Any county or Baltimore City, or any municipality of the State of Maryland, in addition to the powers which it may now have, is hereby authorized to enter into any agreements or contracts with the United States or any agency thereof, public drainage association, public watershed associations and other groups or agencies, including without limitation agreements, contracts, and obligations of repayment pursuant to the area redevelopment program (42 U.S.C. §§ 3161 and 3162), in constructing, erecting, financing, maintaining, using or operating any works of improvement.