; or (2) affects any authority of a State, as in effect on the date of enactment of this Act, to manage water resources within that State. 7. Authorization of appropriations (a) Authorization There is authorized to be appropriated to carry out the planning, design, and construction of the Musselshell-Judith Rural Water System, substantially in accordance with the cost estimate set forth in the feasibility report described in section 4(a), $56,650,000. (b) Cost Indexing The amount authorized to be appropriated under subsection (a) may be increased or decreased in accordance with ordinary fluctuations in development costs incurred after November 1, 2014, as indicated by any available engineering cost indices applicable to construction activities that are similar to the construction of the Musselshell-Judith Rural Water System.