Resources Management Plan

2.5 Greenhouse Gas Emissions

The emissions of greenhouse gases which are likely to arise as a result of supplying water to customers in a normal year are shown in the table below. These figures have been calculated using the 2006/07 base year data in the new UKWIR Carbon Accounting Tool.

Element Drinking water treatment & pumping kgCO2e Electricity 5,883,343 Natural gas 0 Diesel/gas oil 13,152 LPG 0 On site renewable energy use (sale of ROCs) 0 Total 5,896,495

Volume of potable water supplied 2006/07 = 26,543 Ml Resulting in a value of 0.222 tCO2e per Ml

Emissions of Greenhouse Gases

10.00

8.00

6.00

4.00 '000 tonnes CO2e pa '000 CO2e tonnes

2.00

0.00

7 2 3 4 5 6 7 8 9 0 1 6 7 8 9 0 1 2 3 4 5 /0 /1 /1 /1 /1 /1 /1 /1 /1 /2 /2 /2 /2 /2 /2 /3 /3 /3 /3 /3 /3 6 3 4 5 7 8 9 11 12 17 18 19 20 25 26 31 32 33 34 00 007/08 0 0 01 01 01 0 0 0 0 021/22 0 0 02 02 02 0 0 0 0 2 2 2008/092009/102010/112 2 2 2 2 2016 2 2 2 2 2 2022/232023/242024/252 2 2 2 2 2030 2 2 2 2

2.6 Target Headroom

2.6.1 Definition Target headroom is a buffer between supply and demand that is designed to cater for specified uncertainties, such as data accuracy and the accuracy of forecasts linked to individual climate change scenarios. The areas of uncertainty that the Company has taken into account are explained in detail in Appendix 4 to this document.

2.6.2 Method In this plan, target headroom has been assessed using the 1998 UKWIR methodology, A Practical Method for Converting Uncertainty into Headroom. This is a pragmatic approach to quantifying uncertainty, and is particularly suitable for resource zones where there is a healthy supply-demand balance that persists for at least 10 years.

27 Cambridge Water Company Final Water Resources Management Plan

2.6.3 Target Headroom Calculation The target headroom calculation forms Appendix 4 of this plan, and is available on request.

2.7 Baseline Supply-Demand Balance

The Company’ s baseline scenario for the supply-demand balance is represented graphically in Figure 1. No deficit is forecast at any time during the planning period. The assumptions made in the derivation of the graph have been described in detail in the preceding sections, and the main points are summarised below:

 no major impacts on deployable output  outage allowance equivalent to DO of largest single-borehole source  2500 new dwelling connections per year, on average, throughout planning period  transfers to meter (meter optants) continue at historic levels  small increase in demand due to climate change  decrease in demand due to increased water efficiency of new dwellings  overall leakage remains constant at 14 Ml/d

2.8 Option Appraisal

2.8.1 Continuation of Existing Measures The Company plans to continue its existing policies in the major areas of metering, leakage and water efficiency, which form the mainstays of the prudent approach to demand management that Cambridge Water has employed since the early 1990s. These policies go hand-in-hand, and were developed as part of a twin-track approach to securing supplies and curbing peak demands that was formulated in response to the drought sequence of 1989 to 1993. The drought events of the 1990s and 2000s are chronicled in more detail in our drought plan: www.cambridge-water.co.uk/community/statutory_drought_plan.asp

Two separate projects, one to meter existing sprinkler users and the other to meter registered hosepipe users, were undertaken in the mid-1990s. Ensuing initiatives included the offer of free meters, initially for single pensioners, and then for pensioner couples. Latterly, free meter options have been made available to all, and take-up among our customers has been consistent, at a rate of around 3% of unmeasured households per year. Cambridge Water now has one of the highest rates of household meter penetration in the country, exceeding 60% by the end of 2008. The Company plans to continue with its current strategy, which will see up to 88% of households metered by the end of the planning period, and continue to defer capital investment in new resource.

Our leakage target has been achieved in all years, except 2004/05. Since that time a more proactive leakage strategy has been in place. Successive analyses have shown that the Company’s target is below its Economic Level of Leakage: nevertheless, we remain committed to meeting our current target throughout the planning period, despite the scale of new development that is forecast to take place, increasing the length of our network. The substantial investment that has already been made in district meters will provide us with the most cost-effective means of achieving our aim, through improved detection and location of leakage, and more effective targeting of mains renewals.

The Company’s water efficiency strategy is covered in detail in Section 2.3.11 above.

2.8.2 New Measures As the baseline scenario forecasts no deficit at any point in the planning period, the Company does not propose any actions to resolve a deficit. Accordingly, we have not carried out the exhaustive options identification and appraisal process set out in the planning guideline.

28 Cambridge Water Company Final Water Resources Management Plan

However, the overall principles of the process have been followed during the preparation of the Company’s final planning scenario, described in Section 2.9 below.

2.9 Final Water Resources Strategy

2.9.1 Overall Strategy The Company’s overall strategy in preparing this plan has been to consider the influence of a range of factors which may influence the supply-demand balance over the planning period, and to take the most cost-effective action to ensure that a surplus of supply over demand is maintained. Cambridge Water firmly believes that this plan fully addresses all contingencies, and deals with them proportionately, according to their likelihood and consequence. The detailed analysis carried out during the preparation of this plan has identified no deficit at any time in the planning period.

The Company is already addressing those factors within its control (e.g. maximising abstraction capability, reducing planned outages, minimising leakage and demand) through its day-to-day operations and policies. However, some of the factors influencing the overall supply-demand balance are outside the Company’s control.

On the demand side, these factors include:

 overall new property numbers  rate of build of new properties  water usage within new properties  rate of uptake of meter options  climate change effects

On the supply side, the factors include threats to deployable output from:

 non- or part-renewal of time-limited licences  sustainability reductions  unplanned outages  climate change effects

Cambridge Water believes that it has taken a realistic view of these factors and their likely influence. Sensitivity checks have been carried out, to understand the possible effect of under- or over-estimating the demand forecast.

Cambridge Water’s supply area has been designated by the Environment Agency as an “area of serious water stress”, which gives the Company powers to increase meter penetration through a compulsory metering programme. As a result of previous metering initiatives the Company already has one of the highest levels of household meter penetration among water companies and the benefits this level of metering has had in curbing peak demand can be readily seen. Under normal growth, the level of meter penetration is forecast to increase to 88% of all billed households by 2035. Given the Company’s current supply-demand surplus, we do not propose an accelerated metering programme in this plan.

2.9.2 Further Investigations Over the next five years (2010-2015) and beyond, the Company plans to undertake further investigation work to improve the quality of data, thereby increasing confidence in its planning assumptions, and reducing uncertainty. The main areas for investigation and action are listed below:

29 Cambridge Water Company Final Water Resources Management Plan

District Metering: the early completion of the Cambridge city DMA installation project, at the end of 2008, will allow a comparison of leakage performance among DMAs, and provide evidence of the effectiveness of leakage actions. The data obtained will help to inform the Company’s future leakage control strategy. Moreover, better targeting of mains renewals should be possible, increasing their cost-effectiveness.

Nitrate studies: further work will be carried out to improve the Company’s understanding of the likelihood and consequences of a rise in aquifer nitrate levels. This knowledge will ensure that all relevant factors are considered when deciding on the most appropriate mitigation measures.

Source Reliable Output (SRO) studies: the Company’s deployable output figure is based on the SRO work that was carried out in 1997. As pressures on available resource grow it will become increasingly important, as demands increase, to derive an up to date value for deployable output that accurately reflects current conditions. An updated SRO study will therefore be undertaken within the next 5 years.

Grey water recycling and rainwater harvesting: in our Strategic Direction Statement (SDS), published in December 2007, we pledged to support the development of rainwater and grey water use to help reduce demands. The Company is exploring ways of promoting the use of such schemes on appropriate development sites.

Supply pipe ownership: also in its Strategic Direction Statement the Company undertook to lobby to take over the ownership and responsibility for customers’ private supply pipes, as a means of reducing leakage.

Additional boreholes at single borehole sites: the Company’s outage figure represents a relatively high proportion of total deployable output, for reasons explained in Section 2.2.3. We will investigate the construction of additional boreholes at single borehole sites in order to improve security of supply and reduce outage.

30 Cambridge Water Company Final Water Resources Management Plan

3.0 Tables

A workbook comprising the following completed data tables has been included as part of the submission to the Secretary of State, and is available on request to interested parties. The data contained in the tables (with the exception of WRP9) represent the dry year scenario. As the Company has no deficit in its supply-demand balance it has not proposed a final planning solution, nor has it investigated water management options: it has not, therefore, completed tables WRP2, WRP3, WRP4-FP, WRP4a-FP, WRP6a and WRP7a.

WRP1-BL The Company’s baseline supply-demand forecast

WRP1a-BL Supporting data on transfers and deployable output reductions for the baseline scenario.

WRP5 The deployable outputs, for average and peak demands, of the individual sources which comprise the Company’s single resource zone.

WRP6 A breakdown of consumption from measured households according to their water- using characteristics.

WRP7 A breakdown of measured and unmeasured household demand according to the consumption of individual components.

WRP8 Not completed – the Company is not able to provide a breakdown of non-household consumption by Standard Industrial Classification (SIC) categories.

WRP9 A forecast of normal year demand.

31 Table WRP1-BL: Baseline supply-demand components Scenario ROW Year Ref. DERIVATION DESCRIPTION UNITS 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19 2019-20 2020-21 2021-22 2022-23 2023-24 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30 2030-31 2031-32 2032-33 2033-34 2034-35 BASIC RESOURCES BASELINE

1BL Input Deployable Output (Specify individual Source Yields on Table WRP5) Ml/d 110.06 110.06 110.06 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15 111.15

2BL WRP1a-BL 2a BL Reductions in Deployable Output Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3BL Input Outage Allowance Ml/d 12.11 12.11 12.11 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23 12.23

4BL 9BL+11BL Process Losses Ml/d 0.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

5BL 1BL-(2BL+3BL+4BL) Water Available For Use (own sources) Ml/d 97.77 97.95 97.95 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92 98.92

RAW WATER BASELINE

6BL Input Raw Water Abstracted Ml/d 72.85 77.84 78.06 78.39 78.67 79.03 79.44 80.07 80.68 81.29 81.89 82.48 83.10 83.70 84.28 84.87 85.44 85.98 86.55 87.11 87.68 88.22 88.75 89.29 89.83 90.35 90.89 91.40 91.92

7BL WRP1a-BL 7a BL Raw Water Exported (existing) Ml/d 0.00 0.00 0.14 0.14 0.14 0.14 0.14 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28

8BL WRP1a-BL 8a BL Raw Water Imported (existing) Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9BL Input Raw Water Losses and Operational Use Ml/d 0.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

10BL WRP1a-BL 10a BL Non Potable Supplies (existing) Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

POTABLE WATER TO POINT OF DELIVERY BASELINE

11BL Input Treatment Works Losses and Operational Use Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

12BL WRP1a-BL 12a BL Potable Water Exported Ml/d 0.10 0.10 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37

13BL WRP1a-BL 13a BL Potable Water Imported Ml/d 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05

14BL Input Distribution Input Ml/d 72.72 77.89 78.24 78.57 78.85 79.21 79.62 80.11 80.72 81.33 81.93 82.52 83.14 83.74 84.32 84.91 85.48 86.02 86.59 87.15 87.72 88.26 88.79 89.33 89.87 90.39 90.93 91.44 91.96

15BL Input Distribution Losses Ml/d 9.68 10.22 10.20 10.19 10.17 10.15 10.12 10.08 10.04 10.00 9.95 9.91 9.86 9.82 9.78 9.73 9.69 9.64 9.59 9.55 9.50 9.46 9.41 9.37 9.32 9.27 9.23 9.18 9.13

16BL Input Distribution System Operational Use Ml/d 0.01 0.14 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01

17BL 14BL-15BL -16BL Water Delivered Ml/d 63.03 67.53 68.03 68.37 68.67 69.05 69.49 70.02 70.67 71.32 71.97 72.60 73.27 73.91 74.53 75.17 75.78 76.37 76.99 77.59 78.21 78.79 79.37 79.95 80.54 81.11 81.69 82.25 82.82

POTABLE WATER CUSTOMER USE BASELINE

18BL Input Unmeasured Household - Population 000's 133.01 130.99 127.58 124.37 121.22 118.13 115.12 112.18 109.31 106.51 103.77 101.10 98.50 95.95 93.46 91.04 88.67 86.36 84.10 81.91 79.76 77.66 75.62 73.62 71.68 69.77 67.91 66.10 64.33

19BL Input Unmeasured Household - Properties 000's 48.16 46.84 45.36 43.98 42.63 41.33 40.06 38.82 37.63 36.47 35.35 34.26 33.20 32.17 31.18 30.21 29.28 28.37 27.49 26.63 25.80 25.00 24.22 23.46 22.73 22.02 21.33 20.66 20.01

20BL 18BL/19BL Unmeasured Household - Occupancy Rate h/pr 2.76 2.80 2.81 2.83 2.84 2.86 2.87 2.89 2.91 2.92 2.94 2.95 2.97 2.98 3.00 3.01 3.03 3.04 3.06 3.08 3.09 3.11 3.12 3.14 3.15 3.17 3.18 3.20 3.22

