A stoppage is where a canal is impassable because something broke, burst or breached.
Some stoppages you can see coming. It's a gamble for Canal & River Trust: fix now or postpone? (See photo ALT text for examples.)
The UK's 1790s canals transported heavy or fragile goods. Now, canals mean leisure, recreation, fitness, mental health, beauty, waterside property value (tax), wildlife, eco-diversity, tourism.