Dŵr Cymru Welsh Water
Draft Water Resource Management Plan 2013
EXECUTIVE REPORT
Dŵr Cymru Welsh Water Pentwyn Road, Nelson, Treharris Mid Glamorgan CF46 6LY www.dwrcymru.com Dŵr Cymru Cyfyngedig, is a limited company registered in Wales No. 2366777
Page | i Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Preface
One of our most important functions is to maintain safe and reliable supplies of drinking water to our customers. We do this by looking ahead to gauge the effects of climate change and the likely future demands of our domestic and business customers alike, whilst balancing these against the water available for supply, even in the driest years. In recognition of how important this is for our customers, we publish a Water Resources Management Plan (WRMP) which describes how we will manage and develop our available water resources every 5 years.
This document is Dŵr Cymru Welsh Water’s draft Water Resource Management Plan covering the period 2015 to 2040. It describes how we intend to maintain water supplies for all of our 1.3 million domestic and 110,000 business customers in Wales and those adjoining parts of England.
We want our customers to receive a safe and reliable service which meets all their expectations, at a price they can afford. It is therefore important to us that our stakeholders and customers are involved in the key decisions affecting how we should achieve that goal. We want your views on whether our Plan reflects the appropriate balance between the financial, social and environmental costs of the options open to us in maintaining water supplies into the future. Indeed we would welcome comments on any aspect of our Plan.
Given the importance of the Plan, your comments should be sent in the first instance to the Welsh Government, who will then pass them on to us. Comments should be sent by email or post to the Welsh Government at either of the following addresses:
By post to: By email to: [email protected] Water Branch Water Resource Management Plans Consultation Welsh Government Cathays Park Cardiff CF10 3NQ
It would be helpful if the subject title of your email or letter included the words “Representation on Dŵr Cymru Welsh Water’s draft WRMP”. After receiving all your comments we will publish a ‘Statement of Response’ which will outline how we will take your comments into account in our final Water Resource Management Plan which we hope to publish by December 2013.
The issues covered in our Plan will have a fundamental impact on our ability to maintain water supplies to our customers at an affordable price in the years ahead, while minimising our impact on Wales’s high quality water environment. I urge you to contribute to the debate and so help us make the right choices.
Tony Harrington Director of Environment Dŵr Cymru Welsh Water
Page | ii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Executive Summary Introduction
One of our most important responsibilities, as provided for under the Water Industry Act 1991, is to ensure that Dŵr Cymru Welsh Water can always meet the reasonable water needs of our customers now and into the future. We produce an updated Water Resources Management Plan (WRMP) every five years which demonstrates how we will balance the supply and the demand for water from our customers over the subsequent 25 years. As part of this process we are publishing this draft WRMP for public consultation. When this consultation process is complete we will submit our final Plan to the Welsh Government together with any modifications made, in the light of the comments received. Once directed by the Welsh Government thereafter, our Plan will be published and will come into effect on 1 April 2015.
This draft WRMP covers the period up to 2040, and follows the guidance set out by the Welsh Government for such Plans. Our aim is to maintain water supply as efficiently as possible in each of the 24 Water Resource Zones (WRZ) we operate, so that water bills are no higher than they need to be, and the impact on our environment is both understood and minimised.
In order to develop the Plan, we have projected the future demand for water from our domestic and business customers in each WRZ and we have calculated how much will be available from current sources. Where there is a shortfall, we have looked at all the ways of increasing supply and/or reducing demand, such as improving water efficiency to save water, to arrive at the best overall package of solutions for our customers, the economy and the environment.
Over the last 20 years or so the quantity of water we supply to our customers has reduced in a ‘normal’ year from an average of over 1000 million litres per day (Ml/d) to about 800 Ml/day today, with about half of this reduction down to reduced leakage the rest due to reduced demand from heavy industry.
Wales has plenty of rain: we estimate that Dŵr Cymru Welsh Water’s infrastructure captures only some 3% of the effective rainfall, leaving some 97% for the environment, compared to the South East of England where up to 50% is used for public water supply. Our supplies are almost entirely made up from upland reservoir and river sources, which are inherently ‘flashy’ and can both dry out and refill in a few months when compared to those ground water sources in England which typically drain slower but also take longer to refill. On the face of it then, we should not have a water resources problem in Wales. However, during this time the requirements of a variety of new environmental obligations, such as the European Water Framework Directive and the Habitats Directive have driven new and much tighter environmental standards which effectively require this water to be left in our rivers for the environment. These Directives have required the Environment Agency (now Natural Resources Wales – NRW) to reassess the impacts of our abstractions in a process known as the ‘Review of Consents’. To protect the environment and ensure compliance with these Directives, Natural Resources Wales has to make sure that all abstractions, including non water company abstractions, do not adversely impact on the environment, including specific protected plant and animal species.
Over this period we have also gained a much better understanding of climate change, our environment, our assets and our own ability to meet customer demands going forward. The effect of
Page | iii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
the Agency’s review and our better understanding essentially reduces available water at peak demand times in a dry year 1; it does not significantly affect the amount of water we have available in a normal year.
This Plan forecasts demand for water from our customers over the coming 25 years based on the Welsh Government and local authority projections of population and development growth. This assumes no major upturn in the demand for water from heavy industry, other than a small number of specific developments such as the Wylfa B Nuclear Power station proposals. We are reviewing our forecasts for industrial and commercial demand in light of the latest data available and specifically how we anticipate this will change over the next few years in particular. We have included both the possible demands of Wylfa B and industrial demand scenarios which illustrate a range of outcomes for sustainable development in this Plan. If during the consultation period for this Plan better data becomes available for either of these matters, we will notify the Welsh Government and issue an addendum to the Plan if required. We will reflect these findings within our final Plan to ensure that this contains the best and most up to data available.
Taking all these changes into effect is what our WRMP does, with the overall aim of guaranteeing to our customers that the frequency of water restrictions are not more than once in every 20 years on average, for a temporary use ban, and not more than once every 40 years on average, for Drought Orders/Permits. The approach we adopt is conservative so as to ensure we can continue to supply our customers in the driest of years whilst at the same time minimising our impact on the environment.
In summary, our Plan assesses our capability to continue to meet customers’ demand in an extreme set of circumstances, and assesses where we could have shortfalls over the next 25 years.
Significant issues affecting the Plan
In preparing this Plan we have taken account of a range of issues, however there are two particularly significant issues which impact on water resource availability. These are:
Most impactful of all, is the result of Natural Resources Wales ‘Review of Consents’ exercise, undertaken in the light of the European Habitats Directive. A significant feature of this process is that, at designated sites, the ‘precautionary principle’ is applied, so a potential adverse impact of abstraction is presumed unless evidence is available to the contrary, which typically is not the case; and
Secondly, (but less impactful) an updated assessment of the possible impact of climate change on the water environment in Wales, as set out in the latest UK Climate Change Projections published in 2009 (“UKCP09”), which may both reduce the amount of water we have available to supply, and increase demand from our customers.
Together, these two requirements significantly reduce, or eliminate, our water resource surpluses in some zones, even creating deficits that could require significant investment to address.
Natural Resources Wales’s ‘Review of Consents’ process will reduce our Deployable Output (DO) - the water we can make available to customers - in the water resource zone which supplies the South East
1 A “Dry Year” is defined as a year that is characterised by low rainfall and unconstrained demand. The Dry Years that we have experienced and which are incorporated in our modelling include 1976, 1984, and, for some zones, 2003.
Page | iv Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Wales Conjunctive Use System (SEWCUS) by more than 26 Ml/d alone, the equivalent water required to serve over 72,000 homes. SEWCUS represents almost 44% of our customer base, and as can be seen from the figure below which illustrates the deployable output changes included in this Plan, is significantly impacted by the ‘Review of Consents’ (RoC). Accounting for the potential future impact of climate change on the other hand does not impact our water resources significantly other than in Pembrokeshire and those WRZs which supply customers in North Wales. More generally, the resultant tightening of our water resource position means that surpluses that we currently have cannot be regarded as being available to support long term sustainable development in the South East of Wales in particular.
We have taken advice from a wide range of stakeholders in the assessment of these abstraction licence reductions, many of whom are of the view that there is a better way to meet the requirements of the Habitats Directive, whilst ensuring water remains available for sustainable development. To substantiate this case to the Welsh Government we have commenced comprehensive environmental studies, in partnership with a range of stakeholders such as the Canal and Rivers Trust, Wye and Usk Foundation and Natural Resources Wales, in relation to those rivers affected by the Review of Consents, namely the Rivers Wye, Usk, and Cleddau.
These studies have the additional benefit of making it clear what other measures are required, such as improvements to land management, farming practices, the construction of fish passes to allow the migration of salmon and other migratory species to improve further the general health of these rivers. These changes in time will assist meeting the requirements of other EU Directives such as the Water Framework Directive, all of which will be required by 2027. As with all ecological studies, they will need to be undertaken over a number of years before we have sufficient evidence to support any alternative abstraction regimes. Our studies are supported by academia, and will be published and peer reviewed when complete.
To deal with the impact of the Habitats Directive which must have measures agreed and within our abstraction licences to protect those rivers designated as ‘Special Areas of Conservation’ (SACs) by December 2015. This Plan therefore:
Proposes to continue our comprehensive environmental studies to at least December 2015 and to use the results to inform our new regulator, Natural Resources Wales of whatever options may or may not exist for licence changes at that time.
Page | v Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Sets out the investments required to support the Plan, and specifically those required to allow any reductions in our abstraction licences, such that they can be included in our future business planning. These come to £9m of capital investment with an associated annual running cost of up to £0.5m. Further investment in excess of £20m will also be required to improve our water infrastructure so as maintain water quality under the differing abstraction regimes, and to meet the detailed requirements of the licences. These will be included once finalised later this year in our regulatory price review proposals for 2015-20, known as PR14. These proposals feed into Asset Management Plan (AMP) 6 for the period 2015-20.
Confirms that we will not accept or reject any abstraction licence changes until this consultation process is completed.
Confirms that given the impact of any changes to our abstraction licences, such decisions in our view should be supported by the best possible science and should take into consideration the views of customers as well as those of our regulators including Natural Resources Wales, the Water Services Regulation Authority (‘Ofwat’) and the Consumer Council for Water etc. .
Confirms that before the publication of the final Plan towards the end of 2013, we will review the licence position in the light of comments received, Ministerial directions, and other parallel discussions with Natural Resources Wales and the Welsh Government on balancing the various investment pressures we are facing during 2015-2020.
The licence amendments driven by the Habitats Directive require a change in the way we operate our water supply systems during critical dry years and drive investment in new water resources. These new operating regimes present a risk, including the impact upon the raw (i.e. pre treatment) and final quality of the drinking water we supply in relevant zones. Dŵr Cymru Welsh Water’s top priority must be to ensure that our drinking water supplies continue to comply with the stringent statutory standards set by the Welsh Government and policed by the Drinking Water Inspectorate. We must mitigate against these risks prior to agreeing these abstraction changes. We must also ensure that the operation of our SEWCUS water supply system in particular is resilient during critical dry year events and that we are able to maximise the water that is available for abstraction into the future.
From our pre-consultation discussions with Severn Trent Water, we are also aware that our proposals to increase flows from our reservoirs into the River Wye for abstraction downstream impact on those resources we share with them. This means that our proposals may need to be delayed to allow Severn Trent Water to put in place the infrastructure needed to supply their customers during a dry year. To this end, we will maintain an active dialogue with our regulators and Severn Trent Water following the publication of both our Plans, over the timing of licence changes on the River Wye.
This timescale will also allow us to complete our comprehensive environmental survey work and confirm or otherwise the effectiveness of the proposed licence reductions upon river ecology and what, if any, other abstraction regimes might be accommodated which are both environmentally protective, but would allow Dŵr Cymru to retain a sufficient surplus so that we can support sustainable development.
Our Plan summarised
Page | vi Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The draft WRMP (dWRMP) 2013 will be compliant with latest Defra, the Welsh Government, Natural Resources Wales, and Ofwat Guidance, which has been developed in partnership with the water industry. This guidance has driven a number of improvements in the way in which we measure, model, and understand the operation of our catchments, the impact of climate change, and our forecasting of future demand.
We believe compliance with the Habitats Directive can be achieved as we highlighted in our 2012 WRMP, with licence amendments in the SEWCUS zone and those in Pembrokeshire in place in 2015 as required by the Habitats Directive but not taking effect until April 2018 - after we have completed our comprehensive environmental study work. This would also allow us to establish what, if any, other abstraction regimes can be accommodated which are environmentally protective, and we hope allow a significant surplus to be retained so as to support sustainable development. We will also have to take account of the timescale put forward by Severn Trent Water for licence changes on the River Wye, as these should be enacted together.
This balanced and progressive approach also supports the need for further detailed work during 2015-2020, on the way that SEWCUS will be operated to make sure that there is no drinking water quality or other issues which may arise by such radical changes. SEWCUS retains a marginal surplus of approximately 5 Ml/d in 2015, less than 1% of its deployable output. Significant resilience investment will be required during 2015-2020 to ensure we are able and confident to maintain the quality and quantity of supply throughout the zone that our customers currently enjoy.
The results of this much improved assessment confirm that, of our 24 water resource zones, six are now forecast to be in potential supply demand deficit over the planning period to 2040, as depicted by the red areas in the figure below. The purple colour denotes WRZs which have a marginal surplus in the supply demand balance (SDB).
Page | vii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
For Pembrokeshire, where the deficit has been driven by the potential impacts of climate change and the significant impact of the ‘Review of Consents’, we are proposing to continue with our environmental study work which will further illuminate the level of licence reductions that might be required on the Eastern Cleddau. If our studies do not enable us to arrive at an abstraction position which is cost neutral, then we will invest in a network scheme to connect the area impacted by licence reductions to areas with surplus water. After 2028 we will also need to import water from the adjacent Tywi Conjunctive Use System (CUS, also known as Tywi Gower WRZ) and carry out further leakage reduction to maintain a supply demand surplus.
In the Brecon Portis water resource zone, Habitats Directive driven reductions on the River Usk will constrain our abstractions from the Brecon groundwater source reducing the source output. We have developed a new water resource model for the zone. The modelled simulation of the supply system has improved the accuracy of the zonal deployable output given network constraints and that from the licence reduction. The demand forecast for the zone has also been revised taking account of an improved supply demand balance across the zone. As a result we plan to supplement the available flow in the river Usk with additional releases from the Usk reservoir, when required. There will also be a need to make marginal improvements to the connectivity within the zone which will allow not only an increase in the utilisation of the Brecon source at times of peak demand but also improve system resilience between the Portis and Brecon Water Treatment Works (WTW).
In Bala, where the deficit has been driven by an improved understanding of existing demand and its forecasting to 2040, we are proposing to implement increased leakage reduction to overcome the marginal supply demand deficit.
In South Meirionnydd, there is also a small supply demand deficit driven by an improved understanding of existing demand and its forecasting to 2040. We are proposing to implement demand management measures including the retrofitting of household water efficiency devices to overcome the marginal supply demand deficit.
In North Eryri Ynys Môn, a deficit in 2023/24 is driven by a combination of an improved understanding of forecast demand and also the potential impacts of climate change. At this time, we plan to rezone water from a treatment works in the south of the area, and in addition to transfer water from a currently mothballed river abstraction in Snowdonia to a nearby WTW. We also plan to undertake improvements to reduce leakage.
In Tywyn Aberdyfi, the deficit has been driven by the combined potential impact of climate change and an improved demand forecast to 2040. We are proposing to transfer raw water from a new river abstraction in South Meirionnydd and transfer this water to a treatment works which has existing spare capacity, thus maximising the use of this existing asset. Further treatment capacity will be required later in the planning period which will involve the construction of a new WTW.
In summary the impacts of the Habitats Directive and climate change will drive significant changes to the way we treat and supply water to our customers. We have identified in this plan the detailed impacts and the best way of dealing with these in each of our water resource zones. The cost of such
Page | viii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
investments must be weighed against those which we will not be able to afford as a result, such as to reduce sewer flooding to the extent we would otherwise wish. The impacts of environmental pressures on society and the economy must also be properly understood and any decisions made by our Regulators, the Welsh Government or ourselves should be based on sound evidence, in a transparent manner. This Plan supports exactly that.
Page | ix Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Crynodeb Gweithredol Cyflwyniad
Un o’n cyfrifoldebau pwysicaf, yn unol â darpariaethau Deddf y Diwydiant Dŵr 1991, yw sicrhau bod Dŵr Cymru Welsh Water yn gallu diwallu anghenion rhesymol ein cwsmeriaid am ddŵr bob amser, yn awr ac i’r dyfodol. Rydym yn diweddaru ein Cynllun Rheoli Adnoddau Dŵr (CRhAD) bob pum mlynedd er mwyn dangos sut y byddwn yn cydbwyso’r cyflenwad dŵr sydd gennym a’r galw am ddŵr gan ein cwsmeriaid dros y 25 mlynedd dilynol. Fel rhan o’r broses hon, rydym yn cyhoeddi’r CRhAD drafft hwn ar gyfer ymgynghori â’r cyhoedd. Pan fydd y broses ymgynghori hon wedi’i chwblhau, byddwn yn cyflwyno ein Cynllun terfynol i Lywodraeth Cymru gydag unrhyw addasiadau a wnaed yng ngoleuni’r sylwadau a dderbyniwyd. Pan gawn gyfarwyddyd gan Lywodraeth Cymru wedi hynny, fe gyhoeddir ein Cynllun ac fe ddaw i rym ar 1 Ebrill 2015.
Mae’r CRhAD drafft hwn yn cynnwys y cyfnod hyd at 2040 ac mae’n dilyn y canllawiau a bennwyd gan Lywodraeth Cymru ar gyfer Cynlluniau o’r fath. Ein nod yw cynnal y cyflenwad dŵr mewn ffordd mor effeithlon ag y bo modd ym mhob un o’n 24 Parth Adnoddau Dŵr (WRZ), fel nad yw’r biliau dŵr yn uwch nag sydd raid a bod yr effaith ar ein hamgylchedd yn cael ei deall a’i lleihau.
Er mwyn datblygu’r Cynllun, rydym wedi rhagamcanu’r galw disgwyliedig am ddŵr gan ein cwsmeriaid domestig a busnes ym mhob Parth Adnoddau Dŵr ac wedi cyfrifo faint o ddŵr fydd ar gael o’n ffynonellau presennol. Lle ceir prinder, rydym wedi edrych ar yr holl ffyrdd o gynyddu’r cyflenwad a/neu leihau’r galw, e.e. defnyddio dŵr yn fwy effeithlon er mwyn ei arbed, fel y gellir sichrau’n pecyn gorau o atebion ar gyfer ein cwsmeriaid, yr economi a’r amgylchedd.
Ers rhyw 20 mlynedd, mae swm y dŵr yr ydym yn ei gyflenwi i’n cwsmeriaid wedi gostwng mewn blwyddyn ‘normal’ o dros 1000 miliwn litr y dydd (Ml/d) ar gyfartaledd i tua 800 Ml/d heddiw. Y ffaith bod llai’n cael ei golli trwy ollyngiadau sy’n gyfrifol am tua hanner y gostyngiad a llai o alw gan ddiwydiant trwm sy’n gyfrifol am y gweddill.
Mae Cymru’n cael digon o law: rydym yn amcangyfrif mai dim ond tua 3% o’r glawiad effeithiol y mae seilwaith Dŵr Cymru Welsh Water yn ei ddal, sy’n golygu bod tua 97% ar ôl ar gyfer yr amgylchedd, o’i chymharu â’r sefyllfa yn Ne Ddwyrain Lloegr lle mae hyd at 50% yn cael ei ddefnyddio ar gyfer y cyflenwad dŵr cyhoeddus. Daw ein cyflenwadau ni bron i gyd o gronfeydd dŵr mewn tir uchel ac afonydd. Mae’r rhain yn eu hanfod yn anwadal a gallant sychu ac ail-lenwi mewn ychydig fisoedd, yn wahanol i ffynonellau dŵr daear yn Lloegr sydd, fel rheol, yn cymryd mwy o amser i ddraenio ac i ail- lenwi. Ar yr wyneb felly, ni ddylai diffyg adnoddau dŵr fod yn broblem yng Nghymru. Fodd bynnag, yn ystod y cyfnod hwn, mae gofynion nifer o wahanol ofynion amgylcheddol, fel y Gyfarwyddeb Fframwaith Dŵr Ewropeaidd a’r Gyfarwyddeb Cynefinoedd wedi arwain at safonau amgylcheddol newydd, llymach o lawer, sydd mewn gwirionedd yn mynnu bod y dŵr hwn yn cael ei adael yn ein hafonydd ar gyfer yr amgylchedd. O dan y Cyfarwyddebau hyn, mae Asiantaeth yr Amgylchedd (Cyfoeth Naturiol Cymru erbyn hyn) wedi gorfod ailasesu effeithiau ein trefniadau tynnu dŵr mewn proses a elwir yn ‘Adolygiad o Ganiatadau’. Er mwyn gwarchod yr amgylchedd a sicrhau y cydymffurfir â’r Cyfarwyddebau hyn, mae’n rhaid i Cyfoeth Naturiol Cymru ofalu nad yw cynlluniau tynnu dŵr, gan gwmnïau dŵr ac eraill, yn amharu ar yr amgylchedd, yn cynnwys rhywogaethau o blanhigion ac anifeiliaid sy’n cael eu gwarchod yn benodol.
Page | x Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Dros y cyfnod hwn, rydym hefyd wedi dod i ddeall newid yn yr hinsawdd, ein hamgylchedd, ein hasedau a’n gallu ni i ateb y galw gan gwsmeriaid i’r dyfodol, yn well o lawer. Mae effaith adolygiad yr Asiantaeth a’r ffaith fod gennym ni ddealltwriaeth well yn golygu, yn y bôn, bod llai o ddŵr ar gael ar adegau o alw mawr mewn blwyddyn sych2; ond nid yw’n cael effaith arwyddocaol ar swm y dŵr sydd ar gael i ni mewn blwyddyn arferol.
Mae’r Cynllun hwn yn rhagweld y galw am ddŵr gan ein cwsmeriaid dros y 25 mlynedd nesaf ar sail rhagolygon Llywodraeth Cymru ac awdurdodau lleol ynghylch twf yn y boblogaeth a datblygiadau. Mae hyn yn tybio na fydd cynnydd mawr yn y galw am ddŵr gan ddiwydiant trwm, ac eithrio nifer fechan o ddatblygiadau penodol fel y cynlluniau ar gyfer atomfa Wylfa B. Rydym yn adolygu ein rhagolygon ar gyfer y galw diwydiannol a masnachol yng ngoleuni’r data diweddaraf sydd ar gael ac, yn benodol, sut y disgwyliwn i hyn newid dros y blynyddoedd nesaf. Rydym wedi cynnwys y galw posibl gan Wylfa B a senarios posibl ynghylch galw diwydiannol yn y Cynllun hwn ac mae hynny’n dangos nifer o ganlyniadau posibl o ran datblygu cynaliadwy. Os daw data gwell ar gyfer y naill neu’r llall o’r materion hyn i’r fei yn ystod cyfnod ymgynghori’r Cynllun hwn, byddwn yn hysbysu Llywodraeth Cymru ac yn cyhoeddi atodiad i’r Cynllun os bydd angen. Byddwn yn adlewyrchu’r canfyddiadau hyn yn ein Cynllun terfynol er mwyn sicrhau ei fod yn cynnwys y data gorau a diweddaraf sydd ar gael.
Mae ein Cynllun Rheoli Adnoddau Dŵr yn cymryd yr holl newidiadau hyn i ystyriaeth a’r nod cyffredinol yw sicrhau ein cwsmeriaid na cheir gwaharddiad dros dro ar ddefnyddio dŵr fwy nag unwaith mewn 20 mlynedd ar gyfartaledd ac na cheir Gorchmynion/Trwyddedau Sychder fwy nag unwaith ym mhob 40 mlynedd. Rydym yn cymryd agwedd geidwadol er mwyn sicrhau y gallwn barhau i gyflenwi dŵr i’n cwsmeriaid yn y blynyddoedd sychaf ac, ar yr un pryd, amharu cyn lleied ag y bo modd ar yr amgylchedd.
I grynhoi, mae ein Cynllun yn asesu ein gallu i barhau i ateb galw cwsmeriaid mewn set o amgylchiadau eithriadol, ac mae’n asesu lle y gallem gael prinder dŵr dros y 25 mlynedd nesaf.
Materion arwyddocaol sy’n effeithio ar y Cynllun
Wrth baratoi’r Cynllun hwn, rydym wedi talu sylw i nifer o faterion ond mae dau fater arbennig o arwyddocaol sy’n effeithio ar faint o adnoddau dŵr sydd ar gael, sef:
Yr hyn a gaiff yr effaith fwyaf yw canlyniadau ymarferiad ‘Adolygiad o Ganiatadau’ Cyfoeth Naturiol Cymru a gynhelir yng ngoleuni Cyfarwyddeb Cynefinoedd yr Undeb Ewropeaidd. Un o nodweddion arwyddocaol y broses yw ei bod yn golygu dilyn ‘egwyddor ragofalus’ ar safleoedd dynodedig, ac felly tybir y byddai tynnu dŵr yn gallu cael effaith niweidiol os na cheir tystiolaeth i ddangos yn wahanol, ac fel rheol nid oes tystiolaeth felly; ac
Yn ail, (ond gyda llai o effaith), asesiad diwygiedig o effaith bosibl newid yn yr hinsawdd ar yr amgylchedd dyfrol yng Nghymru, fel y’i nodir yn Rhagamcanion Newid Hinsawdd diweddaraf y DU a gyhoeddwyd yn 2009 (“UKCP09”), a allai olygu bod gennym lai o ddŵr i’w gyflenwi a bod mwy o alw gan gwsmeriaid.
2 Diffinnir “Blwyddyn Sych” fel blwyddyn pryd y ceir glawiad isel a galw heb gyfyngiadau. Ymhlith y Blynyddoedd Sych yr ydym wedi’u cael ac sydd wedi’u cynnwys yn ein model mae 1976, 1984, ac, ar gyfer rhai parthau, 2003.
Page | xi Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Gallai’r ddau ofyniad hyn, gyda’i gilydd, olygu bod gennym lai o lawer o adnoddau dŵr dros ben, os o gwbl, mewn rhai parthau ac y gallai fod prinder dŵr, hyd yn oed, gan alw am fuddsoddiad sylweddol.
Bydd proses ‘Adolygiad o Ganiatadau’ Cyfoeth Naturiol Cymru yn golygu bod gennym dros 26 Ml/d yn llai o Gynnyrch Defnyddiadwy (Deployable Output (DO)) - sef y dŵr y gallwn drefnu ei fod ar gael i gwsmeriaid - yn y parth adnoddau dŵr sy’n cyflenwi System Defnydd Cysylltiol De Ddwyrain Cymru (‘SEWCUS’) yn unig, sef swm cyfatebol i’r dŵr sy’n angenrheidiol i wasanaethu dros 72,000 o gartrefi. Mae bron 44% o’n sylfaen gwsmeriaid yn SEWCUS ac, fel y gwelir o’r ffigur isod sy’n dangos y newidiadau yn y cynnyrch defnyddiadwy a gaiff eu cynnwys yn y Cynllun hwn, mae’r ‘Adolygiad o Ganiatadau’ (RoC) yn effeithio’n sylweddol arni. Ar y llaw arall, dim ond yn Sir Benfro a’r Parthau Adnoddau Dŵr sy’n cyflenwi cwsmeriaid yng Ngogledd Cymru y mae effaith bosibl newid hinsawdd yn y dyfodol yn effeithio’n sylweddol ar ein hadnoddau dŵr. Yn fwy cyffredinol, mae’r ffaith bod hyn yn tynhau ein sefyllfa o ran adnoddau dŵr yn golygu na allwn gymryd yn ganiataol y bydd gennym ddigon o ddŵr wrth gefn, fel sydd gennym yn awr, i gynnal datblygu cynaliadwy hirdymor yn Ne Ddwyrain Cymru yn neilltuol.
Rydym wedi cymryd cyngor gan nifer o wahanol randdeiliaid wrth asesu’r cynlluniau i ostwng swm y dŵr y caniateir ei dynnu o dan drwyddedau ac mae llawer ohonynt o’r farn bod gwell ffordd o fodloni gofynion y Gyfarwyddeb Cynefinoedd gan sicrhau, ar yr un pryd, bod digon o ddŵr ar gael ar gyfer datblygu cynaliadwy. I gadarnhau’r achos hwn wrth Lywodraeth Cymru, rydym wedi cychwyn astudiaethau amgylcheddol cynhwysfawr, mewn partneriaeth â nifer o randdeiliaid fel Ymddiriedolaeth y Camlesi a’r Afonydd, Sefydliad Gwy a Wysg a Cyfoeth Naturiol Cymru, mewn perthynas â’r afonydd y mae’r ‘Adolygiad o Ganiatadau’ yn effeithio arnynt, sef Afonydd Gwy, Wysg a Chleddau.
Mae i’r astudiaethau hyn fantais ychwanegol, sef dangos yn glir pa fesurau eraill sy’n ofynnol, fel gwelliannau i ddulliau rheoli tir, arferion ffarmio, adeiladu llwybrau pysgod fel y gall eog a physgod mudol eraill fudo er mwyn gwella iechyd cyffredinol yr afonydd hyn. Mewn amser, bydd y newidiadau hyn o gymorth i fodloni gofynion Cyfarwyddebau eraill gan yr Undeb Ewropeaidd a fydd yn ofynnol erbyn 2027, fel y Gyfarwyddeb Fframwaith Dŵr. Fel sy’n wir am bob astudiaeth ecolegol, bydd angen eu cynnal dros gyfnod o flynyddoedd cyn y bydd gennym ddigon o dystiolaeth i gefnogi unrhyw drefniadau gwahanol i dynnu dŵr. Mae ein hastudiaethau’n cael eu cefnogi gan dystiolaeth academaidd ac fe gânt eu cyhoeddi a’u hadolygu gan gydweithwyr pan fyddant yn barod.
Page | xii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Er mwyn delio ag effaith y Gyfarwyddeb Cynefinoedd sy’n gorfod cael mesurau y cytunir arnynt ac sydd o fewn ein trwyddedau tynnu dŵr i ddiogelu afonydd a ddynodir yn ‘Ardaloedd Cadwraeth Arbennig’ (ACA) erbyn mis Rhagfyr 2015, mae’r Cynllun hwn yn:
Cynnig y dylid parhau â’n hastudiaethau amgylcheddol cynhwysfawr tan o leiaf fis Rhagfyr 2015 gan ddefnyddio’r canlyniadau i hysbysu’n rheoleiddiwr newydd, Cyfoeth Naturiol Cymru, o unrhyw opsiynau sy’n bosibl, neu nad ydynt yn bosibl, ar gyfer newidiadau i’r trwyddedau bryd hynny.
Nodi’r buddsoddiadau sy’n angenrheidiol i gefnogi’r Cynllun ac, yn neilltuol, y rhai sy’n ofynnol er mwyn caniatáu unrhyw ostyngiadau yn ein trwyddedau tynnu dŵr fel y gellir eu cynnwys wrth gynllunio’n busnes at y dyfodol. Mae’r rhain yn dod i £9m o fuddsoddiad cyfalaf a chostau rhedeg blynyddol cysylltiedig o hyd at £0.5m. Bydd angen buddsoddiad ychwanegol o dros £20m hefyd i wella ein seilwaith dŵr er mwyn cynnal ansawdd dŵr o dan wahanol drefniadau tynnu dŵr, a bodloni gofynion manwl y trwyddedau. Pan fydd y rhain wedi’u cwblhau’n derfynol yn nes ymlaen eleni, cânt eu cynnwys yn ein cynigion ar gyfer adolygiad prisiau rheoleiddiol 2015-20, a elwir yn PR14. Bydd y cynigion hyn yn cyfrannu at Gynllun Rheoli Asedau (AMP) 6 ar gyfer y cyfnod 2015-20.
Cadarnhau na fyddwn yn derbyn nac yn gwrthod unrhyw newidiadau i’r trwyddedau tynnu dŵr hyd nes y bydd y broses ymgynghori hon wedi’i chwblhau.
Cadarnhau, o ystyried effaith unrhyw newidiadau i’n trwyddedau tynnu dŵr, ein bod o’r farn y dylai penderfyniadau fel hyn gael eu seilio ar yr wyddoniaeth orau bosibl ac ar ôl ystyried barn ein cwsmeriaid a’n rheoleiddwyr yn cynnwys Cyfoeth Naturiol Cymru, yr Awdurdod Rheoleiddio Gwasanaethau Dŵr (‘Ofwat’) a’r Cyngor Defnyddwyr Dŵr etc.
Cadarnhau y byddwn, cyn cyhoeddi’r Cynllun terfynol tua diwedd 2013, yn adolygu sefyllfa’r trwyddedau yng ngoleuni’r sylwadau a ddaw i law, cyfarwyddiadau’r Gweinidogion, a thrafodaethau cyfochrog eraill gyda Cyfoeth Naturiol Cymru a Llywodraeth Cymru ynghylch cydbwyso’r pwysau o wahanol gyfeiriadau a fydd arnom i fuddsoddi yn ystod 2015-2020.
Mae’r newidiadau i’r trwyddedau a ddaw o ganlyniad i’r Gyfarwyddeb Cynefinoedd yn galw am newid yn y ffordd yr ydym yn gweithredu ein systemau cyflenwi dŵr yn y blynyddoedd sych critigol ac yn hybu buddsoddiad mewn adnoddau dŵr newydd. Mae yna risg ynghlwm wrth y systemau gweithredu newydd, yn cynnwys yr effaith ar ansawdd y dŵr amrwd (h.y. cyn ei drin) ac ansawdd terfynol y dŵr yfed yr ydym yn ei gyflenwi mewn parthau perthnasol. Mae’n rhaid i Dŵr Cymru Welsh Water roi’r brif flaenoriaeth i sicrhau bod ein cyflenwadau dŵr yfed yn dal i gydymffurfio â’r safonau statudol uchaf sy’n cael eu pennu gan Lywodraeth Cymru a’u plismona gan yr Arolygiaeth Dŵr Yfed. Mae’n rhaid i ni geisio lleihau’r risgiau hyn cyn cytuno i’r newidiadau yn y trwyddedau tynnu dŵr. Mae’n rhaid i ni sicrhau hefyd bod system cyflenwi dŵr SEWCUS, yn neilltuol, yn gweithredu’n gadarn yn ystod blynyddoedd sych critigol a’n bod yn gallu sicrhau bod cymaint o ddŵr ag y bo modd ar gael i’w dynnu yn y dyfodol.