21BL WRP6-6.1 BL Measured Household - Population 000's 136.580 144.770 151.143 156.308 162.021 168.261 175.030 182.328 190.156 198.215 206.207 214.133 221.998 229.800 237.541 245.222 252.844 260.409 267.919 275.364 282.768 290.120 297.421 304.673 311.865 319.022 326.131 333.196 340.217

22BL WRP6-6.2 BL Measured Household - Properties 000's 63.966 67.076 70.044 72.412 75.049 77.946 81.104 84.524 88.207 92.004 95.766 99.494 103.190 106.854 110.487 114.090 117.664 121.210 124.729 128.222 131.689 135.131 138.549 141.944 145.316 148.666 151.994 155.302 158.590

23BL 21BL/22BL Measured Household - Occupancy Rate h/pr 2.14 2.16 2.16 2.16 2.16 2.16 2.16 2.16 2.16 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15 2.15

24BL Input Unmeasured Non Household - Population 000's 5.46 5.36 5.25 5.14 5.02 4.91 4.80 4.69 4.58 4.46 4.35 4.23 4.12 4.00 3.89 3.77 3.66 3.54 3.43 3.31 3.20 3.08 2.96 2.84 2.72 2.60 2.48 2.36 2.24

25BL Input Unmeasured Non Household - Properties 000's 1.00 0.97 0.95 0.93 0.91 0.88 0.86 0.84 0.81 0.79 0.77 0.74 0.72 0.70 0.68 0.65 0.63 0.61 0.58 0.56 0.54 0.51 0.49 0.47 0.45 0.42 0.40 0.38 0.35

26BL Input Measured Non Household - Population 000's 21.77 22.21 22.59 22.97 23.35 23.73 24.11 24.49 24.87 25.25 25.62 26.00 26.38 26.75 27.12 27.50 27.87 28.24 28.61 28.98 29.34 29.71 30.07 30.44 30.80 31.16 31.51 31.87 32.22

27BL Input Measured Non Household - Properties 000's 8.90 8.94 9.03 9.11 9.19 9.27 9.35 9.44 9.52 9.60 9.68 9.76 9.85 9.93 10.01 10.09 10.17 10.26 10.34 10.42 10.50 10.58 10.67 10.75 10.83 10.91 10.99 11.08 11.16

28BL 18BL+21BL+24BL+26BL Total Population 000's 296.820 303.330 306.559 308.787 311.615 315.041 319.066 323.689 328.911 334.432 339.951 345.470 350.986 356.501 362.016 367.530 373.040 378.550 384.058 389.564 395.068 400.570 406.069 411.566 417.060 422.552 428.040 433.527 439.011

29BL Input Void Households 000's 2.83 2.63 2.61 2.59 2.57 2.55 2.53 2.51 2.49 2.47 2.45 2.43 2.41 2.39 2.37 2.35 2.33 2.31 2.29 2.27 2.25 2.23 2.21 2.19 2.17 2.15 2.13 2.11 2.09

30BL Input Void Non Households 000's 0.48 0.49 0.50 0.52 0.53 0.55 0.56 0.58 0.59 0.61 0.62 0.64 0.65 0.67 0.68 0.70 0.71 0.73 0.74 0.76 0.77 0.79 0.80 0.82 0.83 0.85 0.86 0.88 0.89

30.1BL 22BL/(22BL+19BL) Total Household Metering penetration (excl. voids) % 57% 59% 61% 62% 64% 65% 67% 69% 70% 72% 73% 74% 76% 77% 78% 79% 80% 81% 82% 83% 84% 84% 85% 86% 86% 87% 88% 88% 89%

30.2BL 22BL/(22BL+19BL+29BL) Total Household Metering penetration (incl. voids) % 56% 58% 59% 61% 62% 64% 66% 67% 69% 70% 72% 73% 74% 76% 77% 78% 79% 80% 81% 82% 82% 83% 84% 85% 85% 86% 87% 87% 88%

31BL 19BL+22BL+25BL+27BL+29BL+30BL Total Properties 000's 125.345 126.955 128.497 129.539 130.881 132.523 134.465 136.707 139.249 141.941 144.633 147.325 150.017 152.709 155.401 158.093 160.785 163.477 166.169 168.861 171.553 174.245 176.937 179.629 182.321 185.013 187.705 190.397 193.089

POTABLE WATER DELIVERED BASELINE

32BL Input Water Taken Unbilled Ml/d 0.17 0.15 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17

33BL Input Water Delivered Unmeasured Household Ml/d 21.52 22.73 22.26 21.85 21.42 21.00 20.58 20.17 19.79 19.38 19.00 18.63 18.28 17.92 17.56 17.22 16.90 16.55 16.23 15.92 15.62 15.32 15.00 14.72 14.45 14.18 13.91 13.65 13.40

34BL Input Unmeasured Household - USPL Ml/d 1.73 1.69 1.63 1.58 1.53 1.49 1.44 1.40 1.35 1.31 1.27 1.23 1.20 1.16 1.12 1.09 1.05 1.02 0.99 0.96 0.93 0.90 0.87 0.84 0.82 0.79 0.77 0.74 0.72

35BL 33BL-34BL Unmeasured Household - Consumption Ml/d 19.79 21.04 20.63 20.27 19.89 19.51 19.14 18.77 18.44 18.07 17.73 17.40 17.08 16.76 16.44 16.13 15.85 15.53 15.24 14.96 14.69 14.42 14.13 13.88 13.63 13.39 13.14 12.91 12.68

36BL (35BL*1000000)/(18 BL*1000) Unmeasured Household - PCC l/h/d 148.76 160.65 161.68 162.95 164.05 165.17 166.24 167.34 168.65 169.63 170.83 172.07 173.46 174.70 175.87 177.21 178.71 179.82 181.21 182.65 184.19 185.67 186.84 188.49 190.19 191.88 193.52 195.26 197.11

37BL Input Water Delivered Measured Household Ml/d 19.95 22.19 23.15 23.92 24.64 25.45 26.31 27.25 28.27 29.31 30.34 31.34 32.36 33.35 34.33 35.30 36.24 37.18 38.11 39.02 39.93 40.83 41.72 42.58 43.45 44.30 45.15 45.97 46.79

38BL Input Measured Household - USPL Ml/d 1.71 1.79 1.86 1.92 1.99 2.06 2.13 2.21 2.29 2.38 2.46 2.54 2.63 2.71 2.79 2.87 2.95 3.02 3.10 3.18 3.25 3.32 3.40 3.47 3.54 3.61 3.69 3.76 3.83

39BL 37BL-38BL Measured Household - Consumption Ml/d 18.24 20.40 21.29 22.00 22.65 23.39 24.18 25.04 25.98 26.93 27.88 28.80 29.73 30.64 31.54 32.43 33.29 34.16 35.01 35.84 36.68 37.51 38.32 39.11 39.91 40.69 41.46 42.21 42.96

40BL (39BL*1000000)/(21 BL*1000) Measured Household - PCC l/h/d 133.52 140.94 140.86 140.75 139.82 139.04 138.15 137.34 136.61 135.88 135.20 134.47 133.94 133.34 132.79 132.26 131.68 131.17 130.68 130.17 129.72 129.28 128.85 128.36 127.96 127.53 127.14 126.70 126.29

40.1BL 5BL+39BL)*1000000)/((18 BL+21BL)*100Average Household - PCC l/h/d 141.04 150.30 150.39 150.59 150.19 149.82 149.29 148.77 148.31 147.67 147.13 146.53 146.08 145.52 144.95 144.43 143.89 143.28 142.75 142.20 141.70 141.18 140.60 140.06 139.59 139.08 138.58 138.05 137.55

41BL Input Water Delivered Unmeasured Non Household Ml/d 0.80 0.79 0.78 0.76 0.75 0.72 0.71 0.69 0.68 0.68 0.66 0.65 0.63 0.62 0.60 0.59 0.57 0.55 0.54 0.52 0.51 0.49 0.48 0.46 0.43 0.42 0.40 0.39 0.37

42BL Input Unmeasured Non Household - USPL Ml/d 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.01

43BL 41BL-42BL Unmeasured Non Household - Consumption Ml/d 0.76 0.75 0.75 0.73 0.72 0.69 0.68 0.66 0.65 0.65 0.63 0.62 0.60 0.59 0.58 0.57 0.55 0.53 0.52 0.50 0.49 0.47 0.46 0.44 0.41 0.40 0.39 0.38 0.36

44BL Input Water Delivered Measured Non Household Ml/d 20.59 21.67 21.67 21.67 21.69 21.71 21.72 21.74 21.76 21.78 21.80 21.81 21.83 21.85 21.87 21.89 21.90 21.92 21.94 21.96 21.98 21.98 22.00 22.02 22.04 22.04 22.06 22.07 22.09

45BL Input Measured Non Household - USPL Ml/d 0.16 0.16 0.16 0.16 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.20 0.20 0.20 0.20

46BL 44BL-45BL Measured Non Household - Consumption Ml/d 20.43 21.51 21.51 21.51 21.52 21.54 21.55 21.57 21.59 21.61 21.63 21.63 21.65 21.67 21.69 21.71 21.72 21.74 21.75 21.77 21.79 21.79 21.81 21.83 21.85 21.84 21.86 21.87 21.89

47BL Input Void Properties - USPL Ml/d 0.12 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11

LEAKAGE BASELINE

48BL 15BL+34BL+38BL+42BL+45BL+47BL Total Leakage Ml/d 13.44 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00

49BL (48BL*1000000)/(31 BL*1000) Total Leakage l/pr/d 107.25 110.28 108.96 108.10 106.97 105.67 104.14 102.39 100.53 98.65 96.77 95.03 93.29 91.68 90.12 88.55 87.10 85.64 84.22 82.91 81.59 80.36 79.11 77.96 76.79 75.65 74.60 73.53 72.49

SUPPLY DEMAND BALANCE BASELINE

50BL 5BL+(8BL+13BL)-(7BL+12BL)-10BL Total Water Available For Use Ml/d 97.72 97.90 97.49 98.46 98.46 98.46 98.46 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32 98.32

51BL Input Available Headroom Ml/d 25.00 20.01 19.25 19.89 19.61 19.25 18.84 18.21 17.60 16.99 16.39 15.80 15.18 14.58 14.00 13.41 12.84 12.30 11.73 11.17 10.60 10.06 9.53 8.99 8.45 7.93 7.39 6.88 6.36

52BL Input Target Headroom Ml/d 4.40 4.40 4.45 4.50 4.52 4.54 4.56 4.58 4.60 4.62 4.64 4.66 4.68 4.70 4.72 4.74 4.76 4.78 4.80 4.82 4.84 4.86 4.88 4.90 4.92 4.94 4.96 4.98 5.00

53BL 51BL-52BL Supply Demand Balance Ml/d 20.60 15.61 14.80 15.39 15.09 14.71 14.28 13.63 13.00 12.37 11.75 11.14 10.50 9.88 9.28 8.67 8.08 7.52 6.93 6.35 5.76 5.20 4.65 4.09 3.53 2.99 2.43 1.90 1.36

Company: Cambridge Water

Resource Zone Name Company wide

Resource Zone Number: 1 of 1

Planning Scenario Name: Dry year

Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Table WRP1a-BL: Baseline WRP1 supporting transfer and DO reductions data Scenario ROW DESCRIPTION Year Ref. DERIVATION [Insert /delete non-numbered lines to suit] UNITS 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19 2019-20 2020-21 2021-22 2022-23 2023-24 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30 2030-31 2031-32 2032-33 2033-34 2034-35

2aBL Input as appropriate Reductions in Baseline Deployable Output: Total here and specify below Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Climate change Ml/d

Linton PS sustainability reduction (indicative only) Ml/d Ml/d

Ml/d

7aBL Input as appropriate Baseline Raw Water Exported (existing). Total here and specify below Ml/d 0.00 0.00 0.14 0.14 0.14 0.14 0.14 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28

to Iceni Waters Ml/d 0.00 0.00 0.14 0.14 0.14 0.14 0.14 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28

to Ml/d

8aBL Input as appropriate Baseline Raw Water Imported (existing). Total here and specify below Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

from Ml/d

10aBL Input as appropriate Baseline Non Potable Supplies (existing). Total here and specify below Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

to Ml/d

12aBL Input as appropriate Baseline Potable Water Exported. Total here and specify below Ml/d 0.10 0.10 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37

to Anglian Water - Ramsey Mereside Ml/d 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01

to Three Valleys - Hadstock + Hadstock LL Ml/d 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09

to Anglian Water - Swaffham Prior Ml/d 0.00 0.00 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27

to Three Valleys - Lowerfield Ml/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

13aBL Input as appropriate Baseline Potable Water Imported. Total here and specify below Ml/d 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05

from Anglian Water - Stoke's Bridge + Earith Bridge Ml/d 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01

from Three Valleys - Odsey Ml/d 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04

to Ml/d

Company: Cambridge Water

Resource Zone Name Company wide

Resource Zone Number: 1 of 1

Planning Scenario Name: Dry year

Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Table WRP5: Baseline resource zone deployable output reconciliation

