List of lakes of Wales
This is a list of lakes in Wales, including those created as reservoirs. The names of most lakes in Wales start with the word "Llyn", which is Welsh for "lake". All lakes listed here are named on the relevant Ordnance Survey map at 1:25000 scale[1]
By area
In terms of surface area, the ten largest lakes in Wales are
- Llyn Tegid (Bala Lake) — 1,196 acres (4.84 km2)
- Llyn Trawsfynydd — 1,180 acres (4.8 km2)
- Lake Vyrnwy — 1,120 acres (4.5 km2)
- Llyn Brenig — 894 acres (3.62 km2)
- Llyn Celyn — 800 acres (3.2 km2)
- Llyn Alaw — 762 acres (3.08 km2)
- Claerwen Reservoir — 655 acres (2.65 km2)
- Llyn Clywedog — 601 acres (2.43 km2)
- Nant y Moch Reservoir — 525 acres (2.12 km2)
- Caban Coch Reservoir — 519 acres (2.10 km2)
All of the above, with the exception of Llyn Tegid, are reservoirs held back by dams. Llyn Tegid was the largest natural lake in Wales though its level is now artificially controlled. The largest natural lake in South Wales is Llangors Lake or Llyn Syfaddan, which is also the second largest natural lake.
By unitary authority
This list of Welsh lakes ordered by unitary authority includes lakes with a surface area of greater than 5 acres (2.0 ha), but excludes those lakes and ponds created as part of an active industrial site (i.e., works ponds) and also excludes service reservoirs used to store drinking water as part of the water supply system. Grid references identify the approximate centre of the lake or the dam in the case of artificial reservoirs. For some lakes the unitary authority boundary passes through a lake; in these cases the lake is represented in the list for each appropriate authority. Known occurrences include Llyn Brenig, Pontsticill Reservoir, Llwyn-on Reservoir, Cantref Reservoir and Dol-y-gaer Reservoir. All occurrences are marked with an asterisk (*).
Anglesey
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llyn Alaw | River Alaw | SH375853 | 762 | Water supply to north Anglesey |
Llyn Bodgylched | No main catchment | SH585770 | ||
Llyn Cefni | Afon Cefni | SH443771 | 167 | Water supply to central Anglesey |
Llyn Coron | No main catchment | SH380700 | 69 | |
Llyn Dinam | No main catchment | SH312778 | 24 | |
Llyn y Gors | No main catchment | SH575748 | Amenity (fishing) | |
Llyn Gwaith-glo | No main catchment | SH450713 | ||
Llyn Llygeirian | No main catchment | SH347898 | ||
Llyn Llywenan | No main catchment | SH347815 | ||
Llyn Llwydiarth | Afon Braint | SH549786 | ||
Llyn Maelog | No main catchment | SH325730 | 65 | Former water supply to Rhosneigr |
Llyn Pen y Parc | No main catchment | SH585751 | Water supply (disused) | |
Llyn Penrhyn | No main catchment | SH313770 | 55 | RSPB bird reserve |
Llyn Rhosddu | No main catchment | SH425648 | ||
Llyn Traffwll | No main catchment | SH325770 | 91 | |
Llyn Treflesg | No main catchment | SH307770 | RSPB bird reserve | |
Blaenau Gwent
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Carno Reservoir | Ebbw River | SO164131 | reservoir | |
Cwmtillery Reservoir | Ebbw River | SO220071 | reservoir | |
Rhyd-y-blew Pond | Ebbw River | SO160112 | ||
Parc Brynbach lake | Sirhowy River | SO127101 | amenity | |
Scotch Pete's Reservoir | Sirhowy River | SO155088 | reservoir | |
Shon-Sheffrey's Reservoir | Sirhowy River | SO158116 | reservoir | |
Bridgend
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Kenfig Pool | River Kenfig | SS797815 | 70 | Natural lake |
Craig yr Aber Reservoir | Nant Craig yr Aber | Man Made Dam | ||
Caerphilly
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Lower Blaen Rhymney Reservoir | Rhymney River | SO103103 | reservoir | |
