[1]
Code reviser's note: Att. B § 24 of Res. 54-2010 deletes Section 16D.06.06 (Stream, Lake and Pond Typing System) and provides: "Refer to Appendix B and C of the SMP, listing shoreline lakes, rivers and streams which are shorelines In Yakima County."
The stream corridor and other hydrologically related critical areas include one or more of the following features:
(1) 
Any floodway and floodplain identified as a special flood hazard area. Special flood hazard areas are those identified by the Federal Insurance Administration in the Flood Insurance Study for Yakima County which, together with accompanying Flood Insurance Maps, is hereby adopted by reference and declared to be a part of this title as set forth in Chapters 16D.05.20 through 16D.05.72;
(2) 
Perennial and intermittent streams, excluding ephemeral streams, including the stream main channel and all secondary channels within the ordinary high water mark;
(3) 
Naturally occurring ponds under twenty acres and their submerged aquatic beds; and manmade lakes and ponds created within a stream channel designated under (2) above;
(4) 
All wetlands that meet the definition found in Section 16D.02.425, as required by WAC 365-190-080(1), and as designated in section 16D.07.02(1) of the wetland chapter;
(5) 
Where specifically cited, any flood-prone area not included in a designated floodway and floodplain but indicated as flood-prone by U.S. Soil Conservation Service soil survey data or geologic evidence developed through professional geologists or engineers;
(6) 
A buffer area extending on a horizontal plane from the ordinary high water mark of a stream channel, lake, or pond, designated in this section or from the edge of a wetland designated in this section according to the distances set forth in Section 16D.06.16 (Vegetative Buffers);
(7) 
Lakes and ponds meeting the designation criteria in the Shoreline Management Act (RCW 90.58.030) listed in Appendix B.[1]
[1]
Editor's Note: Appendix B is included as an attachment to the title.
(Ord. 14-2007 § 1 (Exh. A) (part), 2007)
(1) 
Streams, lakes and ponds and wetlands require a sufficient riparian area to support one or more of the following functional properties:
(a) 
Streambank and shore stabilization;
(b) 
Providing sufficient shade through canopy cover to maintain water temperatures at optimum levels and to support fish habitat;
(c) 
Moderating the impact of stormwater and meltwater runoff;
(d) 
Filtering solids, nutrients, and harmful substances;
(e) 
Surface erosion prevention;
(f) 
Providing and maintaining migratory corridors for wildlife;
(g) 
Supporting a diversity of wildlife habitat;
(h) 
Providing floodplain functions noted below;
(i) 
Contributing woody debris and organic matter to the aquatic environment;
(j) 
Providing altered climatic conditions different from upland areas.
(2) 
Stream channels generally support one or more of the following functional properties:
(a) 
Groundwater recharge and/or discharge;
(b) 
Water transport;
(c) 
Sediment transport and/or storage;
(d) 
Biogeochemical functions (see lakes, ponds and wetland functions below);
(e) 
Channel migration and creation of a dynamic habitat mosaic;
(f) 
Food web and habitat functions.
(3) 
Lakes, ponds and wetlands generally provide similar functions, sometimes to a greater or lesser degree. Wetlands are often located along the margins of lakes and ponds, which often mixes the functions between the two. Lakes, ponds and wetlands generally provide one or more of the following functional properties:
(a) 
Biogeochemical functions, which are related to trapping and transforming chemicals and include functions that improve water quality in the watershed such as: nutrient retention and transformation, sediment retention, metals and toxics retention and transformation;
(b) 
Hydrologic functions, which are related to maintaining the water regime in a watershed, such as: flood flow attenuation, decreasing erosion, groundwater recharge;
(c) 
Food web and fish and wildlife habitat functions, which includes habitat for: invertebrates, amphibians, anadromous fish, resident fish, birds, mammals.
(4) 
Floodplains generally provide one or more of the following functional properties:
(a) 
Floodwater storage and passage, including the movement of high velocity flood waters;
(b) 
Sediment storage and recruitment;
(c) 
Food web and habitat functions;
(d) 
Nutrient sink and/or source;
(e) 
Groundwater recharge and/or discharge.
