Lake Washington GRP

Table of Contents


Site Description

This section provides a description of Lake Washington’s (LKWA) physical features, hydrology, climate and winds, and an overview of the oil spill risks in the region. The LKWA -GRP boundary spans the fresh waters of the lake, two river inputs (Cedar and Sammamish), creeks, and an outlet. The area encompasses embayments on lake shores associated with communities of east Seattle, Lake Forest Park, Kenmore, Kirkland, Bellevue, Renton, and Mercer Island.

Three floating bridges and two girder bridges carry traffic across Lake Washington today. Floating bridges carry State Route 520 and Interstate 90. The SR-520 connects Seattle’s Montlake neighborhood with Medina located in northwest of Bellevue. The Interstate 90 corridor across the lake uses two floating bridges to connect Seattle’s Mount Baker neighborhood to Mercer Island. The Lacey V. Murrow Memorial girder bridge and the Homer M. Hadley Memorial girder bridges carries east and west traffic in the west channel off Mercer Island, and the East Channel Bridge (girder bridges) allows east- and west-bound I-90 traffic to flow between Mercer Island and Bellevue.

The LKWA-GRP planning area borders the Central Puget Sound GRP (CPS-GRP) and the Green River Duwamish GRP (GRD-GRP). LKWA-GRP is within the boundary of Water Resource Inventory Area 8 (WRIA-8, Cedar-Sammamish watershed).

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Developed Areas

Numerous neighborhoods surround Lake Washington, including suburban cities of Lake Forest Park, Kenmore, and Kirkland to the north and northeast; the neighborhoods of Wedgwood and Maple Leaf to the west; the city of Bellevue to the east; the Factoria, Newcastle, and Kennydale neighborhoods, and the city of Renton to the south and southeast; and the Rainier Valley district that includes Bryn Mawr-Skyway Seattle metropolitan area, Lakeridge hillside neighborhood, and Rainier Beach (also known as Atlantic City), Pritchard Island, and the city of Lakewood to the southwest. The planning area is fully located within King County.


The LKWA-GRP is within the usual and accustomed territories of American Indian Tribes. Federally recognized Tribes located within the LKWA-GRP planning area with access to the resources of the Lake Washington GRP planning area may include the Muckleshoot Indian Tribe, Tulalip Tribes of Washington, Suquamish Tribe, Stillaguamish Tribe of Indians, Squaxin Island Tribe, Snoqualmie Indian Tribe, Lummi Nation, Nooksack Indian Tribe, Samish Indian Nation, Sauk-Suiattle Indian Tribe, Swinomish Indian Tribal Community, Upper Skagit Tribe, and the Confederated Tribes and Bands of the Yakima Nation.

Tribes can fill many roles during an oil spill response including full participation in Unified Command, providing resource specialists in the Environmental Unit, monitoring on-scene operations, and more. Information regarding tribal participation in a response is available on the Northwest Area Committee/Region 10 Regional Response Team website. Contact information for the tribes in this planning area can be found in the Resources at Risk section and on the Spill Response Contact Sheet of this GRP.

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Physical Features

Geology & Landscape

Ecoregions in the planning area include Central Puget Lowlands, Riverine Lowlands, Marine West Coast Forests, and Eastern Puget Uplands. Historically, Puget Sound was sculpted by thick and extensive glaciers that advanced south to just beyond Olympia. Glacial sediments (glacial till and outwash) were deposited by numerous glacial advances  and glaciers advancing and retreating created many of the long and narrow hills and lakes within the planning area (WDNR).

Since the ice retreated from the lowlands, the area has been in continuous use by the Coast Salish peoples and their ancestors. Their annual movements and villages were often planned around seasonal salmon runs, which remain central to their cultural celebrations, spiritual beliefs, and economy. (WRIA 8 2020 Progress Report)

The basin of Lake Washington is a deep, narrow glacial trough with steeply sloping sides. Water and sediment accumulated in the lake as historic glaciers melted and continues to accumulate today. Lake Washington’s shoreline is characterized by a 10-foot-high bench, bays, and mostly gentle slopes, several peninsulas, and encloses an island in the south. Most of the area around the lake is developed and urban in nature. Manmade features, including private dwellings, docks, a few lengthy piers, marinas, and water accesses, surround the lake. Protected habitats are a main resource contributing to making the area home to wildlife.

