So this is straightforward. We simply get a list of UK dams and reservoirs and check them one by one. Simples.
BuckinghamshireFoxcote Reservoir, north of BuckinghamWeston Turville Reservoir, between Weston Turville and WendoverCambridgeshireGrafham WaterCheshireBollinhurst ReservoirBosley Reservoir, BosleyHorse Coppice ReservoirLamaload Reservoir, east of MacclesfieldRidgegate Reservoir and Trentabank Reservoir, south-east of MacclesfieldSutton Reservoir, south of MacclesfieldCornwallArgal and College Reservoirs, FalmouthBoscathnoe Reservoir, PenzanceBussow Reservoir, St IvesCargenwen ReservoirColliford Lake, Bodmin MoorCrowdy Reservoir, Bodmin MoorDrift Reservoir, PenzancePorth Reservoir, NewquaySiblyback Lake, Bodmin MoorStithians ReservoirUpper Tamar Lake (Devon and Cornwall)County DurhamBalderhead ReservoirBlackton ReservoirBurnhope ReservoirDerwent ReservoirGrassholme ReservoirHisehope ReservoirHurworth Burn ReservoirHury ReservoirSelset ReservoirSmiddy Shaw ReservoirTunstall ReservoirWaskerley ReservoirCumbriaBorrans Reservoir, north of Windermere (town)Castle Carrock ReservoirChapelhouse Reservoir, south-east of UldaleCow Green Reservoir east of Dufton FellDubbs Reservoir, north of Windermere (town)Ennerdale WaterFisher Tarn east of KendalHarlock Reservoir, Pennington Reservoir, Poaka Beck Reservoir west of the town of UlverstonHaweswater ReservoirHayeswaterKentmere ReservoirKillington ReservoirMeadley Reservoir, by Flat Fell, Ennerdale, CumbriaSimpson Ground Reservoir, east of Newby BridgeThirlmereWet Sleddale ReservoirDerbyshireButterley ReservoirCodnor ReservoirCarsington WaterCombs ReservoirErrwood ReservoirFernilee ReservoirForemark ReservoirHurst ReservoirKinder ReservoirLinacre ReservoirsUpper ReservoirMiddle ReservoirLower ReservoirLongdendale Chain of reservoirsArnfield ReservoirHollingworth Reservoir now drained and a nature reserveBottoms ReservoirValehouse ReservoirRhodeswood ReservoirTorside ReservoirWoodhead ReservoirLoscoe DamMossy Lea ReservoirOgston ReservoirStaunton Harold ReservoirSwineshaw Reservoir (Derbyshire)Toddbrook ReservoirUpper Derwent ValleyLadybower ReservoirDerwent Reservoir with BirchinleeHowden Reservoir Eastern half is in Sheffield (South Yorkshire)Upper Swineshaw Reservoir (Derbyshire)DevonAvon Dam ReservoirBurrator ReservoirChallacombe/Bray ReservoirButter Brook ReservoirDarracott ReservoirFernworthy ReservoirGammaton ReservoirsHolywell ReservoirJennetts ReservoirKennick ReservoirLower Tamar LakeMelbury ReservoirMeldon ReservoirRiver Tavy ReservoirRoadford LakeSlade ReservoirSquabmoor reservoirTottiford ReservoirTrenchford ReservoirUpper Tamar Lake (Devon and Cornwall)Venford ReservoirWheal Jewell ReservoirWistlandpound ReservoirEast SussexArlington ReservoirDarwell ReservoirPowdermill ReservoirEssexAbberton ReservoirArdleigh ReservoirHanningfield ReservoirGloucestershireDowdeswell ReservoirWitcombe ReservoirGreater ManchesterBolton:Belmont ReservoirBryan Hey ReservoirDean Mills ReservoirHigh Rid ReservoirLower Rivington ReservoirRumworth Lodge ReservoirUpper Rivington ReservoirBuryLowercroft ReservoirManchester, Bolton and Bury Reservoir (Elton Reservoir)Manchester:Gorton ReservoirsHeaton Park ReservoirOldham:Ashworth Moor ReservoirBesom Hill ReservoirBlack Moss Reservoir (Greater Manchester)Brownhouse Wham ReservoirBrushes Clough ReservoirCastleshaw ReservoirChew_ReservoirCrook Gate ReservoirDiggle