Upper Blaen Rhymney Reservoir | Rhymney River | SO098104 | reservoir | |
Bute Town Reservoir | Rhymney River | SO101091 | ||
Nant-y-draenog Reservoir | Sirhowy River | ST188935 | 5 | reservoir |
Parc Cwm Darran Lake | Rhymney River | ST117032 | amenity | |
Rhaslas Pond | Rhymney River | SO095072 | ||
Ffrwd Farm lake (west) | Rhymney River | ST154920 | angling | |
Ffrwd Farm lake (east) | Rhymney River | ST155920 | angling | |
Pen-y-fan Pond | Sirhowy River | SO196004 | 14 | Built as canal feed reservoir. |
Cardiff
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Cardiff Bay | River Taff/River Ely | ST190726 | 500 | Amenity |
Hendre Lake | Faendre Reen | ST245805 | 12 | Recreation and amenity |
Llanishen Reservoir | Rhymney River | ST185815 | 59 | Water supply to Cardiff |
Lisvane Reservoir | Rhymney River | ST189822 | Water Supply to Cardiff | |
Roath lake | Rhymney River | ST184795 | 30 | Recreation and amenity |
Carmarthenshire
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llyn Brianne | River Tywi | SN790485 | 530 | Regulation reservoir |
Garn Ffrwd pond? | Gwendraeth Fach | SN508142 | 5 | |
Llanelli North Dock lake | coastal waterbody | SS498996 | amenity (former dock) | |
Llyn Llech Owen Reservoir | Gwendraeth Fawr | SN568151 | amenity/reservoir | |
Cwm Lliedi Reservoir | Afon Lliedi | SS519036 | ex water supply | |
Llyn y Fan Fach | River Tywi | SN803219 | ||
Llyn Taliaris | Afon Dulais | SN634283 | ||
Lower Talley Lake | Afon Cothi | SN633331 | natural lake | |
National Wetlands Centre | coastal waterbodies | SS529986 | conservation/wildlife | |
Old Castle Pond/Pond Twym | coastal lake | SN500003 | amenity | |
Sandy Water | coastal lake | SN495003 | amenity | |
Upper Lliedi Reservoir | Afon Lliedi | SS511045 | reservoir | |
Upper Talley Lake | Afon Cothi | SN631337 | natural lake | |
Usk Reservoir | River Usk | SN832288 | Water supply | |
un-named lake | coastal lake | SS507987 | amenity | |
Ceredigion
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llyn Berwyn | River Teifi | SN743569 | 40 | Natural lake |
Llyn Craigypistyll | River Dyfi | SN722858 | Natural lake | |
Dinas Reservoir | River Rheidol | SN748821 | Hydroelectricity | |
Llyn Du | River Severn | SN800698 | Natural lake | |
Llyn Egnant | River Teifi | SN792674 | Water supply | |
Falcondale Lake | River Teifi | SN563491 | Amenity | |
Llyn Frongoch | River Ystwyth | SN721752 | Lead mining ?/ Natural | |
Llyn Fyrddon Fach | River Severn | SN796701 | Natural lake | |
Llyn Fyrddon Fawr | River Severn | SN800708 | Natural lake | |
Llyn Glandwgan | River Ystwyth | SN707752 | Natural lake | |
Glanmerin Lake | River Dyfi | SN755990 | Natural lake | |
Llyn y Gorlan | River Teifi | SN786670 | Water supply | |
Llyn Gwngi | River Severn | SN839729 | Natural lake | |
Llyn Hir | River Teifi | SN789676 | Water supply | |
Nant-y-moch Reservoir | River Rheidol | SN870636 | Hydroelectricity | |
Llyn Rhosrhydd | River Ystwyth | SN705759 | Natural lake | |
Llyn Syfydrin | River Rheidol | SN723848 | Natural lake | |
Llyn Teifi | River Teifi | SN781675 | Water supply | |
Conwy
Denbighshire
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Brickfields Pond | River Clwyd | SJ012803 | 8.9 | Local nature reserve |
Llyn Brân | SH961592 | 31.4 | ||
Llyn Brenig | River Dee | SH973555 | 920 | Flow regulation |
Llyn Cyfynwy | SJ217546 | 17.5 | ||
Llyn Gweryd | SJ172550 | 13.1 | ||
Llyn Mynyllod | SJ012402 | 6.2 | ||
Nant-y-Ffrith Reservoir | SJ242530 | 12.1 | ||
Pendinas Reservoir | SJ235518 | 16.3 | ||
