Fix your driveway, but be sure to prove that no fish can a)survive/breed in the polluted stream, and,b), can't get as far as your place because of fish barriers before your place.
Research local by-laws about emergency access to your property, and threaten to sue if emergency services can't reach your home because of the councils restrictive measures.
Good luck, and power to you in fighting the system.
PS let EVERYBODY who has a driveway over this creek know what they are in for.
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