MBE Rules · Real Property
Water rights — riparian vs. prior appropriation
The rule
Under the riparian doctrine (eastern states), owners of land bordering a watercourse share reasonable-use rights and cannot unreasonably interfere with other riparians. Under prior appropriation (western states), water rights go to the first person to put water to beneficial use — "first in time, first in right" — and may be lost by non-use, regardless of land ownership.
In plain English
Two competing regimes. Riparian ties water rights to owning the streambank; prior appropriation ties them to who used it first, and it need not be a landowner. Groundwater has its own overlapping doctrines (reasonable use, correlative rights, absolute ownership).
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