18-29-1101.2.3 Storm runoff.

   Construction which is tributary to the combined sewer system of the city of Chicago shall be designed to minimize and/or delay runoff inflow contributions to the combined sewer system in accordance with the following:

   1.   Disconnection. For sites of 5,000 square feet (1,524 m2) in area and smaller, except multiple unit developments, storm runoff will be minimized or delayed by the disconnection of downspouts, temporary or otherwise, in accordance with Section 18-29-1101.2.1 and any other applicable sections of this chapter and the department of water management design standards.

   2.   Detention. For sites greater than 5,000 square feet (1,524 m2), and multiple unit developments, storm runoff shall be detained in accordance with, and is required by, the department of water management design standards. The release rate of detained storm runoff shall be managed on the available capacity of the combined storm sewer system as determined by the department of water management.

(Amend Coun. J. 3-27-02, p. 82090, § 3; Amend Coun. J. 11-8-12, p. 38872, § 375)

18-29-1101.3 Prohibited drainage.

   Storm water shall not be drained into sewers intended for sewage only.

18-29-1101.4 Tests.

   The conductors and the building storm drain shall be tested in accordance with Sections 18-29-312.1 through 18-29-312.9.

18-29-1101.5 Continuous flow.

   The size of a drainage pipe shall not be reduced in the direction of the flow.

(Amend Coun. J. 11-8-12, p. 38872, § 376)

18-29-1101.6 Fittings and connections.

   All connections and changes in direction of the storm drainage system shall be made with approved drainage-type fittings in accordance with Table 18-29-706.3. The fittings shall not obstruct or retard flow in the system.

18-29-1101.7 Roof design.

   Roofs shall be designed for the maximum possible depth of water that will pond thereon as determined by the relative levels of roof deck and overflow weirs, scuppers, edges or serviceable drains in combination with the deflected structural elements. In determining the maximum possible depth of water, all primary roof drainage means shall be assumed to be blocked.

(Amend Coun. J. 10-14-21, p. 37722, Art. XI, § 2)

18-29-1101.8 Cleanouts required.

   Cleanouts shall be installed in the storm drainage system and shall comply with the provisions of this chapter for sanitary drainage pipe cleanouts or as required by the department of water management design standards.

(Amend Coun. J. 3-27-02, p. 82090, § 3; Amend Coun. J. 11-8-12, p. 38872, § 377)

18-29-1101.9 Backwater valves.

   Backwater valves installed in a storm drainage system shall conform to Section 18-29-715.