Whenever any alley or part thereof is graded, paved, or curbed, the Director of Transportation may, if it appears advisable to the Director, provide in the statement of assessments that the payment of the amount so assessed may, at the option of the owners of the respective lots of ground assessed, be made:in equal annual payments, plus interest on the unpaid balance as the Director of Transportation, with the concurrence of the Board of Estimates, determines to be just and proper, and over a definite period of time as the Director of Transportation determines, not to exceed 5 years from the date of the delivery of the statement to the Director of Finance. The assessments so made shall be and continue liens on the respective lots of ground from the date of completion of the contract or portion thereof for the grading, paving, and curbing of such alley, or part thereof, until paid. City Code, 1950, art. 35, §56 1966, art, 26, §4 1976/83, art. 26, §4(1st par.) Ord. 45-273 Ord. 49-599 Ord. 56-644 Ord. 73-438 Ord. 15-435