55,000 properties in Lancaster, Morecambe, Carnforth and the surrounding area are without power following a breach of flood defences at a the main substation serving the area.
Generators are currently being delivered to key sites that are determined to be most in need but residents are being warned that power may not be restored to some areas for a number of days.
Another 4,000 properties are without power across Cumbria and new faults are still being identified due to further flooding.
Mark Williamson, operations director for Electricity North West, said: "We're continuing to work closely with the emergency services to coordinate the best response we can.
"We are prioritising generators for those most in need, including the respite centre at Salt Ayre Leisure Centre. We also have generators en route to Morecambe Fire Station to aid the emergency response. We are doing all we can and our engineers are continuing to work hard to restore power where it is safe to do so."
Electricity North West are working with Lancashire Fire and Rescue Service to monitor the situation at Lancaster's main flooded substation. It is unlikely that engineers will be able to access the substation to assess the damage until lunchtime on Sunday. Properties in Lancaster, Morecambe and the surrounding area could be without power for a number of days.
Electricity North West invested £500k on improved flood defences at the Lancaster substation in 2010 to withstand a '1-in-100-year' flood.
Electricity North West engineers have restored power to more than 12,000 properties throughout the day.
Follow @ElectricityNW on Twitter or visit www.electricitynorthwest.co.uk for updates. To get the latest flood advice and information in your area please go to the Environment Agency.
For more information about flood alerts click here and to keep up-to-date with the weather in your area visit the Met Office.
What to do in a power cut:
- Use a battery operated or wind-up torch
- Have warm clothes and blankets available
- Check on your elderly or sick neighbours and relatives
- Make sure electrical appliances, such as cookers, electric fires etc are turned off
- Join our Priority Service Register if you need extra support electricitynorthwest.co.uk/priority
- Keep your freezer and fridge door closed to prevent defrosting
- If you need any advice ring us 24/7 on 0800 195 4141 or follow @ElectricityNW
During a flood:
- If water is about to enter your property, turn off your electricity supply, but only if safe to do so
- Do not touch any electrical equipment or cables whilst you are standing in flood water
- Do not touch any electrical equipment or cables that have been immersed in flood water