Availability of funds (1) In general Notwithstanding any other provision of law, any amount appropriated or otherwise made available during fiscal year 2018, 2019, 2020, or 2021 for any project relating to the construction of physical barriers, tactical infrastructure, and technology along the southern border shall remain available until expended. (2) Authorization In addition to amounts described in paragraph (1), there is authorized to be made available to carry out this Act the unobligated balances of any amount appropriated or otherwise made available during fiscal year 2022 and each year thereafter for projects described in such paragraph (1). Amounts so authorized shall be authorized to remain available until expended. (e) Use of funds Any amounts appropriated or otherwise made available for fiscal year 2021 that remain available pursuant to subsection (d) may only be used for barriers, technology, or roads that— (1) use— (A) operationally effective designs deployed as of the date of enactment of the Consolidated Appropriations Act, 2017 ( Public Law 115–31 ), such as currently deployed steel bollard designs, that prioritize agent safety