O’n trafodaethau gyda Severn Trent Water cyn yr ymgynghoriad, gwyddom hefyd y bydd ein cynlluniau i gynyddu’r llif o’n cronfeydd ni i Afon Gwy ac yna i dynnu’r dŵr yn is i lawr yr afon yn effeithio ar yr adnoddau yr ydym yn eu rhannu gyda nhw. Mae hyn yn golygu y gall fod angen gohirio’n cynlluniau ni i roi cyfle i Severn Trent Water gael y seilwaith angenrheidiol i gyflenwi eu cwsmeriaid nhw yn ystod blwyddyn sych. I’r perwyl hwnnw, byddwn yn parhau i drafod gyda’n rheoleiddwyr a Severn Trent Water ar ôl cyhoeddi Cynlluniau’r naill a’r llall ohonom, ynghylch amseru newidiadau i’r trwyddedau ar Afon Gwy.
Page | xiii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Bydd yr amserlen hon yn caniatáu i ni gwblhau ein gwaith ar yr arolygon amgylcheddol cynhwysfawr gan gadarnhau, neu beidio, effeithlonrwydd y gostyngiadau y bwriedir eu gwneud i’r trwyddedau ar ecoleg yr afonydd a gweld a oes trefniadau tynnu dŵr eraill y gellid eu mabwysiadu a fyddai’n gwarchod yr amgylchedd ond yn caniatáu i Ddŵr Cymru gadw digon o ddŵr dros ben fel y gallwn hybu datblygu cynaliadwy.
Crynodeb o’n Cynllun
Bydd CRhAD drafft 2013 yn cydymffurfio â chanllawiau diweddaraf Defra, Llywodraeth Cymru, Cyfoeth Naturiol Cymru ac Ofwat, a ddatblygwyd mewn partneriaeth â’r diwydiant dŵr. Mae’r canllawiau hyn wedi annog nifer o welliannau yn y ffordd yr ydym yn mesur, yn modelu ac yn deall y ffordd mae ein dalgylchoedd yn gweithio, effaith newid yn yr hinsawdd, a’n gwaith yn darogan y galw am ddŵr yn y dyfodol.
Fel y soniwyd yn ein CRhAD yn 2012, credwn y gellir cydymffurfio â’r Gyfarwyddeb Cynefinoedd gyda newidiadau i’r trwyddedau ym mharth SEWCUS a Sir Benfro yn eu lle yn 2015 yn ôl gofynion y Gyfarwyddeb Cynefinoedd ond na fyddant yn dod i rym tan fis Ebrill 2018 - ar ôl i ni gwblhau ein hastudiaethau amgylcheddol cynhwysfawr. Byddai hyn yn rhoi cyfle i ni ganfod a oes cyfundrefnau tynnu dŵr eraill y gellid eu mabwysiadu sy’n gwarchod yr amgylchedd a, gobeithio, yn golygu y gellir cadw swm sylweddol dros ben i hybu datblygu cynaliadwy. Yn ogystal, bydd raid i ni dalu sylw i’r amserlen a gynigiwyd gan Severn Trent Water ar gyfer newidiadau i’r trwyddedau ar Afon Gwy, gan y dylid gweithredu’r rhain gyda’i gilydd.
Mae’r dull cytbwys a blaengar hwn yn cadarnhau’r angen am ragor o waith manwl yn ystod 2015- 2020, ar y ffordd y gweithredir SEWCUS er mwyn sicrhau na fydd newidiadau mor radical yn arwain at broblemau ansawdd dŵr na phroblemau eraill. Disgwylir y bydd y swm bychan o 5 Ml/d dros ben yn SEWCUS yn 2015, sef llai nag 1% o’r cynnyrch defnyddiadwy. Bydd angen buddsoddiad gwytnwch sylweddol yn 2015-2020 er mwyn sicrhau ein bod yn abl ac yn hyderus i gynnal ansawdd a swm y cyflenwad y mae ein cwsmeriaid yn ei fwynhau ar hyn o bryd ledled y parth hwn.
Mae canlyniadau’r asesiad hwn, sy’n well o lawer, yn cadarnhau bod disgwyl y gallai’r galw fod yn fwy na’r cyflenwad mewn chwech o’n 24 parth adnoddau dŵr yn ystod y cyfnod cynllunio hyd at 2040, fel y dangosir gan yr ardaloedd coch yn y ffigur isod. Mae’r lliw porffor yn dangos Parthau Adnoddau Dŵr sydd ag ychydig bach dros ben o ran cydbwysedd cyflenwad a galw (SDB).
Page | xiv Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Yn achos Sir Benfro, lle disgwylir diffyg o ganlyniad i effeithiau posibl newid yn yr hinsawdd ac effaith sylweddol yr ‘Adolygiad o Ganiatadau’, rydym yn bwriadu parhau â’n gwaith ar yr astudiaethau amgylcheddol a fydd yn dangos lefel y gostyngiadau ar y trwyddedau a all fod yn angenrheidiol ar afon Cleddau Ddu. Os na fydd ein hastudiaethau’n ein galluogi i gyrraedd sefyllfa gost-niwtral ar gyfer tynnu dŵr, byddwn yn buddsoddi mewn cynllun rhwydwaith i gysylltu’r ardal y bydd y gostyngiadau ar y trwyddedau’n effeithio arni ag ardaloedd lle ceir dŵr dros ben. Ar ôl 2028, bydd angen i ni ddod â dŵr i mewn o System Defnydd Cysylltiol (CUS) Tywi gerllaw, a elwir hefyd yn Barth Adnoddau Dŵr Tywi Gŵyr, a gwneud rhagor o waith lleihau gollyngiadau er mwyn sicrhau bod y cyflenwad yn fwy na’r galw.
Ym mharth adnoddau dŵr Aberhonddu Portis, bydd gostyngiadau o ganlyniad i’r Gyfarwyddeb Cynefinoedd ar Afon Wysg yn cyfyngu ar y dŵr y cawn ei dynnu o ffynhonnell dŵr daear Aberhonddu gan olygu bod llai o ddŵr yn dod o’r ffynhonnell honno. Rydym wedi datblygu model adnoddau dŵr newydd ar gyfer y parth hwnnw. Trwy efelychu’r system gyflenwi, mae’r model yn dangos yn fwy cywir faint fydd cynnyrch defnyddiadwy’r parth o ystyried cyfyngiadau ar y rhwydwaith ac effaith gostwng y trwyddedau. Diwygiwyd rhagolygon galw’r parth hefyd gan dalu sylw i welliant yn y cydbwysedd cyflenwad a galw ledled y parth. O ganlyniad i hynny, bwriadwn ryddhau dŵr ychwanegol o gronfa Wysg, yn ôl yr angen, i ychwanegu at y llif sydd ar gael yn Afon Wysg. Yn ogystal, bydd angen gwneud gwelliannau bychan i’r cysylltiadau yn y parth a fydd yn golygu y gellir gwneud mwy o ddefnydd o ffynhonnell Aberhonddu pan fydd y galw ar ei uchaf a gwella gwytnwch y system rhwng Gweithfeydd Trin Dŵr Portis ac Aberhonddu.
Page | xv Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Yn y Bala, lle mae gwell dealltwriaeth o’r galw presennol a’r hyn a ragwelir hyd at 2040, rydym yn bwriadu gwneud mwy o waith lleihau gollyngiadau er mwyn mynd i’r afael â’r diffyg bychan yn y cydbwysedd rhwng y cyflenwad a’r galw.
Yn Ne Meirionnydd hefyd, rhagwelir diffyg bychan yn y cydbwysedd rhwng y cyflenwad a’r galw o ganlyniad i well dealltwriaeth o’r galw presennol a’r rhagolygon hyd at 2040. Rydym yn bwriadu gwneud gwaith rheoli’r galw yn cynnwys gosod dyfeisiau arbed dŵr mewn tai sy’n bod eisoes er mwyn goresgyn y diffyg bychan o ran cyflenwad a galw.
Yng Ngogledd Eryri/Ynys Môn, disgwylir diffyg yn 2023/24 o ganlyniad i gyfuniad o well dealltwriaeth o ragolygon y galw ac effeithiau posibl newid yn yr hinsawdd. Ar hyn o bryd, bwriadwn drosglwyddo dŵr o waith trin yn ne’r ardal ac, yn ogystal, drosglwyddo dŵr o fan tynnu dŵr yn Eryri nad yw’n cael ei ddefnyddio ar hyn o bryd i waith trin gerllaw. Rydym hefyd yn bwriadu gwneud gwelliannau er mwyn lleihau gollyngiadau.
Yn Nhywyn/Aberdyfi, disgwylir diffyg oherwydd effaith gyfunol bosib newid yn yr hinsawdd a gwell rhagolygon ar gyfer y galw hyd at 2040. Rydym yn bwriadu trosglwyddo dŵr amrwd o fan tynnu dŵr newydd yn Ne Meirionnydd a throsglwyddo’r dŵr hwn i waith trin sydd â lle i drin mwy o ddŵr, gan wneud y defnydd gorau o’r ased presennol hwn. Bydd angen lle i drin rhagor o ddŵr eto yn nes ymlaen yn y cyfnod cynllunio a bydd hyn yn golygu adeiladu Gwaith Trin Dŵr newydd.
I grynhoi, bydd effeithiau’r Gyfarwyddeb Cynefinoedd a newid yn yr hinsawdd yn achosi newidiadau sylweddol yn y ffordd yr ydym yn trin dŵr ac yn ei gyflenwi i’n cwsmeriaid. Yn y cynllun hwn, rydym wedi nodi’r effeithiau manwl a’r ffordd orau o ymdrin â’r rhain ym mhob un o’n parthau adnoddau dŵr. Mae’n rhaid pwyso a mesur cost buddsoddiadau fel hyn yn erbyn rhai na allwn eu fforddio o ganlyniad iddynt, fel gwaith i leihau gorlifiadau o garthffosydd i’r graddau y byddem yn dymuno. Mae’n rhaid deall yn iawn beth yw effeithiau pwysedd amgylcheddol ar gymdeithas a’r economi hefyd a dylai unrhyw benderfyniadau a wneir gan ein Rheoleiddwyr, Llywodraeth Cymru neu ninnau gael eu seilio ar dystiolaeth gadarn a bod yn dryloyw. Dyna’n union yr hyn a gyflwynir gan y Cynllun hwn.
Page | xvi Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Consultation
We hope that after reading this Plan customers and other stakeholders will wish to let us know their opinion of our proposals, including their views on what needs to be done to improve it before we publish the Final WRMP.
To respond to this consultation, please write to the Welsh Government and copy your representation to the Secretary of State for Environment, Food and Rural Affairs. The relevant addresses are:
Water Branch Secretary of State for Environment, Food and Rural Affairs Water Resource Management Plans Consultation Department for Environment, Food and Rural Affairs Welsh Government Water Resources Management Plan Consultation Cathays Park 3rd Floor Nobel House Cardiff CF10 3NQ 17 Smith Square [email protected] London SW1P 3JR [email protected]
Comments may be sent by post or email. It would be helpful if the subject title in your email or letter includes the words ‘Representation on Dŵr Cymru Welsh Water’s draft WRMP’.
Page | xvii Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Contents
Preface ii
Executive Summary iii
Crynodeb Gweithredol x
Consultation xvii
Figures 1
Tables 2
1 Water Resources Management Plan 4 1.1 Introduction 4 1.2 Glas Cymru and Dŵr Cymru Welsh Water 4 1.3 Why we prepare plans 5 1.4 Our approach to the development of this Plan 5 1.5 Ecosystems approach 6 1.6 Our 2013 draft WRMP 7 1.7 Key Stakeholder links 9 1.8 Pre-Consultation 10 1.9 Consultation Process 13 1.10 Compliance with Welsh Government direction 15 1.11 Natural Resources Wales and the Welsh Government expectations for this Plan 15 1.12 Key risks & uncertainties 19 1.13 Annual WRMP Review 20
2 Supplying water in our area 22 2.1 Water resources in our supply area 22 2.2 Water resource zones - general 23
3 Water supply capacity 26 3.1 Deployable output 26 3.2 Levels of Service (LoS) 28 3.3 Outage 28 3.4 Operational use of water 30 3.5 Water transfers 30 3.5.1 Potable supplies 30 3.5.2 Non-potable supplies 30 3.5.3 Other customers 31
Page | 1 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3.6 Climate change 31 3.7 Water available for use 34
4 Demand 35 4.1 Demand for water 35 4.1.1 Introduction 35 4.1.2 Base Year of the Forecast 36 4.1.3 Base Year Populations and properties 36 4.1.4 Forecasting population and property numbers 36 4.2 Base Year household consumption 37 4.3 Water Efficiency Strategy 38 4.3.1 Non-household consumption 41 4.4 Leakage Forecast 43 4.4.1 Determining Baseline Leakage Forecasts 43 4.4.2 Leakage Control Strategy 44 4.5 Final Base Year Forecast 45 4.5.1 Incorporation and effects of climate change on demand 46
5 Headroom 47 5.1 Introduction 47 5.2 Calculating headroom uncertainties 47 5.3 Company risk profile and baseline target headroom 49 5.4 Baseline and Final Planning Target Headroom 49
6 Habitats Directive and the impact on water abstractions 52 6.1 Habitats Directive Review of Consents 52 6.2 Review of Consents 52 6.3 Impacts of the Review of Consents on water abstractions 55 6.3.1 South East Wales Conjunctive Use System (SEWCUS) WRZ 55 6.3.2 Brecon Portis WRZ 56 6.3.3 Pembrokeshire WRZ 56 6.4 Wye and Usk investigations 56 6.5 Eastern Cleddau investigations 57 6.6 Timetable for licence amendments and implementation 58 6.7 Water Framework Directive - Heavily Modified Water Bodies 58
7 Supply demand balance 60 7.1 Calculating the supply demand balance 60 7.2 Baseline supply demand balance 61 7.3 WRZ 8001 - North Eryri - Ynys Mon 63 7.3.1 Final Plan 2012 Status 63 7.3.2 Current Status 63
Page | 2 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.3.3 Wylfa Scenario 64 7.3.4 Cefni compensation release 65 7.4 WRZ 8012 Clwyd Coastal 67 7.4.1 Final Plan 2012 Status 67 7.4.2 Current Status 67 7.5 WRZ 8014 Alwen Dee 68 7.5.1 Final Plan Status 2012 68 7.5.2 Current Status 68 7.6 WRZ 8020 - Bala 69 7.6.1 Final Plan 2012 Status 69 7.6.2 Current Status 69 7.7 WRZ 8021 Tywyn Aberdyfi 71 7.7.1 Final Plan 2012 Status 71 7.7.2 Current Status 71 7.8 WRZ 8026 Blaenau Ffestiniog 73 7.8.1 Final Plan Status 2012 73 7.8.2 Current Status 73 7.9 WRZ 8033 Barmouth 74 7.9.1 Final Plan 2012 Status 74 7.9.2 Current Status 74 7.10 WRZ 8034 Lleyn Harlech 75 7.10.1 Final Plan 2012 Status 75 7.10.2 Current Status 75 7.11 WRZ 8035 Dyffryn Conwy 77 7.11.1 Final Plan 2012 Status 77 7.11.2 Current Status 77 7.12 WRZ 8036 South Meirionnydd 78 7.12.1 Final Plan 2012 Status 78 7.12.2 Current Status 78 7.13 WRZ 8101 Ross-on-Wye 80 7.13.1 Final Plan 2012 Status 80 7.13.2 Current Status 80 7.14 WRZ 8102 Elan Builth 81 7.14.1 Final 2012 Plan Status 81 7.14.2 Current Status 81 7.15 WRZ 8103 Hereford Conjunctive Use System 82 7.15.1 Final Plan 2012 Status 82 7.15.2 Current Status 82 7.16 WRZ 8105 Llyswen 83 7.16.1 Final Plan 2012 Status 83 7.16.2 Current Status 83 7.17 WRZ 8106 Monmouth 84
Page | 3 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.17.1 Final 2012 Plan Status 84 7.17.2 Current Status 84 7.18 WRZ 8107 Pilleth 85 7.18.1 Final Plan 2012 Status 85 7.18.2 Current Status 85 7.19 WRZ 8108 Brecon Portis 86 7.19.1 Final Plan 2012 Status 86 7.19.2 Current Status 86 7.20 WRZ 8110 Vowchurch 88 7.20.1 Final Plan 2012 Status 88 7.20.2 Current Status 88 7.21 WRZ 8111 Whitbourne 89 7.21.1 Final Plan 2012 Status 89 7.21.2 Current Status 89 7.22 WRZ 8121 SEWCUS 90 7.22.1 Final Plan 2012 Status 91 7.22.2 Current Status 91 7.22.3 Compensation flow from Castell Nos reservoir 92 7.23 WRZ 8201 Tywi Conjunctive Use System 93 7.23.1 Final Plan 2012 Status 93 7.23.2 Current Status 93 7.24 WRZ 8202 Mid & South Ceredigion 95 7.24.1 Final Plan 2012 Status 95 7.24.2 Current Status 95 7.25 WRZ 8203 North Ceredigion 96 7.25.1 Final Plan 2012 Status 96 7.25.2 Current Status 96 7.26 WRZ 8206 Pembrokeshire 97 7.26.1 Final Plan 2012 Status. 97 7.26.2 Current Status 97 7.26.3 Revised operation of Pont Hywel abstraction 98 7.26.4 Consideration of inflows for Pembrokeshire catchments 101
8 Option Appraisal and the Preferred Plan 103 8.1 Introduction 103 8.2 Overall methodology 103 8.2.1 Distribution Management Options 105 8.2.2 Customer side options 106 8.2.3 Resource Side Options 107 8.2.4 Water Trading Options 108 8.3 Selecting the preferred option 110
Page | 4 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.4 WRZ 8001 North Eryri - Ynys Mon 111 8.5 WRZ 8020 Bala 115 8.6 WRZ 8021 Tywyn Aberdyfi 117 8.7 WRZ 8036 - South Meirionnydd 120 8.8 WRZ 8108 - Brecon Portis 122 8.9 WRZ 8206 Pembrokeshire 125 8.9.1 Inflow and Pont Hywel lower licence reduction scenarios 127 8.10 WRZ 8121 SEWCUS 129 8.10.1 Zonal Supply Demand Balance 129 8.10.2 Key risks 129 8.10.3 SEWCUS Investigation Programme 133 8.11 Water Framework Directive 135 8.12 Summary of the preferred solutions in deficit zones 136
9 Environmental appraisal 137 9.1 Introduction 137 9.1.1 Strategic environmental appraisal 137 9.1.2 Habitats regulations assessment 137 9.1.3 Consultation 138 9.2 Strategic environmental assessment 138 9.2.1 Environmental objectives 138 9.2.2 Using the findings of the assessment 138 9.3 Habitats regulations assessment 139 9.3.1 The process 139 9.3.2 Review of feasible options 139 9.3.3 Assessment of preferred options 139 9.3.4 Summary of assessment 140 9.3.5 Conclusion 140 9.4 Water Framework Directive 141
10 Further Work in AMP 6 142
11 Glossary of Terms 143
Page | 5 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figures Figure 1-1 Development of a Water Resources Management Plan ...... 8 Figure 2-1 Declining trend in water supplied ...... 23 Figure 2-2 Water resource zones ...... 24 Figure 4-1 Demand Components ...... 35 Figure 4-2 Population forecasts (2012/13 to 2039/40) ...... 37 Figure 4-3 Forecast Household Demand ...... 38 Figure 4-4 AMP5 Water Efficiency Interventions ...... 40 Figure 4-5 Econometric Non Household Model ...... 42 Figure 4-6 Diagram of Sahara tethered acoustic leak detection system ...... 44 Figure 4-7 Historic and Forecast Distribution Input ...... 46 Figure 5-1 Dry year annual average target headroom – one of five ...... 50 Figure 5-2 Dry year annual average target headroom – two of five ...... 50 Figure 5-3 Dry year annual average target headroom – three of five ...... 50 Figure 5-4 Dry year annual average target headroom – four of five ...... 51 Figure 5-5 Dry year annual average target headroom – five of five ...... 51 Figure 6-1 Dŵr Cymru Welsh Water’s abstractions in South East Wales subject to the review of consents process ...... 52 Figure 6-2 Dŵr Cymru Welsh Water’s abstractions in South West Wales subject to the review of consents process ...... 53 Figure 6-3 Dŵr Cymru Welsh Water’s abstractions in North Wales subject to the review of consents process ...... 53 Figure 7-1 Calculating supply demand balance ...... 60 Figure 7-2 Surplus and deficit zones dWRMP 2013 ...... 62 Figure 7-3 NEYM Annual Average SDB position 2015 – 2040 ...... 64 Figure 7-4 NEYM Critical Period SDB position 2015 – 2040 ...... 64 Figure 7-5 NEYM Annual Average SDB position 2015 – 2040 under Wylfa scenario ...... 65 Figure 7-6 NEYM Critical Period SDB position 2015 – 2040 under Wylfa scenario ...... 65 Figure 7-7 NEYM Annual Average SDB position 2015 – 2040 with increased Cefni compensation release ..... 66 Figure 7-8 NEYM Critical Period SDB 2015 – 2040 with increased Cefni compensation release...... 66 Figure 7-9 Clwyd Coastal Annual Average SDB position 2015 – 2040 ...... 67 Figure 7-10 Alwen Dee Annual Average SDB position 2015 – 2040 ...... 68 Figure 7-11 Bala Annual Average SDB position 2015 – 2040 ...... 70 Figure 7-12 Bala Critical Period SDB position 2015 – 2040 ...... 70 Figure 7-13 Tywyn Aberdyfi Annual Average SDB position 2015 – 2040 ...... 71 Figure 7-14 Tywyn Aberdyfi Critical Period SDB position 2015 – 2040 ...... 72 Figure 7-15 Blaenau Ffestiniog Annual Average SDB position 2015 – 2040 ...... 73 Figure 7-16 Barmouth Annual Average SDB position 2015 – 2040 ...... 74 Figure 7-17 Lleyn Harlech Annual Average SDB position 2015 – 2040 ...... 76 Figure 7-18 Dyffryn Conwy Annual Average SDB position 2015 – 2040 ...... 77 Figure 7-19 South Meirionnydd Annual Average SDB position 2015 – 2040 ...... 79 Figure 7-20 South Meirionnydd Critical Period SDB position 2015 – 2040 ...... 79 Figure 7-21 Ross on Wye Annual Average SDB position 2015 – 2040 ...... 80 Figure 7-22 Elan Builth Annual Average SDB position 2015 – 2040 ...... 81 Figure 7-23 Hereford Annual Average SDB position 2015 – 2040 ...... 82 Figure 7-24 Llyswen Annual Average SDB position 2015 – 2040 ...... 83 Figure 7-25 Monmouth Annual Average SDB position 2015 – 2040 ...... 84
Page | 1 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 7-26 Pilleth Annual Average SDB position 2015 – 2040 ...... 85 Figure 7-27 Brecon Portis Annual Average SDB position 2015 – 2040 ...... 87 Figure 7-28 Brecon Portis Critical Period SDB position 2015 – 2040 ...... 87 Figure 7-29 Vowchurch Annual Average SDB position 2015 – 2040 ...... 88 Figure 7-30 Whitbourne Annual Average SDB position 2015 – 2040 ...... 89 Figure 7-31 SEWCUS Annual Average SDB position 2015 – 2040 ...... 91 Figure 7-32 SEWCUS Annual Average SDB position 2015 – 2040 with Castell Nos compensation flow ...... 92 Figure 7-33 Tywi CUS Annual Average SDB position 2015 – 2040 ...... 94 Figure 7-34 Mid and South Ceredigion Annual Average SDB position 2015 – 2040 ...... 95 Figure 7-35 North Ceredigion Annual Average SDB position 2015 – 2040 ...... 96 Figure 7-36 Pembrokeshire Annual Average SDB position 2015 – 2040 ...... 98 Figure 7-37 Pembrokeshire Critical Period SDB position 2015 – 2040 ...... 98 Figure 7-38 Pembrokeshire Annual Average SDB position 2015 – 2040 with reduced restrictions at Pont Hywel ...... 99 Figure 7-39 Pembrokeshire Critical Period SDB position 2015 – 2040 with reduced restrictions at Pont Hywel ...... 100 Figure 7-40 Pembrokeshire Annual Average SDB position 2015 – 2040 with Gwaun inflow sequence...... 101 Figure 7-41 Pembrokeshire Critical Period SDB position 2015 – 2040 with Gwaun inflow sequence ...... 102 Figure 8-1 Summary of Options Identification and Appraisal Process ...... 104 Figure 8-2 Minimum SDB Positions ...... 109 Figure 8-3 Schematic of NEYM WRZ ...... 112 Figure 8-4 Final Supply Demand Balance for the NEYM WRZ ...... 114 Figure 8-5 Final Supply Demand Balance for the Bala WRZ ...... 115 Figure 8-6 Schematic of Tywyn Aberdyfi WRZ ...... 117 Figure 8-7 Final Supply Demand Balance for the Tywyn Aberdyfi WRZ ...... 119 Figure 8-8 Final Supply Demand Balance for the South Meirionydd WRZ ...... 120 Figure 8-9 Final Supply Demand Balance for Brecon Portis WRZ ...... 123 Figure 8-10 Schematic of Pembrokeshire WRZ showing preferred options ...... 125 Figure 8-11 Final Supply Demand Balance for the Pembrokeshire WRZ ...... 127 Figure 8-12 Llandegfedd stocks cumulative frequency distribution ...... 129 Figure 8-13 The SEWCUS water supply system ...... 132
Tables Table 1-1 External Strategies and Plans we have considered ...... 10 Table 1-2 IEAP Membership ...... 12 Table 1-3 Contact Plan ...... 13 Table 1-4 Progress versus EAW and the Welsh Government expectations for dWRMP 2013 ...... 18 Table 2-1 Water resource zones – Key Facts and Figures ...... 25 Table 3-1 Deployable output values for Dŵr Cymru Welsh Water ...... 27 Table 3-2 Outage allowances as a percentage of deployable output ...... 29 Table 3-3 Water transfers ...... 30 Table 3-4 Final vulnerability classifications for Dŵr Cymru Welsh Water ...... 32 Table 3-5 Predicted climate change impacts on min AADO in all zones with climate change vunerability for the 2030s ...... 34 Table 4-1 Population forecasts (2012/13 to 2039/40) ...... 37 Table 4-2 Current Water Efficiency Position ...... 39 Table 4-3 Components of Leakage in 2011/12...... 43
Page | 2 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Table 4-4 AMP 6 SELL profiles ...... 43 Table 4-5 Revised Policy in AMP 6 ...... 45 Table 5-1 Supply-side headroom components ...... 48 Table 5-2 Headroom risk profile used in this plan compared to Final WRMP 2012 ...... 49 Table 6-1 Dŵr Cymru Welsh Water abstractions where the Environment Agency was unable to show that there was no adverse effect on site integrity ...... 54 Table 6-2 HMWB site scenarios ...... 59 Table 7-1 Supply demand deficits ...... 62 Table 8-1 Relative benefits from water efficiency measures ...... 107 Table 8-2 Resource Side Scheme Option Categories ...... 107 Table 8-3 Potential Resource Requirements ...... 108 Table 8-4 Summary of preferred solutions in NEYM WRZ ...... 114 Table 8-5 Summary of preferred solutions in Bala WRZ ...... 115 Table 8-6 Summary of preferred solutions in Tywyn Aberdyfi WRZ ...... 119 Table 8-7 Summary of preferred solutions in South Meirionnydd Zone ...... 121 Table 8-8 Summary of preferred solutions for Brecon Portis WRZ ...... 123 Table 8-9 Summary of preferred solutions for Pembrokeshire WRZ ...... 127 Table 8-10 Summary of preferred solutions for deficit zones in dWRMP 2013 ...... 136 Table 9-1 Summary of water bodies at low risk of deterioration from GES ...... 141
Page | 3 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
1 Water Resources Management Plan
1.1 Introduction This is the Executive Report for Dŵr Cymru Welsh Water’s draft Water Resources Management Plan 2013 (dWRMP 2013). It contains the key information required to understand the dWRMP 2013, without presenting the extensive technical detail that is required to meet the audited requirements of the Environment Agency and Natural Resources Wales. The dWRMP 2013 describes in detail our assessment of the water that will be available for supply in the years between 2015 and 2040 and the demand for water that we anticipate our customers will make. The dWRMP 2013 presents the technical analysis required by our regulators and Government to support our proposed strategy for delivering reliable supplies of water to our customers, reflecting the level of service they expect from us. The dWRMP 2013 also describes how we will manage future demand and minimise the environmental impact of our abstractions.
This section sets out the legal context within which the dWRMP 2013 has been prepared and how we have approached the task of putting it together. This includes a description of how our work has evolved since the previous Plan, which was published in October 2012, and how it links in, at a strategic level, with Government and regulatory policies and requirements.
This Plan is also prepared in the context of Dŵr Cymru Welsh Water’s publication ‘Our Sustainable Future’3, which sets out our over-arching policy priorities for the next 25 years.
As a company owned on behalf of our customers and providing a vital public service, we acknowledge the importance of understanding our customers’ views. It is, after all, our customers’ money that we propose spending to deliver this Plan. Our aim is to ensure that, as far as we reasonably can, our plans for the future properly reflect their opinions, along with the comments made by other key stakeholders. We therefore want to hear the views of all interested parties, particularly our customers on our Plan, and specifically whether our approach and the commitments we make in this Plan are supported.
1.2 Glas Cymru and Dŵr Cymru Welsh Water Dŵr Cymru Welsh Water is a statutory water and sewerage undertaker. We are owned by Glas Cymru, a single purpose, ‘not‐for‐profit’ company: there are no shareholders and any profits which arise are reinvested back into the business on behalf of our customers, or returned as a dividend in some form. This is a unique business model in the water industry. Dŵr Cymru Welsh Water is the principal water company covering most of Wales. We also supply parts of England, including the majority of Herefordshire. We are the sixth largest of the ten regulated water and sewerage companies in England and Wales. We are responsible for providing over 3 million people with a continuous, high quality supply of drinking water and for taking away and properly disposing of the associated wastewater. We also have over 110,000 business customers, so our services are essential in supporting the Welsh economy. In total, we deliver more than 800 million litres of drinking water every day.
3 ‘Our Sustainable Future’ (Dŵr Cymru Welsh Water, 2007)
Page | 4 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
1.3 Why we prepare plans Under the Water Industry Act 1991 water companies must provide domestic and non-domestic customers with a reliable supply of water for domestic and business purposes. At least every five years we must publish Water Resources Management Plans setting out how we will ensure that we are able to meet the demands that we expect will arise in the future.
The Water Act 2003, which updated the Water Resources Act 1991 and the Water Industry Act 1991, introduced a statutory condition for water companies to produce these Plans. This legislation also requires us to consult with stakeholders, including our customers and the wider public, on our dWRMP.
In Wales we operate within the broad strategic water and environmental policy framework set by the Welsh Government . Its duties include approving our Water Resources Management Plans. We are also very mindful of the Welsh Government’s policy position in relation to the ‘ecosystems approach’.
Since its establishment in 1996, the Environment Agency has undertaken the day-to-day regulation of our water resources functions. In preparing this Plan, Dŵr Cymru Welsh Water has liaised with the Environment Agency to ensure that we are meeting its expectations and following its guidelines. The Countryside Council for Wales (CCW) has been the Welsh Government’s statutory adviser on sustaining natural beauty and wildlife and so we have consulted CCW about this Plan specifically with regard to the Strategic Environmental Assessment (SEA) and the Habitats Regulation Assessment (HRA) to ensure that all environmental considerations have been considered appropriately. 1 April 2013 saw the establishment of a new environmental regulator, Natural Resources Wales, formed from an amalgamation of the Environment Agency Wales, CCW and Forestry Commission Wales. Amongst it functions, the new body has inherited the Environment Agency’s statutory functions in relation to the day-to-day regulation of water resources, for example, the setting of abstraction licences.
Limits on the prices we may charge our customers are set every five years by our economic regulator, the Water Services Regulation Authority (‘Ofwat’). In setting our price limits Ofwat takes account of the various obligations we are under, including those relating to water resources. The Water Resources Planning Guideline 2012 was developed conjunctively by the Environment Agency, Ofwat, Defra and the Welsh Government. The Guideline therefore sets out Ofwat’s requirements on how water companies should assess water supply demand issues for the 2015-2020 period.
1.4 Our approach to the development of this Plan The planning of long term water supplies is not a discrete task that takes place every few years: rather, we review on a continual basis our water resource position, the future requirements of our customers, and how they can best be met at least cost to them and at minimal impact to the environment. This Plan therefore represents a ‘snapshot’ of our most up-to-date thinking. It has been prepared in accordance with guidance provided by the Environment Agency4 and, includes a full consideration of the latest projections of the effects of climate change, improved demand
4 Water Resources Planning Guideline (WRPG) (EA, October 2012) http://publications.environment-agency.gov.uk/pdf/GEHO0612BWPD-E- E.pdf, http://publications.environment-agency.gov.uk/pdf/GEHO0612BWPE-E-E.pdf
Page | 5 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
forecasting and the effects of the ‘Review of Consents’ that the Agency has undertaken in the light of the Habitats Directive (see chapter 6 for details).
We have identified that six of our 24 Water Resource Zones are expecting a supply demand deficit during the 2015-2040 planning period. In order to determine how best these can be addressed we have identified all the credible options for increasing supply and/or reducing demand and costed the most feasible of these options, including a full evaluation of their environmental, social and carbon costs. This Plan promotes the best value schemes for customers and the environment (not necessarily least cost) which have arisen, being mindful of the other engineering work we need to undertake within the zones.
It is important that we understand the potential environmental and ecological impact of any plans we put forward. We have therefore undertaken a ‘Strategic Environmental Assessment’ (SEA) and a ‘Habitats Regulations Assessment’ (HRA) of our preferred options for addressing the deficits.
This Plan is aligned to our current policy position detailed in our document, ‘Our Sustainable Future’ , and with our forthcoming Environment Strategy. Key aspects are:
Looking after our assets
“Our priorities to the milestone year 2015 include....providing robust infrastructure to enable continued economic growth and development in Wales.” Responding to climate change
“We will implement changes to our business activities to cope with extreme weather events....through Water Resources Plans and enhanced protection of our key assets.” “Over the next 25 years....our vision is that customers should be able to look forward to....at least a 50% cut in greenhouse gas emissions.” Safeguarding the environment
“....protected areas will not be adversely affected by our water abstractions” Meeting customers’ expectations
“Our Water Resources Plans will be based on a hosepipe ban not occurring at a rate of more than once in every 20 years.”
1.5 Ecosystems approach The water industry in England and Wales aims to provide water services in an equitable, sustainable and affordable way, based on a complex array of regulatory controls. These controls have evolved over many years in response to technological developments and societies’ understanding of environmental pressures and impacts. A wide range of environmental laws and regulatory controls have been enacted with the aim of ensuring that, in effect, the ecosystems services are balanced, whereby environmental objectives are preserved at the same time as ensuring human well being and economic development is being achieved.