Length of Dry year Critical period Source type Annual licenced record Critical Row Ref Derivation Licence number Source name deployable deployable Constraint (GW/SW/Res/Conj. use) quantity (Ml/d) assessed event (Year) output (Ml/d) output (Ml/d) (Years) 5.1 Input 6/33/28/G/50 Abington Park GW 1 4.44 1 5.2 Input 6/33/28/G/7 Babraham GW 9.09 9.09 9.09 5.3 Input 6/33/44/G/221 Brettenham GW 11.34 15.00 11.34 5.4 Input 6/33/30/G/27 Croydon GW 1.99 2.18 1.99 5.5 Input 6/33/34/G/203 Dullingham GW 3.6 3.63 4.5 5.6 Input 6/33/30/G/160 & 167 Duxford Airfield GW 4.56 5.68 4.56 5.7 Input 6/33/30/G/191 Duxford Grange GW 3.41 3.95 3.41 5.8 Input 6/33/42/G/107 Euston GW 8 10.00 8 5.9 Input 6/33/34/G/24 Fleam Dyke GW 15.57 15.97 15.88 5.10 Input 6/33/30/G/26 Fowlmere GW 3.6 5.40 3.6 5.11 Input 6/33/30/G/179 Fulbourn GW 1.49 1.80 1.49 5.12 Input 6/33/34/G/179 Weston Colvillle GW 2.82 2.84 3.65 5.13 Input 6/33/30/G/192 Great Chishill GW 1.15 1.33 1.15 6/33/34/G/123 Great Wilbraham GW 4.58 4.58 5.67 6/33/30/G/169 Heydon GW 1.13 2.27 1.13 6/33/27/G/39 Hinxton Grange GW 5.77 6.82 5.77 6/33/28/G/52 Horseheath GW 2.3 2.88 2.3 6/33/32/G/7 & 20 Kingston GW 1 1.18 1 5.14 Input 6/33/28/G/12 Linton GW 1.93 2.73 1.93 5.15 Input 6/33/30/G/193 Lowerfield GW 3.41 4.27 3.41 5.16 Input 6/33/30/G/156 Melbourn GW 7.94 9.55 7.94 5.17 Input 6/33/30/G/171 Morden Grange GW 1.6 1.60 2.27 5.18 Input 6/33/28/G/51 Rivey GW 2.2 2.75 2.2 5.19 Input 6/33/28/G/13 & 38 Sawston GW 1.49 2.18 1.49 5.20 Input 6/33/26/G/20 St Ives GW 1.2 1.20 1.62 5.21 Input 6/33/34/G/110 Westley GW 11.39 12.30 11.39 5.22 Input 5.23 Input

5.24 Input Sum (5.1:5.24) 5.25 113.56 135.62 117.78 Total reconciled DO

Company: Cambridge Water Resource Zone Name Company wide Resource Zone Number: 1 of 1 Planning Scenario Name: Dry year Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Table WRP6: Baseline breakdown of measured households Scenario Year Row Ref Derivation Description Units 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19 2019-20 2020-21 2021-22 2022-23 2023-24 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30 2030-31 2031-32 2032-33 2033-34 2034-35

6.5BL+6.9BL+6.13BL+6.17BL+ 6.1BL Total Population 000's 6.14 6.76 6.36 5.15 5.70 6.23 6.75 7.28 7.81 8.04 7.98 7.91 7.85 7.79 7.73 7.67 7.61 7.55 7.50 7.43 7.39 7.34 7.29 7.24 7.18 7.14 7.09 7.05 7.01 6.21BL+6.25BL

6.6BL+6.10BL+6.14BL+6.18BL+6.2 6.2BL Total Properties 000's 2.84 3.20 2.96 2.36 2.63 2.89 3.15 3.41 3.68 3.79 3.75 3.72 3.69 3.66 3.63 3.60 3.57 3.54 3.51 3.49 3.46 3.43 3.41 3.39 3.36 3.34 3.32 3.30 3.28 2BL+6.26BL

6.3BL 6.1BL/6.2BL Total Occupancy h/prop 2.16 2.12 2.15 2.18 2.17 2.15 2.14 2.13 2.13 2.12 2.12 2.13 2.13 2.13 2.13 2.13 2.13 2.13 2.13 2.13 2.14 2.14 2.14 2.14 2.13 2.14 2.14 2.14 2.14

6.5BL Input Meter optants Population 000's 3.36 3.09 3.33 3.12 3.07 3.00 2.93 2.85 2.78 2.72 2.65 2.58 2.52 2.46 2.40 2.34 2.28 2.22 2.17 2.10 2.06 2.01 1.96 1.91 1.85 1.81 1.76 1.72 1.67

6.6BL Input Meter optants Properties 000's 1.46 1.37 1.45 1.35 1.32 1.28 1.24 1.20 1.17 1.13 1.09 1.06 1.03 1.00 0.97 0.94 0.91 0.88 0.85 0.83 0.80 0.77 0.75 0.73 0.70 0.68 0.66 0.64 0.62

6.7BL 6.5BL/6.6BL Meter optants Occupancy h/prop 2.31 2.26 2.30 2.31 2.33 2.34 2.36 2.37 2.39 2.40 2.42 2.44 2.45 2.47 2.48 2.50 2.51 2.53 2.54 2.54 2.58 2.59 2.61 2.62 2.62 2.65 2.67 2.68 2.70

6.8BL Input Meter optants pcc l/h/d 106.32 111.70 110.02 110.70 111.53 112.12 112.73 113.36 114.02 114.69 115.38 116.09 116.81 117.56 118.33 119.12 119.92 120.75 121.60 123.21 123.33 124.24 125.17 126.12 127.84 128.06 129.08 130.12 131.18

6.9BL Input New properties Population 000's 2.75 3.63 3.00 2.00 2.60 3.20 3.80 4.40 5.00 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30

6.10BL Input New properties Properties 000's 1.37 1.81 1.50 1.00 1.30 1.60 1.90 2.20 2.50 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65 2.65

6.11BL 6.9BL/6.10BL New properties Occupancy h/prop 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00

6.12BL Input New properties pcc l/h/d 161.93 161.93 161.93 161.93 129.49 129.61 129.72 129.84 129.96 130.07 130.19 130.31 130.42 130.54 130.66 130.77 130.89 131.01 131.12 131.24 131.35 131.47 131.59 131.70 131.82 131.94 132.05 132.17 132.29

6.13BL Input Metering on change of occupancy Population 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.14BL Input Metering on change of occupancy Properties 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.15BL 6.13BL/6.14BL Metering on change of occupancy Occupancy h/prop 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.16BL Input Metering on change of occupancy pcc l/h/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.17BL Input Selective metering Population 000's 0.03 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03

6.18BL Input Selective metering Properties 000's 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01

6.19BL 6.17BL/6.18BL Selective metering Occupancy h/prop 2.80 2.79 2.80 2.80 2.80 2.80 2.90 2.90 2.90 2.90 2.90 2.90 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.10 3.10 3.10 3.10 3.10 3.10 3.20 3.20 3.20 3.20

6.20BL Input Selective metering pcc l/h/d 138.53 144.98 145.07 146.17 146.98 147.82 148.68 149.56 150.47 151.40 152.36 153.34 154.34 155.37 156.42 157.50 158.60 159.73 160.88 162.06 163.24 164.47 165.73 167.01 168.32 169.64 171.00 172.40 173.82

6.21BL Input Compulsory metering Population 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.22BL Input Compulsory metering Properties 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.23BL 6.21BL/6.22BL Compulsory metering Occupancy h/prop 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.24BL Input Compulsory metering pcc l/h/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.25BL Input Other changes to existing metering Population 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.26BL Input Other changes to existing metering Properties 000's 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.27BL 6.25BL/6.26BL Other changes to existing metering Occupancy h/prop 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6.28BL Input Other changes to existing metering pcc l/h/d 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Company: Cambridge Water Resource Zone Name Company wide Resource Zone Number: 1 of 1 Planning Scenario Name: Dry year Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Table WRP7: Baseline household micro-component consumption Scenario Row Description Year Ref Derivation Insert additional components as required Units 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19 2019-20 2020-21 2021-22 2022-23 2023-24 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30 2030-31 2031-32 2032-33 2033-34 2034-35 7.1 Input Unmeasured toilet flushing l/h/d 50.00 54.10 54.40 54.85 55.18 55.51 55.84 56.18 56.51 56.84 57.17 57.50 57.99 58.48 58.97 59.46 59.96 60.45 60.94 61.43 61.92 62.41 62.90 63.39 63.89 64.38 64.87 65.36 65.85 7.2 Input Unmeasured bath use l/h/d 25.71 27.82 27.98 28.21 28.38 28.55 28.72 28.89 29.06 29.23 29.40 29.57 29.82 30.08 30.33 30.58 30.83 31.09 31.34 31.59 31.84 32.10 32.35 32.60 32.86 33.11 33.36 33.61 33.87 7.3 Input Unmeasured shower use l/h/d 9.64 10.43 10.49 10.58 10.64 10.71 10.77 10.83 10.90 10.96 11.03 11.09 11.18 11.28 11.37 11.47 11.56 11.66 11.75 11.85 11.94 12.04 12.13 12.23 12.32 12.42 12.51 12.60 12.70 7.4 Input Unmeasured hand basin l/h/d 32.00 34.62 34.82 35.10 35.32 35.53 35.74 35.95 36.16 36.38 36.59 36.80 37.11 37.43 37.74 38.06 38.37 38.69 39.00 39.31 39.63 39.94 40.26 40.57 40.89 41.20 41.52 41.83 42.14 7.5 Input Unmeasured clothes washing l/h/d 15.71 17.00 17.10 17.24 17.34 17.45 17.55 17.66 17.76 17.86 17.97 18.07 18.23 18.38 18.53 18.69 18.84 19.00 19.15 19.31 19.46 19.62 19.77 19.92 20.08 20.23 20.39 20.54 20.70 7.6 Input Unmeasured dish washing l/h/d 8.04 8.69 8.74 8.82 8.87 8.92 8.97 9.03 9.08 9.13 9.19 9.24 9.32 9.40 9.48 9.56 9.64 9.71 9.79 9.87 9.95 10.03 10.11 10.19 10.27 10.35 10.43 10.50 10.58 7.7 Input Unmeasured garden use l/h/d 6.67 7.21 7.25 7.31 7.36 7.40 7.45 7.49 7.53 7.58 7.62 7.67 7.73 7.80 7.86 7.93 7.99 8.06 8.13 8.19 8.26 8.32 8.39 8.45 8.52 8.58 8.65 8.71 8.78 7.8 Input Unmeasured car washing l/h/d 0.67 0.72 0.73 0.73 0.74 0.74 0.74 0.75 0.75 0.76 0.76 0.77 0.77 0.78 0.79 0.79 0.80 0.81 0.81 0.82 0.83 0.83 0.84 0.85 0.85 0.86 0.86 0.87 0.88 7.9 Input Unmeasured miscellaneous use l/h/d 0.32 0.06 0.17 0.11 0.22 0.36 0.46 0.56 0.90 0.89 1.10 1.36 1.31 1.07 0.80 0.67 0.72 0.35 0.30 0.28 0.36 0.38 0.09 0.29 0.51 0.75 0.93 1.24 1.61 7.10 Input l/h/d 7.11 Input l/h/d 7.12 Input l/h/d 7.13 Input l/h/d 7.14 Input l/h/d 7.15 Input l/h/d 7.16 Input l/h/d 7.17 Input l/h/d 7.18 Input l/h/d 7.19 Sum(7.1:7.18) Unmeasured pcc l/h/d 148.76 160.65 161.68 162.95 164.05 165.17 166.24 167.34 168.65 169.63 170.83 172.07 173.46 174.70 175.87 177.21 178.71 179.82 181.21 182.65 184.19 185.67 186.84 188.49 190.19 191.88 193.52 195.26 197.11

