Chapter 3

Physical Environment

Chapter 5HumanEnvironment

Chapter 3PhysicalEnvironment

© Mary Marsh

Appendices

Chapter 4BiologicalEnvironment

Chapter 1Introduction andBackground

Chapter 2ManagementDirection

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Chapter 3. Physical Environment 3-1 

Chapter 3. Physical Environment 

3.1 Climate and Climate Change 

3.1.1 General Climate Conditions 

The climate at Dungeness National Wildlife Refuge (NWR) is a mild, midlatitude west coast marine 

type. Because of the moderating influence of the Pacific Ocean, extremely high or low temperatures 

are rare. Summers are generally cool and dry while winters are mild but moist and cloudy with most 

of the precipitation falling between November and January (USDA 1987, WRCC 2011a). Annual 

precipitation in the region is low due to the rain shadow cast by the Olympic Mountains and the 

extension of the Coastal Range on Vancouver Island (Figure 3-1). Snowfall is rare or light. During 

the latter half of the summer and in the early fall, fog banks from over the ocean and the Strait of 

Juan de Fuca cause considerable fog and morning cloudiness (WRCC 2011a). 

Climate Change Trends 

The greenhouse effect is a natural phenomenon that assists in regulating and warming the 

temperature of our planet. Just as a glass ceiling traps heat inside a greenhouse, certain gases in the 

atmosphere, called greenhouse gases (GHG), absorb and emit infrared radiation from sunlight. The 

primary greenhouse gases occurring in the atmosphere include carbon dioxide (CO2), water vapor, 

methane, and nitrous oxide. CO2 is produced in the largest quantities, accounting for more than half 

of the current impact on the Earth’s climate. 

A growing body of scientific evidence has emerged to support the fact that the Earth’s climate has 

been rapidly changing and the magnitude of these alterations is largely due to human activities (IPCC 

2007a, NAS 2008, USGCRP 2009). Although climate variations are well documented in the Earth’s 

history, even in relatively recent geologic time (e.g., the Ice Age of approximately 10,000 years ago), 

the current warming trend differs from shifts earlier in geologic time in two ways. First, this climate 

change appears to be driven primarily by human activities such as deforestation and the burning of 

fossil fuels which results in a higher concentration of atmospheric GHG. Second, atmospheric CO2 

and other greenhouse gases, levels of which are strongly correlated with the Earth’s temperature, are 

now higher than at any time during the last 800,000 years (USGCRP 2009). Prior to the start of the 

Industrial Revolution in 1750, the amount of CO2 in the atmosphere was about 280 parts per million 

(ppm). Current levels are about 390 ppm and are increasing at a rate of about 2 ppm/year (DOE 

2012). The current concentration of CO2 and other greenhouse gases as well as the rapid rate of 

increase in recent decades are unprecedented in the prehistoric record (Ibid). 

The terms “climate” and “climate change” are defined by the Intergovernmental Panel on Climate 

Change (IPCC). The term “climate” refers to the mean and variability of different types of weather 

conditions over time, with 30 years being a typical period for such measurements, although shorter or 

longer periods also may be used (IPCC 2007b). The term “climate change” thus refers to a change in 

the mean or variability of one or more measures of climate (e.g., temperature or precipitation) that 

persists for an extended period, typically decades or longer, whether the change is due to natural 

variability, human activity, or both (Ibid). 
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Figure 3-1. Washington State Average Annual Precipitation from 1971 to 2000 

Scientific measurements spanning several decades demonstrate that changes in climate are occurring, 

and that the rate of change has been faster since the 1950s (Figure 3-2). Examples include warming 

of the global climate system, and substantial increases in precipitation in some regions of the world 

and decreases in other regions (e.g., IPCC 2007b, Solomon et al. 2007). In the Pacific Northwest, 

increased greenhouse gases and warmer temperatures have resulted in a number of physical and 

chemical impacts. These include changes in snowpack, stream flow timing and volume, flooding and 

landslides, sea levels, ocean temperatures and acidity, and disturbance regimes such as wildfires, 

insect, and disease outbreaks (USGCRP 2009). All of these changes will cause major perturbations to 

ecosystem conditions, possibly imperiling species that evolved in response to local conditions. 