ReservoirDovestones ReservoirDowry ReservoirGreenfield ReservoirHamer Pasture ReservoirNew Years Bridge ReservoirReadycon Dean ReservoirStrinesdale ReservoirYeoman Hey ReservoirRochdale:Ashworth Moor ReservoirBlackstone Edge ReservoirChelburn ReservoirGreenbooth ReservoirHanging Lees ReservoirHollingworth LakeKitcliffe ReservoirLight Hazzles ReservoirLower Chelburn ReservoirNaden Reservoirs (Higher, Middle and Lower)Norman Hill ReservoirOgden ReservoirPiethorne ReservoirRooden ReservoirWatergrove ReservoirTameside:Audenshaw ReservoirsBrushes ReservoirDenton ReservoirsGodley ReservoirHigher Swineshaw ReservoirLower Swineshaw ReservoirSwineshaw ReservoirsWalkerwood ReservoirWigan:Worthington LakesHertfordshireTring ReservoirsKentBough BeechBewl WaterLancashireAnglezarke ReservoirBelmont ReservoirBlack Moss ReservoirsCalf Hey ReservoirCowm ReservoirDelph ReservoirDingle ReservoirFoulridge ReservoirHigh Bullough ReservoirHolden Wood ReservoirJumbles ReservoirLower Rivington ReservoirLower Roddlesworth ReservoirLower Ogden ReservoirRake Brook ReservoirSpring Mill ReservoirSprings ReservoirStocks ReservoirTurton and Entwistle ReservoirUpper Ogden ReservoirUpper Rivington ReservoirUpper Roddlesworth ReservoirWalves ReservoirWard's Reservoir (Blue Lagoon)Watersheddles Reservoir (owned by Yorkshire Water)Wayoh ReservoirYarrow ReservoirLeicestershireBlackbrook ReservoirEyebrook Reservoir (Corby)Cropston ReservoirKnipton ReservoirNanpantan ReservoirSaddington ReservoirStaunton Harold ReservoirSwithland ReservoirThornton ReservoirLincolnshireCovenham ReservoirDenton ReservoirKnipton ReservoirLondonBrent Reservoir (also known as the Welsh Harp)Grand Junction ReservoirStain Hill ReservoirsStoke Newington West ReservoirSunnyside ReservoirThe following reservoirs form the Lee Valley Reservoir Chain.King George's Reservoir, London Borough of Enfield (also known as King George V Reservoir)William Girling Reservoir, London Borough of EnfieldBanbury Reservoir, London Borough of Waltham ForestLockwood Reservoir, London Borough of Waltham ForestHigh Maynard Reservoir, London Borough of Waltham ForestLow Maynard Reservoir, London Borough of Waltham ForestWalthamstow Reservoirs, London Borough of Waltham Forest, five linked numbered reservoirsEast Warwick Reservoir, London Borough of Waltham ForestWest Warwick Reservoir, London Borough of Waltham ForestNorthamptonshireBarby Storage ReservoirBoddington Reservoir, Oxford canal supply reservoir, Upper Boddington[1]Cransley Reservoir (Kettering)Daventry Reservoir in Daventry Country ParkDrayton Reservoir (Daventry)Hollowell reservoir HollowellNaseby Reservoir, Grand Union Canal supply, Naseby[2]Pitsford WaterRavensthorpe ReservoirStanford Reservoir, between Stanford-on-Avon and South KilworthSulby ReservoirSywell ReservoirThorpe Malsor Reservoir (Kettering)Welford ReservoirNorthumberlandBakethin ReservoirCatcleugh ReservoirColt Crag ReservoirFontburnHallington ReservoirsLittle Swinburne ReservoirKielder WaterWhittle DeneNorth YorkshireAngram ReservoirBeaver Dyke ReservoirsChelker ReservoirCod Beck ReservoirElslack ReservoirEmbsay ReservoirFewston ReservoirGouthwaite ReservoirGrimwith ReservoirLaneshaw ReservoirLeighton ReservoirLindley Wood ReservoirLockwood Beck ReservoirLower Barden ReservoirLumley Moor ReservoirMarch Ghyll ReservoirMossy Moor ReservoirOulston ReservoirRoundhill ReservoirScaling Dam ReservoirScar House