By Ellie Roxburgh, Policy and Advocacy Manager
Plaid Cymru takes the Senedd
For the first time since devolution, a new party holds the reins in the Senedd. Plaid Cymru won the election with 43 seats, followed by Reform with 34.
As expected, the election was very much a two-party race, with Labour, the Greens and the Liberal Democrats doing somewhat worse than polls had predicted. Labour now holds 9 seats, Conservatives have 7, Greens have 2 and Lib Dems have 1.
Plaid falls short of the 49 seats needed for a majority, but with other parties doing worse than expected, they have limited options with whom to form a coalition. Labour and Plaid are unlikely to find common ground on much, given that Plaid just ousted the long-standing party. Reform and the Conservatives together make a substantial opposition, but we are yet to see if they will work together. Prior to the election, the Conservatives leader, Kemi Badenoch, indicated they would not work with any party that is not delivering, and that “the only deal we’re doing is a deal with the Welsh people”, which could be inferred as an alliance with Plaid over Reform.
In his victory speech on Saturday, Rhun ap Lorweth announced that Plaid will be seeking a minority government. He has now been announced as First Minister of Wales, supported by the two Green Party members.
Plaid Cymru yn cipio’r Senedd
Am y tro cyntaf ers datganoli, mae plaid newydd wrth y llyw yn y Senedd. Plaid Cymru enillodd yr etholiad gyda 43 sedd, wedyn Reform UK gyda 34.
Yn ôl y disgwyl, ras dau geffyl oedd yr etholiad hwn, gyda Llafur, y Gwyrddion a’r Democratiaid Rhyddfrydol yn gwneud fymryn yn waeth nag yr oedd y polau piniwn wedi’i ddarogan. Mae gan Lafur 9 sedd erbyn hyn, y Ceidwadwyr 7, y Gwyrddion 2 a’r Democratiaid Rhyddfrydol 1.
Mae Plaid ychydig yn brin o’r 49 sedd sydd eu hangen ar gyfer mwyafrif, ond gyda phleidiau eraill yn gwneud yn waeth na’r disgwyl, cyfyngedig yw’r opsiynau o ran ffurfio clymblaid. Go brin y bydd Llafur a Plaid yn canfod llawer o dir cyffredin ar lawer, o gofio bod Plaid newydd sgubo’r blaid hirsefydlog o rym. Mae Reform a’r Ceidwadwyr yn bresenoldeb gwrthbleidiol sylweddol, ond dydyn ni ddim eto’n gwybod a fyddan nhw’n cydweithio. Cyn yr etholiad, roedd arweinydd Ceidwadwyr Prydain, Kemi Badenoch, wedi dweud na fydden nhw’n gweithio gydag unrhyw blaid nad yw’n cyflawni, gan nodi “the only deal we’re doing is a deal with the Welsh people”, a allai awgrymu cynghreirio gyda Plaid Cymru yn hytrach na Reform.
Yn ei araith ddydd Sadwrn, cyhoeddodd Rhun ap Iorwerth y bydd Plaid Cymru yn ceisio ffurfio llywodraeth leiafrifol. Mae bellach wedi’i gyhoeddi’n Brif Weinidog Cymru, gyda chefnogaeth dau aelod y Blaid Werdd.

What will Plaid do for Welsh rivers?
In 2025, six of the ten UK constituencies with the highest combined sewage overflows were in Wales, cumulating to over 415,000 hours of pollution. Last year, Natural Resources Wales (NRW) announced that seven out of nine protected rivers are failing Good Ecological Status due to phosphorus pollution. Salmon are expected to disappear completely from some Welsh rivers by 2030.
However, while Plaid Cymru’s manifesto offered positive steps towards tackling environmental issues, rivers were notably absent from their first 100 days pledge, launched during the Parties’ Conference in February. Yet with wider water reforms from Westminster imminent, Plaid Cymru will need to outline its position on addressing river pollution.
Beth fydd Plaid Cymru yn ei wneud dros afonydd Cymru?
