This is alist of lakes in Wales, including those created asreservoirs. The names of most lakes in Wales start with the word "Llyn", which isWelsh for "lake". Except where otherwise referenced, all lakes listed here are named on the relevant Ordnance Survey map at 1:25000 scale.[1]
In terms of surface area, the ten largest lakes in Wales are
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 has been artificially controlled by sluices since about 1804.[2] The largest natural lake inSouth Wales isLlangorse Lake (Llyn Syfaddan), which is also the second largest natural lake.
This list of Welsh lakes ordered byprincipal areas (counties and county boroughs) includes lakes with a surface area of greater than 5acres (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 principal area boundary passes through a lake; in these cases the lake is represented in the list for each appropriate authority. Known occurrences includeLlyn Brenig,Pontsticill Reservoir,Llwyn-on Reservoir,Cantref Reservoir andDol-y-gaer Reservoir. All occurrences are marked with an asterisk (*).[3]
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Llyn Alaw | River Alaw | SH375853 | 762 | 308 | water supply to northAnglesey |
| Llyn Bodgylched | No main catchment | SH585770 | |||
| Llyn Cefni | Afon Cefni | SH443771 | 167 | 68 | water supply to central Anglesey |
| Llyn Coron | No main catchment | SH380700 | 69 | 28 | |
| Llyn Dinam | No main catchment | SH312778 | 24 | 9.7 | |
| 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 | Largest natural body of water on Anglesey | ||
| Llyn Llwydiarth | Afon Braint | SH549786 | |||
| Llyn Maelog | No main catchment | SH325730 | 65 | 26 | former water supply to Rhosneigr |
| Llyn Pen y Parc | No main catchment | SH585751 | water supply (disused) | ||
| Llyn Penrhyn | No main catchment | SH313770 | 55 | 22 | RSPB bird reserve |
| Llyn Rhosddu | No main catchment | SH425648 | |||
| Llyn Traffwll | No main catchment | SH325770 | 91 | 37 | |
| Llyn Treflesg | No main catchment | SH307770 | RSPB bird reserve | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Blaen-y-Cwm Reservoir (Blaen Clydach Reservoir) | Ebbw River/River Clydach | SO174131 | 50 | 20 | Reservoir, originally constructed in 1813 to supply theNantyglo Ironworks.[4] |
| Carno Reservoir | Ebbw River | SO164131 | reservoir | ||
| Cwmtillery Reservoir | Ebbw River | SO220071 | reservoir | ||
| Lower Boat Pond | Ebbw River | SO174118 | 6.25 | 2.53 | amenity, formerly industrial supply along with smaller Upper Boat Pond |
| Rhyd-y-blew Pond | Ebbw River | SO160112 | |||
| Parc Brynbach lake | Sirhowy River | SO127101 | amenity | ||
| Shon-Sheffrey's Reservoir | Sirhowy River | SO129116 | reservoir | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Kenfig Pool | River Kenfig | SS797815 | 70 | 28 | natural lake |
| Craig yr Aber Reservoir | Nant Craig yr Aber | SS853857 | man-made dam | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Lower Blaen Rhymney Reservoir | Rhymney River | SO103103 | reservoir | ||
| Upper Blaen Rhymney Reservoir | Rhymney River | SO098104 | reservoir | ||
| Bute Town Reservoir | Rhymney River | SO101091 | |||
| Caerphilly Castle moat | Rhymney River | ST155872 | |||
| Nant-y-draenog Reservoir | Sirhowy River | ST188935 | 5 | 2.0 | reservoir |
| Parc Cwm Darran Lake | Rhymney River | SO117032 | 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 | 5.7 | built as canal feed reservoir. |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Cardiff Bay | River Taff/River Ely | ST190726 | 500 | 200 | amenity |
| Hendre Lake | No main catchment | ST245805 | 12 | 4.9 | recreation and amenity |
| Llanishen Reservoir | Rhymney River | ST185815 | 59 | 24 | water supply toCardiff |
| Lisvane Reservoir | Rhymney River | ST189822 | water supply to Cardiff | ||
| Roath lake | Rhymney River | ST184795 | 30 | 12 | recreation and amenity |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Llyn Brianne | River Tywi | SN790485 | 530 | 210 | regulation reservoir |