Results of scientific analyses presented by the IPCC show that most of the observed increase in 

global average temperature since the mid-20th century cannot be explained by natural variability in 

climate, and is “very likely” (defined by the IPCC as 90 percent or higher probability) due to the 

observed increase in greenhouse gas (GHG) concentrations in the atmosphere as a result of human 

activities, particularly carbon dioxide emissions from use of fossil fuels (IPCC 2007b, Solomon et al. 

2007). Further confirmation of the role of GHGs comes from analyses by Huber and Knutti (2011), 

who concluded that it is extremely likely that approximately 75 percent of global warming since 

1950 has been caused by human activities. 

In the Northern Hemisphere, recent decades appear to be the warmest since at least about A.D. 1000, 

and the warming since the late 19th century is unprecedented over the last 1,000 years. Globally, 

including 2011, the first 11 years in the 21st century (2001 to 2011) rank among the 13 warmest years 

in the 130-year instrumental record (1880 to present) according to independent analyses by NOAA 

and NASA. 2010 and 2005 are tied as the warmest years in the instrumental record and the new 2010 

record is particularly noteworthy because it occurred in the presence of a La Niña and a period of low 
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Chapter 3. Physical Environment 3-3 

solar activity, two factors that have a cooling 

influence on the planet. However, in general, 

decadal trends are far more important than any 

particular year’s ranking. 

Trends in global precipitation are more difficult 

to detect than changes in temperature because 

precipitation is generally more variable and 

subject to local topography. However, while there 

is not an overall trend in precipitation for the 

globe, significant changes at regional scales can 

be found. Over the last century, there have been 

increases in annual precipitation in the higher 

latitudes of both hemispheres and decreases in the 

tropical regions of Africa and southern Asia 

(USGCRP 2009). Most of the increases have 

occurred in the first half of the 20th century and it 

is not clear that this trend is due to increasing 

greenhouse gas concentrations. 

Just as important as precipitation totals are 

changes in the intensity, frequency, and type of 

precipitation. Warmer climates, owing to 

increased water vapor, lead to more intense 

precipitation events, including more snowstorms 

and possibly more flooding, even with no change 

in total precipitation (Dominguez et al. 2012). 

The frequency of extreme single-day precipitation 

events has increased, especially in the last two decades. Paradoxically more droughts and heat waves 

have occurred because of hotter, longer-lasting high pressure systems. 

3.1.2 Air Temperatures 

There is no climate/weather station established on Dungeness NWR; however, temperature data have 

been consistently collected since October 1980 at the Sequim 2 E station (number 457544) located 

approximately 7 miles east of the Refuge. The proximity of this station to the Refuge provides 

valuable regional data. Table 3-1 provides a summary of the period of record. 

As a result of the ocean’s proximity, winter minimum and summer maximum temperatures are 

moderated. On average, 91.7 days per year experience minimum temperatures at or below freezing 

while 0.1 days per year experience temperatures at or below 0°F (WRCC 2011b). The coldest 

weather is usually associated with an outbreak of cold air from the interior of Canada. The first 

occurrence of freezing temperatures is usually in October (WRCC 2011c). The date of the last 

freezing temperatures in the spring ranges from the latter half of April to the first half of May 

(WRCC 2011d). Also, it is only in the extreme occurrences that temperatures have been recorded to 

exceed 90°F (WRCC 2011b). 

 

Figure 3-2. Global Annual Average 

Temperature and CO2 from 1880-2008 

(NOAA 2012a) 
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Table 3-1. Air Temperature Summary near Dungeness NWR (WRCC 2011b) 

Temperatures (°F) Sequim 2 E 

Oct. 1980 – Dec. 2010 

Average Monthly Temperature – High 57.6 

Average Monthly Temperature – Low 39.3 

Monthly Mean Winter Temperature – High 47.0 

Monthly Mean Winter Temperature – Low 31.2 

Monthly Mean Summer Temperature – High 68.6 

Monthly Mean Summer Temperature – Low 49.0 

Daily Maximum Extreme – High 94 

Daily Maximum Extreme – Low 63 

Daily Minimum Extreme – High 39 

Daily Minimum Extreme – Low -3 

Mote (2003) observed that the Pacific Northwest region experienced warming of approximately 

