The adopted program may include an item for miscellaneous unspecified projects in a dollar amount not to exceed ten per cent of the total. The adopted program may also include a separate section for alternate projects which shall be listed in the same manner as required for regular program projects. No construction work shall be done on any alternate project until it has been authorized by resolution. Said resolution shall clearly identify the project as an alternate project, and shall specify which project or projects are being deferred or deleted in order that adequate funding be available for the alternate.