Environment & Sustainability | Surface Water Management (Title 13)
37. Land disturbing activity. An activity that results in a change in the existing soil cover, both vegetative and nonvegetative, or to the existing soil topography. “Land disturbing activity” includes, but is not limited to, demolition, construction, clearing, grading, filling, excavation and compaction. “Land disturbing activity” does not include tilling conducted as part of agricultural practices, landscape maintenance or gardening. 38. Landslide hazard drainage areas. Critical drainage areas where overland flows pose a significant threat to health and safety because of their close proximity to a landslide hazard area as defined by SDC 21.04.040B.191. Landslide hazard areas are also considered landslide hazard drainage areas. Mapped landslide hazard drainage areas are approximate. Public works may determine that areas not mapped as landslide hazard drainage areas may meet this definition. 39. Land use code. Restrictions on the type of development for a specific parcel of land as identified by records maintained by the City of Sammamish as modified or supplemented by information resulting from investigation by the division. Land use codes are preliminary indicators of the extent of impervious surface and are used in the initial analysis to assign an appropriate rate category for a specific parcel. 40. Lake management plan. A plan describing the lake management recommendations and requirements adopted by public rule for managing water quality within individual lake basins. Adopted lake management plans are available from the department. 41. Large project drainage review. The evaluation required by SDC 21.03.050D. for any proposed project that:
excluding pedestrian or bicycle use improvement projects.
34. Hydraulically connected. Connected through surface flow or water features such as wetlands or lakes. 35. Impervious surface. A hard surface area that either prevents or retards the entry of water into the soil mantle as under natural conditions before development; or that causes water to run off the surface in greater quantities or at an increased rate of flow compared to the flow present under natural conditions prior to development (see also “new impervious surface”). Common impervious surfaces include, but are not limited to, roofs, walkways, patios, driveways, parking lots, or storage areas, areas that are paved, graveled or made of packed or oiled earthen materials or other surfaces that similarly impede the natural infiltration of surface water or stormwater. For the purposes of applying the impervious surface thresholds and exemptions contained in the Surface Water Design Manual, permeable pavement, vegetated roofs, and pervious surfaces with underdrains (such as artificial turf) designed to collect stormwater runoff are considered impervious surfaces while an open uncovered flow control or water quality facility is not. However, for the purposes of computing runoff, uncovered flow control or water quality facilities shall be modeled as impervious surfaces as specified in Chapter 3 of the Surface Water Design Manual. 36. Improvement. A permanent, human-made, physical change to land or real property including, but not limited to, buildings, streets, driveways, sidewalks, crosswalks, parking lots, water mains, sanitary and storm sewers, drainage facilities and landscaping.
Revisions | June 29, 2022 Effective | January 1, 2022
136 | Title 21: Sammamish Development Code
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