7.20 Input Measured toilet flushing l/h/d 40.00 42.20 42.20 42.20 41.98 41.75 41.53 41.30 41.08 40.85 40.63 40.40 40.24 40.07 39.91 39.74 39.58 39.41 39.25 39.08 38.92 38.75 38.59 38.42 38.26 38.09 37.93 37.76 37.60 7.21 Input Measured bath use l/h/d 12.86 13.56 13.56 13.56 13.49 13.42 13.35 13.28 13.20 13.13 13.06 12.99 12.93 12.88 12.83 12.77 12.72 12.67 12.62 12.56 12.51 12.46 12.40 12.35 12.30 12.24 12.19 12.14 12.09 7.22 Input Measured shower use l/h/d 15.43 16.28 16.28 16.28 16.19 16.10 16.02 15.93 15.84 15.76 15.67 15.58 15.52 15.46 15.39 15.33 15.27 15.20 15.14 15.07 15.01 14.95 14.88 14.82 14.76 14.69 14.63 14.57 14.50 7.23 Input Measured hand basin l/h/d 32.00 33.76 33.76 33.76 33.58 33.40 33.22 33.04 32.86 32.68 32.50 32.32 32.19 32.06 31.92 31.79 31.66 31.53 31.40 31.27 31.13 31.00 30.87 30.74 30.61 30.48 30.34 30.21 30.08 7.24 Input Measured clothes washing l/h/d 15.71 16.58 16.58 16.58 16.49 16.40 16.31 16.23 16.14 16.05 15.96 15.87 15.81 15.74 15.68 15.61 15.55 15.48 15.42 15.35 15.29 15.22 15.16 15.09 15.03 14.97 14.90 14.84 14.77 7.25 Input Measured dish washing l/h/d 9.64 10.17 10.17 10.17 10.12 10.06 10.01 9.96 9.90 9.85 9.79 9.74 9.70 9.66 9.62 9.58 9.54 9.50 9.46 9.42 9.38 9.34 9.30 9.26 9.22 9.18 9.14 9.10 9.06 7.26 Input Measured garden use l/h/d 6.67 7.03 7.03 7.03 7.00 6.96 6.92 6.88 6.85 6.81 6.77 6.73 6.71 6.68 6.65 6.62 6.60 6.57 6.54 6.51 6.49 6.46 6.43 6.40 6.38 6.35 6.32 6.29 6.27 7.27 Input Measured car washing l/h/d 0.67 0.70 0.70 0.70 0.70 0.70 0.69 0.69 0.68 0.68 0.68 0.67 0.67 0.67 0.67 0.66 0.66 0.66 0.65 0.65 0.65 0.65 0.64 0.64 0.64 0.63 0.63 0.63 0.63 7.28 Input Measured miscellaneous use l/h/d 0.54 0.66 0.58 0.47 0.27 0.23 0.10 0.03 0.06 0.07 0.14 0.17 0.17 0.12 0.12 0.16 0.10 0.15 0.20 0.26 0.34 0.45 0.58 0.64 0.76 0.90 1.06 1.16 1.29 7.29 Input l/h/d 7.30 Input l/h/d 7.31 Input l/h/d 7.32 Input l/h/d 7.33 Input l/h/d 7.34 Input l/h/d 7.35 Input l/h/d 7.36 Input l/h/d 7.37 Input l/h/d 7.38 Sum(7.20:7.37) Measured pcc l/h/d 133.52 140.94 140.86 140.75 139.82 139.02 138.15 137.34 136.61 135.88 135.20 134.47 133.94 133.34 132.79 132.26 131.68 131.17 130.68 130.17 129.72 129.28 128.85 128.36 127.96 127.53 127.14 126.70 126.29

Company: Cambridge Water

Resource Zone Name Company wide

Resource Zone Number: 1 of 1

Planning Scenario Name: Dry year

Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Table WRP9: Normal year final planning supply-demand components Scenario ROW Year Ref. DERIVATION DESCRIPTION UNITS 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19 2019-20 2020-21 2021-22 2022-23 2023-24 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30 2030-31 2031-32 2032-33 2033-34 2034-35 BASIC RESOURCES NORMAL YEAR

3N Input Outage Allowance Ml/d 12.11

5N Input Water Available For Use (own sources) Ml/d 97.77

RAW WATER NORMAL YEAR

6N Input Raw Water Abstracted Ml/d 72.85

7N Input Raw Water Exported (existing) Ml/d 0.00

8N Input Raw Water Imported (existing) Ml/d 0.00

9N Input Raw Water Losses and Operational Use Ml/d 0.18

10N Input Non Potable Supplies (existing) Ml/d 0.00

POTABLE WATER TO POINT OF DELIVERY NORMAL YEAR

11N Input Treatment Works Losses and Operational Use Ml/d 0.00

12N Input Potable Water Exported Ml/d 0.10

13N Input Potable Water Imported Ml/d 0.05

14N Input Distribution Input Ml/d 72.72

15N Input Distribution Losses Ml/d 9.68

16N Input Distribution System Operational Use Ml/d 0.01

17N 14N-15N -16N Water Delivered Ml/d 63.03

POTABLE WATER DELIVERED NORMAL YEAR

32N Input Water Taken Unbilled Ml/d 0.17 0.15 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.00 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17

33N Input Water Delivered Unmeasured Household Ml/d 21.52 21.96 21.53 21.13 20.70 20.27 19.85 19.44 19.05 0.00 18.66 18.28 17.91 17.55 17.19 16.85 16.51 16.18 15.86 15.54 15.23 14.93 14.64 14.35 14.07 13.79 13.52 13.26 13.00

34N Input Unmeasured Household - USPL Ml/d 1.73 1.69 1.63 1.58 1.53 1.49 1.44 1.40 1.35 0.00 1.31 1.27 1.23 1.20 1.16 1.12 1.09 1.05 1.02 0.99 0.96 0.93 0.90 0.87 0.84 0.82 0.79 0.77 0.74

35N 33N-34N Unmeasured Household - Consumption Ml/d 19.79 20.27 19.90 19.55 19.17 18.78 18.41 18.04 17.70 0.00 17.35 17.01 16.68 16.35 16.03 15.73 15.42 15.13 14.84 14.55 14.27 14.00 13.74 13.48 13.23 12.97 12.73 12.49 12.26

36N Input Unmeasured Household - PCC l/h/d 148.76 154.77 155.96 157.17 158.11 158.99 159.90 160.83 161.88 0.00 162.87 163.89 164.95 166.05 167.09 168.28 169.41 170.59 171.83 173.01 174.23 175.54 176.92 178.25 179.66 180.98 182.42 183.95 185.43

37N Input Water Delivered Measured Household Ml/d 19.95 21.44 22.37 23.11 23.79 24.54 25.35 26.23 27.19 0.00 28.16 29.13 30.07 31.01 31.93 32.84 33.74 34.61 35.48 36.33 37.17 38.00 38.82 39.63 40.42 41.20 41.97 42.73 43.48

38N Input Measured Household - USPL Ml/d 1.71 1.79 1.86 1.92 1.99 2.06 2.13 2.21 2.29 0.00 2.38 2.46 2.54 2.63 2.71 2.79 2.87 2.95 3.02 3.10 3.18 3.25 3.32 3.40 3.47 3.54 3.61 3.69 3.76

39N 37N-38N Measured Household - Consumption Ml/d 18.24 19.65 20.51 21.19 21.80 22.48 23.22 24.02 24.90 0.00 25.78 26.67 27.53 28.38 29.22 30.05 30.87 31.66 32.46 33.23 33.99 34.75 35.50 36.23 36.95 37.66 38.36 39.04 39.72

40N Input Measured Household - PCC l/h/d 133.52 135.76 135.70 135.56 134.58 133.63 132.66 131.75 130.93 0.00 130.07 129.33 128.54 127.85 127.16 126.51 125.90 125.23 124.64 124.03 123.45 122.89 122.35 121.82 121.27 120.75 120.23 119.72 119.22

41N Input Water Delivered Unmeasured Non Household Ml/d 0.80 0.76 0.75 0.73 0.72 0.70 0.69 0.67 0.66 0.00 0.65 0.63 0.62 0.60 0.59 0.57 0.56 0.54 0.52 0.51 0.49 0.48 0.46 0.45 0.43 0.41 0.40 0.38 0.37

42N Input Unmeasured Non Household - USPL Ml/d 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.00 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01

43N 41N-42N Unmeasured Non Household - Consumption Ml/d 0.76 0.72 0.72 0.70 0.69 0.67 0.66 0.64 0.63 0.00 0.62 0.60 0.59 0.57 0.56 0.55 0.54 0.52 0.50 0.49 0.47 0.46 0.44 0.43 0.41 0.39 0.38 0.37 0.36

44N Input Water Delivered Measured Non Household Ml/d 20.59 20.94 20.94 20.94 20.93 20.92 20.91 20.90 20.89 0.00 20.88 20.87 20.86 20.85 20.84 20.83 20.82 20.81 20.80 20.79 20.78 20.77 20.75 20.74 20.73 20.72 20.71 20.70 20.68

45N Input Measured Non Household - USPL Ml/d 0.16 0.16 0.16 0.16 0.17 0.17 0.17 0.17 0.17 0.00 0.17 0.17 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.20 0.20 0.20

46N 44N-45N Measured Non Household - Consumption Ml/d 20.43 20.78 20.78 20.78 20.76 20.75 20.74 20.73 20.72 0.00 20.71 20.70 20.68 20.67 20.66 20.65 20.64 20.63 20.62 20.60 20.59 20.58 20.56 20.55 20.54 20.53 20.51 20.50 20.48

47N Input Void Properties - USPL Ml/d 0.12 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.00 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11

LEAKAGE NORMAL YEAR

48N Input Total Leakage Ml/d 13.44 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 0.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00

49N Input Total Leakage l/pr/d 107.22 110.28 108.95 108.08 106.97 105.64 104.12 102.41 100.54 #DIV/0! 98.63 96.80 95.03 93.32 91.68 90.09 88.56 87.07 85.64 84.25 82.91 81.61 80.35 79.12 77.94 76.79 75.67 74.59 73.53

SUPPLY DEMAND BALANCE NORMAL YEAR

50N 5N+(8N+13N)-(7N+12N)-10N Total Water Available For Use Ml/d 97.72

51N Input Available Headroom Ml/d 25.00

52N Input Target Headroom Ml/d 4.40

53N 51N-52N Supply Demand Balance Ml/d 20.60

Company: Cambridge Water

Resource Zone Name Company wide

Resource Zone Number: 1 of 1

Planning Scenario Name: Dry year

Chosen Level of Service: Unrestricted

WRP Tables (as updated draft, with outage reassessment) Cambridge Water Company Final Water Resources Management Plan

4.0 Appendices

Appendix 1 – Consultation

A1.1 Pre-draft consultation

The Secretary of State for the Department of Environment Food and Rural Affairs (Defra), the Environment Agency (EA), and the Water Services Regulation Authority (Ofwat) were all contacted in May 2007, and advised of the Company’s intention to prepare a draft plan and submit it to the SoS by the end of December 2007. The Consumer Council for Water (CCWater) Eastern was also consulted separately.

A summary of the responses received is set out below.

Summary of pre-draft consultation and responses

Ofwat Expect Company to follow latest guidance, but also draw attention to a number of specific areas for consideration: Communication with customers  explain clearly what draft water resources plan is, and set it in context of drought plan  draft plan must be readily understandable by customers, with summary in plain English, minimising use of technical terms, and must be easily accessible, to comply with Section 37B(3)(a) of Water Industry Act 1991 Consult with key stakeholders who may have an influence on, or be influenced by, proposals Levels of service  set out proposed levels of service and what they mean in terms of possible supply restrictions  ensure that levels of service reflect an understanding of customers’ views; explain steps taken to establish those views; and how they are reflected in draft plan Metering, water efficiency and tariffs  explore ways of managing demand as part of twin track approach to maintaining supply-demand balance  take holistic approach in considering costs/benefits of supply- demand options  enhanced metering programmes should consider impact of water efficiency programmes and innovative tariffs  include assessment of robustness and sustainability of projected water savings, and describe supply-side resource options that have been offset as a result of water efficiency measures  consider impact of Code for Sustainable Homes on forecast demand Target headroom and minimising uncertainty  provide breakdown of components of target headroom related to individual sources of assumed supply/demand uncertainty  provide detailed breakdown of uncertainty assumed for new resource developments and demand management measures  carry out work to minimise sources of uncertainty  determine level of uncertainty through actual experience and trials

32 Cambridge Water Company Final Water Resources Management Plan

Summary of pre-draft consultation and responses (cont’d)

Secretary of State, Follow latest EA guidance. Defra Consider EA comments on current water resources plan and any generic comments in EA’s advice to Ministers in the Fifth Annual Review of Water Company Water Resources Plans 2004. Take note of any subsequent information provided by EA on water supply and demand in Company’s area. In areas of serious water stress, include assessment of costs/benefits of compulsory metering alongside costs/benefits of other supply-demand measures. Take account of letter from Defra Head of Water Supply and Regulation to Company’s Regulatory Director about revised policy on dealing with impacts of unsustainable abstractions on Natura 2000 sites Environment Would like Company to consider: Agency  EA draft water resources planning guideline  EA comments on Company’s 2004 water resources plan  EA Chief Executive’s open letter to water company MDs, setting out general principles for WRMPs  EA Regional Director letter to Company’s MD providing information on sustainability reductions Would like Company to address the following issues  improve household demand monitoring and forecasting to ensure better understanding of likely effects of planned growth in Company area  review outage assessment taking account of actual outage date and current methodologies. Expect to consider ways of managing and developing system to reduce current large outage allowance which is an industry outlier CCWater Eastern Is the Company proposing to review the likely effect of climate change? How will Company make plan available to customers, other than on website? Has the Company considered the impact from any inset appointment in its area of supply? Maps are useful, but understand that there are security issues.

The Company believes that this draft plan satisfactorily addresses the issues raised during the pre-draft consultation process.

A1.2 Consultation during preparation of draft plan

During the preparation of the draft plan the Company held regular progress meetings with regional Environment Agency water resource planners. These open meetings proved extremely useful in identifying and addressing areas of concern, prior to publication.

