Tidal_PAD_V1_Sec4.pdf - Snohomish County PUD

More documents

Recommendations

Info

Snohomish County PUD – Pre-Application Document 4 – Description of Existing Environment Table 4-1. Terrestria l an d marine geological and soils characteris tics of the potential Puget Sound tidal project sites Site Name Characteristic Primary topography, geology Admiralty Inlet Spieden Channel Guemes Channel San Juan Channel Deception Pass Agate Passage Rich Passage shallow sill 60 m deep at main channel, deepens to east to 70-120+ m 30 m in center at shallowest, deepens to 100+ m away from narrowest pt under 10m at center, deepens to 30m away from narrowest pt shallow on edges, 30 m in center at shallowest, deepens to 90+ m away from narrowest pt center under 15 m 10 m, uniform depth 10 m, deepening to 30 m to the east Fraser-age glacial till, glacial outwash, glacial lacustine metasedimen tary, sedimentary (Spieden Island), Fraser glacial till Fraser-age glacial till, intrusives Fraser glacial till, glacial drift, Fraser glacial till, glacial drift,metasedi mentary, volcanic/volc aniclastic Fraser glacial till, glacial outwash Fraser glacial till, glacial outwash, alluvium (sm amts) (DON 2006, WSDE 2007, DNR 2000, DNR 2005) Terrestrial Geology and Characteristics Marine Characteristics Primary soils loamyskeletal, fine mixed, sandy mixed, mixed mesic coarse loamy, coase loamy over sand, fine mixed loamyskeletal, fine mixed, loamy-mixed coasrseloamy, coarse-loamy over sand sandy skeletal, loamy skeletal, medial skeletal coarse loam, skeletal mixed, loamy skeletal, mixed medial medial, coarse-loamy Nearby mineral resources? sand & gravel, rock, geothermal Shoreline steepness or instability yes; old and new slides in vicinity of Port Townsend potential grid connection, unstable slopes at northern Whidbey Isl. Connection site Erodible shoreline? (i.e., sand beaches) yes none no S. shore of Spieden island Bottom composition Sha llow sand and gravel; finer toward channel sides rock, gravel & sand Bottom habitat gravel and sand, sand beach, gravel beach rocky intertidal none yes yes mixed, gravel gravel and sand, sand beach none no yes mud, sand & gravel rocky intertidal, gravel and sand beach rock, sand & gravel yes; steep, mostly bedrock but some narrow areas of minimal (small rocky beaches) mixed, bedrock rocky inte rtidal and har bottom instability and old slides none none yes, including recent slides toward S. end of site on Kitshap peninsula yes, primarily small areas on Kitshap peninsula yes yes mud, mixed gravel and sand, sand beach mud, mixed gravel and sand, sand beach Submerged steep areas? on east side of deepest part of channel south side of deepest channel part Faults? yes yes Primary vegetation Kelp, sargassum Kelp no no Sargassum, mixed macroalgae Nearshore vegetation: surfgrass, eelgrass? surfgrass, eelgrass eelgrass eelgrass no yes Kelp surfgrass, eelgrass no (all shallow) no (all shallow) at very southwest corner yes no yes Kelp sargassum sargassum surfgrass, eelgrass eelgrass eelgrass 4-18 January 31, 2008
Snohomish County PUD – Pre-Application Document 4 – Description of Existing Environment 4.3 Water Resources Puget Sound is the second-largest estuary in the United States, where salt water from the Pacific Ocean is mixed with fresh water draining from the surrounding watershed. More than 10,000 rivers and streams drain into Puget Sound (Puget Sound Action Team 2000a). The entire drainage basin has been estimated to have more than 33,000 km 2 of watershed and 8,000 km 2 of marine waters environment (Gelfenbaum et al. 2006). This section summarizes the existing water resources, both quantity and quality, and applicable water quality standards in the project area. 4.3.1 Wind, Tide and Current Characteristics Puget Sound is bordered to the west and east by the Olympic and Cascade mountain ranges, respectively. This topography generally channels winds in a north/south direction, although wind conditions across the Sound can vary depending on local effects. Winds are strongest in the winter and early spring, when sustained winds of 10 to 17 m/s (20-33 knots) from the south are common and gale winds (17.5 to 21 m/s; 34-47 knots) occur. From late spring through early fall, winds are lighter, with speeds of 4 to 7.7 m/s (8-15 knots) in the afternoons (NOAA 2007a). Each day, approximately 6.1 km 3 of water flows in and out of Puget Sound. Tides in Puget Sound generally follow a semi-diurnal cycle over a 25-hour period, w ith two high and t wo low tides that tend to be different in range and timing. The average daily tidal variation is 2.4 m in northern areas of the Sound and 4.3 m in southern areas of the Sound. However, geographic variation in the shape and depth of the Sound influences local tida l patterns. Currents within the Sound are primarily driven by tides and the inputs from surface water sources, although the speed and direction of winds can also be influential. Generally, current velocities in the Sound range from 0.3 to 1.0 m/s (0.5-2.0 knots), although 1.5 m/s (3.0 knots) is normal in some regions (Gilmore et al. 1996). Narrow channels tend to have stronger currents due to the restricted 4-19 January 31, 2008
Page 1 and 2: Section 4 Existing Environment This
Page 3 and 4: Snohomish County PUD -Pre-Applicati
Page 17: Snohomish County PUD -Pre-Applicati
Page 69 and 70:
Snohomish County PUD -Pre-Applicati
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217:
show all

Tidal_PAD_V1_Sec4.pdf - Snohomish County PUD

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?