Warden Washington GRP

  • Interim update: 2021
  • Last full updated: 2017
  • Public Comment: GRPs@ecy.wa.gov

Table of Contents


Site Description

This section provides a description of the physical features, hydrology, climate and winds, and tides and currents found in the Warden Washington GRP planning area, and an oil spill risk assessment in Section 2.6. The planning area extends from the Moses Lake/Crab Creek GRP in the west to the road mileage marker 192 on Interstate 90 in the east. The Warden Washington GRP encompasses a number of irrigation canals that are part of the Columbia Basin Project managed by the U.S. Bureau of Reclamation. Water flows slowly through these canals in a southwesterly direction toward the Potholes Reservoir. Some of the watercourses in this area include East Low Canal, Lind Coulee, Rocky Coulee, and Weber Coulee. The planning area covers approximately 131 square miles and fully resides within the Water Resource Inventory Area Lower Crab (WRIA 41). The communities of Warden and Wheeler are located within the boundaries of this planning area, as well as portions of Grant County.

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Physical Features

Volcanic activity built up a stratum of mud, ash, and lava in the geologic column in the area now known as eastern and central Washington and Oregon during the Eocene (55.8-33.9 million years ago), Oligocene (33.9-23 million years ago), and Miocene (23-5.3 million years ago) Epochs (UCMP). Basalt flows, known as the Columbia River Basalt Group, then covered the area in layers forming a strong foundation of basaltic rock at least one mile thick (HugeFloods). Towards the end of the Pleistocene (~16,000-14,000 years ago) the Missoula floods battered the area over 100 times when the glacial dam forming Glacial Lake Missoula was repeatedly breached. Moses Lake and the surrounding area lie within the Channeled Scablands of east-central Washington, a complex of “vein-like” channels, rock basins, broad coarse-grained alluvial deposits, and loess islands created by these floods. This series of events has been described as one of the greatest flood occurrences in the history of the earth.

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The Warden Washington GRP planning area covers approximately 131 square miles of flat to gently rolling arid farmland directly east of Moses Lake. Most of the surface water in this planning area is in the form of man-made irrigation canals. The largest and longest (10.5 miles) in the area is East Low Canal which brings water south from the Columbia River for irrigation. Other canals in the area include Weber Coulee, Lind Coulee, and Rocky Coulee. The land in this planning area is used almost exclusively for farming. Only one small town, Wheeler, exists within the planning area. No tribal reservations are present, however the Colville, Nez Perce, and Spokane Tribes have potential interests in the area due to their usual and accustomed fishing places. Interstate 90, the major highway in eastern Washington, goes east-west through the center of the area. The only other major road is Highway 17, traversing the western side of the area in a northwest –southeast direction. The Columbia Basin Railroad has 32 miles of track, traveling both north-south and east-west through the planning area.

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The water that sustains agriculture in the planning area is diverted from the Columbia River by the Grand Coulee Dam. A series of dams, reservoirs, and canals moves this water throughout the 670,000-square acre area known as the Columbia Basin Project. The U.S. Bureau of Reclamation manages this project to promote agriculture in Adams, Franklin, and Grant Counties (USBR).

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This irrigation water is recycled before it returns to the Columbia River near Pasco. This practice of water reuse boosts availability by 1 million acre-feet. For example, Potholes Reservoir to the south of Moses Lake collects runoff from the north for use by other farms in the south. In the planning area itself, there are ten miles of the East Low Canal as it directs water to the Scooteney Reservoir to the southeast of Othello. There are no USGS stations tracking velocity and river height.

The planning area resides entirely within Water Resource Inventory Area Lower Crab (WRIA 41).

Lower Crab (WRIA 41):  The Lower Crab Watershed located in eastern Washington includes the portion of the Crab Creek between Ephrata and its confluence with the Columbia River. In addition, there are numerous tributary creeks and streams of which most are seasonal. Annual precipitation ranges from seven inches per year in the Beverly area, to over ten inches in the higher elevations. Only a fraction of this precipitation becomes groundwater available for human and economic uses. Most of the precipitation arrives during the winter months, when water demands are the lowest. During the summer, the snowpack is gone, there is little rain, and naturally low stream flows are dependent on groundwater inflow. This means that groundwater and surface water are least available when water demands are the highest.