Rhyl Marine Lake | River Clwyd | SH999804 | 28.7 | |
unnamed lake on Rûg estate | River Dee | SJ058440 | 8.4 | |
Flintshire
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llyn Helyg | River Clwyd | SJ113772 | 37 | |
Padeswood Pool | SJ278619 | 12.6 | angling | |
Shotwick Lake | River Dee | SJ315725 | amenity | |
unnamed reservoir, Cilcain | SJ155641 | 5.4 | ||
unnamed reservoir, Oakenholt | SJ262710 | 5.7 | ||
Ysceifiog Lake | SJ147716 | 13.8 | ||
Gwynedd
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llyn yr Adar | River Glaslyn | SH655479 | 10 | |
Llyn Anafon | Afon Aber | SH698698 | 13 | Water supply |
Llyn Arenig Fach | SH827417 | 34 | Natural lake | |
Llyn Arenig Fawr | River Dee | SH846380 | 84 | water supply for Bala town, natural lake |
Llynnau Barlwyd | River Dwyryd | SH710484 | 10 + 5 | Industrial water supply |
Llyn y Bi | River Mawddach | SH669264 | 6 | |
Llyn Bodlyn | Afon Ysgethin | SH648239 | 42 | Water supply |
Llyn Bowydd | River Dwyryd | SH725467 | 22 | Industrial water supply. |
Llyn Caerwych | River Dwyryd | SH640350 | 5 | |
Llyn Cau | River Dysynni | SH714123 | 33 | |
Llyn Celyn | River Dee | SH000000 | 815 | River Regulation |
Llyn Conglog | River Dwyryd | SH674473 | 18 | |
Llyn Conglog Mawr | River Dwyryd | SH758387 | 8 | |
Craiglyn Dyfi also written as Creiglyn Dyfi | River Dyfi | SH867225 | 15 | Natural corrie lake |
Llyn Croesor | River Glaslyn | SH661457 | 5 | |
Llyn Cwm Corsiog | Afon Dwyryd | SH663470 | 7 | Industrial water supply (disused) |
Llyn Cwellyn | Afon Gwyrfai | SH559549 | 215 | Water supply |
Llyn Cwm Bychan | Afon Artro | SH640312 | 25 | |
Llyn Cwm Dulyn | Afon Llyfni | SH492495 | 34 | Water supply |
Llyn Cwmffynnon | River Conwy | SH649562 | 20 | |
Llyn Cwm-mynach | River Mawddach | SH678237 | 14 | |
Llyn Cwmorthin | River Dwyryd | SH677463 | 22 | |
Llynnau Cwm Silyn | Afon Llyfni | SH513508 | 15 + 15 | |
Llyn Cwm y Foel | River Glaslyn | SH655468 | 8 | |
Llyn Cwmystradllyn | River Dwyfor | SH561444 | 98 | Natural lake |
Llyn Cynwch | River Mawddach | SH737207 | 26 | Amenity |
Llyn Dinas | River Glaslyn | SH616495 | 60 | Natural lake |
Llynnau Diwaunedd | River Conwy | SH682537 | 19 + 13 | Natural lakes |
Llyn Dulyn | Afon Ysgethin | SH661244 | 5 | Natural lake, reservoir |
Llyn Du'r Arddu | River Seiont | SH600557 | 5 | Natural lake |
Llyn Dwythwch | River Seiont | SH570580 | 24 | |
Llyn y Dywarchen | Afon Gwyrfai | SH560534 | 40 | |
Llyn Edno | River Glaslyn | SH663497 | 10 | |
Llyn Eiddew-mawr | Afon Artro | SH646338 | 22 | |
Llyn Ffynnon y Gwas | Afon Gwyrfai | SH591553 | 10 | |
Llyn y Gadair | Afon Gwyrfai | SH568521 | 50 | |
Llyn Gwynant | River Glaslyn | SH644519 | 85 | |
Llyn Hesgyn | River Dee | SH885442 | 5 | |
Llyn Hywel | SH663266 | 13 | ||
Llyn Idwal | River Ogwen | SH645596 | 28 | |
Llyn Irddyn | Afon Ysgethin | SH629222 | natural lake | |
Llyn Llagi | River Glaslyn | SH649482 | 8 | |
Llyn Llydaw | River Glaslyn | SH629543 | 110 | |
Llyn Llywelyn | River Glaslyn | SH562499 | 6 | |
Llyn Mair | River Dwyryd | SH652412 | 14 | |
Marchlyn Bach reservoir | River Seiont | SH607625 | ||
Marchlyn Mawr | River Seiont | SH615622 | Hydroelectricity | |
Llyn Mwyngil (Talyllyn Lake) | River Dysynni | SH717099 | 220 | |
Llyn Nantlle Uchaf | Afon Llyfni | SH514530 | 80 | |
Llyn Newydd | River Dwyryd | SH722471 | 12 | |
Llyn Peris | River Seiont | SH591595 | 95 | Lower reservoir for pump storage hydro-electricity |
Llyn Padarn | River Seiont | SH572613 | 280 | Natural Lake used for recreation |
Tanygrisiau Reservoir | River Dwyryd | SH679441 | 95 | |
