EXH2209034806

PCHBPollution Control Hearings Board of the State of Washington

I've put together and attached a few photos of several wetland sites that served as a "model" for the shrub and emergent communities planned for the Auburn mitigation site. I have revisited these areas this spring, and feel we are generally on target with the hydrology, given our ability to hold the water level between 41 and 42 feet if needed. Pa:t of the rationale for the planting elevations was to have shrub communities that would out-compete (clue to wetness) blackberry, and emergent communities that were too wet for vigorous growth of reed canary grass. rm going through my notes of our past several meeting, and will provide (probably tomorrow afternoon) a brief list of clarifications for some of the design issues that we discussed and I was unsure of the answer. Jim Kelley jckelley@parametrix.com Parametrix, Inc. Main: 425-822-8880 FAX: 425-889-8808 Direct: 425-828-4202 extn 3315 f ECYo0022075 Exhibit-2209 AR 034806 Seattle-Tacoma International Airport Master Plan Update Improvements EXAMPLES OF SHRUB AND EMERGENT PLANT COMMUNITIES SIMILAR TO THOSE PLANNED FOR THE AUBURN MITIGATION SITE April 23, 2001 FigureI. Floodedshrubcommunitiesalongtheedge of a constructed(ca.1994)pond.The shrubcommunityconsistsofa combinationofplantedandnaturallycolonizedplants.Floodingof0 to12inchesoccursbetweenOctoberandMay;bymid-tolatespring, theshrubsaregrowingonsaturatedsoft. ECY00022076 AR 0,34807 Figure 2. Portions of the shrub communities are flooded with 0-15 inches of water in early spring, with greater depths present during the winter months. AR 034808 Seattle-Tacoma International Airport April 24, 2001 Master Plan Update Improvements 2 Parametrix, Inc. ECYO0022077 g ure 4. Flooded wetland communities _rder l..zke Washington in the Mercer ough. This area is south of Interstate and near…
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