The Company’s Ofwat Reporter was kept informed of the outcome of the discussions that took place with the EA. The final review meeting was a joint one, attended by both the Reporter and EA planners.

Finally, extensive dialogue took place with Natural England as part of the Strategic Environmental Assessment screening process.

33 Cambridge Water Company Final Water Resources Management Plan

A1.3 Consultation on draft plan

The following is a list of specified organisations to whom the Company’s draft Water Resources Management Plan was sent:

Environment Agency Water Services Regulation Authority (Ofwat) Natural England English Heritage Consumer Council for Water (CCW) Eastern East of England Development Agency East of England Regional Assembly GO-East Cambridge City Council South Cambridgeshire District Council Huntingdonshire District Council Cambridgeshire County Council Cambridgeshire Horizons Countryside Agency Conservators of the River Cam Middle Level Commissioners Anglian Water Three Valleys Water

Copies of the plan were also sent to the following non-specified organisations:

Royal Society for the Protection of Birds Campaign to Protect Rural England National Farmers’ Union Country Land and Business Association Great Wilbraham River Society Friends of the Earth Cambridge Preservation Society

The draft plan was published on the Company’s website www.cambridge-water.co.uk and paper copies were made available on request to those who did not have access the internet. Customers were informed of the plan’s publication through the Company’s newsletter, which was included with all water bills. Notice of publication was also given in the local press.

A statement accompanying the plan explained the process for interested parties to make representations.

A1.4 Consultation Responses

A total of 13 representations had been received at the end of the consultation period. The Company compiled a schedule of the representations received, and set out the actions it intended to take as a result: the schedule forms the basis of the Company’s formal Statement of Response (SoR), submitted to the Secretary of State on 6 February 2009. The SoR was published on the Cambridge Water website, and copies were also sent to those who had made representations.

As a result of the representations received, the Company updated its draft plan.

34 Cambridge Water Company Final Water Resources Management Plan

A1.5 Ministerial Review

Our Statement of Response was reviewed by Ministers, who concluded that further work was required by the Company in two areas, outage and metering, before it could be determined whether the plan could be published in its final form, without further changes, or whether a hearing or enquiry would need to be held into areas of the plan that were still considered to be unsatisfactory. The further work was duly completed, and submitted to the Secretary of State for consideration, following which he declared himself satisfied that the Company should publish its final plan.

35 Cambridge Water Company Final Water Resources Management Plan

Appendix 2 – Strategic Environmental Assessment

A.2.1 Background The European Directive on Strategic Environmental Assessment (SEA) is designed to “integrate environmental considerations into the preparation and adoption of certain plans and programmes” and to “provide for a high level of protection of the environment”. The SEA Regulations require the environmental assessment of certain statutory plans or programmes that: a) are prepared for .... water management ..., and b) set the framework for future development consent of projects .... or

which, in view of the likely effect on sites, have been determined to require an assessment pursuant to Article 6 or 7 of the Habitats Directive.

Although it is clear that SEA applies to water companies’ water resources management plans (WRMPs) it is recognised that small, simple WRMPs do not necessarily require SEA.

A.2.2 Applicability of SEA to Cambridge Water draft WRMP In determining whether or not its draft plan requires SEA, Cambridge Water has followed the procedure set out in the recent report Strategic Environmental Assessment – Guidance for Water Resources Management Plans and Drought Plans – UKWIR, 2007. The Company has followed the decision tree process included in the report, and reproduced below, and has concluded that SEA is not required in this case.

36 Cambridge Water Company Final Water Resources Management Plan

The key feature of Cambridge Water’s WRMP is a simple plan, covering a small area, which consists of a single water resource zone. It does not set a framework for development consent for any projects as there are no foreseeable supply and demand problems throughout the planning period. It does not fall within the category of a land use plan and therefore, on the basis of legal advice obtained by Natural England, it does not require an Appropriate Assessment under the Habitats Directive.

The conclusion from the decision tree, therefore, is that Directive does not require SEA to be carried out. However, mindful of the need to demonstrate to statutory consultees that its WRMP is unlikely to have a significant effect on the environment, the Company has undertaken an environmental impact assessment and compiled a report in support of its case, and this is attached as Appendix (i) to this document. Natural England, in particular, were consulted extensively as part of the SEA screening process. The format of the environmental report that has been produced is based on the consultations that took place with NE.

None of the three statutory consultees was opposed to the Company’s view that SEA was not required.

37 Cambridge Water Company Final Water Resources Management Plan

Strategic Environmental Assessment

Appendix (i) - Environmental Report

Introduction

Cambridge Water’s Water Resources Management Plan (WRMP) sets out how the Company intends to maintain the balance between supply and demand over the next 25 years. It is complemented by the Company’s drought plan, which sets out the short-term operational steps Cambridge Water will take as a drought progresses.

The nature of the Company’s business, and therefore the essence of its WRMP, is to provide its current and future customers with a consistent supply of wholesome water at adequate pressure. All the water supplied by the Company is abstracted from boreholes in the chalk aquifer: there are no surface water sources. At present the Company has a healthy surplus of supply over demand, with deployable output exceeding the dry year average daily demand by 40%. Although demands are forecast to rise by around 25% over the planning period, the supply-demand balance is expected to remain in surplus, without the need to increase the current licensed deployable output: there are no proposals within the WRMP to develop new resource.

Framework Adopted for Screening

The Communities and Local Government’s guidance document, A Practical Guide to the Strategic Environmental Assessment Directive suggests that, for small or local plans, SEA is only required where they are “determined to be likely to have significant environmental effects”. The Company considers that its WRMP falls into this category, and that the SEA Directive therefore requires it to take a view on the likely impact of its WRMP on the environment.

Schedule 1 to the Environmental Assessment of Plans and Programmes Regulations 2004 (which transposes the SEA Directive into UK law) lists the criteria for determining the likely significance of effects on the environment, as follows:

1. The characteristics of plans and programmes, having regard, in particular, to:  the degree to which the plan or programme sets a framework for projects and other activities, either with regard to the location, nature, size and operating conditions or by allocating resources,  the degree to which the plan or programme influences other plans and programmes including those in a hierarchy,  the relevance of the plan or programme for the integration of environmental considerations in particular with a view to promoting sustainable development,  environmental problems relevant to the plan or programme,  the relevance of the plan or programme for the implementation of Community legislation on the environment (e.g. plans and programmes linked to waste management or water protection).

2. Characteristics of the effects and of the area likely to be affected, having regard, in particular, to:  the probability, duration, frequency and reversibility of the effects,  the cumulative nature of the effects,  the transboundary nature of the effects,  the risks to human health or the environment (e.g. due to accidents),  the magnitude and spatial extent of the effects (geographical area and size of the population likely to be affected),  the value and vulnerability of the area likely to be affected due to: - special natural characteristics or cultural heritage,

38 Cambridge Water Company Final Water Resources Management Plan

- exceeded environmental quality standards or limit values, - intensive land-use, - the effects on areas or landscapes which have a recognised national, Community or international protection status.

Natural England’s Guidance for Practitioners on SEA sets out a table of biodiversity considerations when determining the likely significance of effects, which is reproduced below:

Criteria for determining likely Possible biodiversity considerations in significance of effects referred to in screening: Article 3(5) "Might the plan…" The relevance of the plan for integration of …influence how environmental issues, including environmental considerations in particular biodiversity, are dealt with in other policies, plans with a view to promoting sustainable and programmes? This could include plans to development enhance biodiversity in the wider countryside, e.g. to implement actions identified by biodiversity partnerships Environmental problems relevant to the …exacerbate existing threats to biodiversity? plan or programme ….involve activities already posing a threat to biodiversity in the study area? The relevance of the plan or programme for …affect other plans that protect or enhance the implementation of EC legislation on the environmental quality? environment The probability, duration, frequency and … have relatively certain effects? reversibility of the effects … have long-term effects (taking into account lengths of lifecycles)? ….have repeated impacts on the same biodiversity resources at such a frequency that their recovery might be compromised? … have irreversible impacts on biodiversity, i.e. impacts from which spontaneous recovery is impossible and there are no known effective mitigation techniques? The cumulative nature of the effects …affect areas where biodiversity is already exposed to significant threat, e.g. through habitat loss or fragmentation? … exacerbate space-crowding with significant effects on certain components of biodiversity or on a high proportion of the resource within the study area? …exacerbate environmental deterioration such that critical thresholds may be reached? …make a significant contribution to ‘in- combination’ or cumulative effects on biodiversity? The magnitude and spatial extent of the … lead to projects that are space- or resource- effects hungry, e.g. occupying large areas or using large volumes of water? The value and vulnerability of the area … affect areas of high biodiversity (whether likely to be affected due to: special natural designated or not) that could be threatened? characteristics or cultural heritage, …affect areas covered by BAPs? exceeded environmental quality standards or limit values, intensive land-use The effects on areas or landscapes which … affect Natura 2000 sites (see Section 5.3)? have a recognised national, EC or …affect Ramsar Convention sites international protection status … affect SSSIs/ ASSIs (see Section 28 of the Wildlife and Countryside Act)? … affect other designated sites? (See Tab.3)

39 Cambridge Water Company Final Water Resources Management Plan

The Company considers that the major area where the environmental impact of its WRMP may be felt is the effect of its abstraction on important wetland sites. It has therefore considered each wetland site in turn, and used the questions posed in Natural England’s table as a checklist for the significance of effects of its abstractions. In most cases the answers have been provided through the results of the National Environment Programme investigations undertaken by the Company over the past 7 years, in co-operation with the Environment Agency. The second source document that has been used in the preparation of this report is the EA table of indicative sustainability reductions, dated December 2007, to be used for calculating impacts on deployable output.

The resultant environmental impact matrix is appended to this report.

Methodology

Identification of Wetland Sites The sites chosen for scrutiny were those wetland areas, comprising Sites of Special Scientific Interest (SSSIs) and Local Nature Reserves (LNRs) that had been identified in the Company’s statutory drought plan as being likely to be affected by groundwater abstractions. This conforms with Natural England’s stated concern over the possible hydrological impacts of the Company’s Water Resources Management Plan upon wetland sites of conservation interest, particularly SSSIs.

Primarily, but not exclusively, the sites that were chosen are those that had been, or are currently being, investigated through the National Environment Programme (NEP). Under the NEP the Company and its consultants have undertaken desk studies; carried out pumping tests (at maximum licensed output) at nearby sources and monitored the effects; and produced and submitted reports. The scope of the work was agreed in advance by the Environment Agency and Natural England, and the conclusions drawn (in respect of those investigations already completed) were accepted and signed off by both organisations.

All the above sites feature in a table prepared by the Environment Agency in support of their proposals to impose sustainability reductions on the Company’s abstractions. Of all the Cambridge Water sources that had been identified by the Agency as having a possible effect on a wetland site, only one has been assigned an indicative sustainability reduction: this is a clear indication that the environmental impact of the Company’s abstractions is considered to be insignificant.

Options Available for Water Supply All of the water supplied by the Cambridge Water is from underground boreholes. 97% of the Company’s deployable output is abstracted from chalk sources to the south and east of Cambridge, and the remainder from greensand sources. As stated in the introduction to this report, deployable output(1) exceeds the current dry year average daily demand by 40%, which allows flexibility in the way in which sites are operated. Under normal conditions, annual abstraction from individual sources ranges typically from 60% to 90% of licensed capacity and the Company is confident that, under normal conditions, sufficient water remains available for environmental needs.

(The Company’s Drought Plan sets out mitigation measures that will be put into place to conserve supplies for its customers, and the environment, in the event of a drought.)

(1) the deployable output of each of the Company’s sources is derived from the Source Reliable Output Study undertaken in 1997. This study determined the quantity of water available from each of the Company’s sources to satisfy average and peak demands, under severe drought conditions. Deployable output is generally equivalent to licensed output, except where local hydro-geological conditions, or pumping infrastructure limitations, constrain output.

40 Cambridge Water Company Final Water Resources Management Plan

Significant housing growth is planned for the Cambridge sub-region over the next 25 years, which will increase the demand for water. The company has already demonstrated its commitment to managing demand through a number of measures, including: metering initiatives; capital investment in district metering as a means of improving leakage control; and support for improved water efficiency in new dwellings. The Company’s Water Resources Management Plan continues to focus on demand management, but acknowledges that demands are still expected to rise by around 25% by the end of the planning period. The Company will meet this rise in demand from its current licensed abstraction capacity. Pumping from existing sources will increase, but their deployable outputs will not be exceeded.

Climate change is likely to have an effect on supply and demand. Hotter, drier summers, and more frequent drought events, may cause an increase in demand, and the possible impacts of climate change have been built into the Company’s demand forecast. Studies have also been carried out on the effects of climate change on the deployable output (DO) of the Company’s sourceworks: here, the impacts are more uncertain, but a possible loss of between 1% and 5% of total DO (depending on which climate change model is used) is predicted, with 1% being the more realistic figure. An appropriate allowance for uncertainty has been included in the WRMP target headroom calculation.