Yn 2025, roedd chwech o’r deg etholaeth yn y DU gyda’r lefelau uchaf o orlif carthffosiaeth gyfun yng Nghymru, gan gronni dros 415,000 awr o lygredd. Y llynedd, cyhoeddodd Cyfoeth Naturiol Cymru (CNC) fod saith o bob naw afon warchodedig yn methu â chyrraedd Statws Ecolegol Da, dynodiad a bennwyd gan ddeddfwriaeth yr UE, yn sgil llygredd ffosfforws. Mae’r dirywiad mewn bywyd gwyllt yn arwydd o hyn, gyda disgwyl i’r eog ddiflannu’n llwyr o rai afonydd Cymru erbyn 2030.
Ond er bod maniffesto Plaid Cymru yn cynnig camau cadarnhaol tuag at fynd i’r afael â materion amgylcheddol, roedd afonydd yn amlwg absennol o’u haddewid 100 diwrnod cyntaf, a lansiwyd yng nghynhadledd y Blaid ym mis Chwefror. Ond gyda diwygiadau dŵr ehangach ar y gweill o du San Steffan, bydd angen i Plaid Cymru amlinellu ei safbwynt ar fynd i’r afael â llygredd afonydd.

Closing the regulatory gap on river pollution
Westminster is expected to announce new legislation to clean up rivers tomorrow (Wednesday 13th May) in the King’s Speech through the ‘Water Reform Bill’. The UK Government has indicated its intention to create a new integrated regulator for the water sector, combining Ofwat, the Drinking Water Inspectorate and some functions of the Environment Agency, with implications for the regulation of Welsh water companies. While Plaid has committed to seeking full devolution of powers over water, interim processes for interaction with NRW will need to be established. This could be a timely opportunity for Plaid to take action on NRW, the Welsh environmental regulator, which is widely recognised as not fit for purpose.
NRW as it currently operates is limited in impact, in part due to a lack of resourcing, but also a failure to implement an effective strategy for reducing pollution from both agricultural sources and the water sector.
One area that River Action has identified is the process by which NRW deals with pollution from industrial livestock. As it stands, NRW has chosen to ‘wash its hands’ of pollution by failing to take into account the environmental impact of manure once it leaves the farm boundary. Any reform of NRW must ensure that, as a regulator, it acknowledges and uses its full powers to act, including placing conditions on permits or refusing them where pollution risks cannot be properly controlled.
Cau’r bwlch rheoleiddio ar lygredd afonydd
Mae disgwyl i San Steffan gyhoeddi deddfwriaeth newydd i lanhau afonydd heddiw (dydd Mercher 13 Mai) yn Araith y Brenin drwy’r ‘Bil Diwygio Dŵr’. Mae Llywodraeth y DU wedi nodi ei bwriad i greu rheoleiddiwr integredig newydd ar gyfer y sector dŵr, gan gyfuno Ofwat, yr Arolygiaeth Dŵr Yfed a rhai o swyddogaethau Asiantaeth yr Amgylchedd, gyda goblygiadau i reoleiddio cwmnïau dŵr Cymru. Er bod Plaid wedi ymrwymo i geisio datganoli pwerau dros ddŵr yn llawn, bydd angen sefydlu prosesau interim ar gyfer rhyngweithio â CNC. Gallai hyn fod yn gyfle amserol i Plaid fynd i’r afael â CNC, rheoleiddiwr amgylcheddol Cymru, sy’n cael ei gydnabod yn eang fel un nad yw’n addas i’r diben.
Mae CNC fel y mae ar hyn o bryd yn gyfyngedig o ran effaith, yn rhannol oherwydd diffyg adnoddau, ond hefyd yn sgil methiant i weithredu strategaeth effeithiol ar gyfer lleihau llygredd o ffynonellau amaethyddol a’r sector dŵr.
