Every bridge across the Ohio River hereafter erected or commenced, wholly or in part within the jurisdiction of this state, contrary to the provisions of the two next preceding sections, and every railroad bridge across the Great Kanawha or Big Sandy River hereafter erected or commenced, wholly or in part within the jurisdiction of the state, contrary to the provisions of said sections, shall be deemed a public nuisance, and, so far as the same is within the said jurisdiction, may be abated and the construction thereof prevented and enjoined by presentment, indictment, or bill in equity in the name of the state or other remedy appropriate to the case; and it shall be the duty of the Attorney General, as well as of the prosecuting attorney of the proper county, to cause proper proceedings to be instituted and prosecuted to abate, prevent and enjoin such work, as soon as they shall be credibly informed that the same has been or is about to be commenced. But the provisions of this and the preceding sections shall not apply to the portion of the Great Kanawha above the falls of said river, known as the falls of the Kanawha.