The department of water resources may issue a conditional water permit for less than the amount of water requested. Except for water permits for incorporated municipalities or rural water systems, the department may not issue a permit for more water than can be beneficially used for the purposes stated in the application. Water permits for incorporated municipalities or rural water systems may contain water in excess of present needs based upon what may reasonably be necessary for the future water requirements of the municipality or the rural water system. The department may require modification of the plans and specifications for the appropriation. The department may issue a permit subject to fees for water use and conditions the department considers necessary to protect the rights of others and the public interest. The fees must be used by the department for planning, research, and administration required to regulate the allocation and appropriation of the waters of the state. Conditions must be related to matters within the department’s jurisdiction. Fees collected under this section must be deposited in the resources trust fund of the state treasury. All conditions attached to any permit issued before July 1, 1975, are binding upon the permitholder.