The water resource planning process reflects this through a range of measures, including:
Page | 6 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The protection of environmental flows, via the Environment Agency’s and Natural Resources Wales’ Catchment Abstraction Management Strategy process;
The protection of habitats and species of international importance via the enactment of EU Habitats and Birds Directives;
The aim of achieving Good Ecological Status (or potential), under the EU Water Framework Directive;
The need to identify the best value solution for maintaining a balance between supply and demand, taking account of the social and environmental costs of schemes, and wider environmental issues via SEA and HRA.
The statutory duty placed upon water companies to promote water efficiency.
Therefore, the policies, legislation, regulations and guidance that sets out how water companies in Wales operate in general, and how they plan to maintain water supplies to meet future demands in particular, reflect the principles of the ‘ecosystems approach’.
1.6 Our 2013 draft WRMP This document is structured as follows. Chapter 1 sets out the context within which the draft Plan has been prepared, and the processes that have been applied. Chapter 2 provides a summary of the key features of our region and the water supply industry in general that are particularly relevant for water resources planning. Chapter 3 then explains the primary measures of water supply capacity, namely ‘deployable output’ and ‘water available for use’ (including the role of ‘outage’), and Chapter 4 describes the main elements of the demand for water in our region together with the basis on which we have forecast demand out to 2040. Chapter 4 also summarises our approach to the management of leakage (leakage being one component of the ‘demand’ for water) and the promotion of water efficiency, both of which will continue to play important roles in our water supply strategy over the Plan period. Chapter 5 then explains ‘Headroom Uncertainty’ and ‘Target Headroom’, the buffer that we build into our projections to allow for uncertainty for the purposes of determining when there is deemed to be a supply demand ‘deficit’.
Chapter 6 describes the effect of the Environment Agency’s review of some of our abstraction licences, the expected ‘sustainability reductions’ that are required in the light of the Habitats Directive. Chapter 7 then brings together the projections of demand, Target Headroom and Deployable Output to present the ‘supply demand balance’ for each of our 24 water resource zones for the period to 2040. Chapter 8 sets out how we have approached the evaluation of options and solutions for closing these deficits. These options range from development of new resource schemes in rivers and groundwater, to encouraging our customers to use water more efficiently. It shows how we have evaluated the options to arrive at a preferred list of viable solutions to the projected deficits. (It sets out our initial estimates of the likely financial and carbon cost of progressing each of these options).
Chapter 9 summarises the environmental appraisals we have commissioned in connection with, and to support this Plan. The implications of these outcomes on our preferred solutions are considered. Finally Chapter 10 briefly considers some work that we would like to undertake in the future to help further our water resource understanding. Figure 1-1 below is taken from the Environment Agency’s
Page | 7 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
guidance on preparing a Water Resources Management Plan and shows a high level view of the process undertaken. A glossary of terms is included at the end of this report.
Figure 1-1 Development of a Water Resources Management Plan
Page | 8 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
1.7 Key Stakeholder links We operate in the broad policy framework set by the WG. We have ensured that we have full regard to its key strategies and policies in preparing the Plan. We have also worked closely with the Environment Agency and Natural Resources Wales, and have discussed details of this Plan with them, particularly the effect that its proposed changes to our licences due to the Habitats Directive will have. The Plan has been prepared with reference to the ‘Guiding Principles’ for water resources planning5, with particular reference to the sections that refer specifically to companies operating in Wales.
We have also consulted with the Countryside Council for Wales and Natural England, particularly regarding the SEA and HRA so we can be confident that we have considered all the key environmental issues. We have summarised in Table 1.2 the main strategies and plans that have helped to shape our thinking in developing this document.
Organisation Document Links to this Plan
Strategic Policy Position Welsh Sets out the Welsh Government’s vision on how water Statement on Water Government resources should be managed in Wales. (2011 update)
Provides guidance to Ofwat on how it should undertake its Welsh Social and Environmental duties in relation to the Welsh Government’s objectives. Government Guidance to Ofwat This will shape Ofwat’s approach and expectations from water companies.
One Wales: One Planet – We need to have regard to the Welsh Government’s Welsh The Sustainable sustainable vision for Wales where ‘land, freshwater and Government Development Scheme of marine environment is best managed to provide the services the Welsh Government of food, wood, water, soil, habitats and recreation’.
People, Places, Future: The Spatial Plan aims to safeguard and protect Wales’ Welsh The Wales Spatial Plan natural and historic assets whilst enhancing their resilience Government 2008 Update to climate change.
Welsh Climate Change Strategy The Welsh Government’s vision on tackling climate change Government for Wales in Wales and what it expects from industry.
Welsh Environment Strategy for 95% of internationally designated sites to be in favourable Government Wales condition by 2010.
Welsh Energy Wales: A Low This policy statement sets out the Welsh Government’s Government Carbon Transition ambitions for low carbon energy in Wales.
Welsh Planning Policy Wales Sets out the land use planning policies of the Welsh Government (Edition 3) Government and the key policy objectives for Local
5 Water resources planning guideline - The guiding principles for developing a water resources management plan. June 2012. Development by Environment Agency, Ofwat, Defra and the Welsh Government
Page | 9 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Organisation Document Links to this Plan
Development Plans (LDPs) in Wales which reflect the sustainable development agenda.
Environment Water for People and the Sets out how Natural Resources Wales believes water should Agency Wales Environment: Water be managed in Wales until 2050 and lists actions and (now Natural Resources Strategy for measures water companies should undertake to achieve its Resources Wales) Wales vision.
Regional Development Local Councils Aspirational development within the Councils’ area. Plans/ Spatial Strategies
Environment Water Resources Agency Wales Sets out the required actions for the relevant parties to Strategy for Wales – First (now Natural deliver Natural Resources Wales’s Water Resources Strategy. Action Plan Resources Wales)
Environment Localised plans containing actions Natural Resources Wales’ Agency Wales Regional Action Plans wishes to be implemented by water users to achieve their (now Natural national strategy aims. Resources Wales)
Environment Water Framework Agency Wales How the European Water Framework Directive will be Directive River Basin (now Natural implemented to achieve ‘good status/ potential’. Management Plans Resources Wales)
Environment Sets out the water resource availability status across surface Agency Wales Catchment Abstraction water/ groundwater catchments in England and Wales. This (now Natural Management Strategies determines the Agency’s licensing policy. Resources Wales)
Sets out Ofwat’s expectation that companies will plan for the Preparing for the future impacts of climate change upon their supply and demand Ofwat – Ofwat’s climate change balances within the water resource planning framework. policy statement
Table 1-1 External Strategies and Plans we have considered
1.8 Pre-Consultation In preparing for this Plan we have undertaken a wide pre-consultation of our stakeholders. The purpose of this was to provide external organizations with an understanding of the overall approach to be taken by us and highlight key differences from our previous plan.
This process began early in 2012 when we wrote to our regulators, Government, neighbouring companies and some key stakeholders such as the Consumer Council for Water, Countryside Council for Wales and Natural England. This was to ask those organisations what they expected from our plan, to highlight any issues that emerged during the previous planning period where action were thought to be required and to raise any potential concerns.
With regard to regulators we have taken an open ‘Working Together’ approach with Natural Resources Wales and the Environment Agency and at numerous meetings, have taken them through
Page | 10 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
the methods that we have used to determine the various components of the plan including the development of new water resource models, our water balance and demand forecast and our inclusion of climate change within Target Headroom assessment. We have discussed a few areas where we are not clear on how to follow guidance and agreed where it was necessary for us to deviate from the guidelines. We have had active dialogue on our approach to abstraction license reductions while developing draft license changes on the Rivers Usk, Wye and Eastern Cleddau. Natural Resources Wales and the Environment Agency are fully conversant with our approaches taken in developing the plan.
We have had a number of teleconference meetings with Ofwat to provide our general approach to the plan and to answer queries on specific topics. We have taken the Welsh Government through the early findings of our plan in order that they can understand any supply demand deficits, proposed solutions and the timing of these.
With regard to environmental stakeholders, we have presented our approaches to our Independent Environment Advisory Panel (IEAP) which includes in its membership the environmental leads from numerous organisations listed in Table .
Organisation IEAP status Ramblers Cymru Member Centre for Ecology & Hydrology Member Elan Valley Trust Member National Parks Wales Member Country Land and Business Association Member Natural Resources Wales (successor to Environment Member and Deputy Chair Agency Wales, Countryside Council for Wales and Forestry Commission Wales) Carmarthenshire Rivers Trust Member RSPB Cymru Member Keep Wales Tidy Member Afonydd Cymru Member Consumer Council for Water Wales Observer Aberystwyth University Member WLGA Member National Trust Member Welsh Government Observer Wildlife Trusts Wales Member Farmer Union Wales Member Marine Conservation Society Member Natural England Member Wales Environmental Research Hub Observer Canal & River Trust/Glandwr Cymru Member National Farmers Union Cymru Member Wye & Usk Foundation Member Cardiff University Member and Deputy Chair The Coal Authority Member
Page | 11 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Table 1-2 IEAP Membership
As part of the options process, water companies are required to consider all options to share resources with other water companies and/or non-water company providers or users of water. Guidance state that ;
“In the water resources management plan, the company should state how it has fully investigated sharing resources. This applies to a company in surplus which could act as a donor (optional for water companies operating wholly or mainly in Wales) or a company in deficit which could act as a recipient and includes water trading within a catchment.”
We have actively sought information regarding any potential water resources options that may be available from neighbouring water companies or third parties. In our correspondence and meetings, we have outlined the information that is required in line with guidance and in September 2012 we published a view of need and availability of water resources across our supply area on our website. Based upon our work in developing our Final WRMP 2012, the document provided details of where we may require additional water resources in the future.
The table below provides a contact plan used in pre-consultation with external organisations:
Organisation Type of Communication Scope of discussions
Meetings , Letters, Telecon’s formal and e-mail informal
Welsh Government General approach to the plan, water resource options and solutions.
Secretary of State General approach to the plan, water resource
(Defra) options.
Environment General approach to the plan, all components Agency Wales (now of plan including identification of water Natural Resources resource options, approach to climate change Wales) and licence reductions. SEA and HRA.
Environment General approach to the plan, specific Agency – Midlands components of plan including identification of region water resource options, approach to climate change and licence reductions. SEA and HRA.
Ofwat General approach to the plan, specific components of plan including approach to climate change.
Countryside General approach to the plan, water resource Council for Wales options.
Page | 12 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Organisation Type of Communication Scope of discussions
Natural England General approach to the plan, water resource options.
Consumer Council General approach to the plan, water resource for Water (Wales) options.
United Utilities General approach to the plan, potential water resource options.
Dee Valley Water General approach to the plan, potential water resource options, joint operations on the River Dee.
Severn Trent Water General approach to the plan, potential water resource options, bulk supplies and joint operations in the Wye catchment.
Albion Water General approach to the plan, potential water resource options , non-potable supply via Ashgrove treatment works Bristol Water General approach to the plan, potential water resource options. Thames Water
Canals and Rivers General approach to the plan, potential water Trust resource options, operations in the Usk catchment.
IEAP General approach to the plan, potential water resource options. Table 1-3 Contact Plan
1.9 Consultation Process This Plan is now available for statutory consultation. You may have obtained this copy of the Executive Report of Dŵr Cymru Welsh Water’s draft Water Resource management Plan (dWRMP) from the Dŵr Cymru Welsh Water website6 or by direct mail, in the case of identified key stakeholders.
Dŵr Cymru Welsh Water is keen to hear customer’s and stakeholders’ views on this Plan. We have prepared the following consultation questions for your consideration. However we are keen to hear your views on any aspect of the plan, not just those covered by these questions.
Q1 Are there any important issues that have not been adequately considered in our assessments of the future water supply and water demand position?
6http://www.dwrcymru.com/en/Environment/Water-Resources/Draft-Water-Resources-Management- Plan-2013.aspx
Page | 13 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Q2 Is our target level of service, i.e. the frequency of water restrictions, acceptable and does it strike the right balance between the needs of customers and the environment?
Q3. Do you agree that the approach taken to the implementation of Habitats Directive Review of Consents abstraction licence modifications will allow us to balance the needs of the environment with society and the economy?
Q4 Are the options we have identified the most appropriate ways of securing future water supplies? Are they both robust and flexible?
Q5 Does our environmental assessment, outlined in our Strategic Environment Assessment and our Habitats Regulations Assessment, identify the most relevant potential impacts of the proposed options?
Q6 Do you think that our proposals represent good value for money?
We hope that after reading this dWRMP you will wish to let us know your opinion of the proposals we have put forward and on what needs to be done to improve it before we publish the Final WRMP.
To respond to this consultation, please write to the Welsh Government and copy your representation to the Secretary of State for Environment, Food and Rural Affairs. The relevant addresses are:
Water Branch Secretary of State for Environment, Food and Rural Affairs Water Resources Management Plans Department for Environment, Food and Rural Affairs Consultation Water Resources Management Plan Consultation Welsh Government 3rd Floor Nobel House Cathays Park 17 Smith Square Cardiff CF10 3NQ London [email protected] SW1P 3JR [email protected]
Comments may be sent by post or email. It would be helpful if the subject title in your email or letter includes the words ‘Representation on Dŵr Cymru Welsh Waters’ draft WRMP’.
Following the three month consultation period, Dŵr Cymru Welsh Water will provide the Welsh Government with a response to consultation responses received, known as a Statement of Response, and update the Plan as appropriate. Once directed to do so by the Welsh Government, the Plan will be released in final form. We will inform you through our Statement of Response how we plan to take your comments into account in preparing our Final WRMP.
Page | 14 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
1.10 Compliance with Welsh Government direction The draft WRMP must comply with The Water Resources Management Plan Direction 2012, which is a legal document issued jointly by Department for the Environment, Food and Rural Affairs and the Welsh Government Ministers and which sets out the principal requirements of the Plan.
This draft Plan complies fully with the 2012 Direction. The specific Direction items are covered in the following report sections:
the planning period (item no. 2) – Executive Summary, Introduction chapter; Technical Report chapter 2
the frequency of customer restrictions (planned and actual) (item no. 3a) – Technical Report chapter 3
the option appraisal methodologies (item no. 3b) – Executive Report chapter 8; Technical Report chapter 11.
the requirement to undertake carbon accounting (item no. 3c) – Technical Report chapter 11;
how account has been taken of climate change (item no. 3d) – Executive Report section sections 3.6 and 5.2; and Technical Report chapter 7
the estimation of household demand (item no. 3e) – section 4.
1.11 Natural Resources Wales and the Welsh Government expectations for this Plan The draft Plan’s compliance with Environment Agency Guidelines is summarised in a table in Appendix 1 of the dWRMP 2013 Technical Report. Please contact us at the e mail address [email protected] if you wish to view a copy of the Technical Report and appendices.
In July 2012 we received a letter from the Environment Agency Wales (now Natural Resources Wales) outlining their expectations for the dWRMP 2013. The Guiding Principles for water resources planning that are specific to Wales are also important considerations. These two sets of information have been used as a useful checklist in the preparation of our Plan. The key requirements are provided in Table 1-4, alongside Dŵr Cymru Welsh Water’s response.
Topic Recommendation from EAW representation Dŵr Cymru Welsh Water’s response
Climate change We expect the company to include the We have included the uncertainties uncertainty uncertainties surrounding your estimation surrounding our estimation of the (issue also of the impacts of climate change on supply impacts of climate change on supply in raised by a in target headroom in your chosen planning target headroom in the chosen number of scenario. We also recommend the planning scenario. We have modelled other company accepts a higher level of risk in the impact of climate change to ensure consultees) future years when setting its risk profile for that our Plan is robust and found that target headroom. This recognises that the issue of setting risk levels for
Page | 15 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
some uncertainties can either be reduced or target headroom does not materially dealt with through time. change the outcomes of the Plan.
Habitats We recommend the company shows the Changes to our abstraction licences on Directive licence impact of making Habitats Directive licence the rivers Wye, Usk and Cleddau will changes changes on the Wye, Usk and Cleddau by be made before Dec. 2015. However, 2015 at the latest to meet the requirements significant work is required to increase of the Habitats Directive resilience to the SEWCUS water supply system prior to licence changes taking effect. Given the timescale required to make these improvements, we have included the impact of licence changes of April 2018. We remain committed to completing our comprehensive environmental studies for these rivers so that alternative compliant abstraction regimes can also be sought in line with this timescale.
Leakage control We recommend that the company plans not Included in the plan. to allow leakage to rise at the company level or in any resource zone to the point at which it drives new supply or demand options.
Sustainable As part of its Short Run SELL assessment for Included in the Plan Economic Level its 2013 draft Plan the company should of Leakage evaluate alternative active leakage control (SELL) policies against its current leakage policy to ensure effective management of the network
Water efficiency We recommend that the company explores Included in the Plan and leakage more innovative and cost effective water control options efficiency measures, working in partnership (several with other organisations and a wider range consultees of leakage control options. The company raised the issue should also present these types of options of a lack of as being flexible and incremental to be able water efficiency to meet actual levels of deficit. and leakage control options in the preferred set of options)
Monetary We recommend the company includes the Included in the Plan benefits of monetary benefit of the leakage control and leakage control demand management options and not just and demand the costs within the environmental and management social costings. options
Page | 16 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Options We recommend the company takes a more Included in the Plan appraisal strategic and risk based approach to its options appraisal. It should consider what’s driving the deficits, the robustness and flexibility of the options to the risks and uncertainties identified, and the wider benefits that certain options can bring (e.g. benefits of reducing demand to mitigate and adapt to climate change). The company should not just rely on the least cost approach.
Sensitivity We recommend the company improves its Included in the Plan analysis sensitivity analysis on this Plan to make sure that the Plan is robust and flexible.
Climate change The Welsh Government Climate Change Included in the Plan. We are also mitigation Strategy sets clear targets for reducing reviewing our overall position on greenhouse gas emissions and a framework carbon and climate change for our to help make sure that Wales adapts to the 2015-2020 business planning impacts of climate change. The water sector proposals. It would be useful if the in Wales needs to play a key role in both the Welsh Government could confirm as emission reduction and adaptation agenda part of the consultation process by providing water and energy advice to whether they intend to continue with consumers. an incentive based regime for such It is essential that water companies in Wales targets or whether actual binding consider fully the costs and benefits of targets are to be set to drive carbon demand side measures to provide a secure emissions down over the planning public water supply. period
An ecosystem The Welsh Government supports measures This Plan aligns with Welsh based approach to encourage innovation and a longer term Government policy on the ‘ecosystems shift towards a system that recognises the approach’. We have specifically value of the water resource available to committed to undertaking further Wales. A high quality water environment is environmental survey work, to inform essential to support a healthy ecosystem, Government of alternative abstraction which, in turn, provides a number of regimes which would be compliant services for people and wildlife. The Welsh with all environmental regulation Government is adopting an ecosystem whilst we hope providing a surplus of approach to managing water, focusing on water which can be used to support ecosystem services as well as meeting economic growth. We believe that European environmental obligations, as set when this Plan is complete it will out in ”A Living Wales". provide a good example of the adoption of an ecosystems approach in Wales.
Future water The Welsh Government recognises that the Our Plan extends to 2040, and the resource planning scope for water resources refinements we have made to the management management plans is 25 years, but that measurement, modelling and should not limit water companies from forecasting work we do, has increased taking a longer term view where it is our confidence significantly in how appropriate. It is essential to take a long climate change in particular will affect term approach to water resources planning our supply of water and the demands
Page | 17 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
to make sure that appropriate measures are of our customers. being taken to consider the impacts of future demands and climate change on our water resources.
Water trading The Welsh Government expects water Our position is aligned to this. We companies operating wholly or mainly in very much want industry to Wales to only agree bulk supplies where it understand we are ‘open for business’, would not be detrimental to the incumbent and keen to welcome new industry to company. Where a water company‘s Wales or those parts of England which preferred solution to meet demand includes we supply. an option to transfer water from a water resource zone of a water company which is wholly or mainly in Wales, it should provide opportunity for Welsh Ministers to give representations on its Plan. The expectation is that any proposals should be explored during the pre-consultation phase of developing a Plan. If such options are likely to be considered as part of the preferred solution, water companies are expected to consult the Welsh Government on these options as early as possible in the process.
Demand The Welsh Government expects water Included in the Plan. Management companies operating wholly or mainly in Wales to demonstrate how they will promote efficient water use in their water resources management plans. Water companies operating wholly or mainly in Wales do not currently have the powers to implement compulsory metering. The Welsh Government does not consider compulsory metering to be an appropriate option for demand management in Wales. However, metering programmes can be used in conjunction with other schemes to tackle affordability.
Natural It is important for water companies We look forward to working in Resources Body operating in Wales to note that in May partnership with our new regulator, in for Wales 2012, the Minister for Environment and particular to provide better evidence Sustainable Development, John Griffiths, to Welsh Government and thus announced that a Natural Resources body support better evidence based policy will be created to bring together the making. We look forward to seeing a Forestry Commission Wales (FCW), more efficient and effective regulator, Countryside Council for Wales (CCW) and who can pass on these efficiencies in the Environment Agency Wales (EAW). This lower charges to industry. new organisation will begin operating in April 2013. Table 1-4 Progress versus EAW and the Welsh Government expectations for dWRMP 2013
Page | 18 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
1.12 Key risks & uncertainties There are a number of key areas that will present great challenges for us over the next 5-10 years. We have summarised these in the following table along with our intended approach to dealing with these challenges.
Challenge Strategy
Habitats Directive Reductions to our abstraction licences on the Wye, Usk and Eastern Cleddau are proposed to take place during the AMP 6 (2015-2020) period. These significant modifications will, in the case of SEWCUS, reduce the available headroom within the zone and for Pembrokeshire remove all available headroom once licence changes are in place. This will have a significant impact upon zonal operations and we can expect reservoir levels to fall to lower levels during critical dry year periods. We will need to ensure that we are able to abstract up to our full licence allocations during future critical (dry) years and this will require system automation at the very least. In addition, in the lead in to these changes we will undertake studies to understand if these changes cause any residual risk to water supply through an impact upon water quality. A need has also been identified in the SEWCUS zone to improve system resilience with regard to strategic transfer capacity so that the all of our assets can be used fully. We are aware that there is a potential conflict between the preferred date for licence changes on the Wye within the Dŵr Cymru Welsh Water and Severn Trent dWRMP 2013 which has yet to be released.
Water Framework In December 2009 the first round of River Basin Management Plans were Directive (WFD) approved by English and Welsh Ministers and set out the actions and strategies for improving water bodies currently failing their objectives. During our current (2010-2015) investment programme we anticipate that WFD investigations that are underway into these failures could lead to further modifications to our operations being required. We will maintain our position on the steering group of key UK Water industry research and or development projects and will therefore contribute to our regulators’ decisions affecting how we should meet the Directive in our current and future investment programmes. We will also continue with WFD and Habitats Directive comprehensive environmental studies to ensure that any decisions made by our regulators are aligned with Welsh Government’s policy position on ecosystem services, and to ensure that our decisions are future proofed for the next few investment cycles.
Restoring Sustainable The Environment Agency’s (now Natural Resources Wales’s) Restoring Abstraction Sustainable Abstraction Programme is ongoing within Wales and we are aware Programme there are a number of sites that Natural Resources Wales wishes to investigate further to assess what impact our operations are having upon the ecological integrity of specific sites. Subject to funding approval, we will undertake environmental studies in partnership with Natural Resources Wales (successor to Environment Agency Wales) in AMP6 to ensure that any such future changes to our abstraction regimes are equitable and aligned with Welsh Government policy on the ‘ecosystems approach’.
Competition in the We will use the WRMP to confirm both our water resource needs and surpluses Water Industry (Water available to other water undertakers and industry. We will also set out what Trading) additional surpluses can be created so as to bring water hungry industry to Wales and those parts of England we supply.
Page | 19 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Challenge Strategy
Natural Resources On 1 April 2013, Environment Agency Wales, Countryside Council for Wales and Wales Forestry Commision Wales formed a new single body known as Natural Resources Wales. Whilst most welcome, this will result in a change to our ways of working with these bodies. We look forward to working closely with Natural Resources Wales and increasing the quality and quantity of evidence we gather with them to ensure the Welsh Government is in a stronger position to drive evidence based policy making and the ecosystems approach.
Water Strategy for In its 2011 ‘Programme for Government’ the Welsh Government undertook to Wales “develop a Water Strategy, which will shape the priorities for water and water services in Wales including priorities for infrastructure investment.” Publication of this key document, which may have a significant affect on water resources policy and our final plan, is still awaited.
Environment Agency In June 2012 the Environment Agency published its latest Water Resources WRMP Guidance on Planning Guideline, which set out its position on amongst other matters how climate change UKCP09 climate change scenarios should be incorporated in water resource assessment management planning for the 2013 draft WRMP submissions. We have and will continue to apply this guidance to our dWRMP 2013. It has increased our confidence in the predicted impacts of climate change and affected the supply demand position in our resource zones. However,we are aware that at least two of the approaches (‘Future Flows’ and CP09) specified within the guidence for assessing the impact of climate change leads to significantly different results. This indicates a degree of uncertainty and sensitivity of Plan outputs in relation to the climate change approach adopted in each WRZ.
1.13 Annual WRMP Review In preparing this draft Plan we have undertaken many detailed studies. However, water resource planning is a dynamic process and we are committed to reviewing and refreshing the key elements of the Plan on an annual basis. This is an improvement to our five yearly planning process and we would appreciate any feedback from stakeholders on how best to effectively consult them for their views.
By 2020 we also intend (subject to necessary funding approval by Ofwat) to:
Publish a revised Drought Plan in 2013 and similarly by 2018 which aligns with our WRMPs. The Drought Plan shows the actions we would take in a drought situation.
Complete our comprehensive environmental investigations to support Habitats Directive sustainability reduction decisions, and publish these by 2018, in time for the next statutory WRMP and 2020-2025 business planning cycle.
Improve our understanding of the quantity and quality of inflows to our catchments to enhance our water resources and reduce the financial and carbon costs associated with water treatment.
More generally, use the next few years to undertake further work on the challenge of meeting water resource objectives in Wales including, in particular, the creation of an improved evidence-based understanding of the environmental impact of our abstractions.
Page | 20 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The major strategic decisions that we make must be the right ones both for current and future generations, and to this end we will seek to work in partnership with our stakeholders, especially our new environmental regulator, Natural Resources Wales.
Page | 21 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
2 Supplying water in our area This chapter provides factual background on our water supply area. It explains some of the critical issues that we must consider and describes how our assets have been developed and managed to ensure that we can provide a reliable supply of water to our customers.
2.1 Water resources in our supply area Dŵr Cymru Welsh Water delivers water supply services to most of Wales and some parts of England, including most of Herefordshire. In total we supply water to over 3 million people, of which 40% are concentrated in the south east of Wales in the Cardiff and Newport area and much of the remainder is located in the main population centres around the coast. These are in sharp contrast to the sparsely populated areas of mid-Wales, where population densities are amongst the lowest in the UK.
Wales has a relatively wet climate when compared to other parts of the UK. We estimate that we only capture and use some 3% of rainfall, on average, for public water supply, which compares with 50% in some parts of South East England. However, the regional picture masks important geographical differences within our supply area: for example, at up to 3,000mm per annum, rainfall in Snowdonia can be more than four times the levels recorded in the border areas and Herefordshire, where 700mm per annum is typical.
The diversity of our water supply systems reflects these regional variations. Most comprise discrete small-scale local supplies, of which we have a considerable number, with only South East Wales being served by the sort of large scale multi-source integrated network that is typical in other water company areas.
Our main sources of water are our 65 impounding reservoirs. These are linked closely to our five major river regulation schemes: on the Rivers Wye and Usk in the south east of Wales; the Rivers Tywi and Cleddau in the south west; and the River Dee in the north.
As a result of the natural landscape and geology of Wales, groundwater accounts for just 5% of the total water supplied. Most groundwater sources are operated conjunctively with surface water sources. However, some sources are critical in supplying local areas that cannot be supplied by other means.
On average we abstract from the environment around 800 million litres a day (Ml/d) for public water supply. This normally increases by around 15 - 20% during the summer. During periods of extreme conditions – long hot summers or sudden thaws following freezing weather – the demands on our supply systems can increase by over 25%, and in some localised areas by nearly 50%.
Underlying these short term variations is a long term steady decline in overall water demand (see chapter 4). This is primarily due to the decline of heavy industry, particularly in South Wales, and the significant reduction in leakage from our networks over the past fifteen years.
Page | 22 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
DCWW Distribution Input 1150
1100
1050
1000
950
Ml/d 900
850
800
750
700
Figure 2-1 Declining trend in water supplied
Against this background, and notwithstanding a general perception that Wales has an abundant supply of water, our future water supply strategy faces a number of challenges, including the Habitats Directive licence reductions and the impacts of climate change, as set out in the remainder of this document.
2.2 Water resource zones - general Our water supply area is divided into 24 Water Resource Zones (WRZs). These zones are defined as the largest area in which all resources can be shared, and hence they represent a group of customers who receive the same Level of Service. The WRZs essentially define the limits of the areas beyond which water supply becomes increasingly uneconomic with the current supply infrastructure. The landscape of our supply area means that each of these WRZs is fairly self-contained, and the scope to move water between zones is limited.
Figure 2-2 shows our 24 WRZs, of which the largest is the South East Wales Conjunctive Use System zone (SEWCUS) which covers 40% of our customers, and the second largest is Tywi Conjunctive Use System (CUS), which covers another 20%. By contrast, the eight smallest zones together cover just 1.5% of our customers. Table 2.1 presents further details on each of the 24 WRZs.
Page | 23 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 2-2 Water resource zones
WRZ No. WRZ Name Area (km2) Population Water Main Source of Water Served (‘000)7 Delivered (average, Ml/d)8
North Wales
8001 North Eryri Ynys Môn 1,336 121 39 Reservoir storage
8012 Clwyd Coastal 152 80 20 Reservoir storage
8014 Alwen Dee 1,142 155 46 Reservoir storage
8020 Bala 391 4 1 Reservoir storage
8021 Tywyn Aberdyfi 68 5 1 River abstraction
8026 Blaenau Ffestiniog 332 6 2 Reservoir storage
8033 Barmouth 85 5 2 Reservoir storage
7 Source: Table 10 June Return 2009 8 Based on average water delivered Table 10 June Return 2006 – 2009 with estimated zonal leakage included.
Page | 24 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8034 Lleyn Harlech 648 35 14 Reservoir storage
8035 Dyffryn Conwy 841 90 29 Reservoir storage
8036 South Meirionnydd 584 7 2 Reservoir storage
South West Wales
8201 Tywi CUS 3,524 695 172 Reservoir storage
8202 Mid and South 1,780 62 18 Reservoir storage Ceredigion
8203 North Ceredigion 469 31 9 Reservoir storage
8206 Pembrokeshire 1,699 117 38 Reservoir storage
South East Wales
8101 Ross on Wye 198 19 7 Bulk supply import
8102 Elan Builth 1,229 18 5 Reservoir storage
8103 Hereford Conjunctive 1,258 128 34 River abstraction Use System (CUS)
8105 Llyswen 353 9 2 River abstraction
8108 Brecon Portis 447 12 4 Groundwater abstraction
8106 Monmouth 104 13 4 River abstraction
8107 Pilleth 366 8 2 Groundwater abstraction
8110 Vowchurch 250 7 2 Groundwater abstraction
8111 Whitbourne 354 15 5 River abstraction
8121 SEWCUS 2,756 1287 370 Reservoir storage
TOTAL 20,366 2915 829
Table 2-1 Water resource zones – Key Facts and Figures
Page | 25 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3 Water supply capacity The purpose of this chapter is to set out how we calculate the amount of water we can supply in each WRZ. This is a function of the ‘Deployable Output’ of our water resource assets together with the allowances and adjustments that are made for the operational losses that are inherent in the treatment of water9, outages, and transfers. We also summarise the latest results in the assessment of climate change on water supply for the 2030s.
3.1 Deployable output Deployable output (DO) is the maximum quantity of water from a source, a group of sources, or from a bulk supply, that can be sustained during a dry year. Output can be constrained by:
river flows, reservoir storage and groundwater levels, as determined by hydrological and/or hydrogeological conditions; or abstraction licence conditions, including environmental needs such as freshet releases (additional releases to support ecology including fisheries) ; the capacity of assets (pumping stations, treatment works, mains); We have assessed Deployable Output in accordance with Environment Agency guidelines and best practice methodologies10. We have also specifically carried out in-depth modelling to re-assess Deployable Output in all of our 24 WRZs with the development of 9 new water resources simulation models for previously un-modelled WRZs.
Table 3.1 presents the Deployable Output values for the company’s 24 Water Resources Zones and the key constraint on that value. The Deployable Output values represent the ‘minimum’ value for the year and peak week in the simulation when demand restrictions are imposed in the model. These restrictions are 5% reductions in demand for a Hosepipe Ban and 10% reductions in demand for a Drought Order and are generally triggered in the modelling process when the simulation of reservoir stocks reduces below the appropriate control line included in the model in accordance with the company’s level of service and Drought Plan.
ZONE Annual Critical Constraint Average Period DO Ml/d DO Ml/d
8014 Alwen Dee 57.0 66.3 Alwen WTW at capacity; also Poutlon abstraction is at licence limit (28Ml/d)
8020 Bala 1.8 2.3 Peak WTW daily licence of 2.27 Ml/d.
8033 Barmouth 2.1 3.2 Levels of Service – number of times in simulation that Llyn Bodlyn is drawn down below the hosepipe ban control line
8026 Blaenau Ffestiniog 3.0 3.3 Garreglwyd WTW at maximum capacity (3.5 Ml/d);
9 Losses from the distribution system are part of leakage and are included in “demand”, as described in chapter 4. 10 Surface Water Yield Assessment (National Rivers Authority, 1995); Reassessment of yield methodology (EA, 1997); A Unified Methodology for Determination of Deployable Output from Water Sources (UKWIR and EA, 2000); Water Resources Planning Tools 2012 – Deployable Output (DO) Report (UKWIR, 2012)
Page | 26 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
maximum river abstraction on Afon Gam.