1.5°F during the 20th century. Fu et al. (2010) found that in Washington State from 1952 to 2002, 

annual mean air temperature increased 1.1°F (daily mean), 0.43°F (daily maximum), and 1.67°F 

(daily minimum), on average. For trends local to the Refuge we turn to the United States Historical 

Climatology Network (USHCN) which provides a high quality data set of daily and monthly records 

of basic meteorological variables from 1,218 observing stations throughout the continental U.S. The 

data have been corrected to remove biases or heterogeneities from nonclimatic effects such as 

urbanization or other landscape changes, station moves, and instrument and time of observation 

changes. The closest station is Port Angeles and trends are provided in Table 3-2 and Figure 3-3. The 

average yearly temperature change has increased 0.34°F over the past 30 years, and more striking are 

the seasonal trends which show warmer winters, summers, and falls than the yearly trends, and 

cooler springs (Table 3-2). 

Table 3-2. Seasonal Temperature Trends, 1981-2010 (USHCN 2012) 

Port Angeles, WA United States Historical Climatology Network Observation Station 

Monthly Absolute Change Maximum Temp. Average Temp. Min. Temp. 

Winter (Dec-Feb) +1.36°F +0.63°F -0.11°F 

Spring (March-May) -0.60°F -0.48°F -0.36°F 

Summer (Jun-Aug) +0.46°F +0.69°F +0.93°F 

Fall (Sept-Nov) +0.36°F +0.56°F +0.77°F 

The graph below illustrates a sample of these temperature trends using monthly data. The most recent 

30-year period is calculated using the slope of the linear trend line, and temperature change is shown 

as an absolute change over the 30-year period. A water year is defined as the 12-month period from 

October 1, for any given year, through September 30 of the following year. The water year is 

designated by the calendar year in which it ends and which includes 9 of the 12 months. 

 
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Figure 3-3. Water Year Temperature 1925-2010 at Port Angeles, WA (USHCN 2012) 

Future Trends 

Scientists use a variety of climate models, which include consideration of natural processes and 

variability, as well as various scenarios of potential levels and timing of GHG emissions, to evaluate 

the causes of changes already observed and to project future changes in temperature and other 

climate conditions (Meehl et al. 2007, Ganguly et al. 2009, Prinn et al. 2011). All combinations of 

models and emissions scenarios yield very similar projections of increases in the most common 

measure of climate change, average global surface temperature (commonly known as global 

warming), until about 2030. Although projections of the magnitude and rate of warming differ after 

about 2030, the overall trajectory of all the projections is one of increased global warming through 

the end of this century, even for the projections based on scenarios that assume that GHG emissions 

will stabilize or decline. Thus, there is strong scientific support for projections that warming will 

continue through the 21st century, and that the magnitude and rate of change will be influenced 

substantially by the extent of GHG emissions (IPCC 2007c, Meehl et al. 2007, Ganguly et al. 2009, 

Prinn et al. 2011). 

The statistical downscaling of an ensemble of 20 global climate models and two carbon emissions 

scenarios for each model run projects average annual temperature for the Pacific Northwest to 

increase 2.0°F (1.1°C) by the 2020s, 3.2°F (1.8°C) by the 2040s, and 5.3°F (3.0°C) by the 2080s, 

relative to the 1970-1999 average temperature (Mote and Salathé 2009, 2010). The projected changes 

in average annual temperature are substantially greater than the 1.5°F (0.8°C) increase in average 

annual temperature observed in the Pacific Northwest during the 20th century. Seasonally, summer 

temperatures are projected to increase the most. The emissions scenarios modeled included the A1B 

scenario, which assumes moderate greenhouse gas emissions in the future, and the B2 scenario, 

which assumes low greenhouse gas emissions in the future. Actual global emissions of greenhouse 
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3-6 Chapter 3. Physical Environment 

gases in the past decade have so far exceeded even the highest IPCC emissions scenario (A2), which 

was not included in Mote and Salathé (2009, 2010) or Salathé et al. (2010). Consequently, if these 

emissions trends continue the climate projections referenced herein likely represent a conservative 

estimate of future climatic changes. 