| Garn Ffrwd pond? | Gwendraeth Fach | SN508142 | 5 | 2.0 | |
| Llanelli North Dock lake | Coastal waterbody | SS498996 | amenity (former dock) | ||
| Llyn Llech Owen Reservoir | Gwendraeth Fawr | SN568151 | amenity/reservoir | ||
| Cwm Lliedi Reservoir | Afon Lliedi | SN519036 | ex water supply | ||
| Llyn y Fan Fach | River Tywi | SN803219 | 25 | 10 | natural |
| Llyn Taliaris | Afon Dulais | SN634283 | |||
| Lower Talley Lake | Afon Cothi | SN633331 | 62 | 25 | natural lake |
| Lagoons atNational 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 | SN511045 | reservoir | ||
| Upper Talley Lake | Afon Cothi | SN631337 | natural lake | ||
| Usk Reservoir | River Usk | SN832288 | water supply | ||
| Delta Lake | Coastal lake | SS507987 | amenity | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Llyn Bach | River Teifi | SN788668 | natural lake | ||
| Llyn Berwyn | River Teifi | SN743569 | 40 | 16 | 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 | SN569499 | 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 | ||
| Llyn y Gorlan | River Teifi | SN786670 | water supply | ||
| Llyn Gwngi | River Severn | SN839729 | natural lake | ||
| Llyn Gynon | River Severn | SN799647 | 70 | 28 | natural lake |
| Llyn Hir | River Teifi | SN789676 | water supply | ||
| Nant-y-moch Reservoir | River Rheidol | SN751872 | hydroelectricity | ||
| Llyn Pond Gwaith | River Teifi | SN781675 | Natural | ||
| Llyn Rhosrhydd | River Ystwyth | SN705759 | natural lake | ||
| Llyn Syfydrin | River Rheidol | SN723848 | natural lake | ||
| Llyn Teifi | River Teifi | SN781675 | water supply | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Brickfields Pond | River Clwyd | SJ012803 | 8.9 | 3.6 | Local nature reserve |
| Llyn Brân | SH961592 | 31.4 | 12.7 | natural | |
| Llyn Brenig | River Dee | SH973555 | 920 | 370 | flow regulation |
| Llyn Cyfynwy | SJ217546 | 17.5 | 7.1 | ||
| Llyn Gweryd | SJ172550 | 13.1 | 5.3 | ||
| Llyn Mynyllod | SJ012402 | 6.2 | 2.5 | ||
| Nant-y-Ffrith Reservoir | River Cegidog | SJ242530 | 12.1 | 4.9 | |
| Pendinas Reservoir | River Cegidog | SJ235518 | 16.3 | 6.6 | |
| Rhyl Marine Lake | River Clwyd | SH999804 | 28.7 | 11.6 | |
| unnamed lake onRûg estate | River Dee | SJ058440 | 8.4 | 3.4 | |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Llyn Helyg | River Clwyd | SJ113772 | 37 | 15 | |
| Padeswood Pool | SJ278619 | 12.6 | 5.1 | angling | |
| Shotwick Lake | River Dee | SJ315725 | amenity | ||
| unnamed reservoir,Cilcain | SJ155641 | 5.4 | 2.2 | ||
| unnamed reservoir,Oakenholt | SJ262710 | 5.7 | 2.3 | ||
| Ysceifiog Lake | SJ147716 | 13.8 | 5.6 | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| 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 | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Llandegfedd Reservoir | River Usk | ST325985 | 434 | 176 | water supply |
| Pwll Pen-ffordd-goch / Keepers Pond | River Usk | SO255109 | amenity, formerly served Garn-ddyrys ironworks | ||
| Wentwood Reservoir | River Usk | ST430929 | 41 | 17 | water supply |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Cwmwernderi Reservoir | SS817902 | reservoir | |||
| Eglwys Nunydd | River Afan | SS791855 | 260 | 110 | industrial water supply, fishing |
| Furzemill Pond | River Afan | SS810857 | 5 | 2.0 | former millpond? |
| Llyn Fach | River Neath | SN905037 | Natural lake | ||
| Rheola Pond | River Neath | SN843043 | |||
| larger un-named lake atAberclwyd | River Neath | SN847043 | amenity | ||
| smaller un-named lake atAberclwyd | River Neath | SN852045 | amenity | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Bosherston Lakes | Coastal stream | SR974946 | artificial | ||
| Llys-y-Frân Reservoir | Western Cleddau | SN036242 | 212 | 86 | water supply |
| Rosebush Reservoir | Western Cleddau | SN061291 | 30 | 12 | 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. At high water levels, Pentwyn Reservoir is continuous with Pontsticill Reservoir, its dam being submerged.