Llyn Tecwyn Isaf | SH629370 | 7 | ||
Llyn Tecwyn Uchaf | River Dwyryd | SH640381 | 31 | |
Llyn Tegid – (Bala Lake) | River Dee | SH911338 | 1,196 | |
Llyn Teyrn | River Glaslyn | SH641547 | 5 | |
Llyn Trawsfynydd | River Dwyryd | SH674377 | 1,180 | Nuclear (formerly) and Hydroelectric energy |
Llyn Tryweryn | River Dee | SH788384 | 20 | |
Llyn Wylfa | Afon Mawddach | SH671162 | 6 | Natural lake |
Merthyr Tydfil
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Cantref Reservoir * | River Taff | SN996154 | Water supply | |
Cyfarthfa Castle Lake | River Taff | SO039073 | amenity | |
Dol-y-gaer (or Pentwyn) Reservoir * | River Taff | SO060118 | Water supply | |
Llwyn-on Reservoir * | River Taff | SO012113 | Water supply | |
Penywern Middle Pond | River Taff | SO073083 | angling | |
Penywern Top Pond | River Taff | SO071086 | angling | |
Pontsticill Reservoir * | River Taff | SO060118 | Water supply | |
Monmouthshire
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Llandegfedd Reservoir | River Usk | ST325985 | 434 | Water supply |
Pwll Pen-ffordd-goch/Keepers Pond | River Usk | SO255109 | Amenity. Served Garn-ddyrys ironworks | |
Wentwood Reservoir | River Usk | ST430929 | 41 | Water supply |
Neath Port Talbot
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Cwmwernderi Reservoir | SS817902 | reservoir | ||
Eglwys Nunydd | River Afan | SS791855 | 260 | Industrial water supply + fishing |
Furzemill Pond | River Afan | SS810857 | 5 | former millpond? |
Rheola Pond | River Neath | SN843043 | ||
larger un-named lake at Aberclwyd | River Neath | SN847043 | amenity | |
smaller un-named lake at Aberclwyd | River Neath | SN852045 | amenity | |
Pembrokeshire
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Bosherston lakes | Coastal stream | SR974946 | Natural lakes | |
Llys-y-Frân Reservoir | Western Cleddau | SN036242 | 212 | Water supply |
Rosebush Reservoir, Rosebush | Western Cleddau | SN061291 | 30 | Water supply |
Powys
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Beacons Reservoir | River Taff | SN987182 | 52 | Water supply |
Caban-coch Reservoir | River Severn | SN924645 | 500See note | Water supply |
Cantref Reservoir * | River Taff | SN996154 | 42 | Water supply |
Claerwen Reservoir | River Severn | SN869963 | 664 | Water supply |
Llyn Clywedog | River Severn | SN911870 | River regulation | |
Craig-goch Reservoir | River Severn | SN893686 | 217 | Water supply |
Cray Reservoir | River Usk | SN883220 | 100 | Water supply |
Dol-y-gaer (or Penwtwyn) Reservoir * | River Taff | SO054144 | Water supply | |
Garreg-ddu Reservoir | River Severn | SN911639 | 500See note | Water supply |
Llyn Gludy | River Usk | SO018298 | ||
Llyn Lluncaws | Afon Tanat | SJ07143169 | Natural lake | |
Llangorse Lake | River Usk | SO132266 | 327 | Natural lake |
Llwyn-on Reservoir * | River Taff | SO012113 | 150 | Water supply |
Llyn y Fan Fawr | River Tawe | SN832216 | ||
Lower Neuadd Reservoir | River Taff | SO030180 | Water supply | |
Upper Neuadd Reservoir | River Taff | SO029188 | Water supply | |
Penygarreg Reservoir | River Severn | SN911673 | 124 | Water supply |
Pontsticill Reservoir* | River Taff | SO060118 | Water supply | |
Talybont Reservoir | River Usk | SO104205 | Water supply | |
Ty Mawr Pool | River Usk | SO074264 | natural lake | |
Lake Vyrnwy | River Vyrnwy | SH000000 | Water supply | |
Ystradfellte Reservoir | River Neath | SN955175 | Water supply | |
Note: Caban Coch and Garreg-ddu reservoirs are separately named but form one contiguous area of water at normal levels. The area quoted is for the two combined.
