It comes after drought was declared across seven areas of England this week, following four heatwaves and one of the driest spells this century.
The BBC also reported canal users across the Midlands feared the situation was only going to get worse, with the CRT and the government both urged to do more.
Notable restrictions and closures currently affecting waterways include:
Atherstone Lock Flight, Warwickshire
Stratford-upon-Avon Canal, from Lock 22 at Lapworth to Stratford-upon-Avon
Grand Union Canal at Hatton Lock Flight, Warwick, between locks 46 and 37
Caldon Canal between Etruria and Cheddleton, Staffordshire
Trent and Mersey Canal at several points, including between Meaford Top Lock and Yard Lock, Stone
Grand Union Canal between Camp Hill Top Lock, Birmingham, and Knowle Top Lock
Wolverhampton Lock Flight
Rushall Lock Flight, Walsall
Ryders Green Lock Flight, West Bromwich
Not all closures are due to weather conditions, with some repair work making the situation even more difficult.
Seward is also on the steering group of Fund Britain's Waterways, which wants a parliamentary debate on the future of the network.
He was part of a 15-boat campaign cruise heading for Preston and Lancaster this year, which he said had been "thwarted completely by lock closures, failed locks, droughts and failed assets".
Describing his passion for boating as "all consuming", he has been on the water since he was 10 and lived through the droughts of 1975 and 1976.
"The canal infrastructure is in a far worse state than it was in the 70s and that's the problem," he explained.
"The locks leak like a sieve more or less or all over the place.
"Over the last 10 days I've seriously thought about the possibility of selling my boat, which I've had for 25 years, because I just fear for the long-term sustainability of the canal system."
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