Lake Washington is the largest lake in Western Washington, the second largest in the state. It is about 20 miles long, 2-4 miles wide with about 80 miles of shoreline including those of Mercer Island. The lake is shallowest at the north and south ends, max depth is 214 feet, mean depth is 108 feet.

Cultural Features

Pritchard Island was a small island on the southwest shore of Lake Washington, and the site of a Duwamish Indian village known as tleelh-chus (“little island”) for generations before the first United States settlers arrived in the area in the 1860s.

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Dams & Irrigation

Lake levels are controlled by the Army Corp of Engineers between 20-22 feet for seasonal uses with the Hiram M. Chittenden Locks in Ballard (Seattle). The “Ballard Locks”, or “The Locks”, are located at the end of the Lake Washington Ship Canal, also known as the Montlake Cut. The Locks operate mainly as a navigation facility with a spillway dam that controls the elevation of the water in the Canal, Salmon Bay, Lake Union, and ultimately Lake Washington. The Locks include an 80’x 825’ lock and a smaller 30’x150’ lock. The

Chittenden complex in Ballard also includes a 235’ spillway with six gates to assist water- level control. Minimum water levels are maintained during the winter months to allow for annual maintenance on docks, walls, businesses, and lakeside residents, minimize wave and erosion damage during winter storms, and provide storage space for high inflow. The storage is used to augment Canal inflows for operating The Locks, the saltwater return system, smolt passage flume, and the fish ladder facility is integrated into the locks for migration of anadromous fish (most notably salmon).

Recreation & Tourism

Notably, Lake Washington is home to parks, preserves, wetlands and facilities vital to the community including schools, the University of Washington campus and arboretum, Boeing airplane factory, and an expansive NOAA Pacific Marine Environment and Oceanography complex.
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Uniquely, Lake Washington has two major influent streams. The Sammamish River at the north end of the lake near Kenmore, that supplies 57% of the annual freshwater load, and the Cedar River at the south end near Renton, supplies 25% of the input. Notable tributaries or sub-basins that drain to Lake Washington include the lower portions of the Cedar and Sammamish Rivers, and downstream areas of Coal, Juanita, Kelsey, Lyon, May, McAleer, Ravenna, Taylor, Thornton, and Yesler Creeks. Less notable inlets are Bear, North and Swamp Creeks. Freshwater inputs to Lake Washington are essential to the hydrologic budget and rainfall plays a key role as well.

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The outflow begins west from the lake; the water narrows and flows westward under the Montlake Bridge from Union Bay in central west Lake Washington. The canal begins at the Montlake Cut, flows into Portage Bay, to Lake Union, to the Fremont cut, Salmon Bay then through The Locks, and into Shilshole Bay on Puget Sound.

Chester Morse Lake, situated in the upper part of the Cedar River serves as a water storage reservoir and is the source for much of the drinking water for the greater Seattle area.

Lake Washington is situated inside the Cedar- Sammamish Water Resource Inventory Area, Cedar-Sammamish (WRIA 8). This watershed includes the Cedar River, originating in the Cascade Mountains, and encompasses the Sammamish River, that connects Lake

Washington and Lake Sammamish. The watershed includes various smaller creeks such as Swamp, Bear, Evans, and North creeks.

The bays that comprise Lake Washington include Andrews, Fairweather, Juanita, Meydenbauer, Moss, Pontiac, Union, Wolf, and Yarrow, Cozy Cove, and shoreline areas of Mercer Island. Lake bays that are adequately sheltered and contain wetlands and upland riparian areas that are biologically rich and sensitive.

Lake Washington undergoes annual stratification, with a strong thermocline developing about 39ft below the surface. As summer progresses, the temperature and density difference between water at the surface and bottom becomes more distinct. Three water layers are formed: upper, middle, and bottom water layers. The upper layer (epilimnion) is characterized by warmer, less dense water, the zone of light penetration where the most biological growth occurs. The middle layer (metalimnion or thermocline) is the narrow band of water colder than water in the upper layer but warmer than the lower waters beneath it. The middle layer helps prevent the mixing of upper and lower water layers. The bottom layer (hypolimnion) holds the coldest water. Plant material either decays or sinks to the bottom and accumulates in this “stagnant” lower water layer.

