Chapter 17.56
DRAINAGE
Sections:
17.56.010 Applicability.
The development standards for surface water drainage shall apply to all new or redevelopment activities in the City of Gladstone that result in the creation or disturbance of 5,000 square feet or more impervious surface except for substantial improvement or lesser remodel or reconstruction of existing single-family or two-family dwellings.
Statutory Reference: ORS Ch. 197 and 227
History: Ord. 1131 §2, 1990, Ord. 1419, 2009.
17.56.020 Standards.
Adequate provisions shall be made to ensure proper drainage of surface waters, to preserve natural flow of watercourses and springs and to prevent soil erosion and flooding of neighboring properties or streets. Such provisions shall include but not be limited to the following:
(1) Generally. All development shall be planned, designed, constructed and maintained to:
(a) Protect and preserve existing drainage channels to the maximum practicable extent;
(b) Protect development from flood hazards;
(c) Provide a system by which water within the development will be controlled and managed without causing damage or harm to the natural environment, or to property or persons within the drainage basin;
(d) Assure that waters drained from new or redevelopment sites are substantially free of pollutants, including sedimentary materials, through the use of stormwater treatment facilities as referenced herein and appropriate erosion and sediment control practices;
(e) Assure that runoff drained from new and redevelopment sites is managed in accordance with criteria outlined in the City of Gladstone Stormwater Treatment and Detention Standards as to not cause erosion to any greater extent than would occur in the absence of development;
(f) Avoid placement of surface detention or retention facilities in road rights of way.
(2) Watercourses. Where culverts cannot provide sufficient capacity without significant environmental degradation, the city may require the watercourse to be bridged or spanned.
(3) Easements. In the event that a development or any part thereof is traversed by any watercourse, channel, stream or creek, gulch or other natural drainage channel, adequate easements for storm drainage purposes shall be provided to the city. This does not imply maintenance by the city.
(4) Obstructions. Channel obstructions are not allowed, except as approved for the creation of a detention or retention facility. Fences with swing gates may be utilized.
(5) Surface Drainage and the Storm Sewer System.
(a) Stormwater treatment and detention facilities shall be designed and installed in accordance with criteria outlined in the Gladstone Public Works Design Standards and the Gladstone Public Works Standard Construction Specifications.
(b) The street cross-sections found in the Gladstone transportation system plan may be modified to accommodate alternative stormwater management methods subject to the approval of the Public Works Supervisor. The Public Works Supervisor may require modification of the typical cross section to accommodate alternative stormwater management methods when associated with development proposals. Such modifications may be applied as conditions of development approval.
Statutory Reference: ORS Ch. 197 and 227
History: Ord. 1131 §2, 1990, Ord. 1419, 2009; Ord. 1483 §2 (Exh. 5), 2017.