Residents in villages near a 19th Century canal under threat of running dry fear a lack of water supply would devastate communities.
Last month, operators warned Monmouthshire and Brecon Canal could run dry in days after limits were placed on taking water from the environmentally sensitive River Usk.
Money earmarked for repairs has since been used to buy an emergency water supply from Welsh Water by the Canal and River Trust, but businesses, visitors and boat owners said a permanent solution was needed.
One pub owner called the uncertainty "insane" adding they expected to lose about 50% in customer fallout if the canal ran dry.
The Welsh government said it recognised the value of the canal but any arrangement between the Canal and River Trust, and Welsh Water would be a "commercial decision" in which it should play no role.
