Cal. Gov. Code § 66959

If the value of any land to be purchased by the agency has been substantially reduced by any statute, ordinance, rule, regulation, or other order adopted after January 1, 1980, by state or local government for the purpose of protecting water quality or other resources in the region, the agency may purchase the land for a price it determines would assure fairness to the landowner. In determining the price to be paid for the land, the agency may consider the price which the owner originally paid for the land, any special assessments paid by the landowner, and any other factors the agency determines should be considered to ensure that the landowner receives a fair and reasonable price for the land.