New development or redevelopment projects located within the city limits shall meet the following minimum requirements:

No. 1 – Preparation of a Storm water Site Plan: Storm water facilities shall be shown on the site plan. For complicated developments, a separate storm water site plan shall be prepared to adequately depict the proposed storm water improvements. To the maximum extent practicable, all runoff shall be retained and disposed of on site. Where subsurface conditions do not allow the use of infiltration as a treatment and disposal method, other methods will be considered. When runoff must exit the site, the runoff rate shall not exceed the rate of runoff from pre-developed conditions and appropriate BMPs shall be utilized.

No. 2 – Erosion and Sediment Control: Sediment and erosion control shall be provided for land-disturbing activities. Exposed soils shall be stabilized to prevent erosion and sediment transport by either wind or water. The plan may be pictorial or narrative and shall include all BMPs proposed for erosion and sediment control. For projects meeting the state regulatory threshold, a storm water pollution prevention plan (SWPPP) shall be prepared.

No. 3 – Construction Access: Access shall be limited to one route. Access points shall be stabilized with quarry spall or crushed rock to minimize the tracking of sediment and pollutants onto roads.

No. 4 – Source Control BMPs: Source control BMPs shall be implemented to remove pollutants from the storm water. Source control BMPS are described in Chapter 8 of the Storm water Management Manual for Eastern Washington. Typically, source control BMPs are needed on sites that generate pollutants that cannot be removed using runoff treatment BMPs.

No. 5 – Runoff Treatment BMPs: All projects shall provide approved treatment of storm water before the water leaves the project property via infiltration or as surface runoff. At a minimum, sediment removal shall be provided prior to infiltration, and basic treatment BMPs, as defined in the Storm water Management Manual for Eastern Washington, shall be utilized for all projects discharging directly or indirectly to surface water that create five thousand square feet of pollutant-generating impervious surface area. All subsurface infiltration systems subject to the UIC requirements shall be registered with the state of Washington.

No. 6 – Preservation of Natural Drainage Systems: Natural drainage systems and runoff patterns shall be maintained, and upstream flows allowed to pass through the site at the rate and volume existing before site development. If discharge is required from a site, it shall not exceed the discharge rate for the pre-developed conditions and shall occur at its natural location.

No. 7 – Streambank Erosion Control: Erosion control shall be provided when storm water is discharged directly or indirectly to a stream or waterway.

No. 8 – Off-Site Analysis and Mitigation: All projects located on or adjacent to a waterway shall examine impacts one-quarter-mile downstream from their site and shall mitigate impacts of the development.

No. 9 – Protection of Adjacent Properties: Appropriate BMPs shall be used to protect adjacent properties from sediment deposition and from damage due to runoff from the developed site.

No. 10 – Water Quality Sensitive Areas: When determined by the city, more stringent controls will be imposed in water quality sensitive areas. For example, additional runoff treatment may be required when infiltration systems are used in wellhead protection areas.

No. 11 – Basin Plans: Basin plans may be developed and implemented to address storm water problems over larger areas, rather than addressing problems on a parcel-by-parcel basis. The level of protection shall be equal to or greater than if only the minimum requirements were imposed on a parcel-by-parcel basis.

No. 12 – Operation and Maintenance: For all storm water facilities located on private property, an operation and maintenance schedule shall be provided for all proposed storm water facilities and BMPs, and the party (or parties) responsible for maintenance shall be identified. After completion, all BMPs shall be regularly inspected and maintained.

No. 13 – Financial Liability: Performance bonding or other appropriate financial instruments shall be required for all projects constructing public storm water facilities to assure compliance with the storm water standards.

No. 14 – Other BMPs: The city may require that other BMPs be used to mitigate the effects of increased runoff and to improve storm water quality. (Ord. 1799, § 1, 2010.)