Lake temperatures allow for substantial vertical mixing by wind action and convective overturn. In Spring, surface waters warm, then sink, and finally mix with deeper water. In Summer, the density of the water changes with the change in water temperature. During the Fall, surface waters cool until they are as dense as the bottom waters, and wind action mixes the lake so water temperature from surface to bottom are nearly the same. Lake temperatures remain around 39-40 degrees throughout the year.

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Climate and Winds

Seattle’s climate is usually described as oceanic or temperate marine; winters are typically mild and wet while summers are usually warm and dry. Temperature extremes are moderated by the adjacent Puget Sound, greater Pacific Ocean, and Lake Washington. The region is largely denied pacific storms by the Olympic Mountains and cold arctic air by the Cascade Range.

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Despite being on the margin of the rain shadow of the Olympic Mountains, the Seattle area has a reputation for frequent rain. Records show that Seattle is usually cloudy more than 200-days per year, and partly cloudy more than 90-days annually. The area receives approximately 37.41 inches of rain a year and statistics show that the city is becoming wetter; the current annual rainfall average reflects an increase of 0.4 inches. Seattle experiences moderate to heavy rain during the months of November, December, and January. The city receives roughly half of its annual rainfall (by volume) during these three months. In late fall to early winter, atmospheric rivers known as “Pineapple Express” systems, strong frontal systems, and Pacific storms are common. Light rain and drizzle are the predominant forms of precipitation during the remainder of the year; for instance, on average, less than 1.6 inches of rain falls in July and August combined.

Winds in the area are variable with the western portion of the lake being affected by marine winds from Puget Sound. Wind speeds often vary by season, with the highest winds generally occurring from November through January. Wind gusts can occasionally reach 50 mph or greater.

Seattle occasionally experiences extraordinary weather events. One such event occurred in November 2006, when sustained and widespread heavy rainfall associated with a strong “Atmospheric River” hit the area. In one day, precipitation totals for were 8.22”at Stampede Pass, 4.31” in Olympia, and 3.29” at Sea Tac Airport.

Microbursts and other weather anomalies can occur. A microburst occurred in Lacey, WA, located south of Seattle, in 2017 that brought extremely high winds, dumped a very large “water balloon” over the area, and caused significant damages to trees, cars and powerlines.

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Tides and Currents

There are no tidally influenced areas within the Lake Washington GRP. The lake’s water level is governed strictly by river and creek inputs, precipitation, and spillway flow at the Ballard Locks (see above).

Risk Assessment

Lake Washington is plentiful in natural, cultural, and economic resources, all at risk of injury from oil spills. Potential risks to sensitive resources in the area include, but are not limited to, oil pipelines, road transportation, vessel traffic, recreational boating and aircraft. This section briefly discusses the risks in the Lake Washington GRP area.

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Oil Pipelines: The Olympic Pipeline (OPL) distributes refined products from the northern refineries to the majority of the terminals and refineries in this area, as well as SeaTac airport, and continues south into Oregon. If the pipeline were to leak or rupture, the impact to natural, cultural, and economic resources could be significant. The OPL main line poses a risk to Lake Washington as it transports refined petroleum products, mainly diesel and gasoline, along the eastside of Lake Washington, and around the southern end of the lake near Renton. The pipeline crosses both major inlets to the lake, the Cedar and Sammamish Rivers, and several rivers and tributary streams that directly or indirectly drain into Lake Washington.

Road Systems: Vehicle traffic on bridges or roadways over or near Lake Washington pose an oil spill risk. Commercial trucks can contain hundreds to thousands of gallons of fuel and oil, and almost any kind of hazardous material or waste. An accident involving a fully loaded tank truck on one of the lake floating bridges, highway I-90 and 520, Interstate 405, or the Maple Valley highway that crosses the Cedar River could result in a substantial oil spill. Smaller vehicle accidents pose a similar risk, commensurate to the volume of fuel and oil they carry. Spills from vehicles onto roadways along shore could cause fuel or oil to flow into the lake from harden surfaces or through storm water systems that drain directly or indirectly into Lake Washington.