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Climate and Winds

The temperatures in the Central Basin area vary dramatically, with winter lows below freezing from November to March, and highs in the high 80s from July to August. Moses Lake averages zero inches of snowfall in the winter months. Total precipitation averages nine inches annually.

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Wind speed at Grant County International Airport averages 7.3 mph. Winds in the Warden area tend to blow from the southwest year-round. Grant County experiences elevated wind speeds, typically in the fall and spring, with wind gusts reaching 45 mph. In December 2016, the highest wind speed was recorded at 36 mph (NOAA).

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Tides and Currents

The flow speed varies based upon the grade of the canals and the time of year.  Fieldwork conducted in March – when the monthly precipitation total is approximately 0.8 inches – recorded current speeds from zero to one knot. Moses Lake experiences the highest amount of precipitation in December and the smallest amount in August.  There is no tidal influence in the planning area.

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Risk Assessment

The Warden Washington area is plentiful in natural, cultural, and economic resources, all at risk of injury from oil spills. Potential oil spill risks include, but are not limited to, road transportation, rail transportation, aircraft, and other oil spill risks. This section briefly discusses these risks and how they could impact the GRP planning area.

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Road Systems: Vehicle traffic on roadways pose an oil spill risk in areas where they run adjacent to the shorelines, or cross over lakes, rivers, creeks, and ditches that drain into the Potholes Reservoir. Interstate 90 carries traffic between Washington and Massachusetts and poses the most significant risk of highway spills, due to the frequency of large tank trucks carrying a number of fuel types. State Highway 17 does not have the traffic capacity of I-90 but is more convenient to move between smaller Central Basin communities, so there is potentially high use by agriculture trucks and local fuel trucks serving the communities of Grant County. A vehicle spill onto one of these bridges or roadways can cause fuel or oil to flow from hardened surfaces into the Warden Washington or its tributaries. Commercial trucks can contain hundreds to thousands of gallons of fuel and oil, especially fully loaded tank trucks, and may carry almost any kind of cargo, including hazardous waste or other materials that might injure sensitive resources if spilled. Smaller vehicle accidents pose a risk as well, a risk commensurate to the volume of fuel and oil they carry.

Rail Transportation and Facilities: Rail companies transport oil via manifest trains in this area. Manifest trains include: up to four locomotives, a mix of non-oil merchandise cars, and one or more 714-barrel (29,998 gallon) capacity USDOT-approved tank cars carrying refined oil products, such as diesel, lubrication oil, or gasoline. These trains may 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 an approximate capacity of 5,000 gallons of diesel fuel.  Manifest trains may also transport biological oils and non-petroleum chemicals.

Within the planning area, the Columbia Basin Railroad owns all 32 miles of commercial railroad tracks. Interchanging with BNSF in Connell, the line runs north to Moses Lake while serving communities along the route like Bruce and Warden. The main commodities hauled on this line are agricultural goods, including biological oils such as canola and soybean.

Aircraft: The Grant County International Airport lies six miles to the northwest of the WWA-GRP area, and is owned and operated by the Port of Moses Lake. It boasts five runways and an onsite FAA control tower. These features make it one of the largest airfields in the country and can accept the biggest aircraft in the world. Given the airport’s capacity, it is a major place to test both military and commercial planes (Port of Moses Lake). Since this airport is close to the planning area, the potential exists for aircraft failures during inbound or outbound flights that result in a spill by releasing aviation fuel to one of the numerous irrigation canals.

Other Spill Risks: Other potential oil spill risks in the area include, fuel storage areas (including waste oil storage), road run-off during rain events, on-land activities where heavy equipment is being operated or stored, and the migration of spilled oil through soil on lands adjacent to the irrigation canals.

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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. A list of economic resources in the area is provided in the appendix.

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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

This area is composed of a variety of aquatic, riparian, and upland habitats. These habitats support a diversity of wildlife species, including large and small mammals, songbirds, birds of prey, upland birds, and other waterfowl, as well as reptiles and amphibians. Some species are resident throughout the year; while others seasonally migrate through the area.

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Several of the species found in this area have been classified under the Federal Endangered Species Act or by the Washington State Fish and Wildlife commission.

