Water rights are considered to be property rights, and are often bought and sold in transactions similar to real estate. The market value of water rights is important for developing water supply. SWE has performed numerous water rights evaluations and appraisals for both buyers and sellers. Factors that affect the value of water rights must be evaluated and include the relative seniority of the water right, historical use, location, dependability of the water source, reliance on return flows by other water rights, and current market activity.