N.Y. TWN Law § 300

§ 300. Apportionment of division fence. Each owner of two adjoining\ntracts of land, except when they otherwise agree, shall make and\nmaintain a just and equitable portion of the division fence between such\nlands, unless both of said adjoining owners shall agree to let their\nsaid lands lie open, along the division line, to the use of all animals\nwhich may be lawfully upon the lands of either; provided, however, that\nthe owner of an adjoining tract of land who does not keep such animals\nthereon within five years of the date of the erection or repair of a\ndivision fence shall not be obligated or liable for erecting,\nmaintaining or repairing such a division fence under this article.\nUnless otherwise agreed, an adjoining owner who erects or repairs a\ndivision fence shall be entitled to recover from the owner of the other\nadjoining tract, twenty percent of the proportionate cost thereof\notherwise ascribable to such other owner for each year or part thereof\nin which the other adjoining tract is regularly used for keeping animals\noccurring within five years of the date of such erection or repair. When\nthe adjoining lands shall border upon any of the navigable lakes,\nstreams or rivers of the state, the owners of the lands shall make and\nmaintain the division fence between them down to the line of low water\nmark, in such lakes, streams or rivers except those lands which overflow\nannually so as to be so submerged with water that no permanent fence can\nbe kept thereon, and known as low flat lands; and when adjoining lands\nshall be bounded by a line between the banks of streams of water not\nnavigable, and the owners or occupants thereof cannot agree upon the\nmanner in which the division fence between them shall be maintained, the\nfence viewers of the town shall direct upon which bank of the stream,\nand where the division fence shall be located, and the portion to be\nkept and maintained by each adjoining owner.\n