The two regional climate simulations (Salathé et al. 2010) using a dynamical downscaling method 

with two global climate models (the CCSM3 and ECHAM5 – to specify boundary climate conditions 

within the region) support the warming increases described above, with small variations – one model 

slightly higher and one slightly lower. Both regional climate models project increases in heat wave 

frequency and the frequency of warm nights throughout the State of Washington. Figure 3-4 shows 

these modeled, downscaled temperature projections for the Dungeness-Elwha watershed (HUC 

17110020) (Hamlet et al. 2010). 

Figure 3-4. Projected Temperature Changes for the Dungeness-Elwha Watershed under Two 

Emission Scenarios (Hamlet et al. 2010) 

Note: A1B is a higher emission scenario than B1. Current rates are higher than both A1B and B1. 
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3.1.3 Precipitation 

The prevailing wind direction across the Olympic Peninsula from the southwest, means that storms 

frequently drop their moisture on the west side of the Olympic Mountains. Consequently, the 

relatively low precipitation at Dungeness NWR is the result of its location in the “rain shadow.” The 

rain shadow is an area that extends east from Port Angeles towards Everett and north into the San 

Juan Islands (Bach 2004). 

The discussion below includes data from the climate station closest to Dungeness NWR, located in 

Sequim. An average of 8.12 inches, or roughly 50 percent of the annual precipitation, at this station 

occurs during late fall and winter in the months of November, December, January, and February. By 

comparison, the summer months of June, July, and August receive an average of 2.11 inches, a scant 

13 percent of the annual precipitation. Additionally, the rate of rainfall within the rain shadow differs 

from other areas on the Olympic Peninsula. This area frequently receives drizzle or light rain while 

other localities are experiencing light to moderate rainfall (WRCC 2011a). On average, 5 days per 

year experience more than 0.50 inch of precipitation and 1 day greater than 1.00 inch (WRCC 

2011e). Snow events are infrequent. However, snowfall increases with distance from water and rise 

in terrain. Consequently, the snow is a major source of water for the Dean Creek system, which 

passes through the Dawley Unit. Precipitation data for Sequim are summarized in Table 3-3. 

Table 3-3. Precipitation Summary near Dungeness NWR (WRCC 2011e) 

Precipitation 

(inches) 

Sequim 2 E 

Oct. 1980 – Dec. 2010 

Average Annual Precipitation 16.02 

Average Annual Snowfall 1.5 

Average Monthly Snowfall Range (winter) 0.2 to 0.9 

Highest Annual Snowfall 13.7 (1989) 

Highest Monthly Snowfall 25.0 (Dec. 1996) 

Wettest Year on Record 20.51 (1997) 

Driest Year on Record 11.35 (1994) 

Wettest Season on Record 9.18 (winter 1997) 

Driest Season on Record 0.41 (summer 2003) 

Longer-term precipitation trends in the Pacific Northwest are more variable than temperature and 

vary with the period of record analyzed (Mote et al. 2005). The Pacific Northwest experiences wide 

precipitation variability based on geography and seasonal and year-to-year variability (Salathé et al. 

2010). Looking at the period 1920 to 2000, total annual precipitation has increased almost 

everywhere in the region, though not in a uniform fashion. Most of that increase occurred during the 

first part of the record with decreases more recently (Mote et al. 2005). 

Precipitation trends from the Port Angeles USHCN observation station shows the average yearly 

precipitation change has decreased more than 5% over the past 30 years, with more striking 

decreases in the winter and increases in the summer (Table 3-4 and Figure 3-5). 

