In a “legal” sense, the beavers have more inherent, natural and prescriptive “right and rights” to the area than either the people or the dogs,
As beavers were there first, people and dogs should thus use the area at their own risk and the city and province is thus not liable to damages and claims if people won’t leash and control their dogs.
The beavers are legal and natural tenants and squatters on the land and have the natural and prescriptive rights there of, preceding the legal status and effects even of the city and province perhaps, not to mention the maternal, innate and natural rights of mothers or fathers protecting the offspring.
The remedy perhaps would be to give proper notice (signage) in the area of the danger, risks and rights of the beavers and the risk to people and or their dogs and perhaps impose a $500 fine for unleashed pets.
The habitat to run dogs is easier to find than the habitat to support beavers.
As well, the beavers provide natural services provide to the area and its ecosystem, which is not recognized or paid for or compensation made to the beavers.
Actually I would encourage the beavers to sue and petition the city or province for violation and abuse of their rights and their property and person and forfeiture of payment for their natural services to the ecosystem in the area.