Duwamish Waterway Self Guided Tour: Turning Basin Number Three and Terminal 105 Aquatic Habitat Restoration Sites

Transcription

1 Duwamish Waterway Self Guided Tour: Turning Basin Number Three and Terminal 105 Aquatic Habitat Restoration Sites Text and illustrations in the following pages include: (1) summary information describing past aquatic and shoreline habitat changes in south Elliott Bay and the Duwamish River estuary (pages 2-10); (2) two examples of recent fish and wildlife habitat restoration projects completed by the port (pages 10-26); and (3) directions for visiting the restoration sites (pages 27-30). For additional information, questions, or to meet at these sites, please contact Geo. Blomberg, Seaport Environmental Programs, Port of Seattle,

2 Figure 1: South Elliott Bay, view toward northeast, with Seattle urban center in middle background Harbor Island, the East and West Waterways, and the lower Duwamish Waterway are visible in the foreground. 2

3 Figure 2: Harbor Island in south Elliott Bay Illustrating the center of the present urban/industrial infrastructure essential to the City and the Port of Seattle. Harbor Island, center right, and adjacent industrial shoreland areas are served by deep draft navigational access in the East Waterway (upper right) and the West Waterway (upper left). The Duwamish Waterway extends upstream in the estuary from the south end of Harbor Island (center of photograph), approximately 5.3 miles, providing water access to the Duwamish industrial area. Prior to 1900 this entire area consisted of intertidal mud and sand flats, estuarine marsh, forested wetland, and meandering shallow river channel. 3

4 Figure 3: Present industrial area and historic river channel This graphic combines the present urban industrial shoreline in south Elliott Bay and the Duwamish Waterway, as illustrated in the Figure 2 photograph, with conditions recorded in All existing marine terminal area, rail and vehicle access facilities, and industrial land in south Elliott Bay have been constructed in former intertidal and estuarine floodplain area (identified by the dark green shading). 4

5 Figure 4: Graphic portraying historic estuarine environment in south Elliott Bay The historic estuary included approximately 1450 acres of intertidal sand and mud substrate, nearly 1300 acres of intertidal marsh, and approximately 1450 acres of tidal swamp (or forested wetland). In addition, the meandering river channel included approximately 17 miles of riparian environment and estuarine floodplain. The combined intertidal and estuarine floodplain habitat area was approximately 5300 acres. 5

6 Figure 5: Westerly perspective -- Spokane Street corridor in 1898 This figure illustrates the extent of intertidal area in south Elliott Bay prior to large scale industrial development. Note piling supported rail lines and vehicle access to west portion of south Elliott Bay. 6

7 Figure 6: Westerly perspective -- Spokane Street corridor in 1998 This photograph is identical in location to the 1898 image (Figure 5). The elevated bridge structure is at the south margin of Harbor Island. The present industrial area includes approximately 8.2 square miles (constructed entirely in former estuarine aquatic area), supporting 75,000 to 80,000 jobs, with an annual payroll of $2.5 billion. 7

8 Figure 7: Graphic illustrating present south Elliott Bay and Duwamish industrial area The present industrial landscape represents a 98 percent reduction in intertidal sand/mud substrate and marsh area. In addition, forested wetland is entirely absent. A system of linear, deep navigation channels has replaced the former shallow, complex river channel. Note also that the former watershed discharging to the estuary was approximately 1640 square miles, with 1900 linear miles of stream habitat accessible to five species of anadromous fish. The present watershed in 73 percent smaller, due to water diversions, and only eight percent of the former stream spawning habitat is available to migratory fish. 8

9 Figure 8: Graphic illustrating significant reduction in estuarine habitat area 1854 to present 9

10 Figure 9: View to northwest illustrating the Duwamish Waterway, foreground, and south Elliott Bay, upper center photograph This is the present environmental context for the Port s long-range marine cargo and industrial infrastructure needs. The Port s objective is to re-develop existing industrial area, expanding the capability of marine cargo facilities and delivering important economic growth opportunity, while providing coincident environmental improvements in the Duwamish industrial area. 10

