Drought conditions are forcing British Waterways to shut almost half of the 203km Leeds and Liverpool Canal
By next month, the reservoirs which feed the canal are predicted to be at only 10% of their capacity, forcing the closure of 96km of the waterway.
The opening of locks causes loss of water so it is hoped shutting the canal to boats will help preserve its levels, and those of the reservoirs serving it, to protect wildlife and fish.
The canal will be closed to boating from Wigan, Lancashire, to Gargrave, North Yorkshire, from Monday, August 2, while the western end of the waterway will be subject to restrictions on when locks can be opened.
The water levels in the seven reservoirs which feed the canal would normally be expected to be around 80% of their capacity at this time of year, according to British Waterways, which manages 2,200 miles of canals and rivers across the country.
But with the UK experiencing the driest first six months of the year for more than 80 years, the reservoirs are now at 28% of their capacity and are expected to fall to just 10% by the beginning of August.
As a result, British Waterways said it would be forced to close off the water supply from the reservoirs to the canal using “stop planks” to better manage the impact of the dry conditions on wildlife and navigation.
The towpaths will remain open, but the organisation urged people to take extra care to stay away from the edge as water levels fall.
Vince Moran, operations director for British Waterways, said: “We have been doing all we can over the last three months to conserve water levels within what is a popular and 200-year-old working canal, and we would only close it as a last resort.”
But unless there was significant rainfall in the next fortnight, the water supply would have to be shut off, he added.