(A) Construction site stormwater control.
(1) During the construction process, the soil is highly vulnerable to erosion by wind and water. Eroded soil endangers water resources by reducing water quality and causing the siltation of aquatic habitat for fish and other desirable species. Eroded soil also necessitates the repair of sewers, ditches, and streams. In addition, clearing and grading during construction causes the loss of native vegetation necessary for terrestrial and aquatic habitat.
(2) As a result, the purpose of this local regulation is to safeguard persons, protect property, and prevent damage to the environment in the county. This chapter will also promote public welfare by guiding, regulating, and controlling the design, construction, use, and maintenance of any development, redevelopment, or other activity that disturbs or breaks the topsoil or results in the movement of earth on land in the county.
(B) Post-construction stormwater control.
(1) Land development projects and associated increases in impervious cover alter the hydrologic response of local watersheds and increase stormwater runoff rates, runoff volumes, flooding, stream channel erosion, and sediment transport and deposition. This stormwater runoff contributes to increased quantities of water-borne pollutants. Stormwater runoff, soil erosion, and non-point source pollution can be controlled and minimized through the regulation of stormwater runoff from development sites. Following the completion of construction activities, dust, dirt, erosion, and runoff from developed areas (parking lots, driveways, rooftops, roadways, and the like) will continue to affect the stormwater facilities and receiving streams, unless post-construction practices are implemented during construction and are maintained in perpetuity.
(2) This chapter establishes minimum stormwater management requirements and controls for the protection of the general health, safety, and welfare of the public residing in watersheds within this jurisdiction. This chapter seeks to meet that purpose through the following objectives:
(a) Minimize increases in stormwater runoff from any development to reduce flooding, siltation, increases in stream temperature, and stream bank erosion, and maintain the integrity of stream channels;
(b) Minimize increases in point and non-point source pollution caused by stormwater runoff from development that would otherwise degrade local water quality;
(c) Minimize the total annual volume of surface water runoff that flows from any specific site during and following development so as not to exceed the pre-development hydrologic regime to the maximum extent practicable; and
(d) Reduce stormwater runoff rates and volumes, soil erosion, and other source pollution, wherever possible, through stormwater management controls, and ensure that these management controls are properly maintained and pose no threat to public safety.
(BC Ord. 2024-09, passed 7-8-24)