11 Figure 10: Turning Basin Number Three Demonstration Site Former environmental conditions at the up-stream end of navigation in the Duwamish Waterway, at Turning Basin Number Three (river mile 5.3) are evident in this photograph. Filled aquatic area is occupied by industrial activities and shoreline areas, including the legacy of more than 80 years of industrial use. This location is the site of the Port s Turning Basin Number Three intertidal habitat demonstration project. 11

12 Figure 11: Turning Basin Number Three Demonstration site graphic The demonstration inter-tidal habitat restoration site (completed 1996) is illustrated in the right portion of this graphic, including re-grading of site elevations and removal of derelict vessels and structures. The large area, at the left, represents the Port s subsequent plans for a larger, compensatory restoration area (completed in 1999), building on the success of the 1996 demonstration project. 12

13 Figure 12: Turning Basin Number Three habitat demonstration site underway The first step in restoration work at the turning basin site was to remove derelict vessels that had been abandoned at the upstream end of the navigation channel over a period of decades. 13

14 Figure 13: Turning Basin Number Three demonstration site grading Restoration of aquatic habitat functions at the turning basin demonstration site included excavation of approximately 3500 cubic yards of previously placed fill material, restoring intertidal elevations at the site. 14

15 Figure 14: Establishing riparian and marsh vegetation at the Turning Basin Number Three site Approximately 0.2 acres of native riparian vegetation and approximately 0.4 acres of emergent plants were installed at the restoration site. All of the site planting was accomplished by volunteers, students, and job trainees. 15

16 Figure 15: Turning Basin Number Three demonstration site following construction in 1996 This photograph illustrates restored intertidal area, marsh plantings, and recently installed riparian vegetation. 16

17 Figure 16: Turning Basin Number Three Demonstration site in 1999 The intertidal marsh plantings and native riparian shrubs and trees are well developed at the demonstration site three years following completion of excavation and grading. Note the fence structures in the intertidal area. Initial marsh plantings disappeared entirely within six weeks of installation, due to feeding by geese. It was necessary to fence the plantings to prevent grazing by Canada geese. Once mature, the marsh plants will withstand waterfowl predation. 17

18 18 Figure 17: 1999, construction of large scale fish and wildlife habitat restoration area at Turning Basin Number Three removal of derelict former Washington State ferry.

19 Figure 18: Illustrating the difficulty in removing obstructions to fish and wildlife, in the form of a derelict ferry hull 19

20 Figure 19: Illustrating removal of approximately 33,000 tons of fill material placed more than 80 years ago at Turning Basin Number Three (recall image from Figure 10) 20

21 Figure 20: Approximately 1.3 acres of restored estuarine aquatic area at Turning Basin Number Three (1999), made possible by coincident redevelopment actions at the port s Terminal 5 container cargo site 21

22 Figure 21: Marsh vegetation planted at the Turning Basin Number Three restoration site, following seven months of growth 22

23 Figure 22: Photograph illustrating native estuarine marsh, with side channel features The historic marsh habitat in the Duwamish estuary contained marsh area similar to the photograph above. Marsh area is now rare in the Duwamish estuary and side channels penetrating marsh area, once abundant, are now entirely absent. The Terminal 105 demonstration site was planned as a means to re-introduce similar marsh and side channel habitat to the estuary. 23

24 Figure 23: Preliminary concept for Terminal 105 Demonstration site This graphic illustrates an early design concept for constructing a side channel intertidal habitat area at Terminal 105. It is important to note that the environmental objective is to restore a former habitat feature to the estuary. In addition, the demonstration project tested how restored estuarine habitat areas could be configured to fit industrial shoreline areas, without impeding important waterway access. Habitat restoration area oriented perpendicular to the shoreline would provide essential environmental attributes and not foreclose industrial access to adjacent shoreline areas. 24

