Harbor Maintenance Act of 2013 - Requires the total budget resources for expenditures from the Harbor Maintenance Trust Fund for harbor maintenance programs to equal the level of receipts plus interest credited to such Fund for that fiscal year. Limits the use of such resources to such programs only.
Declares that it shall be out of order in the House of Representatives or the Senate to consider any bill, joint resolution, amendment, motion, or conference report that would cause total budget resources for the Fund in a fiscal year for harbor maintenance programs to be less than the level of receipts plus interest credited to the Fund for that fiscal year.