8108 Brecon Portis 4.8 5.5 Daily licence to Brecon – Portis WTW (current licence)
8108 Brecon Portis 4.3 4.9 Brecon Review of Consent rules (maximum abstraction (including ROC 3.27 Ml/d when river flow <425 Ml/d - occurs single day reductions) (9/8/95) only)
8012 Clwyd Coastal 26.0 30.2 Plas Uchaf Annual Licence and Planned Levels of Service
8035 Dyffryn Conwy 36.0 40.8 Llyn Cowlyd Annual Licence
8102 Elan Builth 8.4 9.5 Builth Daily Licence
8103 Hereford CUS 49.6 56.3 Broomy Hill Daily Licence
8034 Lleyn Harlech 19.0 21.9 Cwm Dulyn & Llyn Tecwyn Daily licence
8105 Llyswen 4.4 5.0 Llyswen Daily licence
8106 Monmouthshire 6.8 7.7 Daily licences
8202 Mid and South 24.0 31.8 Strata Florida WTW licence and capacity Ceredigion
8203 North Ceredigion 12.8 14.6 Planned Level of Service (Drought Orders)
8001 North Eryri Ynys 50.5 58.3 Planned Level of Service (Hosepipe bans) Môn 8206 Pembrokeshire 79.5 97.6 Preseli WTW Capacity (current licence)
8206 Pembrokeshire 71.2 88.4 Storage in Preseli Reservoir and Planned Level of Service (including ROC reductions)
8107 Pilleth 3.4 3.8 Pilleth Daily Licence
8101 Ross 7.9 9.0 Maximum transfer from Severn Trent Water (9 Ml/d)
8121 SEWCUS (current 436.2 492.9 Asset constraints in High Level part of system licence)
8121 SEWCUS (including 410.3 461.9 Llandegdfedd drawdown ROC reductions)
8036 South Meirionnydd 2.3 2.9 Afon Calettwr intake licence
8201 Tywi CUS 242.0 293.2 Bryngwyn WTW at maximum capacity
8021 Tywyn Aberdyfi 1.7 2.6 Daily Licence on both Afon Fathew and Nant Braich-yr- Rhiw abstractions
8110 Vowchurch 2.4 3.0 Hands off Flow
8111 Whitbourne 5.2 7.0 Hands off Flow Table 3-1 Deployable output values for Dŵr Cymru Welsh Water
Page | 27 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3.2 Levels of Service (LoS) A key role in Water Resources Planning is played by the frequency with which a hosepipe ban or a Drought Order/ Permit would be expected to be required in order to maintain water supplies, the ‘Level of Service’.
We believe that it would be wrong for us to plan for a level of service that would guarantee there would never be any customer restrictions as this would require enormous investment in additional water resource assets (principally reservoirs) which would be used very infrequently. This would require much higher levels of customer bills, which we do not consider could be justified, and would be environmentally unacceptable.
The Company has accordingly set its minimum overall level of service as follows:
not more than once in every 20 years, on average, for a hosepipe ban, and
not more than once every 40 years, on average, for Drought Orders/ Permits.
We view the imposition of rota cuts and standpipes, which represent more severe restrictions on customer use, as unacceptable. This is for several reasons, notably the risk to public health that rota cuts and standpipes entail. We will be asking our customers, as a part of Price Review investment planning for the period 2015-2020 (PR14) for a view on whether they feel that this LoS is appropriate. The full report indicates the sensitivity of Deployable Output to LoS11.
3.3 Outage Outage is defined as the temporary loss of Deployable Output (DO) due to planned and unplanned events in a dry year (or drought period). An allowance for outage is required in order to recognise that at any given time some assets will temporarily be out of action for one reason or another. It is important to estimate outage for each WRZ individually: this is done by taking a pragmatic view of the potential future reduction in Deployable Output that could be caused by asset failures and/ or operational problems. Dŵr Cymru Welsh Water has implemented a comprehensive programme to collect accurate information on actual outage events, and the estimation of future outage is based on these data, at the zonal level.
Table 3-2 presents the revised outage allowances for each water resource zone. Dry year outage allowances range from a minimum of 0.06% of DO in Blaenau Ffestiniog to a maximum of 4.18% of DO in Alwen Dee. The average dry year outage allowance across all zones is 1.7% of DO. Critical period outage (defined as period of high demand, such as hot weather or very cold weather when leakage occurs) allowances range from 0.04% of DO in Blaenau Ffestiniog to 3.90% of DO in Vowchurch. The average critical period outage allowance across all zones is 1.16% of DO.
11 Dŵr Cymru Welsh Water Deployable Output Assessment for 2013 draft Water Resources Management Plan, AMEC UK Ltd, March 2013
Page | 28 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Resource Zone Dry Year Outage Allowance Critical Period Outage (%DO) Allowance (%DO)
North Eryri Ynys Môn 4.0% 2.6%
Clwyd Coastal 4.0% 2.8%
Alwen Dee 4.2% 2.3%
Bala 0.36% 0.26%
Tywyn Aberdyfi 2.2% 2.2%
Blaenau Ffestiniog 0.06% 0.04%
Barmouth 0.11% 0.12%
Lleyn Harlech 0.35% 0.34%
Dyffryn Conwy 0.09% 0.09%
South Meirionnydd 0.27% 0.18%
Ross on Wye 0.00% 0.00%
Elan Builth 2.32% 1.3%
Hereford CUS 0.96% 0.81%
Llyswen 2.8% 1.5%
Monmouth 3.4% 0.52%
Pilleth 0.46% 0.43%
Brecon Portis (current licence) 0.92% 0.92%
Brecon Ports (post ROC licence) 0.93% 0.91%
Vowchurch 4.1% 3.9%
Whitbourne 3.1% 2.8% SEWCUS (current licence) 3.1% 2.0% SEWCUS (post ROC licence) 3.0% 1.8% Tywi CUS 0.10% 0.08%
Mid and South Ceredigion 1.0% 0.21%
North Ceredigion 1.3% 0.87%
Pembrokeshire (current licence) 1.1% 0.8%
Pembrokeshire (post ROC licence) 1.1% 0.70% Table 3-2 Outage allowances as a percentage of deployable output
Page | 29 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3.4 Operational use of water Water is used during the routine operation of raw water mains and water treatment works, such as when mains are flushed. Overall we estimate that around 3.5% of water abstracted is utilised in operational activity, however this varies between WRZs.
3.5 Water transfers
3.5.1 Potable supplies There is some limited scope to transfer water, both raw and treated, between particular parts of zones in our area and in the form of bulk supplies between ourselves and neighbouring water companies. A summary of our transfers is shown in Table 3-3.
Export from Import by Maximum volume(Ml/d) Type
Alwen Dee WRZ Dee Valley Water 0.16 Bulk Supply
Lleyn Harlech WRZ* Barmouth WRZ 1 Transfer
Severn Trent Water South Meirionnydd WRZ 0.45 Bulk Supply
South Meirionnydd WRZ Severn Trent Water 0.12 Bulk Supply
Severn Trent Water Ross-on Wye WRZ 9 Bulk Supply
Hereford CUS WRZ* Whitbourne WRZ 1 Transfer
Hereford CUS WRZ* Ross on Wye WRZ 1 Transfer
Hereford CUS WRZ Vowchurch WRZ 0.45 Transfer
Tywi CUS WRZ SEWCUS WRZ 12.03 Transfer
*Schemes delivered in AMP4 to increase inter-zonal transfer capability Table 3-3 Water transfers
3.5.2 Non-potable supplies In addition to supplying domestic and non-domestic customers with potable water, we do in certain instances and locations supply large industrial users with water that has not been treated to potable standards but that is suitable for their purposes.
In Pembrokeshire we supply numerous industrial users of water in and around the Milford Haven area, mostly involved in the oil refinery, natural gas and power generation industries. The supply of non-potable water is taken account of directly within DO in this zone, as both potable and non- potable supplies are balanced from the same raw water source. At present the supply of water equates to approximately 27 Ml/d. However, there are significant economic pressures to increase development in this area. This presents a significant challenge in maintaining the supply demand
Page | 30 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
balance in this zone where the existing resources are already stretched in response to the Habitats Directive driven process (see chapter 6 for potentially significant reductions in the water available for abstraction).
In SEWCUS we provide non-potable water to Tata Steel (formally Corus). As with Pembrokeshire, this water is directly accounted for within the DO as it is primarily supplied from raw water from our abstractions on the River Usk, which is also used for domestic supply. Our largest non-potable bulk supply is to Severn Trent Water from the Elan reservoir system; however, this is not included within the supply-demand tables as this water is not used to meet Dŵr Cymru Welsh Water’s customer demand.
3.5.3 Other customers There are a number of smaller Industrial customers we supply which are fed directly from an abstraction. These supplies do not influence the supply demand position within any of our WRZs as they do not add available water for use by other customers. Full details of these sources are reported to Ofwat and Natural Resources Wales as part of our annual reporting process.
We also provide a non-potable supply to Albion Water. This water is not accounted for within our supply demand balance for our Alwen-Dee WRZ as the supply is a direct non-potable supply from a single raw water source and has no connectivity with other supplies within the zone. Under the definition of DO, it would be incorrect to include it within baseline tables as the supply cannot contribute to the overall zonal supply demand balance. However, the supply is considered within consideration of options to meet future water demands.
3.6 Climate change It is essential that the potential impacts of climate change on both water supply and demand are adequately accounted for within this Plan. Our Plan incorporates the latest climate scenarios, UK Climate Projections 2009 (UKCP09). The most recent version of the Environment Agency’s Water Resource Planning Guidance (October 2012), states that:
“A water company must assess the likely impact of climate change on its Plan and report the likely implications for deployable output. A water company should agree the vulnerability of the sources to climate change with the Environment Agency before undertaking the climate change impact assessment, and should include the findings of the assessed impacts of climate change when forming its Plan. Where a company believes that climate change is having an immediate impact upon its deployable output, it should present the evidence for this in its Plan.”
The guidance requires Dŵr Cymru Welsh Water to assess the effects of climate change on resource zone deployable output by assessing the implications of climate change on river and reservoir catchment flows. We have also assessed the impact of climate change on future preferred options.
The October 2012 guidance clearly states that the methods applied by a water company to assess the affect of climate change on deployable output should be proportionate to the risk presented by climate change to each water resource zone. To establish this risk a vulnerability assessment must first be undertaken to determine how vulnerable a water resource zone is to the effects of climate
Page | 31 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
change. The outcomes of this assessment have informed the proportionate level of climate change assessment, such as the number of modelling scenarios that should be applied.
For the purposes of water resources planning vulnerability is defined as :
Vulnerability – Climate vulnerability defines the extent to which a system is susceptible to, or unable to cope with, adverse effects of climate change including climate variability and extremes.
The results of the Vulnerability Assessment for Dŵr Cymru Welsh Water are shown in Table 3-4 below.
High Medium Vulnerability Low Vulnerability Climate Change Vulnerability Resilient
Pembrokeshire Blaenau Ffestiniog South Meirionnydd Hereford CUS
NEYM Barmouth Tywi CUS Pilleth
SEWCUS Tywyn Aberdyfi Dyffryn Conwy Vowchurch
Clwyd Coastal Bala Brecon
North Ceredigion Alwen Dee Whitbourne
Lleyn Harlech Mid and South Ceredigion Llyswen
Elan-Builth
Ross
Monmouth Table 3-4 Final vulnerability classifications for Dŵr Cymru Welsh Water
There are a number of smaller zones, which have only river intake and borehole sources (no reservoirs), within which climate change impacts are not predicted to reduce available abstraction. As such no negative impact on baseline Deployable Output is predicted and no climate change modelling has been undertaken. All of these zones are asset constrained (licence or WTW capacity) preventing any increase from baseline Deployable Output. Where there are restrictions such as ‘Hands off flows’ in these zones, an assessment has shown that there are sufficient river flows to maintain supply.
The Water Resource Planning Guidance (October 2012) then outlines four steps which water companies are to follow in the estimation of deployable output under climate change, once the vulnerability assessment has been completed. The stages are as follows:
Stage 1 – Calculate river flows (groundwater recharge is not applicable to this assessment in Wales) for each water resource zone for the 2030s, under the number of climate change projections defined by the vulnerability assessment;
Stage 2 – Calculate deployable output for each of the climate change scenarios, in each water resource zone;
Page | 32 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Stage 3 – Scale the impacts of climate change by determining the change in deployable output for each year of the planning period;
Stage 4 – Determine the uncertainty associated with climate change for inclusion in target headroom.
A full suite of up to 20 projections (depending on the zone) were run through water resource simulation models to assess the climate change impacts on Deployable Output. A summary of the climate change results in terms of minimum annual average DO, for all the zones is presented in Table 3-5 along with a weighted ‘Best Estimate’ of the impact of climate change. Under some of the climate change projections, gains in DO against the baseline are predicted, but the general picture is one of reduced yields.
Water Resource Minimum Annual Average DO (Ml/d) Zone
Baseline Greatest Impact Least Impact Weighted Best Estimate
Pembrokeshire 79.5 50.3 79.5 71.1 (current licence)
Pembrokeshire (post 71.2 59.0 75.2 65.9 ROC licence)
NEYM 50.5 34.1 51.1 44.8
SEWCUS (current 436.3 406.7 436.3 432.3 licence)
SEWCUS (current 410.3 381.4 422.9 403.3 licence)
Blaenau Ffestiniog 3.0 2.8 3.0 2.90
Barmouth 2.1 1.7 2.2 1.9
Tywyn Aberdyfi 1.7 0.7 1.7 1.3
Lleyn Harlech 19.0 17.2 19.6 18.4
Clwyd Coastal 26.0 24.4 26.0 25.3
North Ceredigion 12.8 11.8 13.2 12.3
South Meirionnydd 2.3 2.3 2.3 2.3
Tywi CUS 242.0 239.3 242.0 240.8
Dyffryn Conwy 36.0 35.8 36.0 35.9
Bala 1.7 1.7 1.7 1.7
Alwen Dee 57.0 50.3 57.7 56.5
Mid and South 23.9 23.7 24.1 23.9 Ceredigion
Page | 33 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Table 3-5 Predicted climate change impacts on min Annual Average DO in all zones with climate change vulnerability for the 2030s
3.7 Water available for use Water Available for Use (WAFU) is defined as the volume of water available once we have adjusted Deployable Output for outage, transfers and operational losses, and provides the figure we use for planning purposes as the amount of water we can expect to be able to supply. It is Water Available for Use that provides the figure that, if exceeded by the sum of Demand and Target Headroom, signifies that a zone is in deficit.
Page | 34 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
4 Demand
4.1 Demand for water
4.1.1 Introduction A 25 year demand forecast has been produced for the period commencing 2015/16 along with three ‘pre plan’ years from the base year or the remainder period of AMP5. The forecast has been developed in line with current Best Practice guidance as outlined in ‘Demand Forecasting Methodology’ (UKWIR/NRA, 1995).
The components of demand have been assessed along with variables affecting initial assessments of consumption including policies that drive forecasts such as building standards, climate change impacts on demand, the changing nature of how the customer base is billed over time, the effects of a changing structure within the Water Industry (competition forces driving the efficient use of water) and the current status of the economic recovery.
The demand forecast is underpinned by a recent reassessment of leakage which for the duration of the Plan follows a reducing profile over an optimisation period until being held ‘flat’ to the end of the planning period (2040).
In summary, Normal year demand during the Plan period is forecast to reduce from a Base year level of 824 Ml/d to 785 Ml/d in 2039/40. Current consumption and forecast consumption, as a ratio of total demand are outlined below:
DŴR CYMRU WELSH WATER Demand Components in 2011/12 (Inner) and 2039/40 (Outer)
21.2%
31.5% 10.4% 22.5%
Total NY Demand: 3.8% 2011/12: 823.81 Ml/d 3.1% 2039/40: 784.52 Ml/d 0.6% 0.2% 41.6%
21.9%
22.4%
20.9%
Key: Leakage Unmeasured Non-household Unmeasured Household Minor Components Measured Non-household Measured Household
Figure 4-1 Demand Components
Page | 35 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
4.1.2 Base Year of the Forecast In order to generate a demand forecast, it is necessary to first understand the magnitude of the various components of demand during a historical annual period, the Base Year. It is then possible to examine each of these components separately and to predict the future trends in these, the sum of which is a forecast of total demand over the planning period.
The Base Year for the current demand forecast is 2011/12 using the Water Balance produced for the June Return 2012 within which the components of demand have been reconciled to the observed levels of consumption within this Base Year. The overall level of demand in the Base Year relates to the observed weather patterns. This climatic impact is eliminated by normalising the forecast. The year 2011/12 was slightly drier than average resulting in a ‘normalisation’ factor of 0.995 being applied to demand components.
4.1.3 Base Year Populations and properties Base Year population and property forecasts have been developed in line with methodologies outlined in ‘Methods of Estimating Population and Household Projections’ (Environment Agency, 2012) and supporting Best Practice methodologies.
Total resident population is as reported in the Base year, the population for the forecast has been derived from published Mid Year Estimates (MYEs) procured from CACI Ltd and matches the MYE published at Council area level by the Office of National Statistics (ONS), Department for Communities and Local Government (DCLG) and the Welsh Government. Base Year property counts are as reported in June Return 2012; property numbers are extracted from the company billing system. Property counts are averages for the reporting year.
4.1.4 Forecasting population and property numbers Our approach to producing population and household forecasts also follows the EA guidance stated above. For the current Plan we have actively engaged with the Local/Unitary Authorities (LUAs) within our supply area to gather data regarding the local planning process and development plans, in lieu of a centralised forum delivering this in Wales. Our supply area intersects a total of 29 LUAs which includes 25 Welsh authorities, including 3 National Park Authorities (NPAs) and 4 English Planning Authorities.
The 2011 Census was released in July 2012. The data sets included: Total, Communal and Household population projections for LUAs for both England and Wales. The Census update did not provide data for NPAs. The trend based estimates of population have been rebased to the 2011 Census results.
In recognition of the abolition of the spatial planning approach in England due to the ‘Localism Agenda’ we have actively engaged with English authorities to gain their most up to date forecasts. For Welsh authorities a pragmatic view for interpreting forecasts to actual build ratios has been adopted to derive the most accurate forecasts.
The overall population forecasts derived from the available datasets is outlined in Figure 4-2 and summarised in the table below.
Page | 36 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
DŴR CYMRU WELSH WATER Historic and Forecast Population Unmeasured Household Historic Measured Household Historic Non Household Historic Total Historic 'Unmeasured Household Forecast Measured Household Forecast Non Household Forecast Total Forecast 3500
3000
2500
2000
1500 Population(000s) 1000
500
0
Figure 4-2 Population forecasts (2012/13 to 2039/40)
Component 2011/12 2014/15 2019/20 2024/25 2029/30 2034/35 2039/40
000s 000s 000s 000s 000s 000s 000s
Unmeasured 2114.242 1998.294 1789.483 1595.588 1418.127 1255.966 1110.908 Household Measured 722.652 882.954 1168.960 1436.411 1676.256 1887.916 2081.759 Household Non Household 95.733 96.891 99.865 105.001 110.380 117.151 124.110
Total 2932.627 2978.139 3058.308 3137.000 3204.763 3261.033 3316.777
Table 4-1 Population forecasts (2012/13 to 2039/40)
4.2 Base Year household consumption Base Year household demand is derived from either measured billed volumes or our Domestic Consumption Monitor (DCM). This reports on up to 84 discrete Leakage Control Areas (LCAs) selected to be representative of the socio-economic characteristics of the Company’s customer base. The primary purpose of the DCM is to enable the Company to determine unmeasured household Per Capita Consumption (PCC).
The Base year combined average PCC was reported as 152 litres per household per day (l/h/d), an average of unmeasured household consumption of 163 l/h/d and measured consumption of 119 l/h/d. These values are used as the reconciliation basis of all forecast values. Average PCC is extrapolated across the company providing a range of values between 135 and 160 l/h/d.
Page | 37 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Work is currently ongoing to upgrade the DCM to ensure it remains statistically representative of consumption across the company zones for the foreseeable future and that it is reflective of the drivers of diverse consumption patterns within the company supply boundary.
‘Normal’ year forecasts of unmeasured and measured household consumption are calculated by multiplying together the forecasts of population and PCC described above.
Since the forecasts are based on June Return 2012 result data, the baseline forecasts reflect current levels of domestic metering and water efficiency measures. Future increases in meter optant numbers are taken into account in the forecasts as are increased water efficiency measures such as a move towards more water efficient washing machines and dishwashers and a reduction in toilet flushing volumes.
DŴR CYMRU WELSH WATER Historic and Forecast Total Household Demand
Historic 'Normal' Year Forecast 'Dry' Year Forecast 460
440
420
400
380 Total Household Ml/d Household Total
360
340
Figure 4-3 Forecast Household Demand
4.3 Water Efficiency Strategy The forecast of Household demand includes the benefits from the ongoing programme of measures designed to promote water efficiency. During AMP5 (2010-2015) we are delivering against targets set by Ofwat, the target is 1.31 Ml/yr through predefined interventions. The base service is the equivalent of 1 litre per connected customer given that the Company is operating in a ‘Low Water Stress Area’. This equates to a total of 6.55 Ml/d by the end of the AMP period.
In addition we are delivering against a 0.16 Ml/d saving by the end of AMP 5 under the Sustainable Economic Level of Water Efficiency (SELWE) target identified in the previous WRMP to deliver against a deficit in the Tywyn Aberdyfi WRZ.
Our current approach to delivering water efficiency savings is outlined in Table 4-2 along with actual values for the base year.
Page | 38 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Intervention Ml/d
Toilet Cistern Displacement Devices 0.197
Water Butts delivered 0.0006
Schools Activity including retrofits 0.226
Business customers including retrofits 0.472
Welcome Packs to optant customers 0.466
Universities including retrofits 0.13
Sub-total 1.492
Educational and communication activity 0.4844
Total Savings 1.967
Table 4-2 Current Water Efficiency Position
Base Year demand is considered to be representative of consumption influenced by current company policy for water efficiency. As such, the effects of policy are embedded within the base year reported consumption results. The ongoing savings suppressing demand require current trends in demand to continue through our ongoing activity as a minimum. Our obligations to promote water efficiency and reduce demand is aligned with the ecosystems approach, helping to balance the needs of the environment and society.
Efficiency related demand savings achieved since the start of AMP 5, i.e. 2010, total 3.41Ml/d. Projected savings by the end of the AMP, i.e. 2015, based on maintaining this level of intervention equate to 9.44 Ml/d.
Figure 4-4 below on 2015-2020 (AMP5) Water Efficiency Interventions provides a geographical representation of the current water efficiency activity delivered to date, along with a brief commentary of the intervention type. As expected, uptake of interventions is evenly distributed across the supply area with greater concentrations occurring around the denser conurbations.
Page | 39 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
*NHH = Non household Figure 4-4 AMP5 Water Efficiency Interventions
The key features of our future water efficiency strategy build on the success of the activity delivered in AMP5. During focus groups with customers it is evident that improved communication of the benefits of water efficiency will continue to sustain customer interest and uptake of a range of water efficiency offerings, based on relatively low uptake rates compared with target audience (about 1.5% by zone) suggests that existing modes of delivery are not saturated. These engagement sessions have confirmed the value of:
Promoting positive messages about water efficiency to customers.
Leading by example through ensuring operational assets and offices are water efficient and that we are delivering against our leakage targets.
Page | 40 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Informing customers of the potential financial benefits of water efficiency.
Informing customers of the potential energy and carbon benefits of water efficiency.
Enabling customers to act on saving water through access to products or advice.
Targeting water efficiency interventions in line with the affordability agenda in Wales.
Positively impacting an overall downward trend in Per Capita Consumption (PCC).
Sustained grass roots education through working with Eco-schools through our extensive education programme of outreach and environment centres.
Our future strategy will focus on maximising the potential for broader delivery through;
Working with stakeholders that have existing routes to market through established communications channels.
Working collaboratively with agents delivering energy efficiency retrofit programmes.
Maximising the opportunity to promote water efficiency through existing interaction with customers.
Making water efficiency accessible through web enabled solutions.
In recognition of the changing regulatory environment, and the replacement of the volumetric target for base level activity with a target for the reduction of Per Capita Consumption, our future strategy will adapt to enable water efficiency in the retail sector for non household demand to be delivered through market forces unless identified as a specific supply demand solution for a known deficit. This will allow resources to be invested in a base level delivery model more aligned to the future PCC target.
4.3.1 Non-household consumption CACI Ltd was commissioned to develop an econometric model to forecast measured non-household demand for fourteen industrial sectors at a WRZ and Company level. The previous approach to forecasting this component was to use trend based analysis of historical measured water consumption data across the same 14 sectors. The move to an econometric based model is an improvement in methodology and is in keeping with ‘best practice’ guidance for forecasting this component.
The mechanism built into the model utilises a range of parameters to generate the overall forecasting profile. The parameters used within the model include:
Historical measured non-household demand at sector and WRZ level;
Climate data - temperature, rainfall and sunshine hours from the Met Office and UKCIP09 forecasts;
Econometric data - Base Rate, GDP, Inflation and Unemployment – Bank of England and IMF forecasts up to 2017 (existing extent of published data sets) from which point the values are maintained flat;
Page | 41 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Forecasts of numbers of non-household properties and population;
‘Fuzzy Logic Rules’ – which utilise business knowledge and policies that may influence future non-household demand levels e.g. water efficiency measures / policies, etc.;
The option to include / exclude demand volumes associated with the open and closure of large businesses and/or business expansion and contraction;
The resultant non-household forecast profile also reflects our future water efficiency strategy. Figure 4.3.2 below shows the regional total measured non-household forecasts provided by CACI Ltd. Adjustments for meter under-registration, plumbing losses and reconciliation of the water balance gap using the Maximum Likelihood Estimation statistical technique were added to the CACI forecasts within the Company’s Demand Forecasting Model.
DŴR CYMRU WELSH WATER Historic and Forecast Measured Non Household Demand Historic Measured Non Household Demand 'Pure Econometric Forecast Final Forecast (inc. Water Efficiency Activity) Previous Forecast 230
220
210
200
190
180
170
160
Measured Non Household Ml/d Household Non Measured 150
140
130
Figure 4-5 Econometric Non Household Model
There is a significant variance between the results from the two approaches. However, further calibration points will be available this year which will help in confirming or otherwise the ongoing accuracy of the new modelling approach. Although the dWRMP 2013 is based upon this approach, an alternative demand scenario has been generated to examine the overall impact of this change upon the Plan outputs.
We forecast demand for water from our customers over the coming 25 years based on Government and local authority projections of population and development growth. This assumes no major upturn in the demand for water from heavy industry, other than a small number of specific developments such as the Wylfa B Nuclear Power station proposals. We are reviewing our forecasts for industrial and commercial demand in light of the latest data available and specifically how we anticipate this will change over the next few years in particular.
Page | 42 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
We have included both the possible demands of Wylfa B and a worst case for the economy in industrial growth terms demand scenario in this plan. If during the consultation period for this plan better data becomes available for either of these matters, we will notify the Welsh Government and issue an addendum to the plan if required and reflect these findings within our final plan to ensure that this contains the best and most up to data available.
4.4 Leakage Forecast Total leakage is considered to be the sum of losses from distribution mains, service reservoirs, trunk mains and customer supply pipes. The proportion of leakage reported in JR12 is shown in Table 4-3
Element Component Volume AMP5 Yr 3 Planned Ml/d Ml/d
Distribution Losses Distribution Mains 122.28 146.31
Distribution Losses Trunk Mains & SR 16.64 15.32
Customer Supply Pipe 46.27 26.47
Total Leakage 185.19 188.10
Table 4-3 Components of Leakage in 2011/12
The previous assessment forecasted a total leakage out turn of 184 MLD by the end of 2014/15
4.4.1 Determining Baseline Leakage Forecasts For the current Plan, a full assessment of our Sustainable Economic Level of Leakage (SELL) has been undertaken and is detailed in the supporting report ‘The Short Run SELL’ (RPS Water, 2012). The Base Line leakage as a result of the modelling produces a glide path on DMA leakage from 184 Ml/d in 2014/15 to a revised SELL of 167 Ml/d in 2020/21.
The revised SELL has been calculated at a zonal level and incorporated, along with the revised trunk main and service reservoir estimates into the zonal targets and subsequent water demand forecast. The profiles included in the demand forecast are outlined in Table 4-4 below.
2015/16 2016/17 2017/18 2018/19 2019/20 2040
182.65 175.65 171.79 168.89 166.48 166.48
Table 4-4 AMP 6 SELL profiles
Whereas previously SELL was modelled to increase over the planning period to 2035, the current assessment models the Short Run SELL to be maintained flat at 166.5 Ml/d for the duration of the planning period.
The SELL profiles for AMP 6 will be delivered primarily through active leakage detection and repair and further optimisation of existing pressure management valves. No asset renewal schemes have been selected as part of the Short Run strategy for achieving the SELL.
Page | 43 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
4.4.2 Leakage Control Strategy The company’s current approach to leakage control is based on the establishment of discrete monitoring areas (District Metered Areas) numbering 1003 in 2011 with an average property count of 1500, covering 1.3 million customers and 27,000km of distribution main. Dependent upon the asset, varying policy has historically been adopted based on economic reasoning where the unit cost of water has guided the policy.
Techniques currently deployed within the company include routine sounding of fittings, Network model building, step testing, sub metering, noise correlation, ground microphones and noise correlating data loggers. Underpinning Active Leakage Control is an extensive pressure management strategy that ensures pressure control is optimised through planned service interventions and through advanced pressure management techniques of control valves which suppresses the effects of uncontrolled networks and the Natural Rate of Rise.
More recently Active Leakage Control on the ‘Upstream’ of DMA assets has been undertaken using tethered acoustic leak detection systems (e.g. ‘Sahara’) for large diameter mains, along with bespoke advanced noise Trunk Main correlating equipment for large diameter mains with positive results.
Figure 4-6 Diagram of Sahara tethered acoustic leak detection system
On customer supply pipes, new techniques including tethered systems (e.g. Ferret) have been used and are currently being rolled out across the company due to the high success rate observed through using the equipment.
The current leakage control strategy is based on the policies outlined above on the various parts of the distribution network; however for the AMP6 (2015-2020) and subsequent Plan periods some notable changes to policy are planned as outlined in Table 4-5 Revised Policy in AMP 6 below relating to the supply network assets. The accumulated suppression of demand for the company as a whole over the planning period is in the order of 5 ML/d. This was identified through the SELL modelling process for upstream losses.
Page | 44 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Asset AMP 5 Policy AMP 6 (onwards) Policy
Raw Water Reported leakage policy Proactive leakage targeting and 1 in 5 year full Losses ALC survey
WTW Losses Reported Leakage policy Proactive leakage targeting and 1 in 5 year full ALC survey
Trunk Main Reported leakage policy, 1 in 5 year Proactive leakage targeting and 1 in 5 year full Losses quantification exercise ALC survey. Critical mains internal acoustic (‘Tethered Devices’) survey on planned intervention basis.
DMA Losses Proactive targeting and management Proactive targeting and management policy policy including pressure management including pressure management
LCA Losses Proactive targeting and management Proactive targeting and management policy policy including pressure management including pressure management
Supply Pipe Proactive targeting and management Proactive targeting and management policy Leakage policy Service 1 in 5 year inspection 1 in 3 year inspection Reservoir Losses Table 4-5 Revised Policy in AMP 6
4.5 Final Base Year Forecast ‘Normal’ year forecasts of Distribution Input (DI)12 have been derived by summing the forecasts described above and adding forecast total leakage to produce forecasts for each of the 24 WRZs for each year up to and including 2039/40.
‘Dry’ year and ‘Critical Period’ forecasts for the 24 WRZs have been generated by applying ‘peaking’ factors to the normal year forecasts to account for the expected increase in demand in whole ‘dry’ years and during short periods of increased demand. The critical period forecast is that of the peak 7 day average demand normally termed the Average Day Peak Week (ADPW) demand. Our peaking factors have been derived from analysis of demand data from 2002 to 2007. Since this is currently our most accurate period of demand data, any attempts to lengthen this record to match the longer hydrological records (typically from the early 1970’s) would introduce great uncertainty into the results.
Analysis undertaken within the demand forecast report also confirmed that 2003-2006 events used at zonal level were dry year events and have been selected accordingly depending upon the zone. As agreed with the Environment Agency, this record will be improved as more data becomes available and/ or when a dry year event occurs which would trigger a re-assessment of demand. The results and peaking factors for each zone and the analysis process is discussed in detail in Chapter 5 of our Demand Forecasting Report.
12 This is the volume of treated water input to the distribution network.
Page | 45 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 4.5.1 below shows historic and forecast ‘Normal’ and ‘Dry’ year DI for the period 1992/93 to 2039/40 inclusive for the Dŵr Cymru Welsh Water company area.
DŴR CYMRU WELSH WATER Historic and Forecast Distribution Input
Historic 'Normal' Year Forecast 'Dry' Year Forecast 1100
1050
1000
950
900
850 Distribution Input Ml/d Input Distribution 800
750
700
Figure 4-7 Historic and Forecast Distribution Input
4.5.1 Incorporation and effects of climate change on demand In preparing the demand forecasts it has been assumed that the impact of climate change will be to marginally increase per capita consumption (PCC) and the measured non-household component. The likely impact of climate change on PCC is shown Table 8.1 of the CCDew Report13 which sets out the anticipated regional impacts of climate change on domestic PCC. This translates to an increase in PCC of 1.15% between the Base year and 2024/25, affecting mainly the Garden Watering and Personal Washing micro-components.
The impact of climate change has been incorporated into the modelling of future measured non- household demand. Temperature, rainfall and sunshine data, collected from official sources, e.g. the Met Office and the UK Climate Projections (UKCP09), have been used. These are regressed against the sector level measured non-household demand and, in part, are used to derive the non-household demand forecasts at a sector level. Over the planning period, the overall impact of climate change on measured non-household demand is a 3.29% increase in demand by 2039-2040.
13 Climate Change and Demand for Water, Final Report, February 2003, Downing, T.E, Butterfield, R.E., Edmonds, B., Knox, J.W., Moss, S., Piper, B.S. and Weatherhead, E.K. (and the CCDeW project team); Stockholm Environment Institute Oxford Office, Oxford
Page | 46 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
5 Headroom
5.1 Introduction The term ‘Headroom’ is used to define the difference between supply capability and demand for each WRZ. The term ‘Target Headroom’ is defined within the planning process as the minimum value for this margin or buffer that a water company should allow between supply and demand to cater for specified uncertainties14 in the overall supply-demand balance15.
The approach to the assessment of Target Headroom used for dWRMP 2013 builds on the methods applied in the Final WRMP 2012 but also takes account of the recommendations received from Environment Agency Wales (now Natural Resources Wales) regarding technical aspects of the 2013 draft plan, that:
“We expect the company to include the uncertainties surrounding your estimation of the impacts of climate change on supply in target headroom in your chosen planning scenario. We also recommend that your company accepts a higher level of risk in future years when setting its risk profile for target headroom. This recognises that some uncertainties can either be reduced or dealt with through time.”
The information from the analysis of target headroom undertaken for dWRMP 2013 also takes account of technical discussions between Dŵr Cymru Welsh Water and Environment Agency Wales (now Natural Resources Wales) during the pre-consultation phase.
A new headroom computer application has been developed by consultants for Dŵr Cymru Welsh Water to undertake the Monte Carlo simulations required for the UKWIR (2002a) methodology using the ‘Crystal Ball’ preparatory software. This application provides information on the contribution to Target Headroom of each of the headroom components. The application calculates headroom uncertainty for the whole of the planning period from the base year (2011-2012) to 2039-2040 with the outputs for each WRZ expressed as a probability distribution function; the absolute value of Target Headroom is then chosen according to the company preferred level of risk for each year in the planning period.