25 Figure 24: Terminal 105 Demonstration site under construction Approximately 9400 cubic yards of previously placed fill was removed to create a 0.6 acre intertidal channel approximately 1300 feet in length. During construction a buried vault was discovered, filled with paint and solvent wastes, adding substantial project costs for cleanup and confirmation testing of newly exposed intertidal sediments. 25

26 Figure 25: Completed Terminal 105 demonstration project site 1997 The restoration project is illustrated at low tide note the extent of tidal influence indicated by the wetted bankline. The site is inundated twice daily by tidal water up to five feet in depth. Following grading, the restoration site received 0.3 acres of native riparian trees and shrubs and more than 1100 marsh plants. All site vegetation work was accomplished by community participants. 26

27 Site Directions (1) Turning Basin Number Three and (2) Terminal 105 Please find below driving directions to each of the fish and wildlife habitat restoration sites described. Please note that the restoration sites are difficult to reach using public transit. Turning Basin Number Three West Marginal Place South From north and downtown Seattle: Travel south on Highway 99 (Alaskan Way Viaduct) Follow signs to First Avenue South bridge From south end of First Avenue South bridge, exit to right and follow signs to WA-99 and West Marginal Way South/South Park Curve to right and follow signs for Highway 99 South to South Park (route passes under First Avenue South bridge, via Second Avenue South and Highland Park Way Southwest, resuming Highway 99 south-bound at South Holden Street intersection) Continue south on Highway 99 Exit at Des Moines Drive/14 th Avenue South Follow exit to right to cross Highway 99 overpass and follow signs to 14 th Avenue South At east end of overpass, turn right onto 14 th Avenue South and proceed to stop sign 27

28 Turning Basin Number Three, driving directions, cont. Continue ahead, 14 th Avenue South becomes West Marginal Place South Proceed south on West Marginal Place, past City Light substation and Hamm Creek pull-out Duwamish Waterway visible on the left Look for a small parking area at end of bicycle pathway. Restoration site is east of bicycle pathway From the south: From Inter-state Highway 5 take exit 156 and merge onto Highway 599 to Tukwila/West Marginal Way Highway 599 becomes Highway 99 Take West Marginal Place South exit and turn left to West Marginal Place South Look for small parking area on right, where bicycle pathway ends Restoration area is east of bicycle pathway 28

29 Terminal 105, Driving Directions Terminal West Marginal Way Southwest From north and downtown Seattle: Travel south on Highway 99 and use West Seattle Freeway or low-level Spokane Street bridge to West Marginal Way Southwest Follow West Marginal Way Southwest from four-way intersection at Chelan Avenue Southwest/Southwest Spokane Street/Delridge Way Southwest/West Marginal Way Southwest to south-bound West Marginal Way Southwest Look for Port of Seattle, Terminal 103 sign on left At south margin of Terminal 103 look for blue and white Port of Seattle sign marking Terminal 105 Duwamish Public Shoreline Access site Enter to left, crossing rail line, to public shoreline access and fish and wildlife habitat restoration area 29

30 Terminal 105, Driving Directions, cont. From south: Follow signs from Highway 509 to northbound West Marginal Way Southwest. This requires exiting to right from Highway 509, at last opportunity south of First Avenue South bridge. Turn left at Highway 99/South Holden Street/West Marginal Way intersection, to proceed north-bound on West Marginal Way Southwest, under First Avenue South bridge Ignore signs relating to Highland Park Way, turning right to West Marginal Way Southwest Follow West Marginal Way Southwest north past Terminal 115 and Terminal 107 to area of West Marginal Way Southwest near West Marginal Way Southwest/Dakota Street Southwest intersection North of intersection look for blue and white Port of Seattle sign indicating Terminal 105 Duwamish Public Shoreline Access site Enter to right, crossing rail line, to public shoreline access and fish and wildlife habitat restoration area 30