Ditches and drains made in or through salt marshes and meadows for fencing and draining them, which are five feet wide and three feet deep, and ditches and drains in or through other meadows, which are nine feet wide at the surface of the meadow, four feet and a half wide at bottom, and three feet deep, and lie on a mud or miry bottom, shall be deemed lawful fences.
N.J.S. § 4:20-5