ReservoirScargill ReservoirSwinsty ReservoirTen Acre ReservoirThornton Steward ReservoirThruscross ReservoirUpper Barden ReservoirWinterburn ReservoirOxfordshireClattercote Reservoir (Banbury)[3]Farmoor Reservoir (Oxford)Grimsbury Reservoir,(Banbury)RutlandRutland WaterShropshireChelmarsh ReservoirKnighton ReservoirSomersetAshford ReservoirBarrow Gurney TanksBlagdon LakeChard ReservoirCheddar ReservoirChew Valley LakeClatworthy ReservoirDurleigh reservoirHawkridge ReservoirLeigh ReservoirLitton ReservoirsLuxhay ReservoirNutscale ReservoirOtterhead LakesSutton Bingham ReservoirWimbleball LakeSouth YorkshireAgden ReservoirBroadstone ReservoirBroomhead ReservoirDale Dyke ReservoirDamflask ReservoirElsecar ReservoirHarthill Reservoir, feeder for the Chesterfield canal[4]Howden Reservoir Western half is in DerbyshireIngbirchworth ReservoirLangsett ReservoirMidhope ReservoirMore Hall ReservoirPebley Reservoir (Sheffield)Redmires ReservoirsRivelin DamsRoyd Moor ReservoirScout Dyke ReservoirSnailsden ReservoirStrines ReservoirUlley ReservoirUnderbank ReservoirWeecher ReservoirWharncliffe ReservoirWindleden ReservoirsWinscar ReservoirWorsbrough ReservoirStaffordshireMain article: List of reservoirs in StaffordshireBathpool Park LakeBelvide ReservoirBetley Hall ReservoirBlithfield ReservoirBromley Mill PoolBrookleys LakeCanwell Estate ReservoirChasewaterGailey ReservoirGap PoolHales Hall PoolHatherton ReservoirHanch ReservoirHolly Bush LakeKnypersley ReservoirMinster PoolRudyard LakeStowe PoolSwinfen LakeTixall Park PoolTrentham Gardens LakeTittesworth ReservoirSurreyBessborough ReservoirIsland Barn ReservoirKing George VI ReservoirKnight ReservoirMolesey ReservoirsQueen Elizabeth II ReservoirQueen Mary ReservoirQueen Mother ReservoirStaines ReservoirsWraysbury ReservoirSuffolkAlton WaterWarwickshireDraycote WaterNapton Reservoir, Grand Union Canal[5]Oldbury ReservoirPackington Lakes, Grand Union CanalShustoke ReservoirsStockton Reservoir, Grand Union CanalWormleighton ReservoirWest MidlandsBartley Reservoir (Birmingham)Brookvale Park Lake (Birmingham)Edgbaston Reservoir (Birmingham)Frankley Reservoir (Birmingham)Lifford Reservoir (Birmingham)Netherton Reservoir, DudleyOlton Reservoir, SolihullPerry Barr Reservoir (covered) (Birmingham)Witton Lakes (Birmingham)see also Elan Valley Reservoirs (Wales) which were built by, and supply, BirminghamWest SussexArdingly ReservoirWeir Wood ReservoirWest YorkshireArdsley ReservoirBaitings ReservoirBilberry ReservoirBlackmoorfoot ReservoirBlack Moss ReservoirBlakeley ReservoirBooth Dean Upper ReservoirBooth Dean Lower ReservoirBooth Wood ReservoirBoshaw Whams ReservoirBrownhill ReservoirButterley ReservoirChelker ReservoirCupwith ReservoirDean Head Upper ReservoirDean Head Lower ReservoirDean Head ReservoirDeer Hill ReservoirDigley ReservoirDoe Park ReservoirEccup ReservoirEldwick ReservoirElslack ReservoirGorple Lower ReservoirGorple Upper ReservoirGraincliffe ReservoirGreen Withens ReservoirHewenden ReservoirHolme Styes ReservoirKeighley Moor ReservoirLeeming ReservoirLeeshaw ReservoirLower Laithe ReservoirMarch Ghyll ReservoirMarch Hey ReservoirMixenden ReservoirOgden ReservoirPanorama ReservoirPonden ReservoirRamsden ReservoirRedbrook ReservoirReva ReservoirRiding Wood ReservoirRingstone Edge ReservoirRyburn ReservoirScammonden ReservoirSilsden ReservoirStubden ReservoirSunnydale ReservoirSwellands ReservoirThornton