Over 500 properties have experienced power disruptions due to a prolonged period of heavy rain prompting flood alerts.
The Met Office has issued a yellow weather warning covering north-west England, in effect until 18:00 BST on Wednesday.
According to the forecasters, some areas may receive 50-100mm (2-4in) of rainfall, with localized amounts as high as 150-200mm (6-8in).
The National Grid reported 518 properties without electricity, with 353 homes and businesses in Carmarthen affected by a high voltage fault.
There were also a few instances of power outages reported in Ceredigion.
Additionally, Natural Resources Wales has issued nine flood warnings impacting Swansea, Carmarthenshire, and Powys.