The Department has created and maintains a database of the amount of surface water available for allocation for most of the waters of the state. The database is used to evaluate applications for new uses of surface water. Water availability is the amount of water that can be appropriated from a given point on a given stream for new out-of-stream consumptive uses. It is obtained by subtracting existing in-stream water rights and out-of-stream consumptive uses from the natural stream flow.