Water shortages will see the Leeds and Liverpool Canal completely put out of commission from Monday.
Lack of rainfall has been blamed for tougher restrictions being introduced for the waterway from the bottom locks, in Wigan, to Gargrave, near Skipton.
Last week the Wigan Post reported how boaters were being told that they could only gain access to the Wigan Flight first thing in the morning and lunchtime.
But the ongoing dry spell, even though it has been broken up by some showers over the past week, has led to the Canal and River Trust imposing curbs over a 55-mile stretch from Greater Manchester to North Yorkshire.
A trust spokesman added: “It’s not clear how long the closure will last for but it’s likely to be throughout August and potentially beyond if there is no significant, sustained rainfall.
“While the closure will prevent use of that stretch of canal by boats the towpath will remain open for visitors and the local community alike to enjoy.”
Some parts of the canal network have only seen 30 per cent of the expected rainfall during the months of May and June.
Jon Horsfall, the trust’s head of customer service support, added: “Despite the prolonged dry weather and current heatwave the vast majority of our 2,000 mile network is available for boaters and holiday makers to enjoy as normal but some very localised parts of our network in the north west are starting to feel the heat.
In particular the reservoirs which feed the summit of the Leeds and Liverpool Canal have seen very little rainfall over the past few months.
“So we’ve been monitoring the situation closely and working with boaters and boating businesses to make best use of the available water.
“We’ve taken the decision to temporarily close part of the canal to boats very reluctantly and can assure everyone on that stretch of the canal that we’ll reopen for navigation as soon as we possibly can.”
Further restrictions, affecting the Leigh branch and Lock 88 (Pagefield) and Lock 89 (Ell Meadow), have been in place since mid-March and are also likely to continue for the foreseeable future.