Work is under way to protect properties in West Cumbria from flooding during heavy rainfall.
United Utilities is carrying out the £130,000 modernisation of Victorian sewers at Seaton, near Workington.
New pipes, up to two-and-a-half times larger than the existing ones, will be installed to ensure the system can better cope with sudden downpours.
The improvements began in Milburn Croft on Thursday and are expected to take about two months to complete.
Engineers hope to minimise disruption by feeding the new pipes in from holes at either end of the existing sewer.
Project manager Duncan Fone said: "A little inconvenience will be unavoidable but I'm sure people will agree that it's a small price to pay for the long-term benefits."