Rhondda Cynon Taf
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Dare Valley Country Park lower lake | Afon Cynon | SN977028 | amenity | |
Lluest-wen Reservoir | Afon Rhondda Fach | SN947017 | ||
Llyn Fawr | Afon Cynon | SN917034 | 24 | |
Nant-hir Reservoir | Afon Cynon | SN989069 | ||
Nant-moel Reservoir | Afon Cynon | SN982071 | ||
Penderyn Reservoir | River Neath | SN938072 | ||
?Perthgelyn Reservoir | Afon Cynon | ST053970 | reservoir | |
Swansea
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Lake Fendrod | River Tawe | SS676967 | 13 | Amenity |
Lower Lliw Reservoir | River Lliw | SN650036 | Water Supply | |
Oxwich Marsh Lake | coastal stream | SS503873 | >15 | Natural lake |
Upper Lliw Reservoir | River Lliw | SN661062 | Water Supply | |
Tawe Barrage | River Tawe | SH664926 | Amenity | |
Specimen Lake | River Loughor | SN598056 | 10 | amenity/angling |
Torfaen
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Blaen Bran Reservoir (lower) | Afon Lwyd | ST267971 | ||
Coity Pond | Afon Lwyd | SN233090 | former reservoir | |
Vale of Glamorgan
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Cosmeston Lake | River Cadoxton | ST176692 | Amenity | |
Hensol Lake | River Ely | ST045789 | Amenity and reservoir | |
Hensol Mill Pond | River Ely | ST050790 | 6 | former mill pond |
Wrexham
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use |
---|---|---|---|---|
Cae Llwyd Reservoir | SJ270479 | 10.6 | ||
Chirk Castle Lake | SJ269386 | 11.1 | ||
Fenn's Bank Mere | SJ505386 | 8.4 | ||
Gresford Flash | SJ346536 | 8.2 | amenity | |
Hanmer Mere | SJ452392 | 45.2 | natural lake | |
Monk's Pool | SJ303448 | 5.2 | ||
Pant-yr-ochain Lake | SJ349529 | 14.1 | ||
Penycae Top Reservoir | SJ267452 | 6.2 | ||
Ty Mawr Reservoir | SJ276480 | 21.3 | ||
Wynnstay Park Lake | SJ307428 | 8.9 | ||
Lakes by national park
Lakes and reservoirs within each of Wales' three national parks.
