; (iii) coastal infrastructure, such as a tide gate, that is at long-term risk to sea level rise; and (iv) natural infrastructure that protects and enhances surface transportation assets while improving ecosystem conditions, including culverts that ensure adequate flows in rivers and estuarine systems. (c) Formula awards (1) Distribution of funds to States (A) In general For each fiscal year, the Secretary shall distribute among the States the amounts made available to carry out this subsection for that fiscal year in accordance with subparagraph (B). (B) Distribution The amount for each State shall be determined by multiplying the total amount made available to carry out this subsection for the applicable fiscal year by the ratio that— (i) the total base apportionment for the State under section 104(c); bears to (ii) the total base apportionments for all States under section 104(c). (2) Eligible activities (A) In general Except as provided in subparagraph (B), a State shall use funds made available under paragraph (1) to carry out activities eligible under subparagraph (A), (B), or (C) of subsection (d)(4). (B) Planning set-aside Of the amounts made available to each State under paragraph (1) for each fiscal year, not less than 2 percent shall be for activities described in subsection (d)(3). (3) Requirements (A) Projects in certain areas If a project under this subsection is carried out, in whole or in part, within a base floodplain, the State shall— (i) identify the base floodplain in which the project is to be located and disclose that information to the Secretary; and (ii) indicate to the Secretary whether the State plans to implement 1 or more components of the risk mitigation plan under section 322 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act ( 42 U.S.C. 5165 ) with respect to the area. (B) Eligibilities A State shall use funds made available under paragraph (1) for— (i) a highway project eligible for assistance under this title