 
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Table 3-4. Seasonal Precipitation Trends, 1981-2010 (USHCN 2012) 

Port Angeles, WA, United States Historical Climatology Network Observation Station 

Monthly Precipitation 30-year Change % from 1981 Value 

Winter (Dec-Feb) -17.1% 

Spring (March-May) 14.3% 

Summer (Jun-Aug) -4.1% 

Fall (Sept-Nov) -1.6% 

Figure 3-5. Water Year Total Precipitation 1925-2010 at Port Angeles, WA (USHCN 2012) 

Future Trends 

On a global scale, warmer temperatures are predicted to lead to a more vigorous hydrologic cycle, 

translating to more severe droughts and/or floods (IPCC 1996). Observations of Pacific Northwest 

precipitation trends through the 20th century indicate a region-wide increase of 14% for the period 

1930-1995. Sub-regional trends ranged from 13% to 38% (Mote 2003). However, these trends are 

not statistically significant and depend on the time frame analyzed. Thus, decadal variability has 

dominated annual precipitation trends. Cool season precipitation variability, though, has increased 

(Hamlet and Lettenmaier 2007). 

Using data derived from the statistical downscaling of 20 global climate models, projected changes in 

annual precipitation within the Pacific Northwest throughout the 21st century, averaged over all 

models, are small (+1% to +2%) though individual models produce changes of as much as -10% or 

+20% by the 2080s. Some models project an enhanced seasonal cycle with changes toward wetter 

autumns and winters and drier summers (Mote and Salathé 2010). However, even small changes in 

seasonal precipitation could have impacts on streamflow flooding, summer water demand, drought 

stress, and forest fire frequency. Additionally, researchers have consistently found that regional 

climate model simulations yield an increase in the measures of extreme precipitation. This finding 

suggests that extreme precipitation changes are more related to increased moisture availability in a 
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Chapter 3. Physical Environment 3-9 

warmer climate than to increases in climate-mean precipitation (Leung et al. 2004, Salathé et al. 

2010). Salathé et al. (2010) project increased extreme precipitation events in the State of Washington, 

with stronger increases in the northwestern portion of the state. The fraction of precipitation falling 

on days with precipitation exceeding the 20th century 95th percentile is projected to increase 

throughout the state. It is important to note that the one conclusion shared by researchers is that there 

is greater uncertainty in precipitation projections than that of temperature predictions and models 

(Leung and Qian 2003, CIG 2004, Salathé et al. 2010). Figure 3-6 shows these modeled, downscaled 

precipitation projections for the Dungeness-Elwha watershed (HUC 17110020) (Hamlet et al. 2010). 

Figure 3-6. Projected Precipitation Changes for the Dungeness-Elwha Watershed under Two 

Emission Scenarios (Hamlet et al. 2010) 

Note: A1B is a higher emission scenario than B1. Current rates are higher than both A1B and B1. 

3.1.4 Wind 

During the spring and summer, the semipermanent low-pressure cell over the North Pacific Ocean 

becomes weak and moves north beyond the Aleutian Islands. Meanwhile, a high-pressure area 

spreads over the North Pacific Ocean. Air circulates in a clockwise direction around the highpressure cell bringing prevailing westerly and northwesterly winds. This seasonal flow is 

comparatively dry, cool, and stable (WRCC 2011a). 
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In the fall and winter, the high-pressure cell weakens and moves southward while the Aleutian lowpressure cell intensifies and migrates southward as well. It reaches its maximum intensity in 

midwinter. Wind direction switches to primarily southwesterly or westerly prevailing winds. The air 

mass over the ocean is moist and near the temperature of the water. As it moves inland, it cools and 

condenses, bringing the beginning of the wet season (WRCC 2011a). 

Wind data collected hourly from an automated station located 14.5 miles west of the Dungeness 

NWR at the William R. Fairchild International Airport in Port Angeles, have been used to draw 

generalizations about wind activity in/on the Refuge (Table 3-5). Average wind speeds have been 

calculated on hourly data collected from 1996 to 2006. The highest average wind speeds occurred 

during the summer months of June and July. The calmest months were during the fall months of 

October and November. 

Prevailing wind direction, defined as the direction with the highest percent of frequency, was 

calculated from hourly data during 1996 to 2006. Westerly winds occur from March through 

October, switching to southwesterly winds in November, and then to west-southwest during January, 

and southwest winds in February. 