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Cantref Reservoir * | River Taff | SN996154 | water supply | ||
| Dare Valley Country Park lower lake | River Cynon | SN977028 | amenity | ||
| Lluest-wen Reservoir | River Rhondda Fach | SN947017 | |||
| Llwyn-on Reservoir * | River Taff | SO012113 | 150 | 61 | water supply |
| Llyn Fawr | River Cynon | SN917034 | 24 | 9.7 | Natural but expanded for water supply |
| Nant-hir Reservoir | River Cynon | SN989069 | |||
| Nant-moel Reservoir | River Cynon | SN982071 | |||
| Penderyn Reservoir | River Neath | SN938072 | |||
| ?Perthgelyn Reservoir | River Cynon | ST053970 | reservoir | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Lake Fendrod | River Tawe | SS676967 | 13 | 5.3 | amenity |
| Lower Lliw Reservoir | River Lliw | SN650036 | water supply | ||
| Oxwich Marsh Lake | coastal stream | SS503873 | 15 | 6.1 | natural lake. Area is a minimum figure. |
| Upper Lliw Reservoir | River Lliw | SN661062 | water supply | ||
| Tawe Barrage | River Tawe | SS664926 | amenity | ||
| Specimen Lake | River Loughor | SN598056 | 10 | 4.0 | amenity/angling |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Blaen Bran Reservoir (lower) | Afon Lwyd | ST267971 | |||
| Coity Pond | Afon Lwyd | SO233090 | former reservoir | ||
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Cosmeston Lake | River Cadoxton | ST176692 | amenity | ||
| Hensol Lake | River Ely | ST045789 | amenity and reservoir | ||
| Hensol Mill Pond | River Ely | ST050790 | 6 | 2.4 | former mill pond |
| Lake name | Catchment | Grid ref. | Area | Satatus/Use | |
|---|---|---|---|---|---|
| Acres | Hectares | ||||
| Cae Llwyd Reservoir | River Dee | SJ270479 | 10.6 | 4.3 | |
| Chirk Castle Lake | River Dee | SJ269386 | 11.1 | 4.5 | |
| Fenn's Bank Mere | SJ505386 | 8.4 | 3.4 | ||
| Gresford Flash | River Dee | SJ346536 | 8.2 | 3.3 | amenity |
| Hanmer Mere | SJ452392 | 44.4 | 18.0 | natural lake,SSSI | |
| Monk's Pool | River Dee | SJ303448 | 5.2 | 2.1 | |
| Pant-yr-ochain Lake | River Dee | SJ349529 | 14.1 | 5.7 | |
| Penycae Top Reservoir | River Dee | SJ267452 | 6.2 | 2.5 | |
| Ty Mawr Reservoir | River Dee | SJ276480 | 21.3 | 8.6 | |
| Wynnstay Park Lake | River Dee | SJ307428 | 8.9 | 3.6 | |
Lakes and reservoirs within each of Wales' three national parks.
| Lake name | Catchment | Grid ref. | Area | Status/Use | Principal area/s | |
|---|---|---|---|---|---|---|
| Acres | Hectares | |||||
| Bosherston Lakes | Coastal stream | SR974946 | natural lakes | Pembrokeshire | ||
| Rosebush Reservoir,Rosebush | Western Cleddau | SN061291 | 30 | 12 | water supply | Pembrokeshire |
Many Welsh lakes supply the nation itself with water, however, some lakes and reservoirs supply England.[6][7]
The main reservoirs created for this purpose include:
| Reservoir name | Location | Built by | Supplies water to |
|---|---|---|---|
| Lake Vyrnwy | Powys | Liverpool Corporation | Liverpool, Cheshire and Manchester |
| Claerwen | Elan Valley reservoirs | Birmingham Corporation Water Department | Birmingham |
| Craig-goch | Elan Valley reservoirs | Birmingham Corporation Water Department | Birmingham |
| Pen-y-garreg | Elan Valley reservoirs | Birmingham Corporation Water Department | Birmingham |
| Garreg-ddu | Elan Valley reservoirs | Birmingham Corporation Water Department | Birmingham, |
| Caban-coch[8] | Elan Valley reservoirs | Birmingham Corporation Water Department | Birmingham |
| Alwen Reservoir | Conwy | The Corporation of Birkenhead | Birkenhead[9] |
| Llyn Celyn (via andLlyn Tegid) | Gwynedd | Liverpool Corporation Waterworks | Liverpool |
| Llyn Clywedog | Powys | Reed and Mallick of Salisbury | Shropshire,West Midlands toBristol |
| Lake name | Catchment | Grid ref. | Area (acres) | Status/Use | Principal area |
|---|---|---|---|---|---|
| Bryn-bach Pond[10] | Sirhowy River | SO122100 | formerly industrial use (not same site as modern lake) | Blaenau Gwent | |
| Cairn Mound Impounding Reservoir | River Clydach | SO202136 | former reservoir[11] | Blaenau Gwent | |
| Clyn-mil Pond[12] | River Taff | SO062052 | formerly industrial use | Merthyr Tydfil | |
| Glyn-dyrys Pond[13] | River Taff | SO049047 | formerly industrial use | Merthyr Tydfil | |
| Hirwaun Ponds[14] | River Cynon | SN945060 | formerly industrial use | Rhondda Cynon Taf | |
| Lower Neuadd Reservoir | River Taff | SO030180 | former reservoir (dam breached) | Merthyr Tydfil[15] | |
| Llyn Nantlle-isaf[16] | Afon Llyfni | SH506528 | natural lake | Gwynedd | |
| Pitwellt Pond | River Taff | SO078098 | former reservoir (dam breached) | Merthyr Tydfil | |
| Rhyd-y-blew Pond (Rassa) | Ebbw River | SO160112 | formerly industrial use | Blaenau Gwent | |
| Scotch Peter's Reservoir[17] | Sirhowy River | SO155088 | former reservoir | Blaenau Gwent |
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