Vessel Traffic: Incidents involving the grounding, sinking, collision or allision of commercial and recreational vessels on Lake Washington pose an oil spill risk. Potential exists for vessels on the lake to collide with each other or sink after hitting fixed structures (e.g. docks or bridges). Oil spill risks also include boat refueling and bilge/wastewater pumping. Private and public marinas and docks on Lake Washington that refuel boats or recover waste products from them, for example, the NOAA research ships transit and fuel at the diving school, or locations where boats are launched and recovered from the lake, might be considered potential spill source locations.

Recreational Boating: Accidents involving recreational watercraft in the planning area have the potential to result in spills of a few gallons up to hundreds of gallons of various petroleum products (e.g., gasoline, diesel, lubricants). Examples of such accidents include vessels colliding, grounding, catching on fire, or sinking. Faulty bilge discharges and refueling operations, the most typical types of spills to occur, also have a negative impact on sensitive resources.

Aircraft: SeaTac International Airport, McChord Air Force Base, Boeing Field, several smaller municipal airports, and some seaplane bases are located within the planning area. Landing strips at these airports are used for recreational, commercial, and transit purposes. With airports in the area, the potential exists for aircraft failures during inbound or outbound flights that could result in a release of jet fuel to Lake Washington. Additionally, seaplanes taking off from or landing in Lake Washington or Lake Union are a source of oil spill risk.

Rail Transportation: Rail companies transport bulk oil via both unit trains and manifest trains in this area. Unit trains include up to four locomotives, buffer cars, and 118 loaded tank cars transporting oil in 29,998-gallon capacity USDOT-approved tank cars. Manifest trains include up to four locomotives, a mix of non-oil merchandise cars, and one or more tank cars carrying refined oil products. These trains may also include emptied tank cars, each with residual quantities of up to 1,800 gallons of crude oil or petroleum products. Every train locomotive typically holds a few hundred gallons of engine lubrication oil, plus saddle tanks that each have a capacity of 5,000 gallons of diesel fuel. Manifest trains may also transport vegetable oils as bulk cargo (Ecology).

Other Spill Risks:Other potential oil spill risks in the area include commercial and industrial facilities, dumping, road run-off during rain events, and the migration of spilled oil through soil on lands adjacent to the lake or along or into rivers, creeks or streams and the banks of those waterbodies that are inputs to Lake Washington.

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Resources at Risk

This section provides a summary of natural, cultural, and economic resources at risk in the planning area, including those resources at risk from oils with the potential to sink or submerge. It provides general information on habitat, fish, and wildlife resources, and locations in the area where sensitive natural resource concerns have been identified. It offers a summary of cultural resources that include fundamental procedures for the discovery of cultural artifacts and human skeletal remains. General information about flight restrictions, wildlife deterrence, and oiled wildlife can be found near the end of this section.  You may download a list of economic resources in the area from the LKWA Geographic Response Plan page.

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This section is purposely broad in scope and should not be considered comprehensive. Some of the sensitive resources described in this section cannot be addressed in Response Strategies and Priorities because it is not possible to conduct effective response activities in these locations. Additional information from private organizations or federal, state, tribal, and local government agencies should also be sought during spills. This material is presented with enough detail to give general information about the area during the first phase of a spill response. During an actual incident, more information about resources at risk will be available from the Environmental Unit in the Planning Section.

Note: specific resource concerns related to areas that already have designated protection strategies may be found in the “Resources at Risk” column of the matrix describing the individual strategies.

The information provided in this section can be used in:

  • Assisting the Environmental Unit (EU) and Operations in developing ad hoc response strategies.
  • Providing resource-at-risk “context” to responders, clean-up workers, and others during the initial phase of a spill response in the GRP area.
  • Briefing responders and incident command staff that may be unfamiliar with sensitive resource concerns in the GRP area.
  • Providing background information for personnel involved in media presentations and public outreach during a spill incident.
  • Providing information on benthic and water column species or cultural resources present to assist in planning for oils with the potential to sink or submerge.

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Natural Resources at Risk – Summary

The Lake Washington basin includes a wide variety of aquatic, riparian, and upland habitats. The area provides habitat to all of Washington’s salmonid species and affords a variety of habitat to many bird species as well. These varied habitats support a complex diversity of wildlife species, including large and small mammals; passerine birds, raptors, upland birds, and waterfowl; reptiles; and amphibians. Some species are resident throughout the year; migratory within the sub-basin, or seasonally migrate outside the sub-basin.

