Around 55,000 homes in Lancaster were left without power this weekend after an electricity substation flooded due to a storm.
It happened at around 11pm on Saturday and all supplies were restored this morning.
Engineers were only able to access the substation in Caton Road at 11am on Sunday after it had been “fully submerged”.
Electricity North West invested £7.9 million in flood defences at major sites during the past few years, including Lancaster substation, to protect them against ‘once-in-100 years’ floods.
More than 60 generators have been delivered to key sites and installed to restore power.
In a statement the distribution network operator said: “Those customers who are on a generator are not expected to lose power again but might experience a short outage for a couple of minutes when engineers put them back on main supply.”
The power company tweeted: “Engineers are still working hard at our
#Lancaster substation assessing damage caused by severe flooding.”
Environment Secretary Elizabeth Truss said: “Our thoughts are with those still affected by flooding this morning.
“Flood defences protected 8,600 homes across the north of England and in thousands of other instances, provided vital time for homes and businesses to be evacuated as well as reducing the impact.
“However unprecedented rain and river levels mean we have seen water overtopping defences in places.”
Earlier this year a lighting company showed ELN a bright way of not being left in the dark during blackouts.
People in the UK can dial 105 to report a power cut from April next year.