1. Short title This Act may be cited as the Stop the Spread of Invasive Mussels Act of 2020 . 2. Bureau of Reclamation assistance (a) Definitions In this section: (1) Aquatic invasive species The term aquatic invasive species has the meaning given the term aquatic nuisance species in section 1003 of the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 ( 16 U.S.C. 4702 ). (2) Reclamation State The term reclamation State has the meaning given the term in section 4014 of the Water Infrastructure Improvements for the Nation Act ( 43 U.S.C. 390b note; Public Law 114–322 ). (3) Secretary The term Secretary means the Secretary of the Interior, acting through the Commissioner of Reclamation. (b) Watercraft inspection in reclamation states The Secretary shall provide financial assistance to a reclamation State to prevent the spread of aquatic invasive species into and out of reservoirs operated and maintained by the Secretary, including financial assistance to purchase, establish, operate, or maintain a watercraft inspection and decontamination station that has the highest likelihood of preventing the spread of aquatic invasive species at reservoirs operated and maintained by the Secretary, if the Secretary determines that the financial assistance is— (1) necessary; and (2) in the interests of the United States. (c) Cost share The non-Federal share of the cost of purchasing, establishing, operating, and maintaining a watercraft inspection and decontamination station (including a non-Federal watercraft inspection and decontamination station) under subsection (b), including personnel costs, shall be— (1) not less than 50 percent