Populations of certain species are fragile and their future presence in the sub-basin will require improved information and decisive management actions. Many wildlife species found in the sub-basin are classified as threatened, endangered, sensitive, or of special concern under the federal Endangered Species Act or Washington State guidelines.

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Classification types are listed below:

  • Federal Endangered (FE)
  • Federal Threatened (FT)
  • Federal Candidate (FC)
  • State Endangered (SE)
  • State Threatened (ST)
  • State Sensitive (SS)


Federal and State listed species that may occur within this area include:


  • common loon [SS]
  • marbled murrelet [FT/SE]
  • yellow billed cuckoo [FT/SE]


  • bull trout [FT]
  • chinook salmon (Puget Sound) [FT]
  • steelhead (Puget Sound) [FT]

Amphibians & Reptile:

  • Northwestern Pond Turtle [SE]


Critical habitats are the specific areas, occupied by an endangered or threatened species at the time it was listed, that contain the physical or biological features that are essential to the conservation of that species and may need special management or protection. Critical habitat may also include areas not occupied by the species at the time of listing but are essential to its conservation.

  • bull trout
  • chinook salmon (Puget Sound)
  • steelhead (Puget Sound)

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General Resource Concerns


Nearshore areas and bays provide feeding and resting areas for waterfowl and herons. They are also rearing areas for juvenile fish.

Wetlands consisting of freshwater marshes and forested areas are found around the edges of Lake Washington, especially in the vicinity of Mercer Slough and Union Bay. All wetland types support a diverse array of bird, insect, fish, and wildlife species.

The rivers and streams throughout this region provide spawning and rearing habitat for various salmonid species. The associated riparian scrub and woodlands play crucial roles in supporting a large diversity and abundance of songbird species as breeding, migrating, and overwintering habitat.

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Subsurface Habitats – fresh water

Fine sediments (mud/silt/sand) are associated with slow and still water flows. Sediments may have aquatic vegetation present.

Animals associated with these areas tend to be cold or warm water fishes; birds (dabbling ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (freshwater clams); amphibians and reptiles (frogs, newts, salamanders, turtles, etc.); insects (caddisflies, mayflies, dragonflies, and stoneflies). Many other animals also utilize these areas for foraging.

Coarse sediments (gravel/cobble) – Associated with moderate water flow. Sediments may have aquatic vegetation present.

Animals associated with these areas tend to be: cold or warm water fishes; birds (dippers, harlequin ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (freshwater mussels, crayfish); amphibians and reptiles (tailed frogs, torrent salamanders; insects (caddisflies, stoneflies). Many other animals also utilize these areas for foraging.

Fish & Shellfish:

Several anadromous salmonid species are present in this region (including the listed bull trout, chinook, and steelhead). Spawning occurs throughout the rivers (Sammamish and Cedar) and the numerous smaller streams in the area. Several species of juvenile salmonids use the lower rivers and shallow nearshore areas extensively for feeding and rearing.

Resident fish present in the area include cutthroat and rainbow trout, kokanee salmon, bass, perch, and crappie.

Freshwater mussels (Oregon and western floaters) are present in vicinity of Mercer Island.


Raptors (bald eagle, osprey, and peregrine falcon) and great blue heron nest throughout the area. They may be found year-round.

Sheltered waters, including Union Bay, support significant overwintering waterfowl concentrations. The associated slough and wetland habitats also provide nesting and loafing habitat for resident waterfowl.

Marbled murrelet were documented in the vicinity of Andrews Bay and Seward Park.

Resident and migratory songbirds heavily utilize riparian habitats year-round and are susceptible to response activities in riparian vegetation. These songbirds are also susceptible to oiling or oil ingestion if riparian vegetation and shorelines become contaminated.

Mammals common to the region include deer and semi-aquatic species (beaver, river otter, mink and raccoon). These animals are vulnerable to contact with spilled oil.

Reptiles and amphibians (western pond turtle, salamanders, newts, etc.) are known to be present within the region.

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Specific Geographic Areas of Concern – Overview

Areas of concern include shorelines with natural riparian vegetation, islands, wetlands, stream and river mouths, and shallow water areas – especially adjacent to natural shorelines. Public parks, private lands, and recreational areas also surround the planning area. The number that precedes the area name in the list (below) corresponds to the numbered area on the map.

