there is high variability across the basin in terms of supply and demand for these different types of rights so they follow regional and local trading rules under the basin plan and the basin states water sharing plans in this way the market operated both to maximize the market value of irrigated production and to ration scarce water between competing uses without the need for government intervention reliability refers to the average frequency based on historical records and forecast future water availability with which water allocated under a water access entitlement can be supplied in full