By Joseph G. Ballstaedt
The answer to this question may seem to be a no-brainer. You can’t flood another person’s land, right? Well, it depends. Under Idaho law, it is generally considered trespass to enter another’s land without permission, whether the entry is walking on the land, throwing objects on the land, or allowing water to flood into the land. See Mueller v. Hill, 158 Idaho 208, 213, 345 P.3d 998, 1003. With respect to irrigating specifically, landowners can make re asonable use of their water for irrigation, but they must manage and control their water to prevent damage to their neighbors’ land. See Loosli v. Heseman, 66 Idaho 469, 478, 162 P.2d 393, 397 (1945).
However, in Idaho, a person can obtain a prescriptive easement—or a right to use another’s land—by making open, notorious, continuous, and uninterrupted use of that land for twenty years (the prescriptive period was amended from five to twenty years in 2006). See Backman v. Lawrence, 147 Idaho 390, 396, 210 P.3d 75, 81 (2009). What this means is that a landowner who has been discharging irrigation waste water onto a neighbor’s property for twenty years (or had been doing it for five years in 2006) may have a right to continuing doing so, and such use may not be trespass. See Merrill v. Penrod, 109 Idaho 46, 51, 704 P.2d 950, 955 (Ct. App. 1985).