5.2 Calculating headroom uncertainties We have analysed Target Headroom uncertainties in accordance with the approach recommended by the Environment Agency’s WRMP Guidelines 2012. Headroom uncertainty is calculated by looking at the probability of uncertain events in a similar way to the analysis of allowances for Outage. However, whilst outage examines of potential disruptions of short duration, headroom analysis involves consideration of events and uncertainties of longer duration.
In line with the UKWIR methodology, Target Headroom uncertainty is analysed in terms of nine supply components and four demand components:
14 Except for those relating to Outages, which are treated as part of Deployable Output, as set out in chapter 3 above. 15 A Re-Evaluation of the Methodology for Assessing Headroom” UKWIR, 2002
Page | 47 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Supply-side headroom component Description
S1 Vulnerable surface water licences
S2 Vulnerable groundwater licences
S3 Time limited licences
S4 Uncertainty surrounding bulk imports
S5 Gradual pollution of sources causing a reduction in abstraction
S6 Accuracy of supply-side data
S8 Uncertainty of impact of climate change
S9 Uncertainty of a new scheme
Demand-side headroom component Description
D1 Accuracy of sub-component data
D2 Demand forecast variation
D3 Uncertainty of climate change impact on demand
D4 Uncertain outcome from demand management measures
Table 5-1 Supply- and demand- side headroom components
The components not used in the previous Final WRMP 2012 analysis are shaded grey. Abstraction licence uncertainty is associated with various regulatory and other processes such as the Habitats Directive Review of Consents, implementation of the Water Framework Directive (WFD) and the Restoring Sustainable Abstraction (RSA) programme. However Government and regulators have indicated that measures to reduce, revoke or not renew existing abstraction licences would not be taken until alternative options had been secured to maintain the supply-demand balance and hence security of supply to customers. That view remains unchanged, so components S1 to S3 continue to be excluded from this analysis.
We receive bulk-supply imports from Severn Trent Water into the Ross on Wye and the South Meirionnydd WRZs. Discussions between the two companies have confirmed that these supplies will remain as at current values for the purposes of the plan. The S4 component has therefore not been included in the analysis.
As with the previous analysis, there is no current evidence to suggest that gradual pollution is expected to have an impact on source output, however, catchment studies are planned for AMP6 (2015 – 2020) that will confirm this position or otherwise. The S5 component has therefore been excluded from the analysis for the dWRMP.
Of the remaining categories, the uncertainty surrounding the effects of climate change on supply and the demand forecast uncertainty are generally the largest components that determine target headroom uncertainty at the end of the planning period.
Page | 48 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
5.3 Company risk profile and baseline target headroom Water companies are expected to adopt a level of Target Headroom uncertainty (a risk profile) that meets the principles set out in the Environment Agency Water Resource Planning Guideline, and the company’s own approach to risk in achieving stated levels of service. We have carefully considered how we should approach this for the purposes of planning. On the one hand it would not be appropriate to take an over-precautionary approach to Target Headroom, as this might lead to the need for significant investment to allow for complete certainty in all of the supply and demand components.
On the other hand, it could be argued that it would not be correct to look only at the average probability, ‘50th percentile’ or ‘central projection’, because there is an asymmetry between having too much water and too little water. After due consideration and analysis, a risk profile across the planning period starting at the 95% confidence level then decreasing by 5% in each AMP period to a minimum of 75% has been used.
Years Final WRMP 2012 risk profile dWRMP 2013 risk profile
2011/12 – 2019/20 95% 95%
2020/21 – 2024/25 95% 90%
2025/26 – 2029/30 95% 85%
2030/31 – 2034/35 95% 80%
2035/36 – 2039/40 95% 75%
Table 5-2 Headroom risk profile used in this plan compared to Final WRMP 2012
Target Headroom has been calculated for all 24 WRZs at zonal level16 for both the Annual Average and the Critical Period scenarios.
5.4 Baseline and Final Planning Target Headroom Target Headroom is calculated iteratively as part of the overall planning process. Initially, ‘Baseline’ Target Headroom Is calculated for each WRZ and applied to the derivation of the baseline supply demand balance. If a WRZ is identified as having a supply deficit, options are selected to resolve the deficit. Since implementation of these solutions will also bring uncertainties, Target Headroom is then re-calculated and the process repeated until supply demand balance is achieved. Thus, ‘Final Planning’ Target Headroom is included as part of the Final Planning supply demand balance, in which the supply deficit is fully resolved.
Figure 5-1 to Figure 5-5 show the dry year annual average target headroom profiles as a percentage of DO for each zone, grouped into zones with similar magnitudes of target headroom.
16 Dŵr Cymru Welsh Water - draft Water Resource Management Plan, Headroom Uncertainty, Atkins Global, March 2013
Page | 49 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
30.0%
25.0%
20.0%
15.0%
10.0% Headroom (%DO) Headroom 5.0%
0.0%
2019 2032 2011 2012 2013 2014 2015 2016 2017 2018 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2033 2034 2035 2036 2037 2038 2039 2040
North Eryri Ynys Môn Barmouth Tywyn Aberdyfi Pembrokeshire
Figure 5-1 Dry year annual average target headroom – one of five
8.0% 7.0% 6.0% 5.0% 4.0% 3.0%
Headroom (%DO) Headroom 2.0% 1.0%
0.0%
2012 2017 2022 2027 2032 2037 2011 2013 2014 2015 2016 2018 2019 2020 2021 2023 2024 2025 2026 2028 2029 2030 2031 2033 2034 2035 2036 2038 2039 2040
Clwyd Coastal SEWCUS N Ceredigion
Figure 5-2 Dry year annual average target headroom – two of five
7.0% 6.0% 5.0% 4.0% 3.0%
2.0% Headroom (%DO) Headroom 1.0%
0.0%
2012 2017 2022 2027 2032 2037 2011 2013 2014 2015 2016 2018 2019 2020 2021 2023 2024 2025 2026 2028 2029 2030 2031 2033 2034 2035 2036 2038 2039 2040
Alwen Dee Lleyn Harlech Dyffryn Conwy Monmouth MS Ceredigion Whitbourne
Figure 5-3 Dry year annual average target headroom – three of five
Page | 50 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
5.0% 4.5% 4.0% 3.5% 3.0% 2.5% 2.0% 1.5%
Headroom (%DO) Headroom 1.0% 0.5%
0.0%
2012 2017 2022 2027 2032 2037 2011 2013 2014 2015 2016 2018 2019 2020 2021 2023 2024 2025 2026 2028 2029 2030 2031 2033 2034 2035 2036 2038 2039 2040
Bala Blaenau Ffestiniog South Meirionnydd Ross-on-Wye Elan Builth Hereford Llyswen
Figure 5-4 Dry year annual average target headroom – four of five
6.0%
5.0%
4.0%
3.0%
2.0% Headroom (%DO) Headroom 1.0%
0.0%
2012 2017 2022 2027 2032 2037 2011 2013 2014 2015 2016 2018 2019 2020 2021 2023 2024 2025 2026 2028 2029 2030 2031 2033 2034 2035 2036 2038 2039 2040
Pilleth Brecon Portis Vowchurch Tywi CU
Figure 5-5 Dry year annual average target headroom – five of five
Annual Average headroom uncertainty at the 95 percentile ranges from around 5% to over 45% for Tywyn Aberdyfi. The variation in headroom uncertainty between the WRZs depends primarily on:
The presence, magnitude and direction of any climate change impact on WRZ DO;
The range of variation in the demand forecast over the planning horizon; and
The magnitude and direction of uncertainty in WRZ DO introduced as a result of specific water resource modelling, rather than the use of a generic factor.
Of these factors climate change has by far the greatest impact on Target Headroom during the later years of the planning period.
Page | 51 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
6 Habitats Directive and the impact on water abstractions
6.1 Habitats Directive Review of Consents The European Habitats Directive will have a significant influence on our water resource management plans for the next 25 years.
As the designated ‘competent authority’ for England and Wales the Environment Agency is required to ensure that its ‘permissions’ – i.e. abstraction licences and discharge consents – and its operations have no adverse effect on the ‘integrity’ of the Special Areas of Conservation (SAC) and Special Protection Areas (SPA) that form part of the pan-European network of Natura 2000 sites. As a competent authority ourselves, we must have regard to the requirements of the Habitats Directive so far as they may be affected by the exercise of our functions.
Sustainability reductions is the term given to amendments made by the Environment Agency to existing permissions in order that it can be demonstrated that the permission does not have an adverse impact on a Habitats Directive site.
6.2 Review of Consents The Review of Consents process is the mechanism by which the Environment Agency reviews of all the existing and proposed permissions it has issued that could impact upon EU designated Natura 2000 sites. There are over 90 European Special Areas of Conservation and more than 1,000 Sites of Special Scientific Interest (SSSI) in Dŵr Cymru Welsh Water’s area of operation.
Dŵr Cymru Welsh Water’s abstractions that are affected by the Habitats Regulations are shown in Figure 6-1, Figure 6-2 and Figure 6-3.
Figure 6-1 Dŵr Cymru Welsh Water’s abstractions in South East Wales subject to the review of consents process
Page | 52 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 6-2 Dŵr Cymru Welsh Water’s abstractions in South West Wales subject to the review of consents process
Figure 6-3 Dŵr Cymru Welsh Water’s abstractions in North Wales subject to the review of consents process
Page | 53 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The Habitats Regulations obliged the Environment Agency to review all of its environmental permissions, in this case abstraction licences, to ensure that they have no adverse impact on Special Areas of Conservation. This review took place between 2004 and 2012 and we worked closely with the Environment Agency to understand the issues at each site, and their proposed solutions.
There are 20 Dŵr Cymru Welsh Water abstractions where the Environment Agency Wales was unable to show that there was no adverse effect on site integrity, shown in Table 6-1. It should be noted that none of Dŵr Cymru Welsh Water’s abstractions were considered to be causing adverse impact under the current operation of the abstraction. In the absence of any environmental evidence to the contrary, the abstractions were however considered to be at risk of causing an adverse impact to site integrity if the abstractions were operated at their maximum abstraction rate. It is unlikely that we would need to operate those abstractions at their maximum abstraction rate in the future.
Site Name Adverse effect on site No adverse effect on integrity can be site integrity cannot shown be shown
Combination
Combination
Alone In Alone In
Wye at Hereford Wye at Monmouth (Mayhill) Wye at Monmouth (Wye Transfer) Lugg at Byton Pilleth boreholes Dunfield boreholes Midsummer Meadow well Usk at Llantrisant Usk at Rhadyr (Prioress Mill) Usk at Brecon/Brecon boreholes Tywi at Manorafan Tywi at Nantgaredig Llyn Brianne reservoir Teifi at Llechryd Eastern Cleddau at Pont Hywel Eastern Cleddau at Canaston Western Cleddau at Crowhill Llyn Eiddew Mawr Llyn Morwynion Llwyn Isaf borehole Table 6-1 Dŵr Cymru Welsh Water abstractions where the Environment Agency was unable to show that there was no adverse effect on site integrity
Page | 54 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
In order to demonstrate that the risk of adverse impact to site integrity has been removed, we are currently working with Natural Resources Wales (successor to Environment Agency Wales) to amend our abstraction licences to reduce the amount of abstraction at some sites. We have assumed that these reductions will take place from April 2018 in our Plan. We are however aware that there is a potential conflict between the preferred date for licence changes on the Wye proposed by Dŵr Cymru Welsh Water and that which may be acceptable to Severn Trent Water.
6.3 Impacts of the Review of Consents on water abstractions Following the completion of Stage 4 of the consents review process, we have modelled the Environment Agency’s proposed licence amendments to assess the impacts upon Deployable Output. Overall, the reductions amount to an approximate Deployable Output loss of 34 Ml/d across South Wales including 26 Ml/d in SEWCUS and 8 Ml/d in Pembrokeshire zones. Across North Wales we are not forecasting any loss of Deployable Output in the affected WRZs as a result of the Environment Agency’s proposed licence changes.
In our Plan we have assumed that these reductions and their impact on Deployable Output will take effect from March 2015. However we propose that the reductions take place from April 2018 in order for the assessment of impacts on our operational capability to be taken into account. This will also maximise the time available for ecological monitoring. This is discussed further in section 6.6 below.
6.3.1 South East Wales Conjunctive Use System (SEWCUS) WRZ Since 2007, we have worked with the Environment Agency (now Natural Resources Wales) to develop a series of licence amendment options for the Rivers Wye and Usk to achieve the desired environmental outcomes. This Plan is based on the latest options set out in the technical notes issued by the Environment Agency in 2012 – Wye Option W382b17 and Usk Option U611.18
We have prepared a report that provides full details of the modelling work we have carried out to assess the impacts upon Deployable Output of the final outcomes of the Agency’s review of our related consents.
Within the SEWCUS WRZ, the baseline Dry Year Deployable Output is 436 Ml/d. Implementation of the licence amendments reduces our Dry Year Deployable Output to 410 Ml/d, a loss of 26 Ml/d. This drop in supply capacity is driven by the significant reductions in our Wye and Usk licences, as well as the increase in releases we will have to make from the Elan Valley reservoirs to augment flows in the Wye so as to enable abstraction at Monmouth to be maintained.
We are currently undertaking monitoring of the Rivers Wye and Usk as described in section 6.4 below.
17 Technical Note: Wye Option W382b, EAW, May 2012 18 Technical Note: Usk Option U611, EAW, May 2012
Page | 55 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
6.3.2 Brecon Portis WRZ The impact of the consent review process on Deployable Output in our Brecon Portis WRZ has been calculated as a reduction of approximately 0.5 Ml/d. We are currently undertaking monitoring of the River Usk as described in section 6.4 below to confirm or otherwise what if any impact we are having on the River.
6.3.3 Pembrokeshire WRZ Since 2008 we have undertaken modelling of our Pembrokeshire WRZ to understand fully the impacts of the Environment Agency modifications to our abstraction licences on the Eastern and Western Cleddau Rivers. The Environment Agency has not modelled the impacts themselves but have fully audited our model and have indicated that they are satisfied with the results.
The current baseline Dry Year Deployable Output for Pembrokeshire is 79.4 Ml/d and 97.6 Ml/d for the Critical Period. We have prepared a report that details our modelling work and the impact of the consent review process on Deployable Output in Pembrokeshire.
The impact of the Environment Agency’s proposed changes to licences in Pembrokeshire is a net reduction in annual average Deployable Output from 79.4 Ml/d to 71.1 Ml/d and in critical period Deployable Output from 97.6 Ml/d to 88.4 Ml/d. We are currently undertaking monitoring of the Eastern Cleddau River as described in section 6.5 below to confirm or otherwise what if any impact we are having on the River.
6.4 Wye and Usk investigations In 2012, in partnership with the Canal and Rivers Trust (CRT), Dŵr Cymru Welsh Water developed the Rivers Wye and Usk Abstraction Management Group, a collaborative stakeholder group involving Natural Resources Wales, Environment Agency Midlands Region, CCW, Natural England, Severn Trent Water and Wye and Usk Foundation. The primary purpose of the Group is to establish and implement studies which will enhance the group’s understanding of both riverine catchments whilst seeking alternative management proposals. In addition to ensuring that our abstractions maintain compliance with the Habitats Directive, it is hoped that wider stakeholder and catchment issues can also be addressed which will bring benefits to our customers and the economy of the region.
During 2012, monitoring of both rivers commenced: full habitat mapping has been completed, bullhead, macro-invertebrate and macrophyte monitoring has also been undertaken and completed. These complement existing historical data sets and confirmed good to high ecological status on both rivers. Lamprey surveys were also undertaken; these surveys require extension into 2013. Acoustic tagging of salmon has also been trialled on the River Usk and initial results in terms of tagging technique and implementation have been very successful. These surveys have required considerable input from all stakeholders and Dŵr Cymru Welsh Water (and CRT) is extremely grateful for the support in implementing this work.
During 2013 focus will be given to all remaining designated fish species: salmon, shad and lamprey (brook, river and sea) as well as hydrological and water quality monitoring. Monitoring plans are
Page | 56 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
currently being developed and agreed with all relevant parties. This will include for the first time acoustic tagging of salmon and sea lamprey, targeted sea lamprey ammocoete and mark and recapture studies. We also intend to implement egg and observation studies for shad. This updated targeted monitoring programme, in combination with existing or ongoing surveys for both rivers, will we believe provide invaluable evidence base on which to understand further any possible impacts to designated species on both catchments.
Furthermore, in parallel there has been significant progress between all parties in relation to the hydrological modelling of both rivers, and with specific regard to the Wye and Usk Foundation’s representations to the Revised Draft WRMP 2011. This work is ongoing, but is immensely important to the understanding of our operations and to ensuring delivery of all environmental outcomes under the Agency’s Review of Consents. Once completed, it is hoped that this will deliver an agreed understanding of the hydrological flow regime for both rivers, on which future abstraction decisions can be made, and licences changed accordingly.
At this stage, an eighteen-month period of investigations (from June 2012 to December 2013) has been defined. It is Dŵr Cymru Welsh Waters intention at this stage to review progress and conclusions, particularly with respect to the success of the fish monitoring. Dŵr Cymru Welsh Water is committed to extending this monitoring until at least 2015 if evidence shows that monitoring improves our understanding of the impacts of our abstraction and other influences on the catchment such that our existing licences can be maintained. We believe to date that there has been considerable progress from the formation of the Group in terms of furthering understanding of the key catchment drivers and stakeholder requirements.
It should be noted that these investigations will also provide a valuable understanding of the Wye and Usk, in terms of future AMP 6 WFD investigations, and for the Welsh Government to establish what measures are required to deliver ‘good status’ under the directive in terms of other anthropogenic pressures.
6.5 Eastern Cleddau investigations In 2010 we commissioned a hydroecological study to investigate further the potential impacts of our abstraction at Pont Hywel in the upper reaches of the Eastern Cleddau River. We have undertaken detailed fishery and hydrological surveys to attempt to quantify the current status of Lamprey and Bullhead within this stretch of river and to understand the impacts of abstraction upon the available habitat.
The aim of the study is to collect further data that will allow an alternative licensing strategy to be developed for our Pont Hywel abstraction that still ensures compliance with the Habitat Directive but does not severely limit our ability to use our Pont Hywel abstraction. The current licence proposals from Natural Resources Wales (successor to Environment Agency Wales) essentially mean that through the summer, when the abstraction is traditionally used to supplement storage in Rosebush reservoir, we are unable to abstract and so cannot maintain the required output from Preseli WTW which leaves us with a shortfall in supply requiring significant capital investment in Pembrokeshire to resolve.
Page | 57 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Our survey work has been undertaken in full consultation with Natural Resources Wales (successor to Environment Agency Wales) and CCW to ensure all methodologies and data collected is to the required specification. The final phase of the project is to undertake hydrological surveys at six key cross sections of the river during very low flow conditions i.e. Q95 and below. Unfortunately the extremely wet conditions that prevailed throughout 2012 prevented this from happening but we are committed to continuing this work in 2013.
6.6 Timetable for licence amendments and implementation For those licence amendments affecting our supply to SEWCUS and Pembrokeshire WRZs, Dŵr Cymru Welsh Water propose to have formally amended our affected abstraction licences by no later than December 2015. This gives time for the licence changes and the reduction in abstraction they represent to be informed by evidence collected by our monitoring programme and by the responses to our consultation on the dWRMP 2013.
In this way we can be confident that the licence amendments give maximum benefit to the ecology of the Rivers Usk, Wye and Cleddau whilst still allowing us to supply water to the people of Wales in a cost effective manner. Within the plan we have assumed that the licence amendments take effect from April 2018. Given that the licence changes on the Wye have significant implications for both Dŵr Cymru Welsh Water and for Severn Trent we may need to take account of the impact of these licence changes presented within Severn Trent’s WRMP2013.
This will allow Dŵr Cymru Welsh Water time for a full appraisal of any residual risks to our operational ability to supply our customers, particularly in SEWCUS, associated with the licence amendments to be undertaken so that where appropriate we can implement the required schemes to reduce or eliminate completely these risks. For more information about planned work in SEWCUS please refer to section 8.10 WRZ 8121 - SEWCUS. For the licence amendments at Brecon Dŵr Cymru Welsh Water will accept an implementation date of March 2015 as these amendments are not considered to significantly impact our ability to supply our customers.
6.7 Water Framework Directive - Heavily Modified Water Bodies The European Water Framework Directive (WFD) came into force in December 2000 and became part of UK law in December 2003. EU Member States including the UK must aim to reach ‘good chemical and ecological status’ in inland and coastal waters by 2015 subject to certain limited exceptions. Under WFD, all inland water courses are divided into water bodies. Some water bodies are designated as ‘heavily modified’. A heavily modified water body (HMWB) is an existing body of water that has had it's original character significantly changed to suit a specific purpose. This purpose includes water storage and flow regulation for water supply. Under WFD water bodies are required to reach Good Ecological Status, but where a water body is classified as heavily modified, the aim is that the water body to reach Good Ecological Potential.
Good Ecological Potential (GEP) represents the maximum quality of the water based ecosystem in a HMWB, taking into account the heavily modified nature of the water body.
A number of Dŵr Cymru Welsh Water's assets including impounded reservoirs constitute HMWBs. Dŵr Cymru Welsh Water is currently working with Natural Resources Wales (successor to
Page | 58 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Environment Agency Wales) to assess each HMWB to see whether it is currently considered to reach Good Ecological Potential.
Where a HMWB fails to reach Good Ecological Potential Dŵr Cymru Welsh Water is currently working with the Environment Agency to identify where suitable cost effective mitigation measures can be put in place so that the water body can achieve Good Ecological Potential. Under the WFD these mitigation measures should not have a significant adverse impact upon the use of the water body, in this case on public water supply. These HMWBs will be subject to further assessment and possible options appraisal during the remainder of AMP 5 and AMP 6.
Mitigation measures may include increasing compensation flows from our reservoirs and /or making releases more variable. This has the potential to impact the deployable output available in WRZs. As part of this work on HMWBs, Dŵr Cymru Welsh Water has modelled the impact on deployable output and subsequently the supply demand balance of increasing compensation flow or decreasing lake draw down at three sites across Wales agreed with Natural Resources Wales These sites are shown in Table 6-2 below. The results of these scenarios are provided in Chapter 13 of the dWRMP Technical Report.
It should be noted that the mitigation measures required under the WFD should not be either technically infeasible or disproportionately costly. If mitigation measures are technically infeasible or disproportionately costly then they are not required to meet the requirements of the Directive.
DCWW site WFD water body WRZ Current Modelled scenario name and code operation Cefni Cefni - tidal limit to North Eryri Compensati Compensation flow of 2.55 Ml/d Reservoir Ceint Ynys Môn on flow of GB110102058670 1.82 Ml/d
Cefni Reservoir GB31032926 Tecwyn Uchaf Llyn Tecwyn Uchaf Lleyn Current lake 1. Drawdown should not exceed 2m Reservoir GB31034866 Harlech drawdown more often than 1 year in 5 (on average). 2. Drawdown should not exceed 3m more often than 1 year in 10 (on average). Note: scenario will be modelled as closely possible within Dŵr Cymru Welsh Water model constraints. Castell Nos Afon Rhondda Fach - SEWCUS No required Compensation flow of 6.8 Ml/d from and Lluest source to conf compensatio Castell Nos reservoir Wen Rhondda R n flow reservoirs GB109057027210
Castell Nos Reservoir GB30941377
Lluest-wen Reservoir GB30941303 Table 6-2 HMWB site scenarios
Page | 59 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7 Supply demand balance
7.1 Calculating the supply demand balance The purpose of this section is to present the ‘Baseline’ supply demand position for Dŵr Cymru Welsh Water’s 24 WRZs over the planning period. This indicates where there is a risk of future water supply deficits or where demand management measures such as hosepipe bans would need to be implemented more often than is acceptable to Dŵr Cymru Welsh Water’s customers. These are the zones in which it will be necessary to put measures in place to make up any shortfall in Levels of Service. The water supply demand balance for a WRZ can be summarised by the following equation:
Supply Demand Balance = Water Available For Use – (Dry Weather Demand +Target Headroom)
Where:
Water Available For Use (WAFU) is the amount of water that can be reliably supplied from our water sources during prolonged dry weather (section 3.7)
Dry weather demand is the total customer demand for water and leakage during prolonged dry weather (section 4.5)
Target Headroom is the calculated allowance for uncertainties that are outside the control of Dŵr Cymru Welsh Water (section 5.4).
If the supply demand balance in a WRZ is positive, then there is an adequate supply of water to meet forecast demand in that WRZ and achieve our planned LoS. However, if the supply demand balance is negative or in deficit for any future years then a combination of supply enhancement and/ or demand reduction measures will be required to maintain an adequate supply demand balance. Otherwise hosepipe bans and/ or other drought measures are likely to be required more frequently than our planned LoS to maintain supply.
Figure 7-1 Calculating supply demand balance
Page | 60 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
By definition shortfalls in supply against demand can be produced by a number of factors which impact upon:
1. Forecast increases in demand
2. Reductions in WAFU due to :
a. Abstraction licence reductions
b. The impact of climate change over the planning period
c. An improved assessment of supply capability which indicates a reduction in WAFU;
a. Changes to bulk supply or zonal transfers
b. Changes to the outage or treatment works operational use estimates (See chapter 4)
3. An increased Target Headroom requirement. This could be due to the many factors on which target headroom is derived. This including the risk of climate change (see chapter 5)
All of these can be subject to change where new improved methodologies have been developed through water industry research or the way in which these methodologies have been applied and included within guidance. Methodological changes have been identified and explained within the previous sections.
There are changes in many of the supply and demand components listed above in relation to the Final WRMP2012 but the key ones are shown in Figure 7-2 below. The supply demand balance within each WRZ has been evaluated over both the ‘Annual Average’ period and ‘Critical Period’ with each component of the balance calculated as a dry year estimate. Balances are provided where there is a deficit in supply demand within each zone, and for SEWCUS WRZ where there has been a significant change in supply demand balance from the Final WRMP 2012.
7.2 Baseline supply demand balance A supply-demand deficit is predicted at some point over the planning period in six WRZs, as depicted by the red areas in Figure 7.2. The purple colour denotes WRZs which have a marginal surplus in the supply demand balance.
Page | 61 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 7-2 Surplus and deficit zones dWRMP 2013
The six zones that are forecast to fall into deficit at some point over the next 25 years are Pembrokeshire, North Eryri-Ynys Môn, Brecon Portis, Tywyn Aberdyfi, South Meirionnydd and Bala. Table 7.1 below summarises the position for these six zones:
Zone Max. deficit over Reasons for deficit planning period (Ml/d)
Pembrokeshire 8.8 Review of Consents driven licence changes Climate Change impact on Target Headroom and DO
North Eryri Ynys 3.7 Climate Change impact on Target Headroom and DO Môn Revised demand forecast and base year position
Brecon Portis 1.46 Review of Consents limiting abstraction at low flows. Revised demand forecast and base year position Improved DO assessment from new WR model development.
Tywyn Aberdyfi 1.03 Climate Change impact on Target Headroom and DO Revised demand forecast and base year position
South 0.04 Revised demand forecast and base year position Meirionnydd
Bala 0.09 Revised demand forecast and base year position Table 7-1 Supply demand deficits
Page | 62 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.3 WRZ 8001 - North Eryri - Ynys Mon The area covered by this WRZ includes the mainland adjacent to the Menai Straits (North Eryri) and Ynys Mon (Anglesey).
Water is supplied from five impounding reservoirs; on the mainland Ffynnon Llugwy, Llyn Cwellyn and Llyn Marchlyn Bach and on Ynys Mon, Llyn Alaw and Llyn Cefni.
The resources are operated conjunctively with the ability to feed water from the mainland to parts of the island from the gravity resources of Llyn Cwellyn, Ffynnon Llugwy and Llyn Marchlyn Bach when storage allows. As storage declines, the area of Ynys Mon supported from the mainland is reduced and the area supported by Llyn Alaw and Llyn Cefni increases. This method makes use of the sustainable gravity sources when they are available and reduces the amount of pumping required across the island. There are no exports or imports of water for North Eryri Ynys Mon.
7.3.1 Final Plan 2012 Status The zone was forecast to be in surplus over the planning period. However, the balance provided within the Final Plan did not include the impact of climate change or the development of the proposed Wylfa power station within target headroom. The incorporation of the UKCP09 climate change projections would have placed the zone in deficit by 4.3 Ml/d by 2034/35.
7.3.2 Current Status The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit in 2023/24 with the maximum deficit of 3.69 Ml/d by 2029/30. This deficit represents 9% of Total Water Available For Use (WAFU). Under the Critical Period scenario the zone falls into deficit in 2023/24 to a maximum of 2.53 Ml/d by 2029/30. The deficit in the zone has been driven mainly by the incorporation of the updated UKCP09 climate change methodology into our supply and Target Headroom calculations. The predicted impacts of climate change in this zone are to reduce the available water for supply as a result of potential changes in weather patterns.
Page | 63 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
45 40 35 30 25
Ml/d 20 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-3 NEYM Annual Average SDB position 2015 – 2040
60
50
40
30 Ml/d 20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-4 NEYM Critical Period SDB position 2015 – 2040
7.3.3 Wylfa Scenario The baseline demand forecast described does not include for the development of the proposed Wylfa Power Station. This is due to the uncertainty around both the timing and water supply need from the proposed development. Given this uncertainty, we have reviewed the potential impact of the proposal as a supply’ demand balance scenario. If the construction and power station operation increases demand in the zone by approximately 6Ml/d then the zone would fall into deficit in line with the construction programme if this were assumed to begin in 2015. The zone continues falls into deficit in 2022/23 reaching a maximum deficit of 8.60 Ml/d by 2040 in the Annual Average scenario and 7.28 Ml/d in the Critical Period scenario. The impact over the planning period in the Annual Average Scenario is shown in Figure 7-5 and the impact in the Critical Period scenario is shown in Figure 7-6 below.
Page | 64 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
60
50
40
30 Ml/d 20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-5 NEYM Annual Average SDB position 2015 – 2040 under Wylfa scenario
60
50
40
30 Ml/d 20
10
0
Total WAFU
Figure 7-6 NEYM Critical Period SDB position 2015 – 2040 under Wylfa scenario
7.3.4 Cefni compensation release Cefni reservoir is a WFD Heavily Modified Water Body (HMWB). Dŵr Cymru Welsh Water has agreed with Environment Agency Wales to model the impact on DO of maintaining a Q95 compensation release of 2.2 Ml/d from Cefni reservoir into the Afon Cefni. The change is assumed to take place from 2020 onwards. This is to model the effects of providing increased compensation flows to the Afon Cefni as a mitigation measure for our use of the reservoir for public water supply.
The effect of maintaining this 2.2 Ml/d compensation flow were modelled to assess this would have on DO available in NEYM and consequently on the supply demand balance of NEYM. The reduction in DO was found to have a small impact on NEYM supply demand balance. The zone continues falls into deficit in 2022/23 reaching a maximum deficit of 4.82 Ml/d by 2040 in the Annual Average scenario and 2.45 Ml/d in the Critical Period scenario.
The impact of this scenario on the supply demand balance is approximately 1 Ml/d, as a result of applying simplified climate change assessment in this scenario. Based on this analysis we believe it
Page | 65 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
will be possible to discuss and agree a mutually acceptable approach to resolve the HMWB issues at Llyn Cefni with Environment Agency Wales and we welcome comments regarding this as part of the consultation on this Plan. As part of these discussions we will also want to further consider the combined impact of the potential solutions required if the Wylfa development goes ahead.
Impacts on the supply demand balance are shown in Figure 7-7 and Figure 7-8 below.
50 45 40 35 30 25 20Ml/d 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-7 NEYM Annual Average SDB position 2015 – 2040 with increased Cefni compensation release
60
50
40
30 Ml/d 20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-8 NEYM Critical Period SDB 2015 – 2040 with increased Cefni compensation release
Cefni reservoir Page | 66 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.4 WRZ 8012 Clwyd Coastal The area of this WRZ covers the coastal region from Prestatyn to Colwyn Bay and then further inland to St. Asaph. The WRZ is supplied by the two WTWs at Glascoed and Trecastell. Trecastell WTW is supplied solely from a spring source at Ffynnon Asaph, however, the spring is occasionally affected by turbidity during which time the Prestatyn area is supplied from Glascoed WTW.
All the other sources feed into Glascoed WTW which then serves the majority of the WRZ. The sources are a river abstraction from the Afon Aled at the Bryn Aled Pumping Station which is supported by river regulation releases from the Aled Isaf and Llyn Aled Reservoirs. Abstracted water from the Afon Aled is held in the Plas Uchaf Reservoir which effectively provides bankside storage. This arrangement is the subject of a Section 20 Operating Agreement between Welsh Water and EAW.
The other main source supplying Glascoed WTW is an abstraction from Llannerch boreholes which is supported from the artesian and pumped boreholes at Llanynys and Pont Glanywern, Ruthin, Plas yr Esgob, Llwyn Isaf and Efail Newydd via the River Clwyd. There are no exports or imports of water for Clwyd Coastal.
7.4.1 Final Plan 2012 Status The zone was surplus throughout the planning period to maximum of 4.51 Ml/d in 2014/15 respectively.
7.4.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in surplus throughout the planning period to maximum of 2.22 Ml/d in 2025/26.
25
20
15
Ml/d 10
5
0
Total WAFU Demand plus Target Headroom
Figure 7-9 Clwyd Coastal Annual Average SDB position 2015 – 2040
Page | 67 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.5 WRZ 8014 Alwen Dee The area of this WRZ stretches from the floodplains of the River Dee at Llangollen to the coastal waters at Prestatyn and the industrial complexes on Deeside. The normal supply operation is to meet demand from a combination of water from Bretton WTW (supplied from the River Dee abstraction at Poulton) and from Alwen WTW supplied from Alwen Reservoir.
The River Dee is a regulated source and is managed in accordance to the Dee General Directions which are the responsibility of EAW, supported by the three major water companies in the area (Welsh Water, Dee Valley and United Utilities) and also by the Canal and Rivers Trust. The purpose of the Directions is (amongst other things) to manage the river regulation releases from Llyn Celyn and Llyn Brenig in the headwaters of the Dee for abstraction by the three water companies and the Canal and Rivers Trust (to the Llangollen Canal) in the lower part of the catchment.
There is an export of water from the WRZ to Dee Valley Water which enables them to supply domestic properties in that particular area.
7.5.1 Final Plan Status 2012 The zone was in surplus throughout the planning period to a maximum of 7.96 Ml/d in 2031/32.
7.5.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in surplus throughout the planning period to maximum of 8.64 Ml/d in 2039/40.
50
40
30 Ml/d 20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-10 Alwen Dee Annual Average SDB position 2015 – 2040
Page | 68 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.6 WRZ 8020 - Bala The small WRZ of Bala covers the town of Bala and the immediate surrounding area. In terms of population, this is the smallest of Dŵr Cymru Welsh Water’s WRZs, with approximately 3,500 customers, although it is subject to significant growth through tourism during the summer months.
