canal dues

例句：

1. 1. The city has a mandatory canal dues system for its waterways.
   该市对水道实施强制性的运河税制度。
2. 2. The farmers have to pay canal dues to maintain their fields.
   农民们必须支付运河税来维护他们的田地。
3. 3. The construction of the new canal will require significant canal dues.
   新运河的建设将需要大量的运河税。