Moor ReservoirWalshaw Dean ReservoirsWarland Reservoir (Mostly in West Yorkshire, partly in Greater Manchester)Warley Moor ReservoirWeecher ReservoirWessenden ReservoirWessenden Head ReservoirWiddop ReservoirYateholme ReservoirWiltshireWilton Water header reservoir for the Kennet and Avon CanalWorcestershireBittell Reservoirs (Upper and Lower)Tardebigge ReservoirNorthern IrelandCounty DownSilent Valley ReservoirSpelga ReservoirScotlandCity of AberdeenBraeside ReservoirCattofield ReservoirMannofield ReservoirSlopefield ReservoirSmithfield ReservoirAberdeenshireBluehills ReservoirClochandighter ReservoirGarlogie DamInchgarth Reservoir - CultsLoch of AboyneLoch SaughSilver Dam aka Culter Compensation DamAngusBackwater ReservoirBrewlands ReservoirCrombie ReservoirDen of OgilGlenogilKinnaird LakeLedcrieff LochLinrathenLinrathen Clear Water StorageLoch Auchintaple or Auchintaple LochLoch LeeLoch ShandraLong LochMonikie Clear Water BasinMonikie North PondMonikie South (Island) PondPiperdam LochArgyll and ButeAllt na Lairige - Glen FyneArdlussa Fishing Loch - Isle of JuraAsgog Loch - TighnabruaichAucha Lochy - CampbeltownAuchengaich Reservoir - Glen FruinBeochlich - 9 km NW of InverarayBishop's Glen Reservoir (also known as Dunoon Reservoir) - DunoonBlackmill Loch - MinardCam Loch - North KnapdaleCraignafeich Reservoirs - TighnabruaichCrarae Reservoir - MinardCrosshill Loch - CampbeltownCruachan Reservoir - Loch AweDaill Loch - North KnapdaleDhu Loch - ButeFeorlin - MinardGleann Dubh - BarcaldineGleann Loch - North KnapdaleHelensburgh No. 1 Reservoir - HelensburghHelensburgh No. 2 Reservoir - HelensburghKilduskland Reservoir - ArdrishaigKirk Dam - ButeKnockruan Loch - CampbeltownLeorin Loch - Port Ellen, IslayLindowan Reservoir - KilcregganLoch A' Bharain - North KnapdaleLoch A' Chaorainn - South KnapdaleLoch Allan - Port Askaig, IslayLoch a'Mhuillin - North KnapdaleLoch an Add - North KnapdaleLoch an Droighinn - KilchrenanLoch an Sgoltaire - Isle of ColonsayLoch an Torr - Dervaig, Isle of MullLoch Ascog - Isle of ButeLoch Assapol - Bunessan, Isle of MullLoch Awe - part of the Awe hydroelectric schemeLoch Ba - Gruline, Isle of MullLoch Bearnoch - Lochdon, Isle of MullLoch Beinn Uraraidh - Port Ellen, IslayLoch Cam - Bridgend, Isle of IslayLoch Chaorunn - South KnapdaleLoch Ciaran - Clachan, North KintyreLoch Clachaig - North KnapdaleLoch Eck - CowalLoch Fad - ButeLoch Finlas - 4 km SW LussLoch Gearach - Port Charlotte, IslayLoch Glashan - Lochgair, Mid-ArgyllLoch Gleann - ObanLoch Iarnan - Port Ellen, IslayLoch Leacann - FurnaceLoch Lebdgei (Dubh Loch) - North KnapdaleLoch Lebgei - North KnapdaleLoch Na Bric - North KnapdaleLoch na Creige Crainde - North KnapdaleLoch Na Faoilinn - North KnapdaleLoch Na Sreinge - 9 km NE of KilmelfordLoch Nam Ban - Port Askaig, IslayLoch Nam Breac Buidhe - North KnapdaleLoch Nan Torran - South KnapdaleLoch Righeachan - InverarayLoch Skerrols - Bridgend, Isle of IslayLoch Sloy (Reservoir) - 6 km N of ArrocharLoch Tarsan - Glen Lean, CowalLoch Tralaig - KilmelfordLoch Turamin (New Loch) - Isle of ColonsayLoch Uigeadail - Port Ellen, IslayLochan A' Ghurrabain - Tobermory, Isle of MullLochan Duin - North KnapdaleLochan Ghlas - GarelochheadLochan Gleann Astaile - Isle of JuraLochan Lasgainn Mor - KilmelfordLower Glen Shira - 12 km NE of InverarayLuachrach Loch - ObanMain Glen Shira - 13 km NE of InverarayMishnish Lochs - Tobermory, Isle of MullNant Reservoir - KilchrenanOude Reservoir - KilmelfordPowder Mill Dam - TighnabruaichSholum Lochs - Port Ellen, IslayStill Loch - ArdrishaigStrathduie Water - CampbeltownClackmannanshireGartmorn DamDumfries and GallowayCarsfad LochClatteringshaws LochGlenkiln ReservoirKettleton ReservoirBlack Esk DamWinterhope ReservoirCity of DundeeClatto ReservoirEast AyrshireAfton ReservoirCorsehouse ReservoirCraigendunton ReservoirGlenbuck LochLoch FinlasEast DunbartonshireBankell Reservoir - supplies Milngavie water treatment worksCraigmaddie Reservoir - supplies Milngavie water treatment worksMugdock Reservoir - supplies Milngavie water treatment worksEast LothianLammerlochStobshiel ReservoirWhiteadder ReservoirEast RenfrewshireSee also: Dams to Darnley Country ParkBalgray ReservoirLittleton ReservoirRyat Linn ReservoirWaulkmill Glen ReservoirWalton DamGlanderston DamSnypes DamKirkton DamHarelaw Reservoir, Fereneze Golf CourseHarelaw Reservoir, Eaglesham MoorRouken Glen PondCraighall ReservoirCommore DamWhite LochBlack LochBrother LochLittle LochPilmuir ReservoirLoch CraigBennan LochCorsehouse Reservoir (on the border with East Ayrshire)Long LochLoch GoinDunwan LochHigh DamPicketlaw ReservoirCaplaw Dam (on the border with Renfrewshire)Netherplace Reservoir (at the dye works)Glenburn ReservoirCity of EdinburghClubbiedean ReservoirHarlaw ReservoirThreipmuir ReservoirTorduff ReservoirBonaly ReservoirFalkirkFaughlin ReservoirMillhall ReservoirFifeBallo ReservoirClatto ReservoirCameron ReservoirCastlehill ReservoirDrumain ReservoirHoll ReservoirHarperleas ReservoirStenhouse LochCarriston ReservoirDonald Rose ReservoirCarlhurlie ReservoirCity of GlasgowHogganfield LochHighlandBlackwater Reservoir, near KinlochlevenClunas ReservoirLoch BeneveanLoch Laggan and Loch Treig - both part of the Lochaber hydroelectric schemeLoch Monar - part of the Strathfarrar hydroelectric schemeLoch Quoich and Loch Garry - both part of the Glen Garry hydroelectric schemeLoch Loyne and Loch Cluanie - both part of the Glen Moriston hydroelectric schemeLoch Mullardoch - part of the Glen Affric hydroelectric schemeLoch KatrineLoch GlascarnochInverclydeLoch ThomGryffe ReservoirMidlothianEdgelaw ReservoirGladhouse ReservoirGlencorse ReservoirNorth Esk ReservoirRosebery ReservoirLoganlea ReservoirMorayGlenlatterach ReservoirNorth AyrshireAuldmuir ReservoirBarcraigs ReservoirBusbie Muir ReservoirCaaf ReservoirCamphill ReservoirCuffhill ReservoirGlenburn ReservoirKelly ReservoirKnockendon ReservoirKirkleegreen ReservoirMill Glen ReservoirMuirhead ReservoirMunnoch ReservoirOuterwards ReservoirSkelmorlie Lower ReservoirSkelmorlie Upper ReservoirNorth LanarkshireBirkenburnBroadwood LochDaerDalmacoulterForrestburnGlenhove No. 1Glenhove No. 2Hillend LochLilly LochRoughriggStrathclyde ParkTownhead ReservoirWest CorrieOrkneyWideford Hill Reservoir (drained)Stromness WaterworksPerth and KinrossDunalastair WaterLoch Tummel - part of the Tummel Valley hydroelectric schemeLoch Turret Reservoir and Glenturret Dam. Near CrieffLower Glendevon ReservoirUpper Glendevon ReservoirRenfrewshireRowbank ReservoirScottish BordersAlemoor LochBaddinsgill ReservoirFruid ReservoirMegget ReservoirTalla ReservoirWestwater ReservoirShetlandSandy Loch ReservoirSouth AyrshireBradan Service ReservoirCollenanGlendrissaighLoch BradanLoch RiecawrLoch SpallanderLoch SpoutsPenwhappleRaithSouth