Risk Screening All the environmental sites chosen for study have been identified on the basis of their dependence on groundwater for maintaining a stable habitat. The screening process adopted has therefore been based on an assessment of:

 the present effects of abstraction (determined from the conclusions of past or ongoing studies where possible)  the magnitude of any future changes in site conditions that may be brought about by increases in abstraction at nearby sources (based on the fact that all future abstractions will be within current licence limits, and within the bounds of the pumping tests carried out under the NEP studies)  the sensitivity of each site to the changes (based on the known biodiversity, identified during the NEP studies or from other published material)

The conclusions for each site are set out below, and summarised in the attached table.

Conclusions

Within the planning horizon of its Water Resources Management Plan the Company’s options for providing a public water supply are limited to groundwater abstractions from the chalk aquifer to the south and east of its supply area. The Company believes it has identified all those sensitive wetland sites where its present and future abstractions could have an environmental impact, and has assessed the significance of those abstractions on the ecology of the sites. The conclusions reached for each site are as follows:

Fowlmere Watercress Beds This SSSI was the subject of an investigation by the Company under the National Environment Programme, which resulted in a voluntary abstraction licence reduction at its nearby Fowlmere source, to help protect the hydrological integrity of the site. However, Natural England has expressed some outstanding concerns regarding water stress in drought conditions, when it appears that the River Rhee compensation scheme, operated by the Environment Agency, might be unable to provide sufficient compensation water. Natural England has been in discussion with the Agency as to how hydrological monitoring of the site can be maintained, to inform any possible future action that might be required.

41 Cambridge Water Company Final Water Resources Management Plan

The NEP investigations carried out in 2002 and 2003 concluded that, at historical annual abstraction rates (which had been, on average, around 40% of annual licensed capacity), there had been a limited impact on groundwater levels within the SSSI. However, increasing the abstraction rate above 60 % of licence began to have a noticeable effect on observed groundwater levels. Based on these findings, the Company agreed to a licence reduction down to 40% of the original value.

From the conclusions of its NEP work, the Company believes its future abstractions, which will not exceed the current annual licence, will have no significant impact on the site under normal conditions. For this reason, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect” and “irreversibility of impact”, which are likely to be high, and “threat to high biodiversity”, which is uncertain. The Company’s overall assessment of the risk to this site is “low”.

Mindful of Natural England’s continuing concerns over this site, the Company supports the case for ongoing monitoring, to better inform decisions on the long-term operation of the Fowlmere source and management of the SSSI.

Thriplow Meadows An NEP investigation is in progress at this SSSI, which consists of a mixture of fen meadow and dry neutral grassland. The fen areas within the SSSI are supported by upward seepage from the underlying aquifer, and a stream channel which runs along the northern boundary. Following concerns over increased groundwater abstraction in the area a sub-irrigation system was installed in the 1980s to support the wetland habitat during dry periods, but it has never worked satisfactorily.

Analysis of data from local observation boreholes was undertaken as part of the NEP desktop studies. The conclusions of the studies were contained in a report published in 2006. A supplementary report, published later that year, suggested a realistic maximum drawdown of up to 0.14m at the site as a result of continuous combined pumping at the annual licensed rate from the Company’s three nearby sources: this was small in comparison with the fluctuations in groundwater levels seen in most years. Permanent infiltration ditches were seen as a possible means of supporting higher levels of soil moisture within the SSSI, mitigating against the potential effects of abstraction, although the impacts of abstraction were considered to be small or possibly even zero.

An options identification and appraisal report is to be completed and submitted to the Environment Agency in Spring 2008.

From the conclusions of its NEP work, the Company believes its future abstractions, which will not exceed the current annual licence, will have no significant impact on the site under normal conditions. For this reason, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect”, which is likely to be high, and “certainty of effect”, irreversibility of impact” and “threat to high biodiversity”, which are uncertain. The Company’s overall assessment of the risk to this site is “low”.

Thriplow Peat Holes This SSSI was not part of the National Environment Programme investigations carried out by the Company. Natural England have concerns that there appear to be water stress issues affecting the habitat, and that a water compensation system, used in tandem with Thriplow Meadows, does not appear to have been successful. Because no detailed investigations have been carried out by Cambridge Water, the risks to the relevant criteria specified in the accompanying table have been scored generally as uncertain, apart from “duration of effect”, which is likely to be high. The Company’s current overall assessment of the risk to this site is “uncertain”: however, the Company is mindful of Natural England’s concerns over apparent

42 Cambridge Water Company Final Water Resources Management Plan

water stress issues affecting the habitat, and will play its full part in any future investigations, and subsequent identification of options for the site.

Dernford Fen It was originally intended that the investigation of this SSSI, as part of the NEP work, would be undertaken in conjunction with Sawston Hall Meadows (below) as both sites are in the same vicinity. However, because of access problems at the latter site, the investigations at Dernford Fen went ahead independently. Test pumping was undertaken in 2003 (and again in 2005, in conjunction with the Sawston Hall Meadows investigations). Analysis of the data suggested a drawdown at the site of around 0.06m as a result of abstractions at licensed rates from nearby Company sources: furthermore, the likelihood of any slight change in plant communities was remote.

The final report recommended that any hydrological rehabilitation scheme should focus on re- directing the spring flows from Nine Wells onto the fen, particularly during dry summer periods, and these proposals will be investigated.

From the conclusions of its NEP work, the Company believes its future abstractions, which will not exceed the current annual licence, will have no significant impact on the site under normal conditions. For this reason, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect”, which is likely to be high, and “certainty of effect”, irreversibility of impact” and “threat to high biodiversity”, which are uncertain. The Company’s overall assessment of the risk to this site is “low”.

Sawston Hall Meadows This SSSI was investigated by the Company under the National Environment Programme. Cambridge Water’s consultants concluded that public water supply abstractions at nearby sources had no significant impact on the wellbeing of vegetation within the site, and that a witnessed decline in plant species was more likely due to poor management. Despite this conclusion Natural England has concerns that the hydrology of the site may still possibly be a contributory factor in its decline. NE has therefore asked the Environment Agency if hydrological monitoring can be continued.

NEP investigations, carried out in 2005, concluded that combined pumping from three nearby Company sources, at full daily licensed quantities, would have resulted in a maximum decline in groundwater level at Sawston Hall Meadows SSSI of about 0.05m. The impact on the vegetation in the SSSI was assessed by consideration of the relationship between groundwater table depth, soil moisture level in the root zone, root zone thickness, and soil type. Even during a theoretical period of zero rainfall from April to September, with high evapotranspiration, the potential impact of a 0.05m drop in groundwater level at the SSSI, no stress on vegetation was predicted.

From the conclusions of its NEP work, the Company believes its future abstractions, which will not exceed the current annual licences, will have no significant impact on the site under normal conditions. For this reason, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect”, which is likely to be high, and “threat to high biodiversity”, which is uncertain. The Company’s overall assessment of the risk to this site is “low”.

Despite the conclusions of the NEP studies, Natural England has concerns over the status of Cambridge Milk Parsley (Selinum carvifolia) at this site. Mindful of NE’s concerns, the Company would be keen to participate in a review of any ongoing monitoring work.

43 Cambridge Water Company Final Water Resources Management Plan

Fulbourn Fen; Wilbraham Fen These sites are situated in the same general locality, east of Cambridge, and both exhibit typical fen characteristics of neutral grassland, fragments of fen woodland, scrub, and open water. Neither site has been the subject of detailed investigation by the Company although, for Fulbourn Fen, studies and proposed actions are being progressed by the Environment Agency through the water level management plan.

On the basis that, at both sites, the Environment Agency’s Lodes Granta groundwater scheme operates to mitigate the impacts of the Company’s abstractions, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect”, which is likely to be high, and “certainty of effect”, irreversibility of impact” and “threat to high biodiversity”, which are uncertain. The Company’s overall assessment of the risk to this site is “low”.

Both of these sites are to be reviewed by the Agency under their ‘Restoring Sustainable Abstraction’ (RSA) programme

East Wretham Heath Among the habitats that make up this SSSI are two areas of open water, Ringmere and Langmere. The Company has a nearby abstraction source at Brettenham, whose licence is partly time-limited. In spite of the fact that the source lies some distance from the meres, the Environment Agency thought it prudent to include a ‘Meres Restriction’ clause in the terms of the original licence: this placed a limit on abstraction when water levels in the meres fell below a certain level. As part of its case for renewing its time-limited Brettenham licence in 2004 the Company compiled an environmental report, based on extensive groundwater modelling work by its consultants, which predicted that the long-term impact on mere levels of pumping from the Brettenham source was insignificant. The conclusions of the report were accepted by the EA, who agreed to an extension of the time-limited licence, and the removal of the ‘Meres Restriction’ clause.

Based on the above conclusions, the Company believes its future abstractions, which will not exceed the current annual licences, will continue to have no significant impact on the site under normal conditions. For this reason, the risks to the criteria specified in the accompanying table have been scored generally as low, apart from “duration of effect”, which is likely to be high, and “threat to high biodiversity”, which is uncertain. The Company’s overall assessment of the risk to this site is “low”.

Alder Carr This SSSI was considered as part of the River Granta investigations (see below), where observed river flow data were analysed to determine the impacts of abstractions on the Alder Carr site. Abstractions from the Linton source were concluded to have an effect on groundwater levels, which could be significant in times of drought. A mitigation scheme was suggested, which would provide compensation water at intervals, from a nearby irrigation borehole, to fill ditches and other low lying areas. The Environment Agency has since advised the Company of an indicative sustainability reduction of 0.03 Ml/d from the Linton source (based on 10 days per year but averaged over a year) to balance the requirements of the irrigation borehole.

Based on the results of the NEP investigations, the risks to the relevant criteria specified in the accompanying table have been scored generally as uncertain or high, in line with the assessment for the River Granta, below. The Company’s current overall assessment of the risk to this site is “significant”, but with the expectation that this will become “insignificant” when the sustainability reductions take effect around 2010.

44 Cambridge Water Company Final Water Resources Management Plan

Nine Wells An NEP investigation is in progress at this site, which has Local Nature Reserve (LNR) status. The site is also the subject of a local Biodiversity Action Plan (BAP). Desk studies have concluded that abstractions from the Company’s Babraham source could have an effect on spring flows at the site, but the magnitude of the effects is uncertain, as there is only a limited amount of spring flow data available. Works have been undertaken to facilitate spring flow measurement, with test pumping at Babraham programmed to take place during 2008. Further actions will depend on the results of the test pumping.

Because of the uncertainty described above, the risks to the relevant criteria specified in the accompanying table have been scored generally as uncertain, apart from “duration of effect”, which is likely to be high. The Company’s current overall assessment of the risk to this site is “uncertain”.

A study funded by Natural England has put forward proposed objectives to restore Nine Wells to a favourable condition, and to use it as a potential translocator receptor site for flatworms. The Company will continue to play its full part in the ongoing investigations and subsequent options identification for the site.

River Granta and Catchment This site, although not an SSSI, is the subject of a Biodiversity Action Plan. In the 1990s the river suffered reduced flows, and drying out of its upper tributaries, with some failures in river water quality. The breeding trout population was thought to be at risk. A river support scheme, operated by the Environment Agency to compensate for the impact of abstraction, was thought not to be fully capable of dealing with the problems of low flows.

A desk study, carried out by the Company in 2004 under the National Environment Programme, was followed by test pumping at a number of nearby sources in 2005. The studies concluded that combined abstraction from the Linton and Rivey Hill sources had a detrimental effect on river flows at periods of low flow, with only partial compensation from the EA’s augmentation scheme. A satisfactory level of flow restoration was not determined, but a licence restriction at Linton, linked to low river flows, was suggested as a possible mitigation measure. The Environment Agency has since advised the Company of an indicative sustainability reduction of 1 Ml/d from the Linton source at times of low flow, to replace the losses reported in the NEP studies.

Based on the results of the NEP investigations, the risks to the relevant criteria specified in the accompanying table have been scored generally as uncertain or high. The Company’s current overall assessment of the risk to this site is “significant”, but with the expectation that this will become “insignificant” when the sustainability reductions take effect around 2010.

* * *

The analysis of significant environmental effects, described in detail above and set out in the accompanying table, demonstrates that the effects of the Company’s abstractions on the biodiversity of important wetland sites are generally of very low significance. For those wetland sites where the impacts have been identified as being uncertain, or of higher significance, or where investigations are continuing, mitigation measures have either been implemented, or are proposed.

45 Cambridge Water Company Final Water Resources Management Plan

In summary, the conclusion of this report is that there are no significant environmental effects arising from the Company’s water resources management plan. In reaching this conclusion, the Company acknowledges the concerns voiced by Natural England in discussions held during the preparation of this report. The Company is also mindful of the Environment Agency’s obligations with regard to biodiversity, which the Agency is promoting through its Restoring Sustainable Abstraction programme and Water Level Management Plans, as well as through the implementation of the Water Framework Directive. Cambridge Water will continue to work with both agencies to understand the impacts of its essential public water supply abstractions on the environment, and to explore ways of minimising those impacts.

Finally, although Cambridge Water currently has no plans to develop new resources, we are happy to confirm that request any future resource development proposals possibly affecting European sites will be subject to a more detailed Habitats Regulations Assessment (HRA) before implementation work begins: this is in acknowledgement of the fact that this plan has not been subject to a specific HRA or a full Strategic Environmental Assessment.

