When gravel, rock, sand, silt, or other material from any state-owned aquatic lands is removed by any public agency or under public contract for channel or harbor improvement, or flood control, use of the material may be authorized by the department for a public purpose on land owned or leased by the state or any municipality, county, or public corporation. However, when no public land site is available for deposit of the material, its deposit on private land with the landowner's permission is authorized and may be designated by the department to be for a public purpose. Prior to removal and use, the state agency, municipality, county, or public corporation contemplating or arranging the use shall first obtain written permission from the department. No payment of royalty shall be required for the gravel, rock, sand, silt, or other material used for the public purpose, but a charge will be made if the material is subsequently sold or used for some other purpose. Further, the department may authorize the public agency or private landowner to dispose of the material without charge when necessary to implement disposal of material. No charge shall be required for any use of the material obtained under the provisions of this chapter when used solely on an authorized site. No charge shall be required for any use of the material obtained under the provisions of this chapter if the material is used for public purposes by local governments. Public purposes include, but are not limited to, construction and maintenance of roads, dikes, and levies. Nothing in this section shall repeal or modify the provisions of *RCW
77.55.100 or eliminate the necessity of obtaining a permit for the removal from other state or federal agencies as otherwise required by law.