LanarkshireCamps ReservoirCulter Waterhead ReservoirStirlingCocksburn ReservoirEarlsburn ReservoirNorth Third ReservoirWest DunbartonshireCochno LochJaw ReservoirGreenside ReservoirCarman ReservoirKilmannan Reservoir (on the border with Stirling)Burncrooks Reservoir (on the border with Stirling)West LothianCobbinshaw ReservoirEliburn ReservoirHarperrig ReservoirLochcote ReservoirWestern IslesLoch Mor an Stairr - Isle of LewisRoghadal Reservoir - Isle of HarrisWalesAngleseyLlyn Alaw - water supply to much of north AngleseyLlyn Cefni - water supply to central AngleseyCardiffLlanishen Reservoir - water supply to CardiffLisvane Reservoir - water Supply to CardiffCarmarthenshireUpper and Cwm Lliedi reservoirsLlyn BrianneLlyn y Fan FachUsk ReservoirCeredigionDinas ReservoirTeifi PoolsLlyn TeifiNant y Moch ReservoirConwyLlyn Bodgynydd - supply for the Pandora lead mine (disused)Llyn Brenig - part of Dee Regulation system - also in DenbighshireLlyn Coedty - water supply for Dolgarrog hydroelectric stationLlyn Conwy - water supply for Llanrwst and Betws-y-CoedLlyn Cowlyd - water supply for Conwy and Colwyn Bay and for Dolgarrog hydroelectric stationLlyn Crafnant - water supply for LlanrwstLlyn Dulyn - water supply for LlandudnoLlyn Melynllyn - water supply for LlandudnoLlyn Parc - supply for the Aberllyn mine (disused)Llyn Elsi - water supply for Betws-y-Coed (disused)DenbighshireAled Isaf ReservoirAlwen ReservoirCae Llwyd ReservoirLlyn AledLlyn AlwenLlyn Brenig - part of the River Dee regulation systemLlyn Celyn - part of the River Dee regulation system.Pendinas ReservoirLlyn Tegid (Bala Lake)Nant-y-Ffrith ReservoirTy Mawr ReservoirGwyneddLlyn Anafon - water supply for Llanfairfechan, Dwygyfylchi and PenmaenmawrLlyn Arenig FachLlyn Arenig Fawr - water supply for Bala townLlynnau Barlwyd - supply to Llechwedd slate quarryLlyn Bodlyn - water supply to Barmouth.Llyn Bowydd - supply to the Blaenau Ffestiniog slate quarriesLlyn Cwm Corsiog - supply for Rhosydd slate quarry (disused)Llyn Cwellyn - water supply to Bangor and parts of south AngleseyMarchlyn Mawr - header reservoir for the Dinorwig power station hydroelectric system.Llyn PerisLlyn Padarn - part of the Dinorwig hydroelectric systemLlyn Stwlan - built for the hydroelectric Ffestiniog Power StationLlyn Trawsfynydd - built for the Maentwrog hydroelectric Power StationMerthyr TydfilLlwyn-on ReservoirPontsticill Reservoir, including Pentwyn ReservoirNeath Port TalbotEglwys Nunydd - water supply to Tata Steel Europe steel-works at Port TalbotPembrokeshireBosherston lakes - amenity reservoirLlys-y-Frân ReservoirRosebush ReservoirPowysTaff Fawr reservoirs- a chain of three reservoirs supplying the Rhondda and Taff valley and Cardiff with waterBeacons ReservoirCantref Reservoiralso see Llwyn-on Reservoir in Merthyr TydfilTaff Fechan reservoirs - a chain of four reservoirs also supplying the Taff valley and Cardiff with waterUpper Neuadd ReservoirLower Neuadd ReservoirDoly y gaer ReservoirPontsticill ReservoirElan Valley Reservoirs - a group of reservoirs supplying Birmingham and parts of the West Midlands conurbation with drinking waterClaerwen ReservoirCraig-goch ReservoirPenygarreg ReservoirGarreg-ddu ReservoirCaban-coch ReservoirLake Vyrnwy (Llyn Efyrnwy) - supplies water to the Liverpool areaTalybont ReservoirYstradfellte ReservoirLlyn ClywedogSwanseaCray ReservoirSwansea BarrageTorfaenLlandegfedd Reservoir