The Canal and River Trust say the repairs, which are likely to cost £3m, will not be finished until mid-August, frustrating commercial operators like John Branford, who has been unable to work since December.
Mr Branford restarted freight deliveries from Hull to Leeds in September 2020 after a break of 19 years - only to be put out of action on December 20 when part of the canal wall at Newbridge gave way.
The waterways charity says contractors Kier and Arcadis are about to start work on a “permanent and complex” repair programme at the site, following the breach, which swept away a 20m section of embankment, after heavy rainfall.
The CRT’s engineers have carried out detailed inspections after a temporary dam was installed to create a dry space.
Sean McGinley, director Yorkshire & North East, said one of the biggest challenges looking after ageing waterways was climate change and the increase in extreme weather events.
As well as at Newbridge, they are also having to make major repairs to the Figure of Three Locks on the Calder & Hebble Navigation, at the cost of £3.4m.
He said: “Repairs are becoming increasingly more expensive and complex in their design, to help robustly withstand future flood events, while working under the extra restrictions and challenges created by coronavirus.
“We apologise for the disruption the breach is causing to our waterway and towpath users and we are doing everything possible to get the navigation and towpath back open as soon as possible.”
Mr Branford believes the repairs could have been completed by now, had the CRT agreed to a solution he put forward, which he claims will prevent flooding from the Dutch River in places like Fishlake.
The marine aggregates company he works with in Hull has been approached about putting more freight on the canal, but Mr Branford is unable to do anything until the repairs are done, and even then he says issues on the Aire and Calder are holding him up.
Mr Branford, 75, who captained his first barge aged 15, says he has paid out thousands on renewing licences and maintenance, but earned nothing since the breach occurred.
He said: “We just got nicely going and then we were shut down - you couldn’t make it up. It is frustrating to say the least.
“The canal’s like an obstacle course now compared to what it used to be - with rowing clubs, trees hanging over and boats moored permanently in the wrong places.
“They’ve told us we can’t have extended hours because they have to consider the residents.
“But it is a commercial navigation and we have the right to move all those hours.
“Everyone is saying they want more freight off the roads and onto canals and waterways, but they are not giving us any help.”