Brecon Beacons
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use | Unitary area/s |
---|---|---|---|---|---|
Beacons Reservoir | River Taff | SN987182 | 52 | Water supply | Powys |
Cantref Reservoir * | River Taff | SN996154 | 42 | Water supply | Powys |
Cray Reservoir | River Usk | SN883220 | 100 | Water supply | Powys |
Dol-y-gaer (or Pentwyn) Reservoir * | River Taff | SO054144 | Water supply | Powys | |
Llyn Gludy | River Usk | SO018298 | Powys | ||
Llangorse Lake | River Usk | SO132266 | 327 | Natural lake | Powys |
Llwyn-on Reservoir * | River Taff | SO012113 | 150 | Water supply | Powys |
Llyn y Fan Fawr | River Tawe | SN832216 | Powys | ||
Lower Neuadd Reservoir | River Taff | SO030180 | Water supply | Powys | |
Upper Neuadd Reservoir | River Taff | SO029188 | Water supply | Powys | |
Pontsticill Reservoir* | River Taff | SO060118 | Water supply | Powys | |
Talybont Reservoir | River Usk | SO104205 | Water supply | Powys | |
Ty Mawr Pool | River Usk | SO074264 | natural lake | Powys | |
Ystradfellte Reservoir | River Neath | SN955175 | Water supply | Powys | |
Pembrokeshire Coast
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use | Unitary area/s |
---|---|---|---|---|---|
Bosherston lakes | Coastal stream | SR974946 | Natural lakes | Pembrokeshire | |
Rosebush Reservoir, Rosebush | Western Cleddau | SN061291 | 30 | Water supply | Pembrokeshire |
Snowdonia
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use | unitary area/s |
---|---|---|---|---|---|
Llyn yr Adar | River Glaslyn | SH655479 | 10 | Gwynedd | |
Llyn Anafon | Afon Aber | SH698698 | 13 | Water supply | |
Llyn Arenig Fach | SH827417 | 34 | Natural lake | Gwynedd | |
Llyn Arenig Fawr | River Dee | SH846380 | 84 | water supply, natural lake | Gwynedd |
Llynnau Barlwyd | River Dwyryd | SH710484 | 10 + 5 | Industrial water supply | Gwynedd |
Llyn y Bi | River Mawddach | SH669264 | 6 | Gwynedd | |
Llyn Bochlwyd | River Ogwen | SH654592 | 10 | Conwy | |
Llyn Bodgynydd | SH760592 | 14 | Industrial supply (dis) | Conwy | |
Llyn Bodlyn | Afon Ysgethin | SH648239 | 42 | Water supply | Gwynedd |
Llyn Bowydd | River Dwyryd | SH725467 | 22 | Industrial water supply | Gwynedd |
Llyn Caerwych | River Dwyryd | SH640350 | 5 | Gwynedd | |
Llyn Cau | River Dysynni | SH714123 | 33 | Gwynedd | |
Llyn Celyn | River Dee | SH000000 | 815 | River Regulation | Gwynedd |
Llyn Coedty | River Conwy | SH754666 | 11.6 | Hydroelectricity | Conwy |
Llyn Conglog | River Dwyryd | SH674473 | 18 | Gwynedd | |
Llyn Conglog Mawr | River Dwyryd | SH758387 | 8 | Gwynedd | |
Llyn Conwy | River Conwy | SH780462 | 101.3 | Water supply for Llanrwst | Conwy |
Llyn Cowlyd | River Conwy | SH727624 | 269 | Water supply for Conwy | Conwy |
Llyn Crafnant | River Conwy | SH749610 | 52 | Former water supply | Conwy |
Creiglyn Dyfi | River Dyfi | SH867225 | 15 | Natural corrie lake | Gwynedd |
Llyn Croesor | River Glaslyn | SH661457 | 5 | Gwynedd | |
Llyn Cwm Corsiog | SH663470 | 7 | Indust. water supply (dis) | ||
Llyn Cwellyn | Afon Gwyrfai | SH559549 | 215 | Water supply | Gwynedd |
Llyn Cwm Bychan | Afon Artro | SH640312 | 25 | Gwynedd | |
Llyn Cwm Dulyn | Afon Llyfni | SH492495 | 34 | Water supply | Gwynedd |
Llyn Cwmffynnon | River Conwy | SH649562 | 20 | Gwynedd | |