The WRZ is served from a single impounding reservoir, Llyn Arenig Fawr. The live storage of the reservoir is 1629 Ml. There is no compensation water requirement and we are licensed to abstract 2.27 Ml/d (829.6 Ml/yr).
There are no exports or imports of water for Bala.
7.6.1 Final Plan 2012 Status The zone was in surplus throughout the planning period to a maximum of 0.11 Ml/d in 2016/17.
7.6.2 Current Status The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit in 2015/16 with the maximum deficit of 0.06 Ml/d by 2019/20. Under the Critical Period scenario the zone falls into deficit in 2015/16 to a maximum of 0.09 Ml/d by 2019/20. This deficit represents 4% of Total WAFU. This zonal deficit has been realised by updating the demand forecast within the zone.
Bala Lake
Page | 69 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
2.0
1.5
1.0 MlD
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-11 Bala Annual Average SDB position 2015 – 2040
2.5
2.0
1.5
Ml/D 1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-12 Bala Critical Period SDB position 2015 – 2040
Page | 70 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.7 WRZ 8021 Tywyn Aberdyfi The WRZ covers the small coastal area around the towns of Tywyn and Aberdovey, supplying approximately 5000 people from two small river abstractions; on the Afon Fathew and the Nant Braich Y Rhiw.
The Nant Braich y Rhiw source is subject to a Hands-Off-Flow condition that comes into operation during most summer periods. The abstraction from the Afon Fathew is licensed to abstract a quantity equivalent to Penybont WTW capacity of 2.6 Ml/d.
There are no exports or imports of water for Tywyn Aberdyfi.
7.7.1 Final Plan 2012 Status The zone was in surplus under both the Annual Average and Critical Period planning scenarios to maxima of 0.14 Ml/d in 2019/20 and 0.23 Ml/d in 2019/20 respectively.
7.7.2 Current Status The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit in 2015/16 reaching a maximum deficit of 0.68 Ml/d in 2029/30. Under the Critical Period scenario the zone drops into deficit in 2015/16 to a maximum of 1.03 Ml/d by 2030/31. This deficit represents 55% of Total WAFU.
The revised supply demand balance in the zone has been driven by an updated demand forecast, along with the incorporation of updated methodologies for calculating the effects of climate change on deployable output and Target Headroom.
Figure 7-13 Tywyn Aberdyfi Annual Average SDB position 2015 – 2040
Page | 71 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3.5
3.0
2.5
2.0
Ml/D 1.5
1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-14 Tywyn Aberdyfi Critical Period SDB position 2015 – 2040
Page | 72 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.8 WRZ 8026 Blaenau Ffestiniog This WRZ covers the village and surrounding area of Blaenau Ffestiniog. Blaenau Ffestiniog WRZ is a single-source zone comprised of Llyn Morwynion which supplies Garreglwyd WTW. Llyn Morwynion is supported by a river abstraction from the nearby River Gam to aid refill during the winter months.
There are no exports or imports of water for Blaenau Ffestiniog.
7.8.1 Final Plan Status 2012 The zone was in surplus throughout the whole planning period, reaching a maximum of 0.65 Ml/d in 2011/12.
7.8.2 Current Status Only the Annual Average planning scenario is reported for this zone. The zone is in surplus throughout the whole planning period, reaching a maximum of 0.85 Ml/d in 2035/36.
3.0
2.5
2.0
1.5 Ml/d
1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-15 Blaenau Ffestiniog Annual Average SDB position 2015 – 2040
Page | 73 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.9 WRZ 8033 Barmouth The area of Barmouth WRZ covers the coastal region from Harlech to Barmouth. This small WRZ is served from a single impounding reservoir, Llyn Bodlyn, which feeds Eithinfynydd WTW. Peak demands (caused primarily by influxes of tourists) during dry periods often approach the daily abstraction licence limit.
There is an internal transfer of water between the Lleyn Harlech WRZ and the Barmouth WRZ, as part of the Rhiw Goch scheme summarised in the Lleyn Harlech section, to help meet a supply demand deficit in this WRZ.
7.9.1 Final Plan 2012 Status This zone was in surplus throughout the planning period reaching a maximum of 0.23 Ml/d in 2011/12.
7.9.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in balance throughout the planning period.
2.0 1.8 1.6 1.4 1.2
1.0 Ml/d 0.8 0.6 0.4 0.2 0.0
Total WAFU Demand plus Target Headroom
Figure 7-16 Barmouth Annual Average SDB position 2015 – 2040
Page | 74 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.10 WRZ 8034 Lleyn Harlech This WRZ covers the entire Lleyn Peninsula and the coastal strip south to Harlech. The WRZ can be divided into two systems:
the northern ‘Lleyn’ system of Llyn Cwmystradllyn, Llyn Cwm Dulyn and Afon Dwyfor; and
the southerly ‘Cilfor – Harlech’ system of Llyn Eiddew Mawr and Llyn Tecwyn Uchaf. The operation of Llyn Cwmystradllyn, in combination with the abstraction from the regulated Afon Dwyfor at Dolbenmaen pumping station, is the subject of a Section 20 Operating Agreement with EAW.
The abstraction rate from Llyn Eiddew Mawr was previously constrained to 1 Ml/d by the hydraulic capacity of the raw water main, which runs from the reservoir to Rhiw Goch WTW, and the WTW was also limited in its treatment capacity to 1.2 Ml/d. A capital scheme was completed at the end of AMP 4 to resolve the supply constraints associated with this raw water main and WTW, which now allows treatment of up to the source licensed limit of 2.27 Ml/d
There is an internal export of water from the Lleyn Harlech WRZ to the Barmouth WRZ, as part of the Rhiw Goch scheme summarised above, to help meet a supply demand deficit in Barmouth WRZ. There is no routine import of water, but the Rhiwgoch link has also been designed to offer operational support from Barmouth WRZ to Lleyn Harlech WRZ when required.
7.10.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 5.32 Ml/d in 2015/16.
7.10.2 Current Status Only the Annual Average planning scenario is reported for this zone. The zone is in surplus throughout the whole planning period, reaching a maximum of 4.79 Ml/d in 2015/16.
Page | 75 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
20 18 16 14 12
10 Ml/d 8 6 4 2 0
Total WAFU Demand plus Target Headroom
Figure 7-17 Lleyn Harlech Annual Average SDB position 2015 – 2040
Page | 76 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.11 WRZ 8035 Dyffryn Conwy The area of this WRZ stretches from the coastal region of Llandudno, inland to the Snowdonia National Park close to Blaenau Ffestiniog. The area is supplied solely from the two impounding reservoirs of Llyn Cowlyd and Llyn Conwy.
The principal resource is Llyn Cowlyd which feeds Bryn Cowlyd WTW. The storage in Llyn Cowlyd is managed between Welsh Water and RWE Innogy, who operate a Hydro Electric Power scheme. Of the storage, 53% is for Welsh Water’s exclusive use and 47% is shared between Welsh Water and RWE Innogy.
Llyn Conwy is the secondary source in the WRZ. The Llyn Conwy WTW is currently constrained in its treatment capacity, but an AMP5 capital scheme will be addressing that constraint. Following completion of this scheme, Llyn Conwy will, along with its own supply area, be able to feed part of the ‘normal’ Llyn Cowlyd supply area.
There are no exports or imports of water for Dyffryn Conwy.
7.11.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 4.20 Ml/d in 2016/17.
7.11.2 Current Status Only the Annual Average planning scenario is reported for this zone. The zone is in surplus throughout the whole planning period, reaching a maximum of 6.16 Ml/d in 2038/39.
35
30
25
20
Ml/d 15
10
5
0
Total WAFU Demand plus Target Headroom
Figure 7-18 Dyffryn Conwy Annual Average SDB position 2015 – 2040
Page | 77 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.12 WRZ 8036 South Meirionnydd The area of this WRZ stretches from the coastal town of Tywyn and the Dysynni estuary, north westwards to Dolgellau and the western fringes of Lake Vyrnwy and serves approximately 7,500 people.
South Meirionnydd WRZ comprises a series of relatively minor sources that supply a network of small communities; these include the spring sources of Abergynolwyn, Llanymawddwy and Brynllys and river abstractions on the Afon Gwril and Afon Calettwr.
Llyn Cynwch is the principal resource for the WRZ, feeding Penycefn WTW, although it has a small catchment area relative to its storage volume and is slow to refill. In the aftermath of the 1995 dry summer, for example, Llyn Cynwch did not spill until April 1999. This concern for refill during winter periods caused Dŵr Cymru Welsh Water to pursue a pump refill scheme into the reservoir from the Afon Wnion.
Water transfers include an export to Severn Trent Water (STW) to supply a small number of domestic properties where it is operationally challenging for STW to meet the demand. There is a corresponding and larger import of water from STW where it is operationally difficult for us to supply domestic properties.
7.12.1 Final Plan 2012 Status This zone was in surplus throughout the planning period until 2029‐30, when due to the Target Headroom Risk profile adopted by Welsh Water, the zone fell marginally into deficit, reaching a maximum deficit of 0.08 Ml/d in 2034‐35. As outlined in the Final Plan 2012 report (section 8.2), given the marginal nature of this deficit late in the planning period and that significant revisions to the water resources planning process were planned to be undertaken over the next 12 months by Welsh Water it was not considered necessary or appropriate to subject South Meirionnydd to a full options appraisal at this time to mitigate against this marginal deficit.
7.12.2 Current Status The zone is forecast to be in deficit under the Critical Period planning scenario only. Under the Critical Period scenario the zone falls into deficit in 2015/16 to a maximum of 0.04 Ml/d. This deficit represents 1% of Total WAFU.
The revised supply demand balance in the zone has been driven by an updated demand forecast, along with the incorporation of updated methodologies for calculating the effects of climate change on deployable output and Target Headroom.
Page | 78 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3.0
2.5
2.0
1.5 Ml/D
1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-19 South Meirionnydd Annual Average SDB position 2015 – 2040
3.0
2.5
2.0
1.5 MlD
1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-20 South Meirionnydd Critical Period SDB position 2015 – 2040
Page | 79 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.13 WRZ 8101 Ross-on-Wye As the name suggests, this WRZ covers the small area and hamlets surrounding the market town of Ross-on-Wye.
The WRZ is supplied in its entirety by the Bulk Supply of potable water from Severn Trent Water’s (STW) Mitcheldean WTW. Our existing Alton Court Borehole has been withdrawn from routine supply and is preserved as a standby source in the event of a drought.
The raw water for Mitcheldean WTW is abstracted from the River Wye at Lydbrook. Whilst the licence is held by STW, the licence conditions specify that 9Ml/d supplies the Ross-on-Wye WRZ. Should the Ross-on-Wye demand be less than 9Ml/d, the licence conditions preclude STW from using the balance within their own Lower Severn resource WRZ.
There is an internal import of water from the Hereford WRZ. There are no exports of water.
7.13.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 2.32 Ml/d in 2014/15.
7.13.2 Current Status Only the Annual Average planning scenario is reported for this zone. The zone is in surplus throughout the whole planning period, reaching a maximum of 3.77 Ml/d in 2036/37.
10 9 8 7 6 5 Ml/d 4 3 2 1 0
Total WAFU Demand plus Target Headroom
Figure 7-21 Ross on Wye Annual Average SDB position 2015 – 2040
Page | 80 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.14 WRZ 8102 Elan Builth This WRZ covers a large area of Powys, centred around the Elan Valley reservoirs and Builth Wells, supplying the small towns and villages of the area. The WRZ is supported by two sources, the Elan Valley Reservoirs and a river abstraction from the River Wye at Builth Wells, with the greater reliance placed on the supply from the Elan Valley Reservoirs.
Our abstraction from the Elan Reservoirs for direct treatment and supply in the Elan Builth WRZ is for a maximum of 5 Ml/d compared to the maximum quantity of raw water supplied to Severn Trent Water (STW) of 386.4 Ml/d. In addition, the Elan Reservoirs are the subject of a Section 20 Operating Agreement between Welsh Water and EAW to provide the release quantities for the River Wye regulation scheme. This supports abstractions from the lower part of the River Wye by STW at Lydbrook (see the above Ross on Wye WRZ section) and by Welsh Water at Monmouth (see the sections on Monmouth WRZ and SEWCUS WRZ). The provision of the raw water bulk supply from the Elan Reservoirs to STW is the subject of a detailed Supply Agreement between Welsh Water and STW.
7.14.1 Final 2012 Plan Status The zone was in surplus throughout the whole planning period, reaching a maximum of 2.96 Ml/d in 2014/15.
7.14.2 Current Status Only the Annual Average planning scenario is reported for this zone. The zone is in surplus throughout the whole planning period, reaching a maximum of 2.75 Ml/d in 2038/39.
8 7 6 5
4 Ml/d 3 2 1 0
Total WAFU Demand plus Target Headroom
Figure 7-22 Elan Builth Annual Average SDB position 2015 – 2040
Page | 81 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.15 WRZ 8103 Hereford Conjunctive Use System As the name suggests, this WRZ covers the city of Hereford and the surrounding area and rural villages as far north as Leintwardine.
The supply is dominated by an abstraction from the River Wye at Hereford. The Dunfield boreholes and Leintwardine borehole serve small local areas of the WRZ. There is an abstraction from the River Lugg at Byton which is currently not used; however, it is retained for potential emergency use.
There are small internal exports of water from the Hereford WRZ to the Ross-On-Wye, Whitbourne and Vowchurch WRZ’s. There are no imports of water.
7.15.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 14.63 Ml/d in 2015/16.
7.15.2 Current Status The Annual Average planning scenario is in surplus throughout the planning period. The maximum surplus under the Annual Average scenario is 9.21 Ml/d in 2030/31.
50 45 40 35 30
25 Ml/d 20 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-23 Hereford Annual Average SDB position 2015 – 2040
Page | 82 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.16 WRZ 8105 Llyswen The WRZ covers the small rural communities in and around Hay- on-Wye.
A single source supplies this WRZ and is based on an abstraction from the River Wye at Llyswen.
There are no exports or imports of water for Llyswen.
7.16.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 1.74 Ml/d in 2011/12.
7.16.2 Current Status The Annual Average planning scenario is in surplus throughout the planning period. The maximum surplus under the Annual Average scenario is 0.78 Ml/d in 2035/36.
4.0 3.5 3.0 2.5
2.0 Ml/d 1.5 1.0 0.5 0.0
Total WAFU Demand plus Target Headroom
Figure 7-24 Llyswen Annual Average SDB position 2015 – 2040
Page | 83 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.17 WRZ 8106 Monmouth This WRZ supplies the market town of Monmouth and the surrounding villages.
The WRZ is heavily dependent on the Mayhill abstraction from the River Wye at Monmouth, located approximately 500 metres downstream of the abstraction for the Wye transfer scheme to Court Farm WTW (SEWCUS WRZ). There are also spring abstractions at Buckholt and Ffynnon Gaer which supply a small high level area to the north of Monmouth and a small localised area south of Monmouth, respectively.
There are no exports or imports of water for Monmouth.
7.17.1 Final 2012 Plan Status The zone was in surplus throughout the whole planning period, reaching a maximum of 2.01 Ml/d in 2011/12.
7.17.2 Current Status The Annual Average planning scenario is in surplus throughout the planning period to a maximum of 2.20Ml/d in 2035/36.
7
6
5
4
Ml/d 3
2
1
0
Total WAFU Demand plus Target Headroom
Figure 7-25 Monmouth Annual Average SDB position 2015 – 2040
Page | 84 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.18 WRZ 8107 Pilleth This WRZ supplies the small rural area surrounding Presteigne. The WRZ also extends into the adjacent catchment of the River Teme and serves Knighton. Around 7500 people are supplied in total.
The WRZ is supplied from a single source of four boreholes located in the gravel aquifer adjacent to the upper River Lugg at Pilleth. Industrial usage in Presteigne is a disproportionately large component of demand in this WRZ and we supply a number of large industrial users of water.
There are no exports or imports of water for Pilleth.
7.18.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 1.12 Ml/d in 2014/15.
7.18.2 Current Status The Annual Average planning scenarios is in surplus throughout the planning period to a maximum surplus of 1.34 Ml/d in 2038/39.
4.0 3.5 3.0 2.5
2.0 Ml/d 1.5 1.0 0.5 0.0
Total WAFU Demand plus Target Headroom
Figure 7-26 Pilleth Annual Average SDB position 2015 – 2040
Page | 85 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.19 WRZ 8108 Brecon Portis This WRZ is situated in the headwaters of the River Usk, in the immediate vicinity of the towns of Brecon and Sennybridge and the Usk Reservoir. The Usk Reservoir has two main uses:
to supply Bryngwyn WTW that serves the upper area of the Tywi CUS WRZ.
to supply Portis WTW that serves the Sennybridge area of the WRZ.
There are three boreholes at Brecon which meet the larger proportion of the WRZ demand. The boreholes are located in the gravel aquifer at Brecon, adjacent to the River Usk.
As mentioned above, the only transfer of water is the export of water to the Tywi CUS WRZ via Bryngwyn WTW.
River Usk at Brecon
7.19.1 Final Plan 2012 Status The zone was in deficit to a maximum deficit of 0.96 Ml/d by 2034/35.
7.19.2 Current Status The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit in 2015/16 reaching a maximum deficit of 1.10 Ml/d in that year. Under the Critical Period scenario the zone drops into deficit in 2015/16 to a maximum of 1.46 Ml/d in that year. This deficit represents 34% of Total WAFU. This supply demand balance assumes that the Habitats Directive licence amendments are implemented throughout the planning period.
This zone is one of nine for which new water resource models have been developed. The new model indicates a lower deployable output than that previously estimated, based simply on abstraction license quantities. The deficit in the zone has been driven by this lower deployable output estimate, the impact of the EAW’s Habitats Directive driven abstraction licence reductions at the Brecon borehole source, which will be implemented by December 2015, and by an improved demand forecast.
Page | 86 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 7-27 Brecon Portis Annual Average SDB position 2015 – 2040
7 6 5 4
Ml/D 3 2 1 0
Total WAFU Demand plus Target Headroom
Figure 7-28 Brecon Portis Critical Period SDB position 2015 – 2040
Page | 87 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.20 WRZ 8110 Vowchurch This WRZ covers the small rural area south of Hay On Wye supplying approximately 6200 people.
The WRZ is supplied by four boreholes that abstract from the gravel aquifer adjacent to the River Dore at Vowchurch. The River Dore is a tributary of the Monnow that in turn is a tributary of the River Wye.
Welsh Water has invested significantly in Vowchurch, identified previously as a deficit zone, to reduce leakage and promote water efficiency. Additionally network developments in the Hereford WRZ have extended the customer supply area of that zone, significantly reducing customer demand in Vowchurch.
There is a small internal import of water from the Hereford WRZ. There are no exports of water.
7.20.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 1.09 Ml/d in 2011/12.
7.20.2 Current Status The Annual Average planning scenario is in surplus throughout the planning period to a maximum of 0.21 Ml/d in 2037/38.
3.0
2.5
2.0
1.5 Ml/d
1.0
0.5
0.0
Total WAFU Demand plus Target Headroom
Figure 7-29 Vowchurch Annual Average SDB position 2015 – 2040
Page | 88 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.21 WRZ 8111 Whitbourne The WRZ is located in east Herefordshire adjacent to the Worcestershire border and supplies the rural towns and villages in the area surrounding Bromyard. The supply is from a single abstraction from the River Teme at Whitbourne some 20 km upstream of the Teme confluence with the River Severn.
Operationally it is possible for limited support to be provided through network adjustment. As such, there is small internal import of water from the Hereford WRZ. There are no exports of water.
7.21.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum 2.01 Ml/d in 2014/15.
7.21.2 Current Status The Annual Average planning scenario is in surplus throughout the planning period to a maximum of is 0.13 Ml/d in 2035/36.
6
5
4
3 Ml/d
2
1
0
Total WAFU Demand plus Target Headroom
Figure 7-30 Whitbourne Annual Average SDB position 2015 – 2040
Page | 89 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.22 WRZ 8121 SEWCUS In addition to the six deficit zones described above, we have also included information on the supply demand balance of SEWCUS WRZ.
This is the largest of all our 24 WRZ’s and serves some 1.5 million domestic customers. It covers the large conurbations of Cardiff and Newport as well the towns and villages of the South Wales valleys.
In total, there are over 40 resources that are used to supply the SEWCUS WRZ which include a mixture of upland reservoir sources with abstractions from the larger rivers in the east of the WRZ.
The abstractions from the Rivers Wye and Usk in the east of the WRZ are taken from the lowland stretches of these rivers and are supported by large catchment areas. Under low river flow conditions the abstractions from the Wye at Monmouth are maintained by regulation releases from the Elan Valley Reservoirs in the headwaters of the River Wye. The regulation arrangements for the River Wye are subject to a Section 20 Operating Agreement with EAW.
The SEWCUS WRZ is integrated to allow supplies from the lowland river sources to be transferred further west, through the WRZ, to relieve the demand on the upland impounding reservoirs whose storage declines relatively quickly in dry weather. This preserves the storage in the upland sources and allows them to supply their immediate demand areas through an extended drought.
Of the 40 sources that supply the SEWCUS WRZ, there are five major reservoir systems (the ‘Big 5’), which provide the major proportion of the water going into supply. These are:
Usk Reservoir Talybont Reservoir Llandegfedd Reservoir Taf Fawr Reservoirs (Llwynon, Cantref & Beacons Reservoirs) Taf Fechan Reservoirs (Pontsticill & Neuadd Reservoirs)
However, a significant proportion of the Usk reservoir storage is allocated to meet Tywi CUS demand. Llandegfedd is a pumped storage reservoir which fills from abstraction on the River Usk at Prioress Mill.
Probably the single most important element within SEWCUS is balancing the output from the larger works which is key to maintaining supply within the WRZ including supply to several large industrial users of water.
There is an internal import of water from the Tywi CUS, which supplies the area north-west of Cardiff around Talbot Green and Llantrisant. There are no exports of water.
Page | 90 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.22.1 Final Plan 2012 Status The Annual Average planning scenario was forecast to be in deficit from 2028/29 reaching a maximum of 12.4 Ml/d by 2034/35.
The deficit in the zone was driven by the incorporation of EAW’s abstraction licence reductions under the EU Habitat’s Directive and the impacts of UKCP09 climate change projections on Deployable Output.
7.22.2 Current Status The revised supply demand balance in the zone has been driven by three key factors; by updated and improved demand forecasting in SEWCUS water resource zone, the incorporation of updated methodologies for calculating the effects of climate change on deployable output and Target Headroom and the impact of proposed licence changes on the Rivers Wye and Usk.
The Annual Average planning scenario remains in surplus throughout the planning period. The zone will remain in good surplus until the licence reductions on the Wye and Usk are implemented. If the licence reductions in the zone are implemented at the Natural Resources Wales (successor to Environment Agency Wales) preferred timescale of December 2015 the surplus under the Annual Average scenario is estimated at only 5 Ml/d in 2015. Throughout the planning period there is a minimum surplus of just 3 Ml/d under the Annual Average scenario by 2039/40. This represents under 1% of Total Water Available for Use (WAFU).
Within the plan, we propose that the licence amendments are implemented in April 2018 as described in section 6.6, Timetable for licence amendments and implementation. This is reflected in both the baseline and final planning data tables (Appendix A).
The additional three years will allow us time for a full appraisal of any residual risks to our operational ability to supply our customers in SEWCUS associated with the Natural Resources Wales licence amendments, so that where appropriate we can implement the required schemes to reduce or eliminate completely these risks.
400
350
300
250
200 MlD 150
100
50
0
Total WAFU Demand plus Target Headroom
Figure 7-31 SEWCUS Annual Average SDB position 2015 – 2040
Page | 91 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.22.3 Compensation flow from Castell Nos reservoir Castell Nos reservoir is a WFD Heavily Modified Water Body (HMWB). Dŵr Cymru Welsh Water has agreed with Natural Resources Wales to model the impact on DO of maintaining a Q95 compensation release of 6.8 Ml/d from Castell Nos reservoir into the Afon Rhondda Fach. We do not currently have a requirement to maintain any compensation flow into the Afon Rhondda Fach. The change is assumed to take place from 2020 onwards.
This is to model the effects of providing increased compensation flows to the Rhondda as a mitigation measure for our use of the reservoir for public water supply.
The effect of maintaining this 6.8 Ml/d compensation flow was modelled to assess what impact this would have on DO available in SEWCUS and consequently on the supply demand balance of SEWCUS. The reduction in DO was found to have a significant impact on SEWCUS supply demand balance. Where SEWCUS was previously in marginal surplus throughout the planning period it now falls into deficit in 2020 reaching a maximum deficit of 16.8 Ml/d by 2039/2040 in the Annual Average scenario.
This supply demand balance scenario for the provision of a compensation release of 6.8 Ml/d from Castell Nos reservoir assumes that the Habitats Directive licence amendments are implemented in April 2018. This is in line with our proposals for the timetable for licence amendments as described in section 6.6 Timetable for licence amendments and implementation.
The supply demand balance for this scenario is shown in Figure 7-32 below.
400
350
MlD 300
250
200
Total WAFU Demand plus Target Headroom
Figure 7-32 SEWCUS Annual Average SDB position 2015 – 2040 with Castell Nos compensation flow
Page | 92 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.23 WRZ 8201 Tywi Conjunctive Use System This is the largest WRZ in South West Wales, extending in the east from the Vale of Glamorgan to west of Carmarthen and stretching northwards past Llanwytrd Wells.
The WRZ is managed as a conjunctive use system across a range of impounding reservoirs and regulated river intakes, The upland reservoirs of Ystradfellte and Crai supply the upper parts of the Neath, Afan and Tawe Valleys by gravity. During periods of high reservoir storage and low demand the supply areas of these two reservoirs extend down the valley into parts of Swansea and Neath. As storage in the upland reservoirs declines, the area served is gradually reduced and water from Felindre WTW is moved progressively further up the valleys.
At Nantgaredig, on the River Tywi, raw water is pumped to the Lower Lliw Reservoir and direct to Capel Dewi WTW. When flows in the River Tywi fall below 681.9Ml/d (the licence hands-off-flow) the river is augmented by releases from Llyn Brianne Reservoir to match and support the Nantgaredig abstraction rate. The operation of Llyn Brianne Reservoir and the Tywi river regulation scheme is the subject of a Section 20 Operating agreement between Welsh Water and EAW.
There is a transfer into the SEWCUS WRZ via Cefn Hirgoed Service Reservoir to serve the area north- west of Cardiff around Talbot Green and Llantrisant. Similarly, there is an import of water from Usk Reservoir (in the SEWCUS WRZ) to Bryngwyn WTW.
7.23.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period to a maximum of 32.98 Ml/d in 2014/15.
7.23.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in surplus throughout the planning period to maximum of 35.7 Ml/d in 2035/36.
Page | 93 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
250
200
150 Ml/d 100
50
0
Total WAFU Demand plus Target Headroom
Figure 7-33 Tywi CUS Annual Average SDB position 2015 – 2040
Page | 94 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.24 WRZ 8202 Mid & South Ceredigion Mid & South Ceredigion covers the Teifi Valley and the coastal area from south of Cardigan, northwards to just south of Aberystwyth.
The WRZ is supplied from two sources:
Llechryd WTW, which is reliant on the run of river abstraction from the River Teifi, at Llechryd; Strata Florida WTW located near Pontrhydfendigaid in the upper Teifi catchment, which is supplied by three small reservoirs – Llyn Teifi, Llyn Egnant and Llyn Pondygwaith, which are collectively known as Teifi Pools. There are no exports or imports of water for Mid & South Ceredigion.
7.24.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 6.40 Ml/d in 2020/21.
7.24.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in surplus throughout the planning period to maximum of 4.54 Ml/d in 2037/38.
25
20
15 Ml/d 10
5
0
Total WAFU Demand plus Target Headroom
Figure 7-34 Mid and South Ceredigion Annual Average SDB position 2015 – 2040
Page | 95 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.25 WRZ 8203 North Ceredigion This WRZ covers the land around the coastal and inland area surrounding Aberystwyth. The majority of the WRZ is supplied from the impounding reservoirs of Llyn Craig-y-Pistyll and Llyn Llygad Rheidol, which are supported by river abstractions from the Nant-y- Moch and Maesnant streams.
In the south west of the WRZ, groundwater abstractions from the two boreholes at Lovesgrove meet the demand. Borehole 1 at Lovesgrove is constrained by the abstraction licence quantity. Whilst Borehole 2 is currently in the groundwater licence exempt area of West Wales, changes to the licensing legislation following the Water Act 2003 mean that such an exemption will be terminated in the foreseeable future and the source will become licensed.
There are no exports or imports of water for North Ceredigion.
7.25.1 Final Plan 2012 Status The zone was in surplus throughout the whole planning period, reaching a maximum of 1.93 Ml/d in 2011/12.
7.25.2 Current Status Only the Annual Average planning scenario is reported for this zone. The Annual Average planning scenario is in surplus throughout the planning period to maximum of 3.18 Ml/d in 2016/17.
14
12
10
8
Ml/d 6
4
2
0
Total WAFU Demand plus Target Headroom
Figure 7-35 North Ceredigion Annual Average SDB position 2015 – 2040
Page | 96 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.26 WRZ 8206 Pembrokeshire This WRZ covers the far south west corner of Wales, stretching from Pendine sands in the east to the Pembrokeshire Coastal National Park in the west and from the villages of Manobier in the south to Newport in the north.
The largest treatment works in the WRZ is Bolton Hill WTW, which is supplied by an abstraction at the Canaston intake on the Eastern Cleddau, which in turn is supported by river regulation releases from Llys-y-Fran Reservoir. In addition to potable water production for public water supply, the Canaston – Bolton Hill arrangement supplies raw industrial water to the oil refineries south and north of Milford Haven.
Dŵr Cymru Welsh Water also has an abstraction on the Western Cleddau at Crowhill and this is a direct river abstraction. Raw water abstracted at Crowhill also supplements the water available from Bolton Hill WTW.
Preseli Reservoir is located upstream of Llys-y-Fran Reservoir and the compensation discharge from Preseli Reservoir flows into Llys-y-Fran. Dŵr Cymru Welsh Water is able to support Preseli WTW with a transfer from Llys-y- Fran and a river abstraction from the Eastern Cleddau at Pont Hywel, which provides a pump-refill facility for Preseli Reservoir.
Pendine borehole supplies to the eastern part of the WRZ and the supply area can be extended further West under similar conditions; however, these three sources are in the currently groundwater licence exempt area of West Wales and changes to the licensing legislation following the Water Act 2003 will mean that such an exemption will be terminated in the foreseeable future and the sources will become licensed.
There are no exports or imports of water for Pembrokeshire, excluding the non-potable supplies to the industrial users near Milford Haven.
7.26.1 Final Plan 2012 Status. The zone was forecast to be in deficit under both the Annual Average and Critical Period planning scenarios to a maximum of 12.7 Ml/d by 2034/35. The deficit in the zone was driven by the incorporation of the EAW’s abstraction licence reductions under the EU Habitat’s Directive and climate change projections into the supply calculations.
7.26.2 Current Status The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit in 2015/16 with the maximum deficit of 8.8 Ml/d by 2039/40. This deficit represents 25% of Total WAFU. Under the Critical Period scenario the zone falls into deficit in 2023/24 to a maximum of 5.7 Ml/d by 2039/40.
Page | 97 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The deficit in the zone has been driven by the incorporation of the EAW’s abstraction licence reductions under the Habitats Direction, and incorporation of the updated UKCP09 climate change methodology into our supply calculations.
This supply demand balance assumes that the Habitats Directive licence amendments are implemented in December 2015. Our plan shows the implementation of the licence amendments in April 2018 as described in section 6.6, Timetable for licence amendments and implementation. This is reflected in both the baseline and final planning data tables (Appendix A).
50 45 40 35 30 25 MlD 20 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-36 Pembrokeshire Annual Average SDB position 2015 – 2040
60
50
40
30 Ml/D
20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-37 Pembrokeshire Critical Period SDB position 2015 – 2040
7.26.3 Revised operation of Pont Hywel abstraction In that studies are ongoing to better understand the impact of the abstraction at Pont Hywel on the Eastern Cleddau, there remains the possibility that licence reductions will not be as severe as initially indicated by the EAW in taking the precautionary approach of using river flows as a surrogate for evidenced river ecology. For this reason the EAW have requested that a scenario is examined in
Page | 98 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
which the Pont Hywel intake is able to abstract at a constant rate of 10Ml/d, with a hands-off flow of 4.5Ml/d, instead of using the abstraction rule currently applied under the proposed EAW Review of Consents changes for this zone.
The modelling of this alternative operation of Pont Hywel results in an average annual DO of 78.1 Ml/d and a critical period DO of 97.5Ml/d due to the potential to increase abstraction at Pont Hywel intake. These values are 6.9Ml/d and 9.2Ml/d higher than the respective baseline DO values. The effect of this scenario on the baseline supply-demand balance for Pembrokeshire is presented in Figure 7-38 and Figure 7-39. The effect of reduction of the impact on DO is to reduce the maximum deficit in Pembrokeshire during the planning period to 2.1 Ml/d under the Annual Average scenario and to remove Pembrokeshire from deficit into surplus throughout the planning period under the Critical Period scenario.
This supply demand balance scenario for reduced restrictions at Pont Hywel assumes that the Habitats Directive licence amendments are implemented in April 2018. This is in line with our proposals for the timetable for licence amendments as described in section 6.6, Timetable for licence amendments and implementation.
50 45 40 35 30 25 MlD 20 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-38 Pembrokeshire Annual Average SDB position 2015 – 2040 with reduced restrictions at Pont Hywel
Page | 99 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
70 60 50 40
30Ml/D 20 10 0
Total WAFU Demand plus Target Headroom
Figure 7-39 Pembrokeshire Critical Period SDB position 2015 – 2040 with reduced restrictions at Pont Hywel
Page | 100 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
7.26.4 Consideration of inflows for Pembrokeshire catchments There is a degree of uncertainty around the accuracy of inflows to the catchments within the Pembrokeshire WRZ. For the Final WRMP2012 inflows were based on transposition from the Gwaun gauged flow sequence, however it is understood that the quality and length of record is poor resulting in significant uncertainty around the flows that might be seen during a critical period event. In response, Hysim models have been developed for the key Pembrokeshire catchments with the aim to improve the data and reduce the uncertainty in transposed data sets.
The Hysim model outputs are significantly different to those produced when using inflows generated by transposition of Gwaun flows. Although the Hysim models offer a longer record based upon good rainfall data, the magnitude of the differences cannot be explained and there remains some uncertainty over the inflow values which flags the need for improved data capture during low flow events. We have attempted to monitor low flows at several key sites across the zone during 2011 and 2012 but have been unable to capture sufficient data to update the Hysim model calibration. Although the Hysim models provide the best evidence for inflow estimation, we have used the Gwaun transposition data as a sensitivity check on investment need.