The lower sections of tributaries that drain to Lake Washington that are largely developed remain sensitive. They provide good habitat for the rearing of juvenile salmonids and support concentrations of migratory and wintering birds. Upstream areas are home to a large variety of wildlife, including fish and waterfowl. Wetlands are contained within these heavily developed urban areas. Public parks, private lands, and recreational areas surround the lake. Specific areas of concern are listed below and depicted on the map in Figure 6.1.

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  1. McAleer Creek: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Western brook
  2. Lower Sammamish River: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat.
  3. Saint Edward State Park: Forest and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Bald eagle and marbled murrelet. State
  4. Matthews Beach Park: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Raptors and great blue heron. City
  5. Juanita Bay: Wetland habitat. Waterfowl concentrations. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. City
  6. Yarrow Bay: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Raptors and
  7. Union Bay and University Slough: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Wetlands at the mouth of University Slough, along the Union Bay Natural Area, Foster Islands, and shoreline associated with the University of Washington Arboretum provide nesting and loafing opportunities for dabbler species, including wood ducks. Raptors, herons, and common loons present. Waterfowl concentrations area. Western pond turtles and river
  8. Andrews Bay/Baily Peninsula: Forest, wetland and riparian habitats. Marbled murrelet and raptors. Heron rookery adjacent to bay. City
  9. Mercer Slough: Wetland and riparian habitats. Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Heron and freshwater mussels. Western brook lamprey.
  10. May Creek: Forested and emergent wetlands along creek and tributaries (including Lake Boren). Salmonid (including listed chinook and steelhead) spawning and rearing habitat. Raptors. City
  11. Lower Cedar River: Wetland and riparian habitats. Salmonid (including listed bull trout, chinook and steelhead) rearing
  12. Quendall restoration site: Protected wetland habitat under CERCLA with 100′


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Specific Geographic Areas of Concern – Maps and Descriptions (Figure 6.1)


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Cultural Resources at Risk – Summary

Culturally significant resources are present within the planning area.  Information regarding the type and location of cultural resources is maintained by the Washington Department of Archeology and Historic Preservation (WDAHP). This sensitive information is made available to the Washington Department of Ecology for oil spill preparedness and response planning. The Tribal Historic Preservation Offices (THPOs) or Cultural Resource Departments of local tribes (see table below) may also be able to provide information on cultural resources at risk in the area and should be contacted, along with WDAHP, through normal trustee notification processes when significant oil spills, or smaller spills above reportable thresholds, occur in the area.

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During a spill response, after the Unified Command is established, information related to specific archeological concerns will be coordinated through the Environmental Unit. To ensure that tactical response strategies do not inadvertently harm culturally sensitive sites, WDAHP should be consulted before disturbing any soil or sediment during a response action, including submerged soils or sediments. WDAHP and/or the Tribal governments may assign a person or provide a list of professional archeologists that can be contracted, to monitor response activities and cleanup operations for the protection of cultural resources at risk. Due to the sensitive nature of such information, details regarding the location and type of cultural resources present are not included in this document.

LKWA-GRP Cultural Resource Contacts

Contact Phone Email
Washington Department of Archaeology and Historic Preservation (360) 890-2615
Muckleshoot Indian Tribe (253) 876-3272
Snoqualmie Tribe (425) 888-6551


Discovery of Human Skeletal Remains

The finding of human skeletal remains will be reported to the county medical examiner/coroner and local law enforcement in the most expeditious manner possible. The remains will not be touched, moved, or further disturbed. The county medical examiner/coroner will assume jurisdiction over the human skeletal remains and make a determination of whether those remains are forensic or non-forensic. If the county medical  examiner/coroner determines the remains are non-forensic, then they will report that finding to the Department of Archaeology and Historic Preservation (DAHP) who will then take jurisdiction over the remains. The DAHP will notify any appropriate cemeteries and all affected tribes of the find. The State Physical Anthropologist will make a determination of whether the remains are Indian or Non-Indian and report that finding to any appropriate cemeteries and the affected tribes. The DAHP will then handle all consultation with the affected parties as to the future preservation, excavation, and disposition of the remains.