Table 3-5. Wind Data Summary for Port Angeles (WRCC 2011f) 

Port Angeles 

Prevailing Wind Direction W 

Average Annual Wind Speed 5.2 mph 

Average Monthly Wind Speed Range 4.2 (Jan., Oct., Nov.) – 6.6 (Jun., Jul.) mph 

The open waters of the Strait of Juan de Fuca periodically allow very strong winds to develop, 

particularly during midlatitude cyclone events (Reed 1980). Wantz and Sinclair (1981) published 

estimates of extreme winds in the Northwest. They estimate that speeds within the vicinity of 

Dungeness NWR sustained for an average of one minute and recurring on average every two years 

are as high as 50 mph, while fifty-year events would produce winds of approximately 68 mph. Peak 

gusts would be about 32% higher. 

As a rule, tornadoes are infrequent in Washington and generally small in the northwestern part of the 

United States. The National Climatic Data Center maintains a database that provides information on 

the incidence of tornadoes reported in each county in the United States. This database reports that 

107 tornadoes were reported in Washington from 1950 to 2011. No tornadoes have ever been 

reported in Clallam County (NCDC 2011). 

3.1.5 Climate Cycles in the Pacific Northwest 

Two climate cycles have major influences on the climate and hydrologic cycles in the Pacific 

Northwest: the El Niño/Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). In 

El Niño years, average sea surface temperatures in the central and eastern equatorial Pacific Ocean 

are warmer than average and easterly trade winds in the tropical Pacific are weakened. A La Niña is 

characterized by the opposite – cooler than average sea surface temperatures and stronger than 

normal easterly trade winds. These changes in the wind and ocean circulation can have global 

impacts to weather events. The ENSO influence on Pacific Northwest climate is strongest from 

October to March. During an El Niño event, the winters tend to be warmer and drier than average. La 

Niña winters tend to be cooler and wetter than average. Each ENSO phase typically lasts 6 to 18 
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Chapter 3. Physical Environment 3-11 

months and the shift between the two conditions takes about four years (CIG 2011, Conlan and 

Service 2000). 

Like ENSO, the PDO is characterized by changes in sea surface temperature, sea level pressure, and 

wind patterns. The PDO is described as being in one of two phases: warm and cool. During a warm 

phase, sea surface temperatures near the equator and along the coast of North America are warmer 

while in the central north Pacific they are cooler. During a cool phase, the patterns are opposite. 

Within the Pacific Northwest, warm phase PDO winters tend to be warmer and drier than average 

while cool phase PDO winters tend to be cooler and wetter than average. A single warm or cool PDO 

phase lasts 20-30 years. The triggering cause of the PDO phase shift is not understood. 

The potential for temperature and precipitation extremes increases when ENSO and PDO are in the 

same phases and thereby reinforce each other. When ENSO and PDO are in opposite phases, their 

opposite effects on temperature and precipitation can cancel each other out, but not in all cases and 

not always in the same direction (CIG 2011). 

Future Trends 

Based on the evidence of the history of ENSO and PDO events, it is likely that these cycles will 

continue to occur far into the future. However, the potential influence of anthropogenic climate 

change on ENSO and PDO is unknown because more information is needed by the experts. 

3.2 Hydrology 

3.2.1 Refuge Hydrology 

The circulation of Salish Sea region, which includes the Straits of Georgia, Juan de Fuca, and Puget 

Sound, is driven by tidal currents, the surface outflow of freshwater from river systems, and the deep 

inflow of saltwater from the ocean. The two major fresh water sources affecting the Refuge, the 

Dungeness River and Dean Creek, originate from the Olympic Mountains. 

The headwaters of the Dungeness River begin in the steep alpine watershed of Olympic National 

Park. The Dungeness River and its tributaries drain about 200 square miles (322 square kilometers) 

and contain over 546 miles (879 kilometers) of river (Thomas et al. 1999). The Dungeness River 

flows generally north for about 32 miles, crossing the broad alluvial fan of the Sequim-Dungeness 

peninsula and into Dungeness Bay. The Dungeness and Graveyard spits separate Dungeness Bay and 

Harbor from the Strait of Juan de Fuca. 

