10412 ROSEWOOD AVE ROSEWOOD PARK WHOLE SITE DEVELOPMENT 2017-04-07

There were no surface indicators of saturation or inundation in the non-wedand azeas. It appears that the areas mapped as non-wetland aze not saturated for a period greater than S% of the growing season and therefore do not meet the wetland hydrology criteria. Because direct hydrolo�ic indicators aze lacking, and neither hydric soils nor hydrophytic veeetation dominated in these areas, it appears that these areas do r.�t meet criteria for wedands. WETL 1ND FUNCTIONS AND VALUES �Iethodology The methodolo�y for this functions and values assessment is base�d on professional opinion developed through past field analyses and interpretatic:�. This assessment pertains specifically to the on-site wetlands, but is typical for assessments of similar systems common to Westem Washington. Functions and Values Components Wedands in Western Washington perform a variety of ecosystem functions. Included among the most important functions provided by wetlands are stormwater control, water quality improvement, fish and wildlife habitat, aesthetic value, recreational oppoRuniues, and education. The most commonly assessed functions and their descriptions are listed below. Assessments of these functions for the project site are provided in the "Analysis" section of this report. Stonttwater Stornge/Floodflow Attenunrron Wetlands often function as natural water storage areas during periods of precipitation and flooding. By storing water that might othenvise be channeled into open flow systems, wetlands can attenuate or modify potentially damagin� effects of stonn events, reducing erosion and peak t]ows to downstream systems. Additionally, the soils underlying wetlands are often less permeable, providing lon;-term storaee of stormwater or floodf7ow and controlling base flow of downstream systems. Stormwater storage capacity and floodt]ow attenuation are eenerally a function of the size of the wetland, their topographic characteristics, and vegetative components. 6 &'��