Maybe some kind of reasonable retrofit could be done to make them less hazardous, especially on popular rivers.
They are reworking the one on our city's main river, but it isn't a simple or cheap solution; its a 6.4 million dollar project. If you're interested, you can check out the project here:
harviepassage.caI don't know if there are cheaper or simpler solutions, but knowing our city council I'd guess there are

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