For this scenario we have modelled the zonal DO using inflows based on transposition from the Gwaun gauged flow sequence. Pembrokeshire annual average DO is 63.9 Ml/d, which is 7.3 Ml/d less than the value used in the baseline supply-demand balance for this zone. This would result in a baseline deficit of reaching a maximum deficit of 22.8 Ml/d by 2040 in the Annual Average scenario and 25.5 Ml/d in the Critical Period scenario.
This scenario assumes that the Habitats Directive licence amendments are implemented in April 2018. This is in line with our proposals for the timetable for licence amendments as described in section 6.6, Timetable for licence amendments and implementation.
The effect of this scenario on the baseline supply demand balance for Pembrokeshire is presented in Figure 7-40 and Figure 7-41.
45 40 35 30 25
MlD 20 15 10 5 0
Total WAFU Demand plus Target Headroom
Figure 7-40 Pembrokeshire Annual Average SDB position 2015 – 2040 with Gwaun inflow sequence
Page | 101 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
60
50
40
30 Ml/D
20
10
0
Total WAFU Demand plus Target Headroom
Figure 7-41 Pembrokeshire Critical Period SDB position 2015 – 2040 with Gwaun inflow sequence
Page | 102 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8 Option Appraisal and the Preferred Plan
8.1 Introduction In chapter 7 we presented details of the six zones where we are projecting that at some point during the next 25 years demand will exceed the available water supply and the zone will enter deficit, along with SEWCUS which is in marginal surplus. This section explains how we evaluate the options available to address those deficits. To maintain our relevant Level of Service, both at a company level and in each of the two WRZs, we either need to increase supply or reduce demand (or a combination of the two). Without such intervention these zones may experience a frequency of water restrictions such as hosepipe bans in excess of what we have established as the minimum level of service.
8.2 Overall methodology Our option appraisal approach follows national best practice and is consistent with the requirements of the Environment Agency’s Guideline.
The most important reference document on option appraisal is “The Economics of Balancing Supply and Demand” (EBSD) (UKWIR/EA 2002). The EBSD report sets out how water companies should identify, assess and compare alternative options for addressing supply demand deficits. In accordance with the Environment Agency’s Guideline we have also used
Assessment of Benefits for Water Quality and Water Resources Schemes in the PR04 Environment Programme (EA, 2002), commonly referred to as the Benefits Assessment Guidance (BAG). This methodology provides non-prescriptive guidance on how to assess the environmental and social costs of options, and was updated in 2012 (EA, 2012); and
Providing Best Practice Guidance on the Inclusion of Externalities in the Economic Level of Leakage Calculation (Ofwat, 2007). This report provides guidance on how to assess the environmental and social costs of leakage reduction schemes
The stages of the options appraisal process are set out in Figure 8-1 Summary of Options Identification and Appraisal Process
Page | 103 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Unconstrained list of options Complete and exhaustive list of all technically feasible options
Screening
Feasible list of options Options that satisfy the screening criteria
Economic appraisal
Preferred list of options Option or combination of options that have been selected as best able to address the planning problem
.
Figure 8-1 Summary of Options Identification and Appraisal Process
The option appraisal process considers the widest possible range of potential solutions to any shortfall against demand and target headroom in a particular area. In doing so, an ‘Unconstrained list’ is first developed.
A set of screening criteria are then applied to select a feasible list of options from the unconstrained list of options. Our screening process was based on the Multi Criteria Assessment (MCA) first implemented in the PR09 Plan. This approach was adopted as we consider it reflects the 12 core environmental receptors listed in Schedule 2 (6) of the Strategic Environmental Assessment (SEA) Regulation (biodiversity, population, human health, fauna, flora, soil, water, air, climatic factors, material assets, cultural heritage and landscape).
The justification as to why any options have been rejected at that stage has been included within the dWRMP 2013 Technical Report. This screening has resulted in a feasible list of options that contains sufficient options to allow real choices when moving to the preferred options set and to make sure alternative solutions can be formed.
It is worth noting that, as described in chapter 4, we will continue to tackle leakage and encourage water efficiency as a baseline activity. The leakage and water efficiency options that we have identified will be in addition to this baseline activity.
The UK Government, Environment Agency and Ofwat recognise the need for greater sharing of resources between water companies as a sustainable way of balancing supply and demand. This has led to all companies being asked to consult on the need and availability of water with neighbouring companies and third parties. No third parties or neighbouring water companies have presented any specific water supply options to us for inclusion within this options appraisal process.
The Economics of Balancing Supply and Demand report sets out the range of options that should be considered and summarises them into four main categories:
Page | 104 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Distribution Management - options which reduce consumption from the point of input into the network to the customer property (leakage options and mains replacement); Customer-side Management - options which reduce customers’ consumption (water efficiency and tariffs); Production Management - options which reduce/modify usage from where it is abstracted to where it enters the network. There are only a limited number of this type of option available; and Resource Management - options that vary yield, including schemes based on resources within Dŵr Cymru Welsh Water’s supply area and those that are proposed by third parties. For each feasible option we have determined:
Capital expenditure (CAPEX); Design, planning and construction time (the lead time); Operational expenditure (OPEX); Gain in zonal Deployable Output or the savings in demand; Environmental and social costs and benefits Carbon impact of construction and operation Average Incremental Social Costs. Average Incremental Social Cost is a measure of the overall financial, environmental and social cost of an option. It is usually expressed in terms of pence per cubic metre of water (p/ m3). The calculation of Environmental and Social costs is aligned with ecosystems approach by identifying impacts on the environment and society and including these as costs to be considered alongside financial costs.
8.2.1 Distribution Management Options The full range of leakage options has been considered based on the short-run sustainable economic level of leakage profiles for each WRZ, as described in chapter 4. These have been incorporated into the baseline demand forecasts to identify any WRZs in the baseline supply-demand balance where a deficit would arise over the 25-year planning period.
In deficit WRZs, distribution options include further reductions in leakage below the economic levels defined in the forecast baseline leakage. If leakage schemes are selected in deficit WRZs during the least cost planning exercise, the lower level of leakage resulting from implementation of the scheme is regarded as the long run SELL.
Further leakage intervention schemes provided to Dŵr Cymru Welsh Water for least cost planning purposes comprised the following distribution leakage reduction options:
Enhanced Active Leakage Control (based on the current methods of reducing leakage); Pressure management; Asset renewal (distribution infrastructure); Trunk mains repair and Trunk mains renewal.
Page | 105 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.2.2 Customer side options Dŵr Cymru Welsh Water has worked with expert consultants AMEC , RPS and Aqualogic to develop a range of customer side options with varying delivery mechanisms and water savings. These are shown in Table 8-1 below.
Water efficiency scheme costs and water savings will vary depending on the assumptions made regarding each of the options. We have discussed and agreed the key assumptions on option savings, costs and uptake rates within our expert consultants, taking account of published information on water efficiency schemes e.g. from the Waterwise Evidence Base. The final installation rate of water efficiency devices is a key variable in estimating costs and savings which will depend on a number of factors including the marketing effort undertaken, the method of delivery and the ease of installation of particular devices. Again, these were based on industry standard estimates.
The final installation rate and the total number of properties in a WRZ will determine the absolute number of installations possible in a particular WRZ, and therefore the total costs and savings of the water efficiency activity in the zone. As a result there is wide range of potential savings from water efficiency schemes. For example, a household audit retrofit scheme in SEWCUS delivers an annual saving of 0.14Ml/d over the planning period, at a discounted total cost of £1.95m (taking account of capex, opex and social and environmental costs). The same scheme in NEYM delivers 0.013 Ml/d at a discounted cost of £0.18m.
Delivery Water Saved Water Efficiency Options Domestic/Commercial mechanism (Ml/d) Option WE002 - Low Flow Shower Household Self retrofit 0.06 Retrofit Option WE003 - Household Tap Flow Household Visit retrofit 0.06 Regulation Option WE007 - Household Toilet Household Self retrofit 0.06 Variable Flush Retrofit Option WE008 - Household Toilet Household Self retrofit 0.02 Cistern Displacement Device Option WE019 - Household Audits & Household Visit audit and 0.07 Fit retrofit Option WE019A - Household Audits & Household Visit audit and 0.07 Fit (Collaboration) retrofit Option WE020 - Household Education Household Self audit / 0.00 education Option WE025 - Household Water Household Self retrofit 0.024 Butts Option WE027 - Household Hosepipe Household Self retrofit 0.017 Trigger Option WE029 - Household Welcome Household Self retrofit 0.048 Pack Option WE037 - Non Household Non-household Self retrofit 0.141 Showerhead Replacement Option WE038 - Non Household Tap Non-household Self retrofit 0.117 Flow Regulation Option WE041- Non Household Toilet Non-household Self retrofit 0.034 Cisterns Displacement Devices Option WE043 - Non Household Urinal Non-household Visit retrofit 0.125
Page | 106 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Delivery Water Saved Water Efficiency Options Domestic/Commercial mechanism (Ml/d) Flush Controls Option WE054 - Non Household Non-household Visit retrofit 0.008 Leakage Reduction - Internal Option WE058- Non Household Indoor Non-household Visit audit and 0.151 Audits and Fit retrofit Option WE071 - Non Household Non-household Visit audit and 0.160 Outdoor Audits retrofit Option WE072 - Non Household Toilet Non-household Visit retrofit 0.146 Variable Flush Retrofit Option WE076 - Non Household Non-household Self audit / 0.001 Promoting Water Efficiency education Option WE077 - DCWW Do As I Do Non-household Self audit / 0.009 Campaign education Table 8-1 Relative benefits from water efficiency measures
Water efficiency schemes in smaller zones that deliver individual devices such as tap retrofits or low flow showerheads will deliver even smaller savings. For this reason we developed two small-zone specific water efficiency options for the smallest deficit zones in this Plan: South Meirionnydd and Bala. For these audit and retrofit options we assumed that uptake rates would be maximised (at 65% of total property numbers) based on a concerted recruitment and installation effort.
8.2.3 Resource Side Options Resource side options have been defined and costed for each water resource zone. The Technical Report and associated annexes describe the ‘unconstrained’ and feasible list of options in detail as these are all site specific. More generically as described in the WRMP Guidance, these fall into the categories listed below in Table 8-2.
Resource side Schemes Scheme Sub-Categories/Sub-Components
New reservoir storage On-stream reservoirs Pumped-storage reservoirs Direct river abstraction Reservoir raising Groundwater wells (boreholes) Desalination Reclaimed water Reclaimed domestic wastewater Reclaimed industrial and commercial wastewater (for domestic, commercial and industrial users) Bulk transfers (both inside and outside the By canal company‘s own supply area) By river By pipeline Water Trading (with other water companies or 3rd parties) Tankering of water Improved/sophisticated conjunctive management Table 8-2 Resource Side Scheme Option Categories
Page | 107 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.2.4 Water Trading Options As part of the options process, water companies are required to consider all options to share resources with other water companies and/or non-water company providers or users of water.
However, the Welsh Government have advised through guidance that Welsh Water should only agree to sharing resources and water trading where it would not be detrimental to our current operations and customers and furthermore that:
“In the water resources management plan, the company should state how it has fully investigated sharing resources. This applies to a company in surplus which could act as a donor (optional for water companies operating wholly or mainly in Wales) or a company in deficit which could act as a recipient and includes water trading within a catchment.”
To make ourselves aware of the potential for neighbouring water companies or 3rd parties to provide water resources where required within our area we have actively sought this information. As part of our pre-consultation for the plan, we published a view of need and availability of water resources across our supply area. This document provided details of where we may require additional water resources in the future. This view was based on a view of anticipated deficit zones from work in developing our Final Plan 2012. This was:
Water Resource Zone Potential Resource Potential Resource requirements by 2020 requirements by 2035 South East Wales Conjunctive 10 - 50 Ml/d 10 - 50 Ml/d Use System (SEWCUS) Pembrokeshire 5 - 10 Ml/d 10 - 20 Ml/d Brecon – Portis 0.5 - 1.0 Ml/d 0.5 - 1.0 Ml/d Ross 1.0 - 2.0 Ml/d 1.0 - 2.0 Ml/d Table 8-3 Potential Resource Requirements
In addition, we highlighted those zones where there was a risk of a supply demand balance deficit where previous plans have indicated marginal balances. These are:
North Eryri Ynys Mon South Meirionydd Tywyn/Aberdyfi Bala Alwen/Dee Clwyd Coastal
These zones above include all of those that are now demonstrated to be in deficit in this plan (See Figure 8-2 Minimum SDB Positions below). We have to date had no respondents to this publicised position and have in response not included any new bulk supply or trading options within this plan. We will update our website with our latest supply demand balance position at the same time as publishing the draft plan for consultation. We would still welcome discussions with any third party that feel they have available water resource within any of our deficit zones that might prove better value than the schemes put forward here.
Page | 108 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
0.8
-3.7 2.8 0.0
0.9 4.2 -0.1
0.0 -0.04 -1.0 0.4
2.7 0.0 1.4
3.3 0.5 1.9 -1.5 0.0
-8.8* 0.2 29.0 3.0* 1.3
Marginal Surplus Deficit Surplus * Assumes Licence changes in place - values shown in Ml/d
Figure 8-2 Minimum SDB Positions
In addition to our statement of need we have also been in discussions with our neighbouring water companies regarding data and information sharing relating to existing bulk supplies and the further feasibility of water resource sharing. We have had a number of meetings with Severn Trent, and Bristol Water and conversations with Dee Valley and United Utilities along these lines.
Chapter 7 shows that once review of consents licence changes are in place, that there is very little surplus water resource that might be used to trade with other water companies. This is particularly true of the WRZs which border the DCWW region to the east. However, there are a number of good value scheme on the feasible list of options that could be progressed. If this water resource were to be developed then additional infrastructure would be required to transfer this water to the border areas and it would also be necessary for the receiving company to also develop infrastructure.
We have confirmed to Severn Trent Water that there are options available within our SEWCUS WRZ that we are not proposing to develop in the near future and that could be compared to schemes within their plan. Although, the costs of these schemes for use within the DCWW have been estimated, the full cost of a transfer and the price to Seven Trent Water has not been established and this would be subject to further discussions between the two companies.
Page | 109 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
This type of transfer would also require the understanding of the Welsh Government as stipulated within the WRMP Guidelines. It is proposed to continue with these commercial discussions through the consultation period.
We are continuing with discussions regarding an extension to our Bulk Supply from Sever Trent Water in to the South Meirionydd WRZ. However, this is not for the purpose of resolving the minor zonal deficit but to add resilience against potential outages at Dinas Mawddwy and Llanymawddwy.
We have confirmed with Bristol Water that we only have a small Supply Demand Balance surplus within our SEWCUS WRZ and that this could not easily be accessed due to the network limitations. To make water resource available to this area adjacent to the Seven Estuary for further transfer on to Bristol Water, we would need to construct significant infrastructure from the Newport area to beyond Chepstow.
An alternative would be to develop a substantial new water resource in the south east of the zone. A new strategic water resource option has been identified in our unconstrained options list, however, full access to this water cannot be confirmed at the current time as this would require the completion of commercial discussions. As a result this, potential scheme has been removed from our feasible options set and we have informed Bristol Water that this source is unlikely to be developed before the end of the AMP6 period. We will update Bristol Water if there is any change in this position during the consultation period on their draft WRMP. Therefore, there is no scope currently to transfer significant volumes of water to the border between our companies at this time.
We do not have any significant quantity of water resource available adjacent to the WRZ’s in the north of the DCWW region and so we have not presented any options to either Dee Valley or to United Utilities during pre-consultation.
8.3 Selecting the preferred option For the 2008 Draft Plan, Jacobs UK were commissioned to develop a bespoke Least Cost Optimisation model 19,20 to assist in scheme optimisation. In the 2008 Draft Plan audit, the model was commended by the independent Ofwat reporter who concluded that “Dŵr Cymru Welsh Water had developed an appropriate optimising tool resulting in programmes of work that were likely to be optimal...”
The model calculates the supply demand balances, from the individual components, for each WRZ then evaluates the least cost combination of options, from the range of options and cost data, which could be implemented to meet the forecast deficits. The model:
determines the cost benefit indices which are used in the relative assessment of the various options (Average Incremental Cost (AIC) & Average Incremental Social Cost (AISC) which also takes account of the social, environmental and carbon costs of each option.) These indices are based upon the net present value of all relevant financial, environmental, social and carbon costs discounted over an eighty-year period;
identifies the least-cost combination/ mix of options that best meets the supply demand deficit for each WRZ; and
19 Lot 5 – Least-Cost Water Resources Planning Model – Functional Description (Jacobs 2008a). 20 Lot 5 – Least-Cost Water Resources Planning Model – User Guide (Jacobs 2008b).
Page | 110 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
derives the preferred set of options that meets the supply demand balance deficit, for each WRZ, at the least long-run marginal cost.
The model has been developed to allow changes in the various components of the supply demand balance to be rapidly incorporated to take account of, for example, potential climate change scenarios and sustainability reductions.
The model allows for the identification of options links and dependencies. For example, the model will only select one option, if programmed to do so, where multiple source options have been identified to supply one WTW, or, where there are transfers from one source to multiple WRZ’s.
The model also includes a GIS interface that allows the options to be visualised and their relationship, for example, with existing Welsh Water infrastructure and their proximity to environmentally sensitive areas.
As the preferred option set will likely form the basis of the Plan submission, the model also produces the optimisation run results in the required format for Tables WRP2 and WRP3, as required by the Environment Agency’s Guideline.
As laid out within the WRMP guidance, the chosen programme of solution does not necessarily have to be least cost but should represent best value for customers and the environment. This allows for any issues identified throughout the SEA and HRA and any efficiencies with other business drivers such as water supply system resilience to be taken into account in choosing the best value solutions. The SEA and HRA assessment processes are outlined in chapter 9 Environmental Appraisal.
The following sections outline the preferred solutions for the zones where there is a supply against demand deficit over the planning period and where this differs from the least cost solution or where there are other benefits from the chosen solution, these are outlined.
8.4 WRZ 8001 North Eryri - Ynys Mon As detailed in chapter 7, under the annual average scenario the zone falls into deficit in 2023/24 with the maximum deficit of 3.69 Ml/d by 2029/30. Under the Critical Period scenario the zone falls into deficit in 2023/24 to a maximum of 2.53 Ml/d by 2029/30. However, under both the scenario in which the demand increases due to the development of the Wylfa power station or where there is a proven environmental need for compensation release from the Cefni, the deficit position is brought forward.
The optimiser has been used to assess the relative cost against benefit values for a full suite of water efficiency, leakage and water resource options. The most practical water resource options available within the WRZ are to:
Connect Afon Rhythallt to Cwellyn WTW Transfer of water from Cwm Dulyn to the North Eryri WRZ Raise the Ffynnon Llugwy dam Raise Alaw reservoir Connect Cefni to Alaw Reservoir Construct a desalination plant
Page | 111 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
TRANSFER TO CWELLYN
Figure 8-3 Schematic of NEYM WRZ
Out of these, the least costs options to meet the baseline deficit within the zone is a combination of the Cwm Dulyn and Afon Rhythallt options and these will deliver a benefit of circa 5Ml/d for the zone. The best value water efficiency options cost less than the Afon Rhythallt scheme, however, the level of savings are insufficient on their own or in combination with the Cwm Dulyn scheme to fill the deficit required. Leakage options to around 1Ml/d are cost effective when compared to the Afon Rhyhalt resource scheme but again provides insufficient benefit to resolve the deficit position on its own or with the Cwm Dulyn option.
The lease cost option and preferred solution under the base scenario is therefore to increase the available supply within the WRZ in combination with target leakage reduction in 3 stages: The first stage of the preferred solution will be achieved by a transfer of water from Cwm Dulyn WTW (in Lleyn Harlech WRZ). There is some abstraction licence surplus at Cwm Dulyn therefore there is no need for additional consents. Some work will be required on the network to enable this transfer.
Page | 112 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The second stage of the preferred solution will be achieved through enhanced leakage detection.
The third stage of the preferred solution will be achieved by commissioning a river intake on the Afon Rhythallt and utilising the abstraction licence (maximum quantity of 3.4 Ml/d) we still hold for the site. The raw water will be transferred directly to Cwellyn WTW where it will be treated and delivered into supply to meet the demands of the WRZ. As the supply of water has been used in the past, it is a known reliable source. No new abstraction licence would be required.
As the scheme progresses we will undertake further more detailed investigations and should significant environmental (or other) issues arise, then alternative options will be considered through the planning process.
The outputs of the SEA and HRA were taken into consideration when determining the preferred solutions for the WRZ. In this zone, the transfer of water from Cwm Dulyn to the North Eryri WRZ was the option with the least negative impacts under the SEA as a result of either construction or operation as well as a comparatively low AISC. This reflects the nature of the option which requires very few actions to construct or operate.
The implementation of leakage reduction was not assessed as having significant negative effects during construction and had only minor positive effects during operation under the SEA. This reflects the nature of the option as having limited short term impacts during the repair of leaks and ongoing benefits once a leak is repaired in terms of lower operating, environmental and social and carbon costs.
The connection of the Afon Rhythallt to Cwellyn WTW was assessed as having some negative and some positive impacts as a result of either construction or operation under the SEA. This result was not significantly different to several supply side options considered in the zone which involve river abstractions or the upgrade or new building of WTWs. The connection of the Afon Rhythallt to Cwellyn WTW is the least cost of these supply side options.
The least cost solutions comprise two options with few negative and several positive effects under the SEA and one option with impacts similar to those of options of a similar nature, though more expensive. Therefore we consider that the least cost solutions represent best value for customers and the environment in this zone.
Page | 113 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
60
55
50
45 Ml/d
40
35
30
Total WAFU Cwm Dulyn transfer Enhanced leakage detection Rhythalt river abstraction Demand plus Target Headroom
Figure 8-4 Final Supply Demand Balance for the NEYM WRZ
WRZ WRZ Max. deficit Start of deficit Solution name (s) no. name over planning period (Ml/d)
8001 NEYM 3.69 2023/24 Transfer of water from Cwm Dulyn to the North Eryri WRZ
Enhanced Leakage detection
Rhythalt river abstraction and transfer to Cwellyn WTW Table 8-4 Summary of preferred solutions in NEYM WRZ
Under the higher demand scenario in which the proposed Wylfa B power station is developed on Anglesey, the preferred solutions will still remain cost effective but will not be able to meet the demands on the zone over the full planning period. However, the water requirements of the proposed power station are not clearly defined at this time and therefore cannot be included in our demand forecasts. Previous discussions with Horizon Ltd have indicated a need of 6 Ml/d, pre, and post construction. This quantity could be a combination of raw and treated water, and would include the water supply required for the decommissioning of the existing Wylfa A nuclear power station.
We have already considered a range of additional resource schemes to meet the additional Wylfa B demands in the document ‘Wylfa B Fresh Water Supply Feasibility Study’, and there are additional resource schemes which may be considered once there is more certainty surrounding the water supply requirements.
We remain closely involved in the planning for the future demands and as soon as they are known we will start the planning process to ensure a healthy supply demand balance is maintained in this zone.
Page | 114 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.5 WRZ 8020 Bala The anticipated deficit within the Bala WRZ over the planning period is relatively small at an annual average value of 0.06 Ml/d and Critical Period value of 0.09 Ml/d. The preferred solution to meet this imbalance is to reduce demand within the WRZ. A range of options including transferring resource from the neighbouring Alwen Dee zone were considered, of which leakage reduction was found to be the least cost solution.
This will be achieved through enhanced leakage detection.
The implementation of leakage reduction was not assessed as having significant negative effects during construction and had only minor positive effects during operation under the SEA. This reflects the nature of the option as having limited short term impacts during the repair of leaks and ongoing benefits once a leak is repaired in terms of lower operating, environmental and social and carbon costs.
Therefore we consider that the leakage reduction represents best value for customers and the environment in this zone.
2.60
2.40
2.20
2.00 Ml/d
1.80
1.60
1.40
Total WAFU Leakage Demand plus Target Headroom
Figure 8-5 Final Supply Demand Balance for the Bala WRZ
WRZ no. WRZ name Max. deficit Start of deficit Solution name (s) over planning period (Ml/d)
8020 Bala 0.12 2015/16 Leakage reduction
Table 8-5 Summary of preferred solutions in Bala WRZ
Page | 115 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Example of leakage detection
Page | 116 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.6 WRZ 8021 Tywyn Aberdyfi The zone is forecast to be in deficit under the Annual Average scenario in 2015/16 reaching a maximum deficit of 0.68 Ml/d in 2029/30. Under the Critical Period scenario the zone drops into deficit in 2015/16 to a maximum of 1.03 Ml/d by 2029/30.
Finding options to meet the deficit in Tywyn Aberdyfi WRZ is challenging due to the remote nature of zone which makes inter-zone connections difficult. Available leakage savings are limited as considerable leakage reduction work is planned within AMP 5 for this zone. In addition, we are currently promoting water efficiency within the zone against a Sustainable Economic Level of Water Efficiency target of 0.16 ML/d saving by the end of this AMP period. There are diminishing returns from further effort in this area but we will collect evidence on effectiveness of the current initiative for future cost analyses.
A range and various combinations of resource options have been considered the elements of which include:
New abstraction from Afon Dysynni at Pont Y Garth New abstraction from Afon Dysynni near to Abergynolwyn WTW Transfer of Dysynni raw water to the Tywyn WRZ New Abstraction from Afon Dyfi The use of the existing spare Pen y Bont WTW capacity Desalination Tywyn Aberdyfi WRZ Enlargement of the Pen y Bont WTW Construction of a new WTWs at Abergynolwyn
ABSTRACTION FROM AFON DYSYNNI
Figure 8-6 Schematic of Tywyn Aberdyfi WRZ
The least cost planning model indicates that the preferred solution in AMP 6 would be to construct a new intake, raw water main and pumping station from Afon Dysynni . A new licence will be required for an abstraction from the Dysynni. The precise location of the intake has yet to be concluded and is subject to detailed investigations. The raw water will be transferred directly to Penybont WTW where it will be treated and delivered into supply to meet the demands of the WRZ, this making use of existing spare capacity at the Penybont works. The AISC of this option is circa £580/Ml. In order to fill the increased deficit later in the planning period, the least code planning model indicates that there is scope for some limited further water efficiency savings to be made during the AMP 7 period prior to the development of further water treatment capacity.
Page | 117 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
For the longer term we would maximise the benefit from the new Dysynni abstraction by developing new treatment plant at either Abergynolwyn or by extending the existing Pen y Bont works. This scheme links to the capital maintenance requirements at Abergynolwyn.
The outputs of the SEA and HRA were taken into consideration when determining the preferred solutions for the WRZ. In this zone, a new abstraction from Afon Dysynni at Pont Y Garth and a new or extended treatment plant were both was assessed as having some negative and some positive impacts as a result of either construction and operation under the SEA. This result was not significantly different to several supply side options considered in the zone which involve river abstractions or the upgrade or new building of WTWs. A new abstraction from Afon Dysynni at Pont Y Garth and a new or extended treatment plant is the least cost of the similar supply side options involving river abstraction.
Under the SEA, water efficiency options were not assessed as having significant negative effects during construction and only minor positive effects during operation under the SEA. However water efficiency options alone do not provide sufficient savings to meet the deficit in this zone. Therefore we consider that the least cost solutions represent best value for customers and the environment in this zone.
5.0 4.5 4.0 3.5 3.0
2.5 Ml/d 2.0 1.5 1.0 0.5 0.0
Total WAFU New abstraction from the Afon Dysynni
Further abstraction from the Dysynni Demand plus Target Headroom
Page | 118 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Figure 8-7 Final Supply Demand Balance for the Tywyn Aberdyfi WRZ
WRZ no. WRZ name Max. deficit Start of deficit Solution name (s) over planning period (Ml/d)
8021 Tywyn 1.02 2015/16 New abstraction from Afon Dysynni at Pont Aberdyfi Y Garth
Further abstraction and construction of a new WTW
Household Toilet Variable Flush Retrofit
Table 8-6 Summary of preferred solutions in Tywyn Aberdyfi WRZ
Page | 119 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.7 WRZ 8036 - South Meirionnydd The zone is forecast to be in deficit under the Critical Period planning scenario only. Under the Critical Period scenario the zone falls into deficit in 2015/16 to a maximum of 0.04 Ml/d. A range of water resource options have been examined for comparison with leakage and water efficiency schemes. These include:
New abstraction from Afon Dysynni including a new treatment works Demand Management options including leakage control Transfer from the Bala WRZ Transfer from the Tywyn WRZ
The remote nature of the zone makes inter zonal connections both difficult from an engineering perspective and costly. Given the relatively small deficit over the planning period, the least cost planning model indicates that the preferred solution is the retrofit of household water efficiency devices. This solution aligns well with the water efficiency initiatives being progressed within the neighbouring Tywyn Aberdyfi WRZ during the AMP5 period and this work should help to maximise the benefit of this work.
The implementation of the retrofit of household water efficiency devices were not assessed as having significant negative effects during construction and had minor positive effects during operation under the SEA. This reflects the nature of the option as having limited short term impacts during the installation of household water efficiency devices and ongoing benefits once devices are installed in terms of lower operating, environmental and social and carbon costs. Therefore we consider that the retrofit of household water efficiency devices represents best value for customers and the environment in this zone.
3.0 2.9 2.8 2.7 2.6
2.5 Ml/d 2.4 2.3 2.2 2.1 2.0
Total WAFU Household water efficiency Demand plus Target Headroom
Figure 8-8 Final Supply Demand Balance for the South Meirionydd WRZ
Page | 120 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
WRZ no. WRZ name Max. deficit Start of deficit Solution name (s) over planning period (Ml/d)
8036 South 0.04 2015/16 Retrofit of household water efficiency Meirionnydd devices Table 8-7 Summary of preferred solutions in South Meirionnydd Zone
Page | 121 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.8 WRZ 8108 - Brecon Portis The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone falls into deficit immediately, reaching a maximum of 1.10 Ml/d by 2015/16. Under the Critical Period scenario the zone drops into deficit immediately, reaching a maximum of 1.46 Ml/d by 2015/16.
The drivers for this deficit are the improved information compiled to develop the demand forecast, the use of a new water resource model which is able to better simulate the water resource system and the impact of a licence change at the Brecon source driven by the Habitats Directive review of consents.
Although there are a number of water resource options that would support the zone, these are limited due to the restrictions placed on abstraction by EAW in relation to the environmental needs of the ecology within the River Usk catchment. The preferred solutions to meet the deficit relate directly to the causes and drivers of this deficit position. We have agreed that licence amendments affecting Brecon Portis WRZ can be implemented by March 2015 because we are able to more easily change our operations to cope with the impact of the licence changes.
To alleviate the restriction on volumes of abstraction allowed at Brecon by the EAW’s proposed changes to our licence, we are able to make regulation releases from Usk reservoir to augment flows in the River Usk at Brecon. This will ensure that our abstraction does not impact upon the ecology of the river and will allow us to continue to operate as we are currently at Brecon. This is a low cost scheme to implement and one which we can implement immediately, even prior to formal licences being put in place.
To meet the further deficit relating to our improved understanding of both supply capability and zonal demand, we are also proposing to improve the connectivity of the zone and to increase trunk mains repair effort. The zonal model results indicate that there is a pinch point between the demand centres primarily served from the Portis WTWs and those supplied by that at Brecon. An upgrading of the network infrastructure will enable the area supported by Brecon WTW to be extended in to the Portis WTW supply area. This will service the increased demands we have forecast in this section of the water resource zone.
In parallel with the implementation of these supply side schemes, the least cost model indicates that it is cost effective to reduce truck mains leakage within the zone by around 0.1Ml/d.
The outputs of the SEA and HRA were taken into consideration when determining the preferred solutions for the WRZ.
Regulation releases from Usk reservoir was assessed as having no impacts as a result of construction and uncertain or positive impacts as a result of operation under the SEA. Leakage reduction was not assessed as having significant negative effects during construction and minor positive effects during operation under the SEA.
The upgrading of the network infrastructure between Brecon WTW and Portis WTW was assessed as having minor negative impacts as a result of construction and no impacts during construction.
Page | 122 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The implementation of leakage reduction was not assessed as having significant negative effects during construction and had only minor positive effects during operation under the SEA. This reflects the nature of the option as having limited short term impacts during the repair of leaks and ongoing benefits once a leak is repaired in terms of lower operating, environmental and social and carbon costs.
Therefore we consider that the least cost solutions represent best value for customers and the environment in this zone, and reflect the causes of the deficit in the zone.
7.00
6.00
5.00
4.00 Ml/d 3.00
2.00
1.00
0.00
Total WAFU River Usk flow augmentation Trunk mains repair Increased zonal connectivity Demand plus Target Headroom
Figure 8-9 Final Supply Demand Balance for Brecon Portis WRZ
WRZ no. WRZ name Max. deficit Start of deficit Solution name (s) over planning period (Ml/d)
8108 Brecon Portis 1.46 2015/16 River Usk flow augmentation
Increased zonal connectivity
Leakage reduction – trunk mains repair Table 8-8 Summary of preferred solutions for Brecon Portis WRZ
Page | 123 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Usk Reservoir
Page | 124 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.9 WRZ 8206 Pembrokeshire The zone is forecast to be in deficit under both the Annual Average and Critical Period planning scenarios. Under the Annual Average scenario the zone will fall into deficit in 2018/19, driven by the combined impact of the EAW’s changes to our abstraction licences and the predicted impacts of climate change, reaching a maximum deficit of 8.8 Ml/d by 2039/40. As part of our preferred solution we have proposed that licence amendments affecting Pembrokeshire WRZ are implemented from April 2018 to allow us to complete our ecological monitoring in this zone and for a full appraisal of any residual risks to our operational ability to supply our customers in Pembrokeshire.
A range of supply side schemes have been developed for comparison with the demand management options. These include:
Transfer water from Bolton Hill WTW to Preseli WTW
Various sizes of transfer from the Tywi CUS WRZ
Reinstate Milton boreholes with treatment
Reinstatement and upgrade of other sources (Pendine, Parc Springs, Middle Mill)
Abstraction from the Afon Taf and transfer to the Pembrokeshire WRZ
TRANSFER FROM BOLTON HILL TO PRESELI
TRANSFER FROM TYWI GOWER
Figure 8-10 Schematic of Pembrokeshire WRZ showing preferred options
Page | 125 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The total suite of potential water efficiency measures put forward for the zone might decrease demand by between 0.5 and 1Ml/d. Even if this was enhanced through improved delivery mechanisms, the level of savings will not significantly reduce the forecast level of deficit and this would be costly. Potential leakage reduction options are greater in magnitude with schemes to save up to 4Ml/d initially included within the least cost model for assessment against alternative schemes.