Un maes a nodwyd gan River Action yw’r broses lle mae CNC yn delio â llygredd da byw diwydiannol. Fel y mae pethau ar hyn o bryd, mae CNC wedi dewis ‘golchi ei ddwylo’ ar lygredd trwy fethu ag ystyried effaith amgylcheddol tail ar ôl iddo adael ffiniau’r fferm. Rhaid i unrhyw broses o ddiwygio CNC sicrhau ei fod, fel rheoleiddiwr, yn cydnabod ac yn defnyddio ei bwerau llawn i weithredu, gan gynnwys gosod amodau ar drwyddedau neu eu gwrthod lle nad oes modd rheoli risgiau llygredd yn iawn.

What about the water companies?
Plaid’s manifesto set out a commitment to set up a new Welsh water regulator, with powers to set price controls, limit bonuses, and direct capital investment to reduce sewage spills, upgrade infrastructure and make environmental improvements.
While better regulation is certainly part of the solution, the ability of water companies to prioritise financial returns over customers and the environment remains a fundamental issue. As a not-for-profit, Dwr Cymru Welsh Water can still pay executives and bondholders high amounts. Although it does have lower bills than many English water companies and fewer pollution incidents, it continues to contribute to unacceptable levels of environmental pollution.
Plaid has also committed to setting out pathways towards the nationalisation of Welsh Water. Public ownership would help address the issue of financial extraction from essential water services. There are also other alternatives, such as municipally ownership, or community-interest models, which could attract the investment needed while prioritising environmental protection and public benefit. Whatever structure is chosen, water companies and the regulator should have a statutory duty to prioritise the environment and public health.
It is now up to this new Senedd Government to decide whether stronger regulation alone will set the Welsh water sector on a path to environmental recovery, or whether more fundamental structural reform of Dwr Cymru Welsh Water is needed to stop the pollution of Welsh rivers and waterways.
Beth am y cwmnïau dŵr?
Roedd maniffesto Plaid yn nodi ymrwymiad i sefydlu rheoleiddiwr dŵr newydd yng Nghymru, gyda phwerau i osod rheolaethau prisiau, cyfyngu ar fonysau, a buddsoddiad cyfalaf uniongyrchol i leihau achosion o ollwng carthffosiaeth, uwchraddio’r seilwaith a gwneud gwelliannau amgylcheddol.
Er bod rheoleiddio gwell yn rhan o’r ateb heb os, mae gallu cwmnïau dŵr i flaenoriaethu enillion ariannol dros gwsmeriaid a’r amgylchedd yn parhau’n broblem sylfaenol. Fel sefydliad nid-er-elw, mae gan Dŵr Cymru filiau is na llawer o gwmnïau dŵr yn Lloegr a llawer llai o achosion llygredd, ond mae’n parhau i gyfrannu at lefelau annerbyniol o lygredd amgylcheddol.
Mae Plaid hefyd wedi ymrwymo i fraenaru’r tir tuag at wladoli Dŵr Cymru. Byddai perchnogaeth gyhoeddus yn helpu i fynd i’r afael â’r mater o echdynnu arian o wasanaethau dŵr hanfodol. Mae yna ddewisiadau amgen eraill hefyd, megis perchnogaeth fwrdeistrefol, neu fodelau buddiannau cymunedol, a allai ddenu’r buddsoddiad sydd ei angen gan flaenoriaethu diogelu’r amgylchedd a budd y cyhoedd. Pa bynnag strwythur gaiff ei ddewis, dylai cwmnïau dŵr a’r rheoleiddiwr fod â dyletswydd statudol i flaenoriaethu’r amgylchedd ac iechyd y cyhoedd.
Mater i’r Llywodraeth newydd hon yn y Senedd yw penderfynu a fydd rheoleiddio cryfach ar ei ben ei hun yn gosod sector dŵr Cymru ar drywydd adferiad amgylcheddol, neu a oes angen diwygio strwythurol mwy sylfaenol ar Dŵr Cymru er mwyn atal llygredd afonydd a dyfrffyrdd Cymru.