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 Threatened, Endangered, and Sensitive species that may occur within this area, at some time of the year, include:


  • Columbian Basin pygmy rabbit [FE/SE]


  • American white pelican [ST]
  • common loon [SS]
  • sandhill crane [SE]
  • yellow-billed cuckoo [FT/SE]


  • Spalding’s catchfly [FT]

Critical habitats:

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

There is no federally designated critical habitat within this area.

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General Resource Concerns


  • Streams and watercourses are important habitat features throughout in this semi-arid region and help support numerous wildlife species including resident fish.
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  • Wetlands in this region range from freshwater emergent, freshwater forested, freshwater ponds and lakes. All wetland types support a diverse array of bird, insect and fish and wildlife species.
  • Riparian areas serve as transitional zones between the uplands and the rivers and consequently are heavily used by a variety of wildlife. They contribute to nearshore fish habitat by providing shade, cover, and food. They also play a crucial role in supporting a large diversity and abundance of songbird species as breeding, migrating, and overwintering habitat.
  • Shrub-steppe habitat in this region supports many species of wildlife, including some that can only be found in these semi-arid communities – such as greater sage-grouse, sage sparrow, sage thrasher, and Columbian Basin pygmy rabbit.
  • Subsurface habitats

The shallow subsurface habitats that occur within this region include:

  • Fine sediments (mud/silt/sand) – Associated with slow/still water flows. May have aquatic vegetation present.
    • Animals associated with these areas may be: resident fishes; birds (dabbling and diving ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (freshwater clams); amphibians and reptiles (frogs, newts, salamanders, turtles, etc.); insects caddis flies, mayflies, dragonflies, and stoneflies). Many other animals also utilize these areas for foraging.
  • Coarse sediments (gravel/cobble) – Associated with moderate water flow. May have aquatic vegetation present.
    • Animals associated with these areas may be: resident fishes; birds (dippers, harlequin ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (western pearlshell mussels, crayfish); amphibians and reptiles (tailed frogs, torrent salamanders; insects caddis flies, stoneflies). Many other animals also utilize these areas for foraging.


  • Resident species including trout (cutthroat and rainbow) and various warm water species (bass, etc.) are also present throughout this area.


  • Waterfowl concentrations of various species may be found throughout the region in wetlands and agricultural fields near rivers and creeks. Large concentrations are especially prevalent from fall through spring.
  • Resident and migratory songbirds heavily utilize riparian habitats year-round and are susceptible to response activities that disturb riparian vegetation.
  • Mammals common to the region include managed species such as mule and whitetail deer, etc. Other mammals present include semi-aquatic species such as beaver, muskrat, river otter, mink and raccoon. These latter species are vulnerable to contact with spilled oil because of their habitat preferences.
  • Amphibians and reptiles are found throughout this area.

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Specific Geographic Areas of Concern – Overview

  1. Agricultural fields (south of Moses Lake): Significant waterfowl concentration area with very large overwintering concentrations of waterfowl.
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  1. Rocky Coulee (Road W NE): Shrub-steppe and isolated wetland habitats.
  2. Water Impoundment (vicinity of I-90/Rd U NE): Waterfowl concentration and breeding area. WDFW Wildlife Area.
  3. Lind Coulee: Shrub-steppe, riverine, and wetland habitats. Pheasant, burrowing owl, and songbird presence. Resident fish.

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Specific Geographic Areas of Concern – Maps and Descriptions

Figure 1: Specific Geographic Areas of Concern for Warden Washington GRP.

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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 6‑1) 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. In order 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.

Table 6-1: WWA-GRP Cultural Resources Contacts

Contact Phone Email
Washington Department of Archaeology and Historic   Preservation (WDAHP) (360) 586-3065  Rob.Whitlam@dahp.wa.gov
Coeur D’Alene Tribe, THPO  (208) 686-1572  jwagner@cdatribe-nsn.gov
 Confederated Tribes of the Colville Reservation, THPO (509) 634-2695  guy.moura@colvilletribes.com
Nez Perce Tribe, Spill Response and Water Quality (208) 621-3893  keithb@nezperce.org
 Spokane Tribe of Indians, THPO (509) 258-4315  randya@spokanetribe.com

Discovery of Human Skeletal 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.

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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.

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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.

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 federal wildlife refuges or wilderness areas within this area.

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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