Their concerns - expressed in a series of parliamentary questions at Holyrood - echo those of canals pressure group Keep Canals Alive! and various local authority councillors.
East Dunbartonshire Council, which runs a flagsip Canals Festival, is among those seeking a solution that will keep the lifting bridge at Bonnybridge open permanently.
As revealed in the Falkirk Herald, Keep Canals Alive!, through spokesman Ronnie Rusack MBE, has urged local authorities to put pressure on quango Scottish Canals to “meet its statutory obligations”,
It fears a one-time bold vision of fully integrated canals, boosting tourism and quality of life, is being allowed to slide into decay and dereliction.
Scottish Canals argues it is doing its best in the context of a £70million repairs backlog - and that the canals are “as vibrant as ever”.
It also argues it has to use a substantial proportion of its budget on canalside investments, in order to create long term viability.
This is dismissed out of hand by Keep Canals Alive! (representing eleven different organisations), which claims the worth of these investments will be undermined by “progressive dereliction”.
The Scottish Conservatives say the SNP Government has failed to satisfactorily answer concerns, and that “dozens” of boat trips have been cancelled.
Central Scotland list MSP Alison Harris said: “The death of the direct link between Scotland’s two biggest cities - made possible by the multi-million pound construction of the Falkirk Wheel - is a huge wasted opportunity.
She said a Freedom of Information request revealed 35 cancellations by holiday hire fleets since the closurfe of canal sections in Bonnybridge and Twechar.
Ms Harris claims the Scottish Government “hasn’t bothered” maintaining the Glasgow-Edinburgh route, adding that its claimed inaction amounts to “a slap in the face to communities in central Scotland”.
East Dunbartonshire councillor Alan Moir said “We need to get answers quickly on what is going on with the future funding and maintenance of the Canal.
“The closure of two road bridges at Twechar and Bonnybridge gives us all concerns about the immediate and longer term effects on the economic, social and environmental impact to East Dunbartonshire and the neighbouring local authorities.
“It is outrageous that it is only 17 years since £78.4m was invested on the Millennium Link project to have the Canal reopened, and to now have years of continued hard work including voluntary contributing to the success of the Canal being undermined is completely unacceptable.”