46 Cambridge Water Company Final Water Resources Management Plan

Impact of Cambridge Water Company Abstractions on the Biodiversity of Wetland Sites During the Period of the Water Resources Management Plan

Significance of effect on specified criterion, on a scale of 1 to 3, where

1 = insignificant threat SSSI? projects

2 = uncertain environment duration of effect certainty of effect Natura 2000 site? cumulative effects

3 = highly significant threat to BAP area irreversibilty of impact other designated site? significant contribution to threat to high biodiversity Ramsar Convention site? exacerbate environmental space- or resource-hungry exacerbate existing threats exacerbate space-crowding affect other plans that protect deterioration to critical threshold involve activities already posing a

Site Mitigation

Fowlmere Watercress Beds Abstraction licence at nearby source reduced in 2004 following NEP relic fen habitat on low-lying chalk, 1 1 1 1 3 3 1 1 1 1 2 N/A x x  x investigations. River Rhee compensation scheme (operated by EA) with open shallow water and chalk mitigates effects of CW abstractions grassland Thriplow Meadows species-rich neutral pasture of 1 1 1 2 3 2 1 1 1 1 2 N/A x x  x NEP investigations ongoing: to be completed in 2008 variable drainage characteristics, with many uncommon plants

Thriplow Peat Holes To be reviewed under Restoring Sustainable Abstraction (RSA) remnants of relic fen and alder carr 2 2 1 2 3 2 1 1 1 1 2 N/A x x  x habitats, characteristically rich in programme invertebrate life

Dernford Fen Mitigation works likely to be undertaken as a result of NEP relic of a much larger area of rough 1 1 1 2 3 2 1 1 1 1 2 N/A x x  x fen, ranging from dry grassland to investigations reedbed and alder carr Sawston Hall Meadows NEP investigations concluded that CW abstractions had no adverse relic of wet pasture land, consisting 1 1 1 1 3 1 1 1 1 1 2 N/A x x  x effects on the ecology of the site. To be reviewed under RSA of an area of meadows overlying programme spring-fed peat over chalk

Fulbourn Fen EA Lodes Granta groundwater scheme mitigates effects of CW species rich neutral grassland on 1 1 1 2 3 2 1 1 1 1 2 N/A x x  x calcareous loam and peat, with abstraction. To be reviewed under RSA programme fragments of 'fen' woodland

Wilbraham Fen EA Lodes Granta groundwater scheme mitigates effects of CW large area of fen and neutral 1 1 1 2 3 2 1 1 1 1 2 N/A x x  x grassland with associated scrub abstraction. To be reviewed under RSA programme and open water communities East Wretham Heath Exhaustive investigations by consultants proved no significant effects on area of Breckland grassland, with 1 1 1 1 3 1 1 1 1 1 2 N/A x x  x Breckland Meres from CW abstractions. Findings accepted by EA in two fluctuating meres directly granting extension of time-limited Thetford abstraction licences influenced by chalk groundwater

Alder Carr Reviewed as part of NEP investigations into River Granta (see below). rare example of wet valley 2 2 1 3 3 3 1 1 1 1 2 N/A x x  x alderwood on fen peat, of great To be reviewed again under RSA programme value to invertebrates Nine Wells historically important site containing 2 2 1 2 3 1 1 1 1 1 2 2 x x x  NEP investigations ongoing: to be completed by 2010 several chalk springs: the source of Hobson's Conduit

River Granta and Catchment NEP investigations concluded that nearby abstractions inhibited river a tributary of River Cam. Much of 2 2 1 3 3 3 1 1 1 1 2 2 x x x  flows. Sustainability reductions to be applied. To be reviewed again its flow is made up of groundwater discharges from chalk springs. under RSA programme Supports breeding trout population 47 Cambridge Water Company Final Water Resources Management Plan

Appendix 3 – Sustainable Economic Level of Leakage Assessment

This calculation is included as part of the submission to the Secretary of State, and is available on request to interested parties.

48 Cambridge Water Company Final Water Resources Management Plan

Appendix 4 – Target Headroom Calculation

The assumptions made in the calculation of target headroom are set out on this page. The calculation itself is included as part of part of the submission to the Secretary of State, and is available on request to interested parties.

The 1998 UKWIR Headroom Methodology considers a number of factors which may lead to uncertainty within the supply-demand forecast, and makes an appropriate allowance for that uncertainty, in the form of a target headroom buffer. The factors included in the methodology, and the way in which they have been addressed in the target headroom calculation for the Company’s draft plan, are listed below:

Supply-related factors

Vulnerable surface water licences: the Company has no surface water licences.

Vulnerable groundwater licences: no allowance has been made, as no groundwater licences are thought to be vulnerable.

Time-limited licences: no allowance has been made, as the planning guidance specifically advises against the inclusion of an uncertainty for time-limited licences.

Bulk transfers: there are no bulk transfers into the Company’s area.

Gradual pollution causing a reduction in abstraction: there is no evidence to suggest a reduction in abstraction cause by gradual pollution, and no score has been entered.

Accuracy of supply-side data: the Company has well-documented, accurate records over the last 25 years, and a low score has been calculated.

Single source dominance and critical periods: the Company’s Fleam Dyke source accounts for 13% of water available for use (WAFU). The critical period for the resource zone is the peak week. Both factors contribute to a modest score.

Uncertainty of climate change on yield: Studies show that climate change impacts are expected to be small, but different models predict a range of results. We have used the methodology to address the variation in Water Available for Use (WAFU) forecasts predicted by the two climate change models we have considered.

Demand-related factors

Accuracy of sub-component data: the target headroom score for this factor reflects the range of reliability of the data used by the Company to forecast demand.

Demand forecast variation: the Company considers that its demand forecast tends towards an over-estimate, rather than an under-estimate, with a corresponding low expectation that the forecast will be exceeded.

Uncertainty of climate change on demand: research suggests that the impacts of climate change on demand through the planning period are low, and a low headroom score has been assigned to cover the uncertainty of this assumption.

49 Cambridge Water Company Final Water Resources Management Plan

Appendix 5 – Effects of Climate Change on Supply

The following is the unabbreviated text of a study undertaken by Cambridge Water’s consultants into the possible effects of climate change on the Company’s deployable output.

Potential impacts of climate change on groundwater sources

Abbreviations

The Agency The Environment Agency CWC Cambridge Water Company DAPWL Deepest advisable pumping water level DO Deployable Output ECHAM4/OPYC3 Max Planck Institut fur Meterologie, Germany GCM Global Climate Model HadCM3 Hadley Centre for Climate Prediction and Research, UK non-PWL Non-pumping water level PWS Public water supply SRO Source Reliable Output UKWIR United Kingdom Water Industry Research WRMP Water Resources Management Plan

Introduction

Cambridge Water Company is in the process of producing a Water Resources Management Plan (WRMP). The plan has to include an indicative assessment of the impacts of climate change on the DO of the company’s groundwater abstraction sources. The draft plan should also include a commitment to producing a definitive assessment of impacts on DO, based on a UKWIR methodology and Environment Agency guidelines, if this is appropriate. The definitive assessment might be included in the final WRMP, to be produced in 2009.

A brief study of the impacts of climate change was undertaken for the draft WRMP. The study included the following tasks:

. A review of the general impacts of climate change on groundwater levels and the output of groundwater abstraction sources.

. A brief assessment of all existing SRO reports for Cambridge Water sources. The SRO reports were used to identify sites which might be vulnerable in future droughts, as a result of climate change.

. An assessment of potential changes in DO at the vulnerable sites.

. For one site for which there is no existing SRO assessment (Sawston), brief analysis was undertaken using readily available data for the site.

. Providing recommendations for future work.

Climate change models

Environment Agency guidelines for assessing the impacts of climate change on DO values for groundwater sources are based on methodologies produced by UKWIR 'Effects of Climate Change on River Flows and Groundwater Recharge: A Practical Methodology for Recharge and Groundwater Level Impact Assessment ' (Faherty et al, 2007). The UKWIR methodologies include six different global climate models (GCMs). The GCMs give rise to a

50 Cambridge Water Company Final Water Resources Management Plan considerable range of climate change impacts. Of the six, the following two models are considered particularly relevant to concerns over the impacts of climate change on groundwater conditions:

o The ECHAM4-OPYC3 model produces the greatest negative impacts on recharge and groundwater levels. The impacts result from a general reduction in rainfall and increase in evapotranspiration, leading to reduced recharge and a decline in groundwater levels.

o HadCM3, which represents an approximate median case for the six GCMs. HADCM3 was produced in the UK and is therefore considered particularly applicable to UK conditions. Impacts on recharge and hence groundwater levels are much less severe than for ECHAM4-OPYC3.

Both the ECHAM4-OPYC3 and HADCM3 models indicate reductions in groundwater levels in drought conditions which are generally greater than for historical drought conditions. However, the additional declines in groundwater levels using the ECHAM4-OPYC3 model are much more severe than for the HADCM3 model. The choice of GCM is one of the main sources of uncertainty in predicting future climate change impacts. It should also be noted that some of the models give rise to increased recharge and hence a rise in groundwater levels.

Assessment of impacts on deployable output (DO)

Information already available in the SRO study reports for the CWC PWS sources, produced in 1997 and 1998, was used to make a rapid assessment of sources at which the DO might be affected by climate change. The information used in this exercise comprised mainly:

o The UKWIR Summary Diagrams for Average and Peak Demand.

o The hydrographs for observation boreholes close to the site. The hydrographs were used in the SRO assessments to define drought non-PWLs at the sources.

The summary diagrams were used to determine the critical drought PWL at each PWS source for the average demand and peak demand conditions. An additional decline in groundwater level at each source was allowed for climate change. DO values would be reduced if the additional decline in groundwater level, resulting from climate change, reduces the drought groundwater level below the deepest advisable pumping water level (DAPWL) for the site.

Any reductions in DO values were then calculated. The calculations took into account the effect of the additional decline in groundwater level on drought bounding curves shown on the summary diagrams.

There is no general, easily applied rule relating the additional decline in minimum groundwater levels in drought conditions resulting from climate change, to historical variations in groundwater levels. However, from experience, for the ECHAM4-OPYC3 model, the additional decline in groundwater levels in droughts is generally up to about 50% of the difference between historical drought levels and groundwater levels occurring in more normal years with approximate average recharge conditions. For the HadCM3 model, the equivalent decline is generally up to about 10% of this difference. Therefore, the HadDCM3 model indicates a decline in groundwater levels of about 20% of the decline predicted by the ECHAM4-OPYC3 model.

The decline in groundwater levels indicated for the ECHAM4-OPYC3 model was used in assessing at which PWS sources the DO might be affected by climate change. The reduction in DO was also calculated for the ECHAM4-OPYC3 model. The reduction in overall DO was

51 Cambridge Water Company Final Water Resources Management Plan then assessed for the HadCM3 model to give what should be a more representative indication for UK conditions.

It should be clearly understood that the assessment of how climate change could affect the DO of groundwater sources is very uncertain. In many cases, the existing SROs give only a guide to the reliable output of PWS sources. There are also very substantial uncertainties attached to current assessments of the impact of climate change. Further uncertainties are added in attempting to simplify the impacts of climate change on groundwater levels and then applying these changes to groundwater levels at abstraction sources.

The assessment serves as a screening exercise to determine which sources may be under pressure as a result of climate change. It provides only the broadest indication of what the change in DO might be at these sources.

Results of assessment

The results of the assessment of the impact of climate change on the DO of CWC sources are summarised in Table 1 below:

Table 1: Assessment of PWS sources

Risk Likelihood that PWS sources affected Number group climate change of could reduce DO sources 1 Very unlikely Abington Park, Babraham, Brettenham, 10 Fowlmere, Hinxton Grange, Horseheath, Kingston, Linton, Rivey Hill, Sawston 2 Unlikely Croydon, Duxford Airfield, Euston, Great 6 Wilbraham, Heydon, Lowerfield 3 Possibly not Dullingham, St Ives 2 4 Possible Fleam Dyke 12”, Fulbourn, Morden Grange 3 5 Probable Duxford Grange, Fleam Dyke main site, Great 6 Chishill, Melbourn, Westley, Weston Colville

The following comments on individual sources were noted during the assessment:

o Conditions in the licences for the sources at Fowlmere, Brettenham and Euston indicate that the licensed quantities could change in 2015. However, for the assessment of the impacts of climate change, it was assumed that the licensed quantities would be at the current levels.

o No assessments were undertaken for the sources at Fenstanton, Lord’s Bridge and Sawston Mill. These three sources have been inoperable for some time. Sawston Mill is part of a combined licence with the Hinxton Grange source. The licensed quantities can be abstracted from either Sawston Mill or Hinxton Grange.

o Kingston is a confined Lower Greensand source. It was non-operational at the time of the SRO assessments in 1997/98 and was subsequently assigned DO values (equal to licensed rates) by CWC. Lower Greensand groundwater levels have risen as a result of a general reduction in abstraction over the past few years. Therefore it is assumed the DO will not be affected by climate change.

o There are no PWL data available for St Ives. The source is in river gravels which are presumably well connected to the local drainage in the Great Ouse. Presumably the groundwater storage in the gravels, which is likely to depend on river levels, will not be affected greatly by climate change as the river is unlikely to run dry.

