N.Y.C. Admin. Code § 24-515: § 24-515 Overflow sewers; where discharged.

a. All overflow sewers deemed necessary for the relief of any main sewers may be discharged into the Gowanus canal or any other canal or inlet within, or water adjacent to, the city.

b. The city shall keep all canals free of any obstruction that may be occasioned by the discharge of such overflow sewers into them. For that purpose, the commissioner of environmental protection shall dredge the same from time to time.