Any human remains, burial sites, or burial-related materials that are discovered during a spill response must be treated with respect at all times (photographing human remains is prohibited to all except the appropriate authorities). Refer to National Historic Preservation Act Compliance Guidelines (NWACP Section 9403) during an emergency response.

Procedures for the Discovery of Cultural Resources

If any person monitoring work activities or involved in spill response believes that they have encountered cultural resources, all workers must stop immediately and notify the Unified Command and Cultural Resource Specialist. The area of work stoppage must be adequate to provide for the security, protection, and integrity of the material or artifact(s) discovered.

Prehistoric Cultural Resources (May include, but are not limited to, any of the following items):

  • Lithic debitage (stone chips and other tool-making byproducts)
  • Flaked or ground stone tools
  • Exotic rock, minerals, or quarries
  • Concentrations of organically stained sediments, charcoal, or ash
  • Fire-modified rock
  • Rock alignments or rock structures
  • Bone (burned, modified, or in association with other bone, artifacts, or features)
  • Shell or shell fragments
  • Petroglyphs and pictographs
  • Fish weirs, fish traps, and prehistoric water craft
  • Culturally modified trees
  • Physical locations or features (traditional cultural properties)
  • Submerged villages sites or artifacts

Historic cultural material (May include any of the following items over 50 years old):

  • Bottles, or other glass
  • Cans
  • Ceramics
  • Milled wood, brick, concrete, metal, or other building material
  • Trash dumps
  • Homesteads, building remains
  • Logging, mining, or railroad features
  • Piers, wharves, docks, bridges, dams, or shipwrecks
  • Shipwrecks or other submerged historical objects

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Economic Resources at Risk – Summary

Socio-economic sensitive resources are facilities or locations that rely on a body of water to be economically viable. Because of their location, they could be severely impacted if an oil spill were to occur. Economically sensitive resources are separated into three categories: critical infrastructure, water dependent commercial areas, and water dependent recreation areas. Another section lists economic resources for this planning area.

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General Information

Flight Restriction Zones: The Environmental Unit (Planning Section) may recommend flight restriction zones to minimize disturbance or injury to wildlife during an oil spill. Pilots/operators can decrease the risk of aircraft/bird collisions, prevent the accidental driving of wildlife into oiled areas, and minimize abandonment of nests by keeping a safe distance and altitude from these identified sensitive areas.

The Air Operations Branch (Operations Section) will manage all aircraft operations related to a response and will coordinate the establishment of any Flight Restriction Zones as appropriate. Environmental Unit staff will work with the Air Operations Branch Director to resolve any conflicts that arise between flight activities and sensitive resources.

In addition to restrictions associated with wildlife, Tribal authorities may also request notification when overflights are likely to affect culturally sensitive areas within reservations. See Oil Spill Best Management Practices (NWACP Section 9301) for more information on the use of aircraft and helicopters in open water and shoreline responses.

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Wildlife Deterrence: The Wildlife Deterrence Unit within the Wildlife Branch (Operations Section) manages wildlife deterrence operations. These are actions intended to minimize injuries to wildlife by keeping animals away from the oil and cleanup operations. Deterrence activities may include using acoustic or visual deterrent devices, boats, aircraft or other tools. The Wildlife Branch works with state and federal agencies, and the Environmental Unit (Planning Section), to develop deterrence plans as appropriate.

For more information, see the Northwest Wildlife Response Plan (NWACP Section 9310) and Northwest Area Wildlife Deterrence Resources (NWACP Section 9311).

Oiled Wildlife: Capturing oiled wildlife may be hazardous to both personnel and the affected animals. Incident personnel should not try to approach or capture oiled wildlife but should report any observations of oiled wildlife to the Wildlife Branch (Operations Section). For more information, see the Northwest Wildlife Response Plan (NWACP Section 9310).

Wildlife Refuges and Wilderness Areas: There are no federally designated wilderness areas present in this GRP region.

Aquatic Invasive Species: The waters of this region may contain aquatic invasive species (AIS) – species of plants and/or animals that are not native to an area and that can be harmful to an area’s ecosystem. If so, preventative actions may be required to prevent the spread of these species as a result of spill response activities and the Environmental Unit is able to recommend operational techniques and strategies to assist with this issue.

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