Title 15 - Public Improvements

15.10 Stormwater Management Program - Standards and Permitting

15.10.200 Methods of Conveying Stormwater.

As required by Section 13.10.020, the City Engineer will adopt, maintain and make available the Standards for methods of conveyance for stormwater, except for building roof drains which are regulated by the currently adopted version of the International Building Code. Additionally, 18.365 establishes City criterion for protecting natural streams and Section 18.365.030 provides specific exceptions which allow storm sewer improvements.

Methods of conveying stormwater vary, depending on the natural watershed size. Watersheds with tributary areas less than 40 acres may utilize the natural stream OR underground storm sewers combined with overland flow. Watersheds with tributary areas greater than 40 acres shall utilize the natural stream for stormwater conveyance. When the watershed’s tributary area is greater than 40 acres, underground storm sewer systems may be authorized only when one of the following is met:

  1. A.
    18.365 criterion provides relief from dedication of a stream corridor.
  2. B.
    The project qualifies for an exception in Section 18.365.030.
  3. C.
    A deviation is granted, as provided in Section 18.365.100.

Engineered channels and/or relocating natural streams are not approved methods of conveyance for stormwater; however, the City Engineer may adopt standards for these methods of conveyance for use under the following conditions:

  1. A.
    A deviation, as specified in Section 18.365.100, is granted.
  2. B.
    A variance may be granted by the Governing Body when the Section 18.365.100 deviation process does not apply.
  3. C.
    In an RE District, if the watershed is less than 40 acres and the channel is outside of street right-of-way, an engineered channel is allowed. In addition to the setback requirements established in 18.365, no building shall take place within 60 feet of the centerline of any channel in the RE District.
  4. D.
    A natural conveyance swale, or similar facility permitted for conveying stormwater ​​​​​​​is designed as an integral part of a stormwater treatment facility. Limitations for usage, locations and building setbacks for such facilities are provided in the Stormwater Treatment Standards as set forth under 16.210 of this Code.

(History: Ord., SWM-3426 §1, 2024; ​​​​​​​Ord. SWM-2853 §3, 2010; SWM-2668 §3, 2008; SWM-2505 §1, 2004; SDR-2390 §1, 2002; SDR-2192 §9, 2000; SDR-1820 §1, 93; SDR-1612 §1, 89; SDR-1558 §1, 88; SDR-1340 §2, 85; SDR-1275 §7, 84; SDR-703 §3-8, 72; SDR-349,B §3-8, 71; SDR-349 §3-8, 65)

Effective on: 1/1/1901