52 Cambridge Water Company Final Water Resources Management Plan

It should also be noted that, regardless of the likelihood of a reduction in DO, the ECHAM4- OPYC3 and HadCM3 models would result in reductions in groundwater levels at all the sources during droughts. The assessment cannot take account of the impacts of increased pumping head or decline in groundwater level below existing pump cut-out levels on the output of borehole pumps. It is assumed that in a drought, operational measures such as lowering pumps or even replacing pumps would be undertaken in order to maintain output.

An assessment for all the CWC sources indicates a possible reduction of up to 5 Ml/d in total DO in both average and peak demand conditions. The assessment was undertaken for the ECHAM4-OPYC3 model. This may represent the maximum loss, taking into account the current understanding of the consequences of climate change. The greatest potential impacts in terms of absolute loss in DO could be at the Fleam Dyke main site, Duxford Grange, Weston Colville, Westley and Melbourn sources.

Based on the general assessment of the impacts of the GCMs, it is reasonable to assume that the impact of the much less severe conditions predicted by the HadCM3 model would produce a reduction in DO of 20% or less of the value predicted for the ECHAM4-OPYC3 model. The assessment of the reduction in total deployable output using the HadCM3 model would therefore be about 1 Ml/d.

As already discussed, the estimates for the reduction in DO give only a broad indication of the actual reduction in DO which might occur.

Recommendations for further work

Environment Agency guidelines and the UKWIR methodology for assessing the impacts of climate change on DO values for groundwater sources provide a framework for assessing the impacts of climate change on groundwater recharge using three different approaches:  GR1 – Based on developing a statistical method that relates antecedent precipitation conditions to minimum annual groundwater levels for each source, to estimate the impacts of climate change on minimum groundwater levels.  GR2 – A spreadsheet model that undertakes lumped calculations of recharge and groundwater level to calculate the impacts of climate change on groundwater levels on a catchment basis. The model is calibrated with observed groundwater level and surface river flow data.  GR3 – An existing regional groundwater model is utilised to assess the impacts of climate change on recharge and groundwater levels.

In the case of the CWC sources, it is unlikely that application of the methods GR1 and GR2 would produce a significantly improved assessment of the potential loss in DO than is provided here. The two methods are only very approximate. However, the Environment Agency is currently developing regional groundwater models covering all the locations of CWC sources. The models should be available for use as predictive tools by 2010. In addition, new climate change models should be available by the end of 2008 from the UK Climate Impacts Programme.

It is recommended that approach GR3 is adopted. CWC could wait until 2010 to use the Agency’s regional groundwater models, together with the new climate change models, to attempt more accurate predictions of the impacts of climate change on DO. The assessment should be done for the PWS sources in risk groups 3, 4 and 5 shown in Table 1. A review of the need for carrying out the assessment for sources in risk groups 1 and 2 should also be done once results are available for groups 3, 4 and 5.

53 Cambridge Water Company Final Water Resources Management Plan

Appendix 6 – Outage Assessment

The full text of the report compiled by Cambridge Water’s consultants following their reassessment of the Company’s outage figure is included as part of the submission to the Secretary of State and is available to interested parties on request.

54 Cambridge Water Company Final Water Resources Management Plan

Appendix 7 – 25 Year Appraisal of Metering Policies

Background

Prior to 1989, virtually all of the Company’s household customers were unmeasured.

1989 saw the introduction of universal metering of all new households. During the 1990s the Company had various domestic metering policies to promote metering unmeasured properties, for example: 1993 – all sprinkler users to be metered; 1995 – free meters for lone pensioners plus those customers affected by mains renewals schemes; 1997 – free meters to pensioner couples; 2000 onwards – free meters for optants.

During the report year 2007-2008 we had achieved 59% household meter penetration. This is compared to the national average of approximately 30%.

Although we do not have a projected supply-demand deficit to address within the next 25 years (as shown in Figure 1 Baseline Forecast, Draft Water Resources Management Plan), we have appraised four different metering policies to understand the resource impacts and costs/benefits of our chosen approach to metering against the available alternatives. Should we be required at a later date to utilise an enhanced metering policy will we will be equipped with an understanding of which would be the most cost effective.

The four policies appraised were:-

1. Free household meter options – Statutory requirement and our stated method of meter penetration increase. 2. Selective non-household metering – Enhanced metering policy 3. Compulsory household metering on change of occupier – Enhanced metering policy. 4. Universal metering households by 2015 - Enhanced metering policy.

Free household meter options Free household meter options have been available as a requirement of the Water Industry Act since 2000. We have seen continued demand for meters since 2000 and despite OFWAT projects of declining optants across AMP4 we have seen the reverse effect. This is shown in Figure A. We have assumed in our plan that 3% of the previous year’s unmetered households will opt to be metered each year.

Fig A – Optant requests vs predicted number of installations.

55 Cambridge Water Company Final Water Resources Management Plan

Selective Non-household metering

In the period 2007-2008 we had just over 10,400 non-households within our supply area. Of which 90% were metered. Unmeasured non-households use an average of 780 litres of water per day (2007-2008 value) compared to an unmeasured household average of 440 litres. Non-household metering therefore potentially has the greatest available water saving per meter installation. The policy appraised is to meter the remaining unmeasured properties in the period 2010-2015.

Compulsory household metering on change of occupier

This option has been available to companies for a number of years; however, Cambridge Water has not previously exercised these rights from the Water Industry Act as a result of the high level of meter penetration already achieved and the continued demand for meter optants.

We see approximately 10,000 changes of occupier on our billing system each year but we anticipate a large amount are due to the student population (we see peaks in September and May, which corresponds with the start and end of the educational year) this means that a single property may change occupier at least once a year and as we have a high level of meter penetration many of the properties will already be metered. We therefore have not assumed that 10,000 meters would be fitted per year under that policy, but that the rate would decline in line with the decrease in unmeasured property penetration. e.g if the measured – unmeasured split was 80%-20% then we have assumed 8000 would be metered property occupier changes and 2000 unmetered. The % was recalculated each year in the analysis and then reapplied to obtain the profile for the subsequent year.

Universal metering by 2015

This is to convert all our current ‘unmeasured’ households to ‘measured’ within a 5 year period. We have assumed that the installation profile would be linear.

Methodology

In order to appraise the four policies we have followed the methodology given in the ‘Economics of Balancing Supply & Demand (EBSD) Guidelines’ report ref 02/WR/27/4, supported by our Cost Benefit Analysis tool developed by WRc.

Utlising standard monetary investment elements and perceived benefits of metering we established a list of the Costs and Benefits of metering. We then identified if those items were quantifiable (Quantifiable is defined as company data available to support, or a recognised calculation methodology exists).

Table 1 Shows the Costs and Benefits identified, whether they are quantifiable and applicable to the various metering policies.

56 Cambridge Water Company Final Water Resources Management Plan

Table 1 – Costs and benefits identified Applicable and included in appraisal Cost Quantifiable Free Selective Compulsory Universal household non- household metering meter household metering on households options metering change of by 2015 occupier Meter installation      Customer service costs of      a metered account. Meter replacement costs      Carbon costs of installation      Social costs      Additional supply pipe   N/A   repair costs Applicable and included in appraisal Benefit Quantifiable Household Selective Compulsory Universal meter non household metering options household metering on households metering occupier by 2015 change Energy saved from reduced pumping as a      result of reduced consumption. Reduced treatment costs      from reduced consumption. Reduced carbon costs from reduced pumping/ treatment energy saved      through reduced consumption. Saved customer service costs of an unmeasured      account. Reduced administration costs of updating business  N/A  N/A N/A rates within our billing system. Energy savings from reduced pumping as a      result of leakage reduction. Reduced treatment costs      from leakage reduction. Reduced carbon costs from reduced pumping/      treatment energy saved through leakage reduction. Water efficiency      improvements Improved water balance      calculation Improved leakage      calculation Facilitation of alternative      tariffs Facilitation of competition      Social – provides a fairer      method of charging

57 Cambridge Water Company Final Water Resources Management Plan

We calculated the potential water savings after implementation, using savings from reduced customer consumption and from leakage reduction as a result of any external metering. There is a large degree of uncertainty within the industry as to the level that metering contributes to the reduction in consumption with values from 5-15% with potentially larger savings at peak times. There are though no definitive conclusions on the effects and so we have assumed a value of 10%. For meter options this equates to 29 l/prop/day. We assume that properties that opt for a meter use approximately 65% of the average unmeasured household total which for 2007-2008 was 440 litres/property/day. For compulsory meter policies a 10% reduction from the average is assumed i.e. 44 litres/property/day.

For reduced leakage we have taken the difference between our estimated supply pipe leakage from an unmeasured property (36 l/prop/day) and an externally metered property (18 l/prop/day). This has been applied only to externally metered properties as our normal preferred installation location is internal and we currently install at 70:30 ratio internal to external meters on meter option.

Table 2 shows the calculated water savings annually across the 25 year period.

Table 2 – Annual water savings m3

Free household Selective non- Compulsory household Universal meter optants household metering metering on change of household by occupier 2015

Year 1 0 0 0 0 Year 2 2582 848 66614 159466 Year 3 5085 2050 126117 318932 Year 4 7510 3252 180210 478398 Year 5 9855 4454 228893 637883 Year 6 12141 5657 273971 797367 Year 7 14349 5657 313639 797367 Year 8 16497 5657 349701 797367 Year 9 18567 5657 383960 797367 Year 10 20577 5657 414613 797367 Year 11 22529 5657 441659 797367 Year 12 24421 5657 466903 797367 Year 13 26254 5657 490343 797367 Year 14 28028 5657 511980 797367 Year 15 29742 5657 531814 797367 Year 16 31418 5657 549845 797367 Year 17 33034 5657 566073 797367 Year 18 34591 5657 580498 797367 Year 19 36109 5657 594923 797367 Year 20 37587 5657 607544 797367 Year 21 39006 5657 620166 797367 Year 22 40386 5657 630985 797367 Year 23 41726 5657 641803 797367 Year 24 43027 5657 650819 797367 Year 25 44288 5657 659834 797367

58 Cambridge Water Company Final Water Resources Management Plan

We have quantified the costs and benefits where able in line with table 1 for each option. Table 3 shows the total 25 year costs for each element.

Table 3 – Total values of costs and benefits.

Free Selective Compulsory Universal household non- household household meter household metering on metering by optants metering change of 2015 occupier

Number of meters to be installed 23,090 860 37,094 44,222 Total installation costs (£ 000's) 6,001 446 10,568 12,599 Total metered account operating costs (£ 000's) 1,357 85 2,607 4,203 Total meter replacement cost (£ 000's) 2,377 179 5,093 9,195 Total carbon cost (£ 000's) 33 2 51 54 Total social costs (£ 000's) 231 9 371 442 Total additional supply pipe repairs cost (£ 000's) 104 0 206 332 Total energy saving benefit (£ 000's) 138 20 265 428 Total nitrate treatment savings benefit (£ 000's) 87 12 167 267 Total carbon benefit (£ 000's) 61 8 116 181 Total reduced unmeasured account operating benefit (£ 000's) 792 50 1,521 2,452 Total Administration savings of updating business service charges (£ 000's) 0550 0

The annual yield, costs and benefits were input into our WRc developed CBA model. This model using a 6.5% Cost of capital discount rate calculates the Net Present Values summarised in table 4.

Table 4 – NPV of Yield and cost/benefits

Free Selective non- Compulsory Universal household household household household meter optants metering metering on metering by change of 2015 occupier NPV of Yield (Ml/d) 5.44 0.86 15.82 28.34 NPV of Costs (£ 000's) 5,570 548 11,537 19,325

This then allows us to calculate the Average Incremental Social Cost (AISC) for each policy.

Results

Free Selective non- Compulsory Universal household household household household meter optants metering metering on metering by change of 2015 occupier AISC (p/m3) 280.52 174.68 199.81 186.82 59 Cambridge Water Company Final Water Resources Management Plan

Conclusions

As can be seen from table 4 selective metering of non–households offers the lowest AISC of the four policies and a policy of metering on change of occupier the highest. This was to be anticipated as the savings in water are greater for metering non-households above households but the costs are not proportionally larger. If a compulsory policy were to be selected for households the universal metering of all households is shown to be the most cost effective option.

Discussions

As a demand management tool metering has a part to play. Cambridge Water has already realized a large proportion of the initial benefits of metering in reduced consumption as a result of its metering policies to date. In our current supply demand forecasts we are not required to establish a more aggressive stance to metering to control any possible deficit with the next 25years. Therefore we can let the meter penetration grow organically in the period to the anticipated 88% by 2035 without having to place an immediate increased pressure on consumer’s bills to fund such a stance. There are also other methods to affect demand that could provide more cost effective management e.g. water efficiency measures that could also be considered as an alternative to metering.

There are a number of uncertainties particularly climate change that could affect this position and as a result we are committed to continually evaluating our strategy to ensure that we acting in the best interests of all stakeholders.