(5) 
Some functions, as, for example, supporting a diversity of wildlife habitat, require larger areas which may not be achievable due to existing development and construction constraints. In these instances, adjustments to the minimum standards to accommodate such constraints may be necessary. However, a reduction of standards impairs the hydrologically related critical area's ability to support some functional properties. Reductions of standards should be offset by enhancement, restoration or preservation measures which replace lost functions or strengthen other functional properties if replacement of the lost functions is not possible.
(Ord. 14-2007 § 1 (Exh. A) (part), 2007; Res. 54-2010 § 4 (Att. C § 11), 2010)
Wetlands within Yakima County are defined in Section 16D.02.425 and are shown on the data maps referenced in Section 16D.06.08 (Maps). Most, but not all, of the wetlands within Yakima County occur near streams. All wetlands deserve a standard of protection, through the use of vegetative buffers, that is directly related to their contribution to the functional properties listed in Section 16D.06.05 (Functional Properties) and section 16D.07.04 (Wetland Functions and Rating). For regulatory purposes, wetlands are classified into four categories according to the wetland rating system found in section 16D.07.04(2) (Wetland Functions and Rating) of the wetland chapter.
(Ord. 14-2007 § 1 (Exh. A) (part), 2007)
Shorelines of the state as well as certain fish and wildlife habitat and hydrologically related critical areas have been inventoried and are depicted on a series of paper and electronic maps maintained at the Yakima County Public Services Department. The best available graphic depiction of critical areas within the county will be used and continuously updated as reliable data becomes available. Maps may be both regulatory and nonregulatory in nature as described below:
(1) 
Regulatory maps are created with a defined process not necessarily corresponding directly with easily observable physical features such as streams and wetlands. These maps define the regulated critical areas. They are also formally adopted by the Board of Yakima County Commissioners and may only be changed by that body. Regulatory maps include the following:
(a) 
Any floodway or floodplain identified as a special flood hazard area by the Federal Insurance Administration in the Flood Insurance Study for Yakima County.
(2) 
Administrative maps are intended to indicate the approximate presence, location and/or typing of the subject critical area features, and act as a trigger for further investigation of the extent and characteristics of critical areas in a specific project location. These maps were created using reconnaissance level or better data. Given site-specific variations in reconnaissance level data, more detailed information developed at the site-specific level may be used to modify the maps as it is developed; the maps maintained by the Yakima County Public Services Department do not officially define the extent or characteristics of specific critical areas; rather the physical characteristics that exist "on the ground" define the boundaries of the regulated critical areas. Administrative maps include, but are not limited to, the following;
(a) 
Wetlands;
(b) 
Streams;
(c) 
Channel migration zone;
(d) 
Species and Habitats of Local Importance. Mapped habitat areas for newly listed species will be generated as needed to supplement the existing maps. Habitats of local importance currently include:
(i) 
Type 2 Streams, lakes and/or ponds listed in Appendix A[1] and described in section 16D.06.06(2) above.
[1]
Editor's Note: Appendix A is included as an attachment to the title.
(e) 
Upland Wildlife Habitat Analysis Map;
(3) 
Other Information Sources. These are maps or other data sources, including special studies and management plans, which are neither produced or maintained by the Yakima County Public Services Department, which are used to indicate the presence of critical areas, importance or ranking of critical areas functions, or hazard or risk associated with critical areas. These information sources include, but are not limited to:
(a) 
Comprehensive flood hazard management plans and associated studies;
(b) 
Soil survey of Yakima County;
(c) 
Natural resource management plans, such as local and federal recovery plans, or forest plans prepared by the U.S. Forest Service;
(d) 
Surficial geologic maps;
(e) 
Historic and current aerial photo series;
(f) 
Geohydraulic Studies. Geologic cross sections showing aquifers and confining units.
(Ord. 14-2007 § 1 (Exh. A) (part), 2007; Res. 54-2010 § 2 (Att. B § 25), 2010)