The key driver for the zone is the proposed loss of abstraction licence from the Eastern and Western Cleddau rivers and most significantly that at Pont Hywel. This loss of licence will prevent the refill of the Rosebush (Preseli) reservoir and significantly reduce supply capability from the Preseli WTW. This not only reduces the overall water supply capability within the zone but has an impact upon the conjunctive use of the available water resource. Out of the schemes listed above only the Bolton Hill to Preseli network scheme is able to meet the impact caused by the loss of licence at Pont Hywel. This will allow an increased transfer of potable water from the Bolton Hill WTW system into the Preseli WTW supply area. This option has the significant benefit of improving the conjunctive nature of the zone whilst directly alleviating the main area of impact from the EAW’s licence changes.
This scheme is able to meet the SDB deficit until 2027/28 when additional schemes would be required. The least cost solution to meet this baseline supply demand deficit is an array of leakage and water efficiency measures, however, there is a degree of uncertainty around achieving predicted demand savings.
We are aware of a lack of resilience in the WRZ and specifically the water supply area predominantly served by the Pendine source. We have seen sporadic outages at this source related to turbidity and that this may require resolution into the future. Although not a least cost scheme, a transfer of treated water from Tywi CUS WRZ would add resource capability to the Pembrokeshire zone and also add significant resilience against the loss for any reason of the Pendine source.
The outputs of the SEA and HRA were taken into consideration when determining the preferred solutions for the WRZ. The implementation of leakage reduction were not assessed as having significant negative effects during construction and had minor positive effects during operation under the SEA. This reflects the nature of the option as having limited short term impacts during the repair of leaks and ongoing benefits once a leak is repaired in terms of lower operating, environmental and social and carbon costs.
Two of the lower cost options, the transfer of water from Bolton Hill WTW to Preseli WTW and transfer from Tywi CUS WRZ were both flagged in the SEA as having a negative impact on climate change, due to the scale of the construction work required to install the options. Other options were available which had lesser negative impacts for construction, but are more expensive.
When operation effects of the options are considered, the option transfer from Tywi CUS WRZ had no significant negative impacts, and the transfer of water from Bolton Hill WTW to Preseli WTW had one significant negative impact on climate change, due to the level of pumping required. This compared favourably with other options assessed in the SEA, many of which had significant negative impacts and possible or unknown impacts on Biodiversity.
Page | 126 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Considered over the whole life of the Plan and the assets, it was considered that some negative impacts during construction would be offset by the comparatively low impacts during the operation, particularly avoiding the need for additional abstraction from sources in Pembrokeshire.
Therefore we consider that the solutions in Table 8-9 represent best value for customers and the environment in this zone.
57
52
47 Ml/d
42
37
32
Total WAFU Bolton Hill to Preseli transfer Import from Tywi Gower WRZ Enhanced leakage detection Demand plus Target Headroom
Figure 8-11 Final Supply Demand Balance for the Pembrokeshire WRZ
WRZ no. WRZ name Max. deficit Start of Solution name (s) over planning deficit period (Ml/d)
8206 Pembrokeshire 8.8 2018/19 Transfer water from Bolton Hill WTW to Preseli WTW
Enhanced leakage detection
Transfer from Tywi CUS WRZ Table 8-9 Summary of preferred solutions for Pembrokeshire WRZ
8.9.1 Inflow and Pont Hywel lower licence reduction scenarios In considering the sensitivity of the zonal deficit in relation to the two scenarios examined, these would have a significant influence on scheme requirements. With regard to the Pont Hywel scenario, the requirement for the Bolton Hill transfer scheme is removed but not that of the Tywi CUS transfer. However, the Bolton Hill transfer scheme adds significant value in terms of its resilience benefits.
Page | 127 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The supply demand balance for the zone is sensitive to the variation in inflows as described in chapter 7. The use of inflows based upon those transposed from the River Gwaun as an example, increase the deficit during AMP 6 to between 9 and 18Ml/d pre- and post currently proposed licence reductions. Although we understand that the Gwaun flow gauged record is poor we are not able to fully rationalise the discrepancy between inflow results based upon this data and that deduced from Hysim modelling.
As a priority we will undertake further investigations into the hydrology of the catchments which will enable greater confidence to be gained in current DO estimates. If the outcome of this work is that we need to develop infrastructure beyond that already included within this plan then we will raise this issue through annual reviews to the relevant regulators.
In conclusion, it is proposed that we continue with current studies into both catchment inflows and River Cleddau ecology and as a base position for this plan, we will plan for the implementation of abstraction licence changes on the Cleddau Rivers by April 2018. This will allow sufficient time for agreement with NRW whether there should be a reduced level of licence reductions and to understand any residual risk to our operation prior to the construction and commissioning of the Bolton Hill transfer scheme in a timely manner. We plan to make licence changes as soon as we are able prior to Dec 2015.
Design work on both the Bolton Hill and Tywi CUS transfer schemes will be commissioned as required by study findings. This Plan will allow flexibility to deliver both schemes earlier if studies demonstrate that there is a significant risk of our under estimation of catchment inflows. We would also look to develop either a larger transfer scheme from Tywi CUS, to develop the Milton source and or enhance leakage reduction to satisfy the proven increased deficit within the zone. The lead time for the reinstatement of the Milton source for industrial purposes is relatively short given that only partial treatment will be required.
The location of this source means it is ideally placed to provide raw water directly into the pipeline that feeds the industrial users south of the Haven and so will reduce the volumes of water abstracted at Canaston, thus freeing up increased resource for treatment at Bolton Hill. We will have to undertake discussions with current industrial users regarding any change to water quality received. The Target Headroom allowance in the Pembrokeshire zone is c5Ml/d by 2018. This mitigates against the risk of the uncertainty in the inflows.
If, however, ecological studies demonstrate that less significant licence reductions are require, then the Bolton Hill transfer scheme will be shelved, with the Tywi CUS transfer scheme developed in line with the newly proposed licence changes.
Page | 128 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.10 WRZ 8121 SEWCUS
8.10.1 Zonal Supply Demand Balance Although SEWCUS does not have a SDB deficit during the planning period, the balance is marginal in relation to the size of the WRZ once licence changes on the Wye and Usk are implemented. In that the SEWCUS zone is also DCWWs largest WRZ the risks associated with an abrupt fall in Deployable Output of 26Ml/d needs to be fully understood and viewed with some caution. This section provides a summary of the findings from previous sections and strategic position.
If the licence reductions in the zone are implemented at the Natural Resources Wales preferred timescale of December 2015 the surplus under the Annual Average scenario is estimated at 5Ml/d and under the Critical Period scenario only 7Ml/d. There is a minimum surplus of just 3Ml/d under the Annual Average scenario and 7Ml/d under the Critical Period scenario by 2040; this represents just 0.7% of Total Water Available for Use (WAFU).
Figure 8-12 shows a modelled cumulative frequency distribution for Llandegfedd Reservoir stocks with and with and without Review of Consents driven licence reductions in place.
Figure 8-12 Llandegfedd stocks cumulative frequency distribution
This indicates, whereas for the baseline scenario minimum stocks are shown to be 40-50%, for the RoC scenario, stocks reduce as low as 20%. For SEWCUS overall, reservoir volumes drop to lower levels more frequently.
8.10.2 Key risks The proposed licence changes will place extra strain upon our current resources and operational systems. Before we can formally accept these licence changes, we need to ensure that a full
Page | 129 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
appraisal of any residual risks associated with this has been undertaken so that where appropriate we can implement the required schemes to reduce or eliminate these risks completely.
We have commissioned an independent report to identify the range of risks and to understand the scope of investigations required to fully understand the level of risk created by the impact of these licence reductions. This report is not yet complete so we are unable to document the full findings at this time. However, an initial draft report has been produced and this confirms four key areas of potential risk, these being: water resource assets, water quality, treatment capability and network flexibility. These issues are explored further below.
1) Water Resource Assets - Our consultants have reviewed the water resource assets in terms of impact of operation at low or very low reservoir water levels. The potential risks that have been identified are:
A need for up to date bathymetric data to confirm current storage capacity of key reservoirs;
The potential upgrade of reservoir abstraction systems to ensure operation of lower draw- off points;
The potential loss of lowest draw-off points due to sediment accumulations;
The timeline for necessary remedial works; and
Implementation of alternative water supply schemes.
2) Water Quality - During a particularly dry spell our supply reservoirs will be drawn down to low levels where we know that the quality of water present may not be as good due to lower oxygen levels, increased sedimentation, colour, turbidity and nutrient loading. Implementation of the licence changes means that our reservoirs will be drawn down to these lower storage levels more frequently and so it is important we understand the quality of this raw water. The risks identified by consultants for water quality are:
Increased turbidity resulting from rapid refilling of reservoirs of mobilisation of bed deposits;
Increased potential for algal bloom development from increased nutrient availability from sediment accumulations and the water abstracted from the River Usk;
Impacts of reduced water quality status and increased draw-down on reservoir aquatic ecology;
Effects of reduced water quality status in reservoirs on compensation releases on downstream receiving WFD water bodies;
Impacts of reduced water quality on recreational amenity, for example the development of cyanobacteria blooms.
Page | 130 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
3) Water Treatment Assets - Our treatment works will need to cope on a more regular basis with this poorer quality water. The key risks identified for treatment are:
Increased potential for treatment works output reductions during poor water quality conditions;
Increased potential for outage of treatment works; and the increased impact if the treatment works are being used closer to their capacity as a result of the reduced abstraction;
Upgrade of treatments works to manage higher throughput to balance resources across the system; and
Higher treatment costs associated with elevated turbidity in supply water;
4) Networks Assets- The SEWCUS zone has two distinct water resource types namely, the upland impounding reservoirs situated along the Heads of the Valleys and at the top of the Rhondda valleys and the lowland river sources of the Rivers Wye and Usk (see Figure 8-13). The upland reservoirs and associated WTWs feed directly into local communities with additional key links from the Heads of the Valleys and Rhondda down the Taff Valley to Cardiff. The Lowland river sources feed into the Llandegfedd pumped storage reservoir and through associated WTWs which feed into Newport, Chepstow and also into the Cardiff Area.
Due to the strategic network links, the sources are currently able to be used conjunctively to feed demands across the SE Wales conurbations. However, there is not unlimited connectivity between all of the sources as the transmission network between WTWs and demand centres will always be limited so some extent.
During a critical dry or drought period it is necessary to gradually drawdown all of these reservoirs at the same time and balance the available resource across the system. This ensures that the available water resource is both maximised across the system and that all of the demand centres can be supplied during the dry period.
The implementation of the licence changes will mean that the margin for error in the balancing we undertake each summer between our 'high' and 'low' level sources to ensure continued supply, becomes much less. We have to be confident that when we are changing the operation of the SEWCUS supply system that our key sections of water mains and pumping stations can operate as required. These changes may be required more frequently once the licence changes are in place and so we need to be confident that the extra usage placed on some elements of our SEWCUS supply system are able to cope with the extra demands placed upon them.
The system may need to respond to any number of permutations in plant and network outages. We are able to make a broad allowance for these in terms of the impact upon water resources within our outage allowance calculations but less so in terms of the network capacity required to re- balance the system in response to a combination of outages. We are therefore proposing to put forward a number of network improvements within our forthcoming PR14 business plan that will add greater system flexibility and resilience.
Page | 131 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
We have ongoing monitoring and hydraulic modelling studies underway to define these schemes. It is essential that there is a sufficient lead time to construct and commission these schemes prior to licence reductions being implemented.
The new licence changes being proposed by the EAW are far more complex than before with abstraction limits imposed on a sub-daily, daily, seasonal and annual basis. These are also based upon the river flow conditions apparent during each day. We need to ensure that we have appropriate software and automation of river intake pumps and reservoir releases valves to ensure that we always remain compliant with the conditions of our amended abstraction licences whilst at the same time ensuring that we maximise these diminished abstractions during critical dry periods.
As these are high profile rivers with valuable fishery interest any non-compliance could be particularly costly for Dŵr Cymru Welsh Water as the species present in these rivers are protected by Europe Law, namely the Habitats regulations. Again it will be necessary to construct and commission this apparatus prior to licence changes being made.
Figure 8-13 The SEWCUS water supply system
Page | 132 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.10.3 SEWCUS Investigation Programme The current investigation programme is in two strands. Ecological investigations are ongoing on the Wye and Usk as described in Chapter 6. At this stage, an eighteen-month period of investigations (to December 2013) has been defined. It is Dŵr Cymru Welsh Waters intention at this stage to review progress and conclusions, particularly with respect to the success of the fish monitoring. Dŵr Cymru Welsh Water is committed to extending this monitoring until at least 2015 if evidence shows that monitoring improves our understanding of the impacts of our abstraction and other influences on the catchment such that our existing licences can be maintained.
It should be noted that these investigations will also provide a valuable understanding of the Wye and Usk, in terms of future AMP 6 WFD investigations, and for the Welsh Government to establish what measures are required to deliver ‘good status’ under the directive in terms of other anthropogenic pressures.
The second strand of investigations relate to the resilience of SEWCUS to the currently proposed licence changes. Pilot studies are ongoing to develop water quality models for 5 Welsh Water reservoirs, including Talybont in the SEWCUS area. This work is still in progress and is expected to be completed by the end of June 2013. These investigations have included the use of 3D models incorporating the analysis of inflows, outflows, catchment land use, water quality and bathymetry and also examine up to eight water quality parameters to try and predict the risk of algal bloom development.
The Talybont model has been developed using the Delft 3D code and from the information provided is expected to be capable of considering the following:
Establishment of reservoir stratification, thus providing more detailed information on the current and future likelihood of increased frequency of the onset of stratification;
Nutrient transfer;
Reservoir mixing; and
Effects of drawdown on any or all of the above.
It is the intention to roll out this modelling approach to the remaining key SEWCUS reservoirs based upon the pilot studies along with the recently contracted work described. This will require a significant baseline monitoring programme. There will be need to collate all available data and undertake a gap analysis to inform future survey and monitoring requirements and allow a co- ordinated and scheduled programme of assessment work to be implemented.
A firm programme of investigations has yet to be defined but the draft report already received suggests that this monitoring and modelling will take at least three years. The Final SEWCUS risk assessment report which will identify the work programme will be delivered by July in line with reservoir/catchment pilot studies.
Given the uncertainties that currently exist around the study programme, we plan to make licence changes prior to Dec 2015. However, as a base position for this plan, the implementation date for
Page | 133 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
these abstraction licence changes on the Wye and Usk Rivers have been set at April 2018. At this time we will have completed our risk assessment work and introduced resilience measures as required, subject to funding approval through the PR14 process. If the programme for this work falls outside of the April 2018 timescale, then we would seek a variation to the licences agreed in 2015 to allow for this.
This timescale will also allow us to complete our comprehensive environmental survey work and confirm or otherwise the effectiveness of the proposed licence reductions upon river ecology and what, if any, other abstraction regimes might be accommodated which are both environmentally protective, but would allow Dŵr Cymru Welsh Water to retain a sufficient surplus so that we can support economic growth.
The risks raised by our consultants need to be fully considered and although these may not result in the need for mitigating actions to deal with these, we believe that our customers expect us to be precautionary in our approach to understanding these risks to water supply and also to be cautious, but not overly so, in the programme of works to investigate these.
There are two additional constraints to achieving the environmental flow objectives set by EAW in taking a precautionary approach to the protection of Wye and Usk river ecology. We are aware that there is a potential conflict between the preferred date for licence changes on the Wye proposed by Dŵr Cymru Welsh Water and that which may be acceptable to Severn Trent Water. This means that although we may be in a position to volunteer changes to our licences on the River Wye in 2018 Severn Trent may not be able to operate within proposed licence changes at this time. There are interdependencies between the licences on the Wye and it may be the case that we will need to work to the timescales set by Severn Trent Water.
On the River Usk, the achievement of flow objectives will only be met once the Canal and Rivers Trust also reduce their substantial abstraction at Brecon. This abstraction is currently licence exempt and will need to be voluntarily reduced or be brought into the licensing regime by Welsh Government. We are unaware of the date by which this large abstraction at Brecon might be able to be reduced. But we have been in discussion with the trust regarding potential options to mitigate against these abstraction reductions.
We believe that it is essential that all licence reduction actions should be applied fairly and simultaneously in the Usk and Wye catchments if we are to avoid penalising economic growth prospects in Wales against those in England.
Page | 134 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.11 Water Framework Directive As part of the WFD, Natural Resources Wales are reviewing what measures are required in the Wye and Usk catchments to reduce nutrient levels. This work becomes particularly important post 2018 as to reduce the risks from algal blooms it is essential to reduce nutrient levels in raw water. We expect nutrient management plans to be implemented fairly and even headedly by NRW to reduce the potential for algal blooms in Llandegfedd Reservoir in the new regime by 2018.
The result of a HMWB environmental improvement scenario requested by EAW was presented in Chapter 13. This relates to the release of 6 Ml/d of compensation water from the Castell Nos reservoir and has a significant impact upon DO and resultant impact on the SEWCUS supply demand balance. Where SEWCUS is in a marginal surplus throughout the planning period it would fall into a substantial deficit of 16.8 Ml/d by 2040 if this compensation release were to be required.
In order to fill the deficit in this area of SEWCUS WRZ, extensive network upgrades would be required to connect the Maerdy and Porth areas to the Rhondda link main and this main would also need to be up rated. Significant new water resource or demands management options would also be required at significant cost. Dŵr Cymru Welsh Water considers such investment disproportionately costly, and will be developing a case as required to illustrate this as part of our work on the WFD.
Page | 135 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
8.12 Summary of the preferred solutions in deficit zones Preferred solutions discussed in sections 8.4 - 8.9 are summarised in Table 8-3 below.
WRZ no. WRZ name Max. deficit Start of deficit Solution name (s) over planning period (Ml/d)
8001 NEYM 3.69 2023/24 Transfer of water from Cwm Dulyn to the North Eryri WRZ
Leakage reduction
Connect Afon Rhythallt to Cwellyn WTW
8020 Bala 0.12 2015/16 Leakage reduction
8021 Tywyn Aberdyfi 1.02 2015/16 New abstraction from Afon Dysynni at Pont Y Garth
Further abstraction and construction of a new WTW
8036 South 0.04 2015/16 Retrofit of household water efficiency Meirionnydd devices
8108 Brecon Portis 1.46 2015/16 River Usk flow augmentation
Increased zonal connectivity
Leakage reduction – trunk mains repair
8206 Pembrokeshire 8.8 2018/19 Transfer water from Bolton Hill WTW to Preseli WTW
Enhanced leakage detection
Transfer from Tywi CUS WRZ Table 8-10 Summary of preferred solutions for deficit zones in dWRMP 2013
Page | 136 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
9 Environmental appraisal
9.1 Introduction This section presents the work we have undertaken to identify and assess the potential effects of our Plan on the environment. It describes how we have undertaken this assessment, the results of that assessment, and any further work that we need to carry out.
Overall, the environmental appraisal shows that our Plan, and specifically the preferred options it presents, is not expected, at this stage, to have any significant environmental impacts. However, in the event that any of our preferred options are found to have significant environmental impacts once we reach the stage of detailed investigations and scheme design, we have identified a number of alternative options that could be implemented instead.
9.1.1 Strategic environmental appraisal Under the Plan we have identified the best value combinations of options to meet the predicted supply shortfalls over the next 25 years. In doing so we included, within the costing process, the potential environmental and social costs of each option, including carbon costs.
In addition to this, we have prepared a Strategic Environmental Assessment. This Assessment is a statutory process21 that identifies and assesses potentially significant environmental effects of the Plan, and, where appropriate, how negative impacts might be mitigated and positive impacts enhanced.
9.1.2 Habitats regulations assessment In addition to carrying out a Strategic Environmental Assessment, we have also assessed the potential impacts of this Plan against the conservation objectives for designated European sites.22 This is known as a Habitats Regulations Assessment 23 and is driven by the Habitats Directive.24
The Habitats Regulations Assessment determines whether there will be any ‘likely significant effects’ on any European site as a result of the implementation of the Plan (either on its own or ‘in combination’ with other plans or projects) and, if so, whether these will adversely affect the integrity of the site.
21 The Water Industry, through UK Water Industry Research Ltd (UKWIR) recognises that WRMPs may be subject to a SEA under the requirements of the European Directive 2001/42/EC (the SEA Directive). The SEA Directive has been transposed into UK legislation as Regulations. 22 HRA is required by law for all European Sites (Regulation 48). A European Site is any classified SPA and any Special Area of Conservation from the point where the Commission and the Government agree the site as a Site of Community Importance. HRA is also required, as a matter of Government policy, for potential SPAs, candidate Special Areas of Conservation and listed Ramsar Sites for the purpose of considering development proposals affecting them (PPG9 paras. 13 and C7). As such, pSPAs, cSpecial Areas of Conservation and Ramsar Sites must also be considered by any HRA. Within this report ‘European site’ is used as a generic term for all of the above designated sites 23 Appropriate Assessment’ has been historically used as an umbrella term to describe the process of assessment as a whole. The whole process is now more accurately termed ‘Habitats Regulations Assessment’ (HRA), and ‘Appropriate Assessment’ is used to indicate a specific stage of a HRA. 24 Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora.
Page | 137 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
The Habitats Regulations Assessment, like the Strategic Environmental Assessment, has been an integral part of the development of the options from the outset and hence this Draft Plan. In essence, the Strategic Environmental Assessment and Habitats Regulations Assessment process proceed alongside one another (and alongside the WRMP process) with the outcomes of the Habitats Regulations Assessment being incorporated into the Strategic Environmental Assessment Environmental Report. The approach we took to carrying out the Habitats Regulations Assessment is described in Section 9.3.
9.1.3 Consultation We have worked closely with the Countryside Council for Wales and Natural England in preparing both the Strategic Environmental Assessment and the Habitats Regulations Assessment, and have discussed with them our approach to undertaking the environmental appraisal, the evaluation of the preferred options, and the format of the Strategic Environmental Assessment and Habitats Regulations Assessment reports. We believe that through this process we have achieved a robust and appropriate appraisal of the potential environmental impacts of the Plan.
9.2 Strategic environmental assessment
9.2.1 Environmental objectives Defining the environmental baseline, relevant issues and the context is important in setting the framework for the Strategic Environmental Assessment.
Each of the feasible options was assessed against eleven key Environmental Objectives to identify its potential impacts. These were assessed on the basis of the nature of the effect, its timing and geographic scale, the sensitivity of the people or environmental receptors that could be affected, and how long it might last.
The Strategic Environmental Assessment Environmental Report fully details the Themes, Objectives and assessments for each of the deficit WRZs.25
9.2.2 Using the findings of the assessment The assessment helped to highlight the range of potential environmental and social impacts, including those that had been quantified and those that could only be identified qualitatively. The assessment did not highlight any major effects that we had not already considered in developing the most economic combinations of options, although it helped to identify where there are more minor effects and how some of the potential negative impacts can be mitigated.
The full Strategic Environmental Assessment report can be accessed via Dŵr Cymru Welsh Water’s website at http://www.dwrcymru.com/en/Environment/Water-Resources/Draft-Water-Resources- Management-Plan-2013.aspx
25 Strategic Environmental Assessment of Draft Water Resources Management Plan, Draft Environmental Report,AMEC UK Limited, March 2013.
Page | 138 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
9.3 Habitats regulations assessment
9.3.1 The process As stated, we have undertaken a Habitats Regulations Assessment of this Plan, which is reported separately.26 The Habitats Regulations Assessment was undertaken as an iterative process alongside the development of the Plan, to help to ensure that the Final Plan will not have adverse effects on any European Sites when implemented. The Habitats Regulations Assessment has identified whether any feasible options would have unacceptable effects on a European Site. This process informed the selection of the preferred options. Further assessment was then undertaken on the preferred options to ensure that any likely significant effect or adverse effects were identified and appropriate measures developed to ensure that these effects would be avoided or reliably mitigated when the Final Plan is implemented.
9.3.2 Review of feasible options The Feasible options were reviewed for their possible effects on European Sites using a preliminary screening method. This identified those European Sites that could potentially be affected by the implementation or operation of each feasible option, given the characteristics of the Site, the means by which it might be affected by the option, and the distance from the option to the Site.
9.3.3 Assessment of preferred options Following from the screening of feasible options through both the Habitats Regulations Assessment and Strategic Environmental Assessment process, the initial preferred options were re-screened and assessed in greater detail for their likely impacts on European Sites.
Where potential effects were identified as ‘uncertain’ (as is often the case when the examination is at a comparatively strategic level) an assessment of likely significant effect was made and avoidance measures or mitigation proposed to help to ensure that there would be no adverse effects. For some options, any such effects are likely to be localised and can therefore be more appropriately assessed at the more detailed planning stages. In this case, the assessment identified the risk of effects but assumed that Habitats Regulations Assessment of lower level strategies or the individual options themselves will be sufficiently rigorous to avoid significant or adverse effects.
Since the precise manner and timescale in which the various options could be implemented is unknown, not all the possible effects can be assessed at the strategic level and some can only be determined at a project level. This means that the Habitats Regulations Assessment must assume that all normal controls will be applied (i.e. at a project-level Habitats Regulations Assessment) and that likely significant effect can only be concluded where the level of development required is unlikely to be accommodated, regardless of project-level mitigation.
For example, an option requiring construction work within a Special Area of Conservation may initially appear certain to have likely significant effect; however, that option may involve simply refitting existing operational structures, which can almost certainly be easily accommodated without likely significant effect or adverse effects. The opposite is also true. This means that the strategic
26 “Habitats Regulation Assessment of Draft Water Resources Management Plan Draft Report, AMEC UK Limited, March 2013.
Page | 139 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
Habitats Regulations Assessment must consider whether the likely level of development required for the option can be accommodated and (if this is uncertain) whether there are other practicable options available that will not have a likely significant effect.
9.3.4 Summary of assessment The Habitats Regulations Assessment concluded that most of the feasible and preferred options had the potential for likely significant effect on at least one European Site; however, for most options it was very clear that the potential effects were of a scale and type that could certainly be avoided at the scheme level with standard and accepted measures.
There are two options where the available data strongly suggests that there will be no adverse effects, but this cannot be concluded with certainty at the strategic level. These schemes are:
Brecon Portis: additional releases from Usk Reservoir; and
Tywyn Aberdyfi: Abstraction from Afon Dysynni
We believe that it is acceptable to include these schemes in the Plan for now on the basis that Habitats Regulations Assessments and assessments at the scheme level can be expected to resolve the uncertainties (since scheme-specific Habitats Regulations Assessment will be a legal requirement before these schemes can be implemented), provided that potential alternatives with ‘no adverse effects’ are identified within the Plan. The Plan has therefore included these schemes as preferred options, with the proviso that ‘alternative’ options have been identified that could be employed should the options in question prove to have adverse effects that are unavoidable. This process and the ‘alternative’ options are detailed fully in the Habitats Regulations Assessment report.
The full Habitats Regulations Assessment report can be accessed via Dŵr Cymru Welsh Water’s website at http://www.dwrcymru.com/en/Environment/Water-Resources/Draft-Water-Resources- Management-Plan-2013.aspx
9.3.5 Conclusion Overall the Habitats Regulations Assessment has concluded that the Final Plan will not have any significant adverse effects on any European Site (alone or in combination with other plans and programmes) as a result of its implementation, since the preferred options:
either will have no significant or adverse effect as they stand; or
can be implemented using established and reliable best-practice mitigation/ avoidance measures to ensure no significant or adverse effects; or
can be replaced by options that have no likely significant effect or adverse effects from the feasible options list, should scheme-specific investigations demonstrate that adverse effects are certain and cannot be avoided or mitigated.
All options will, in any case, be subject to project-level Habitats Regulations Assessment, as a matter of legal requirement, which will provide an additional safeguard.
Page | 140 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
9.4 Water Framework Directive Under the Water Framework Directive (WFD) surface water flow regime is a supporting element to the biological status of water bodies. This means that excessive pressures on a flow regime, such as high levels of abstraction, discharge or river regulation could compromise the achievement of good ecological status (GES). However, the causal relationship between flow and ecological status is poorly understood, and is likely to be site-specific.
The Environment Agency (succeeded by Natural Resources Wales) has developed methodologies for assessing:
The likelihood of river and lake water bodies achieving or failing the relevant Water Framework Directives (WFD) objectives in 2027, as a result of artificial influences on flows; and The risk of deterioration in WFD water bodies as a result of artificial influences on flows up to 2027. This assessment is an update of the evaluation undertaken for the first cycle of River Basin Management Plans (RBMPs), and includes updates and refinements to the data and methods used.
The Environment Agency’s assessment shows that there are a only six water bodies in the Western Wales, Dee or Severn RBMP areas, i.e. the RBMPs that contain Dŵr Cymru Welsh Water’s supply area, where there is a risk of deterioration as a result of artificial flow. These water bodies are:
River Basin EA Region/ EA WB ID Water Body Name District Country Severn Midlands GB109054032520 Ell Bk - source to conf R Leadon Severn Midlands GB109055029670 Valley Bk - source to conf R Wye Severn Midlands GB109055036870 R Dore - source to conf Worm Bk Severn Wales GB109055042020 R Lugg - conf Bleddfa Bk to conf Cascob Bk Western Wales Wales GB110059025480 Tre-Beddrod - headwaters to tidal limit Western Wales Wales GB110059032090 Lliedi - headwaters to tidal limit Table 9-1 Summary of water bodies at low risk of deterioration from GES
These water bodies are considered to be at low risk of deterioration. All other water bodies were considered to be at no risk of deterioration. No water bodies were considered to be at medium or high risk of deterioration.
None of the water bodies presented in Table 9-1 Summary of water bodies at low risk of deterioration from GES are affected by our preferred options to resolve the deficit in our six deficit zones. Therefore we are confident that our plan is not at risk of causing WFD deterioration.
For more information on WFD risk of deterioration and discussion the impact of our current operation please refer to chapter 12 of the dWRMP 2013 Technical Report.
Page | 141 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
10 Further Work in AMP 6 Dŵr Cymru Welsh Water is keen to continue to progress and update its assessment of key supply and demand components. It is also important to us that we follow any new industry methodologies and ensure that our assumptions are based on the most up to date information available. The details of the areas we are committed to addressing during the AMP6 period are:
To produce annual Water Resource Management Plan updates outlining progress against the final WRMP;
To use of the Independent Environmental Advisory Panel to guide future water resource planning initiatives;
To continue the current ecological monitoring studies on the Rivers Usk and Wye as required;
To undertake resilience studies which will fully appraise the risks to our operation, from the licence amendments on the Wye and Usk;
To undertake evidence led WFD studies with solutions implemented where appropriate for no regrets measures;
To deliver a programme of water resource solutions as outline within this plan.
Page | 142 Dŵr Cymru Welsh Water dWRMP 2013 Executive Report
11 Glossary of Terms
Abstraction The removal of water from any source, either permanently or temporarily.
The authorisation granted by the Environment Agency or Natural Resources Wales to allow the removal of Abstraction licence water from a source.
Annual average The total demand in a year, divided by the number of days in the year.
The difference (in Ml/d or percent) between water available for use (including imported water) and demand Available headroom at any given point in time.
Average incremental The ratio of present social costs over present net value of additional water delivered or reduced demand social costs
A sample of properties whose consumption is monitored in order to provide information on the consumption Consumption monitor and behaviour of properties served by a company.
The implementation of policies or measures which serve to control or influence the consumption or waste of Demand management water (this definition can be applied at any point along the chain of supply).
The output of a commissioned source or group of sources or of bulk supply as constrained by: • environment • Licence, if applicable Deployable output • Pumping plant and/or well/aquifer properties • raw water mains and/or aquifers • treatment • water quality
Distribution input The amount of water entering the distribution system at the point of production.
Made up of losses on trunk mains, service reservoirs, distribution mains and communication pipes. Distribution losses Distribution losses are distribution input less water taken.
An authorisation granted by the Secretary of State under drought conditions, which imposes restrictions Drought order upon the use of water and/or allows for abstraction/impoundment outside the schedule of existing licences on a temporary basis.
An authorisation granted by the Environment Agency or Natural Resources Wales under drought conditions, Drought permit which allows for abstraction/impoundment outside the schedule of existing licences on a temporary basis.
Economic level of The level of leakage at which it would cost more to make further reductions than to produce the water from leakage (ELL) another source
The scenario of water available for use and final planning demand forecast which constitute the company’s Final planning scenario best estimate for planning purposes, and which is consistent with information provided to Ofwat for the Periodic Review.
Habitats Regulations An assessment, required under the EU Habitats and Species Directive, of the potential effects of a proposed Assessment (HRA) plan, programme or project on one or more Natura 2000 sites.
The frequency with which a hosepipe ban or a Drought Order/ Permit would be expected to be required in Level of Service order to maintain water supplies
Meter optants Properties in which a meter is voluntarily installed at the request of its occupants.
Meter programme Properties, which are to be metered according to current company metering policy.
Theoretical increase in amount of water that would be lost from the supply network if no leakage Natural Rate of Rise management activities we to take place.
The difference between the discounted sum of all of the benefits arising from a project and the discounted Net Present Value sum of all the costs arising from the project.
Properties receiving potable supplies that are not occupied as domestic premises, for example, factories, Non-households offices and commercial premises.
Outage A temporary loss of deployable output.
The point where the supply pipe rises above ground level within the property, usually the inside stopcock or Point of consumption an internal meter.
The point at which water is transferred from mains or pipes, which are vested in the water supplier into, Point of delivery pipes which are the responsibility of the customer. In practice this is usually the outside stopcock, boundary box or external meter.
Point of production The point where treated water enters the distribution system.
The mechanism by which the Environment Agency and Natural Resources Wales undertake their review of Review of Consents all the existing and proposed permissions that could impact upon EU designated sites
Risk A measure of the probability and magnitude of an event and the consequences of its occurrence.
A named input to a resource zone. A multiple well/spring source is a named place where water is abstracted Source from more than one operational well/spring.
Strategic Environmental A process of assessing the environmental opportunities and restrictions of a project, and identifying and Assessment (SEA) managing its implications.
The difference between water available for use (including imported water) and demand at any given point in Supply-demand balance time (c.f. available headroom).
Supply pipe losses The sum of underground supply pipe losses and above ground supply pipe losses.
Reductions in deployable output required by the Environment Agency to meet statutory and/or Sustainability reduction environmental requirements.
The threshold of minimum acceptable headroom, which would trigger the need for water management Target headroom options to increase water available for use or decrease demand.
Total leakage The sum of distribution losses arid underground supply pipe losses .
Treatment work Treatment process water i.e. net loss, which excludes water returned to source water . operational use
Underground supply pipe Losses between the point of delivery and the point of consumption. losses
Unrestricted demand The demand for water when there are no restrictions in place .
Water available for use The value calculated by deducting allowable outages and planning allowances from deployable output in a (WAFU) resource zone.
The largest possible zone in which all resources, including external transfers, can be shared and hence the Water Resource zone zone in which all customers experience the same risk failure from a resource shortfall of supply (WRZ)