Llyn Cwm-mynach | River Mawddach | SH678237 | 14 | Gwynedd | |
Llyn Cwmorthin | River Dwyryd | SH677463 | 22 | Gwynedd | |
Llynnau Cwm Silyn | Afon Llyfni | SH513508 | 15 + 15 | Gwynedd | |
Llyn Cwm y Foel | River Glaslyn | SH655468 | 8 | Gwynedd | |
Llyn Cwmystradllyn | River Dwyfor | SH561444 | 98 | Natural lake | Gwynedd |
Llyn Cynwch | River Mawddach | SH737207 | 26 | Amenity | Gwynedd |
Llyn Dinas | River Glaslyn | SH616495 | 60 | Natural lake | Gwynedd |
Llynnau Diwaunedd | River Conwy | SH682537 | 19 + 13 | Natural lakes | Gwynedd |
Llyn Dulyn | Afon Ysgethin | SH661244 | 5 | Natural lake, reservoir | Gwynedd |
Dulyn Reservoir | River Conwy | SH700665 | 33 | Water supply | Conwy |
Llyn Du'r Arddu | River Seiont | SH600557 | 5 | Natural lake | Gwynedd |
Llyn Dwythwch | River Seiont | SH570580 | 24 | Gwynedd | |
Llyn y Dywarchen | Afon Gwyrfai | SH560534 | 40 | Gwynedd | |
Llyn Edno | River Glaslyn | SH663497 | 10 | Gwynedd | |
Llyn Eiddew-mawr | Afon Artro | SH646338 | 22 | Gwynedd | |
Llyn Eigiau | River Conwy | SH720651 | 120 | Conwy | |
Llyn Elsi | River Conwy | SH783552 | 26 | Water supply | Conwy |
Llyn Ffynnon y Gwas | Afon Gwyrfai | SH591553 | 10 | Gwynedd | |
Llyn-y-foel | Afon Lledr | SH714547 | natural lake | Conwy | |
Llyn y Gadair | Afon Gwyrfai | SH568521 | 50 | Gwynedd | |
Llyn Geirionydd | River Conwy | SH763608 | 45 | Conwy | |
Llyn Goddionduon | River Conwy | SH753586 | 10 | Conwy | |
Llyn Gwynant | River Glaslyn | SH644519 | 85 | Gwynedd | |
Llyn Hesgyn | River Dee | SH885442 | 5 | Gwynedd | |
Llyn Hywel | SH663266 | 13 | Gwynedd | ||
Llyn Idwal | River Ogwen | SH645596 | 28 | Gwynedd | |
Llyn Irddyn | Afon Ysgethin | SH629222 | natural lake | Gwynedd | |
Llyn Llagi | River Glaslyn | SH649482 | 8 | Gwynedd | |
Ffynnon Lloer | River Ogwen | SH662621 | 6 | Conwy | |
Ffynnon Llugwy | River Conwy | SH692627 | 40 | Conwy | |
Llyn Llydaw | River Glaslyn | SH629543 | 110 | Gwynedd | |
Llyn Llywelyn | River Glaslyn | SH562499 | 6 | Gwynedd | |
Llyn Mair | River Dwyryd | SH652412 | 14 | Gwynedd | |
Marchlyn Bach reservoir | River Seiont | SH607625 | Gwynedd | ||
Marchlyn Mawr | River Seiont | SH615622 | Hydroelectricity | Gwynedd | |
Llyn Mwyngil (Talyllyn Lake) | River Dysynni | SH717099 | 220 | Gwynedd | |
Llynnau Mymbyr | River Conwy | SH000000 | 58 | Conwy | |
Llyn Nantlle Uchaf | Afon Llyfni | SH514530 | 80 | Gwynedd | |
Llyn Newydd | River Dwyryd | SH722471 | 12 | Gwynedd | |
Llyn Ogwen | River Ogwen | SH659604 | 78 | Conwy | |
Llyn y Parc | River Conwy | SH792588 | 22 | Conwy | |
Tanygrisiau Reservoir | River Dwyryd | SH679441 | 95 | Gwynedd | |
Llyn Tecwyn Isaf | SH629370 | 7 | Gwynedd | ||
Llyn Tecwyn Uchaf | River Dwyryd | SH640381 | 31 | Gwynedd | |
Llyn Tegid – (Bala Lake) | River Dee | SH911338 | 1,196 | Gwynedd | |
Llyn Teyrn | River Glaslyn | SH641547 | 5 | Gwynedd | |
Llyn Trawsfynydd | River Dwyryd | SH674377 | 1,180 | Nuclear (formerly) & HEP | Gwynedd |
Llyn Tryweryn | River Dee | SH788384 | 20 | Gwynedd | |
Llyn Wylfa | SH000000 | 6 | Gwynedd | ||
Former lakes
Lake name | Catchment | Grid ref. | Area (acres) | Status/Use | Unitary area |
---|---|---|---|---|---|
Pitwellt Pond | River Taff | SO078098 | former reservoir (dam breached) | Merthyr Tydfil | |