I don't have a problem with that in principle. If the states along the ICW
want to allocate cost on that basis, seems to me that's a legitimate choice.
But as I say, no reason to reach into the pocket of the guy out in the
Arizona desert to pay for it.

The navigable waters of the United States are much like the Interstate Highway
system. When the guy in AZ pays his federal taxes and some of that tax money
goes to build a freeway in Wisconsin, the overall economy benefits by improved
transportation efficiencies. The $5 of the AZ taxpayer's annual bill that goes
to a federal highway project in AZ comes back, maybe, by Wisconsin cheese
costing him
$5 less per year due to savings in transportation costs.

If we get completely carried away and say that people living outside of a
certain state should never have to pay anything for a public benefit in a
neighboring state, we'd have no need for a federal government.
Heck, if Fidel Castro raised an army to invade FLA, the other 49 states could
all sit back and say, "not our problem since he hasn't invaded our state yet."
:-)