Dungeness Spit is a narrow, high-energy spit which extends approximately 5 miles northeasterly into 

the Strait of Juan de Fuca. Graveyard Spit is a broader, sheltered spit which extends south 1.4 miles 

from and in the lee of Dungeness Spit at a point about 3 miles out, creating a narrow channel 

between its southern terminus and the mainland. Graveyard Spit separates Dungeness Bay into two 

parts: the outer Bay and the inner Bay. The inner portion of Dungeness Bay, also known as 

Dungeness Harbor, has a surface area of 1.8 square miles or 1,151.5 acres (Rensel 2003). 

Larger amounts of snow fall in the upper part of the Dungeness River drainage basin. This snow, 

along with glacier ice, is a major source of water to the Dungeness River system (BOR 2002). The 

river is a bimodal flow river, showing two peaks over the course of the year: a smaller peak 

associated with winter storm flows and a larger peak associated with snowmelt and runoff in the late 
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3-12 Chapter 3. Physical Environment 

spring and early summer (EDPU 2005). According to the Dungeness-Quilcene Water Resources 

Management Plan (Jamestown S’Klallam Tribe 1994), “there is relatively little storage in the upper 

watershed, so that current-year precipitation directly controls runoff... and the rain shadow location 

exacerbates the late-summer low flow.” Where the river empties into Dungeness Bay, the river flow 

situation is even more complex due to irrigation diversion and hydraulic continuity between the river 

and the shallow aquifer (Simonds and Sinclair 2002). 

Groundwater is recharged primarily by precipitation, the Dungeness River and irrigation water. 

Recharge from irrigation ditch leakage may be predominating over precipitation recharge in some 

areas of the lower Dungeness watershed. Flow is generally south to north, following the slope of the 

land with the exception of some confined aquifers where vertical movement up or down is attributed 

to an artesian effect. 

Dean Creek is an intermittent stream draining about one square mile. The creek drains the east side 

of Burnt Hill and the northwest side of Lookout Hill, flowing behind the 7 Cedars Casino into the 

southwest corner of Sequim Bay. A short (0.25 mile) reach of the creek runs through the Dawley 

Unit beginning at river mile 0.6 from Sequim Bay. The headwaters of Dean Creek begin at an 

elevation of 690 feet, approximately four miles from its mouth. The creek is in a degraded condition, 

with culverts in various locations, and incidents of severe flooding (EDPU 2005). 

Tidal salt marshes are found on both the northern and southern ends of Graveyard Spit. Barrier 

lagoons and mudflats are located within the Refuge in the interior of both spits. Refuge mudflats are 

also east of Graveyard Spit in Dungeness Bay. Small (< 0.10 acre) seasonal freshwater wetlands are 

located within the Dungeness and Dawley units. For more information on Refuge wetlands, see 

Chapter 4. 

A historic tidal lagoon and marsh was located at the base of Dungeness Spit. Today, dikes or old 

roadbeds, possible remnants of the old railroad grade or wharf, alter the hydrology of this tidal 

lagoon. 

3.2.2 Tides and Salinity 

The nearest National Ocean Survey tidal benchmarks to Dungeness NWR are located in Port 

Angeles, approximately 13 miles west, and Port Townsend, approximately 18 miles east. 

Additionally, soundings collected in Dungeness Bay bathymetry in 2000 were analyzed and modeled 

to provide local tidal datums (Rensel 2003). Tidal benchmark information for Port Angeles and Port 

Townsend for the 1983-2001 period and tidal datums calculated for inner Dungeness Bay are 

summarized in Table 3-6. Historic records of tides and water levels from the Port Angeles and Port 

Townsend tide stations are summarized in Table 3-7. Data for each station include mean ranges, 

diurnal ranges, and the minimum and maximum water levels on record where available. The mean 

range is the difference in height between the mean high water and the mean low water. The diurnal 

range is the difference between the mean higher high water and the mean lower low water of each 

tidal day. 
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Table 3-6. Tidal Benchmark Summary for Port Angeles and Port Townsend, Washington and 

Tidal Datum Summary for Inner Dungeness Bay (NOAA 2011a, NOAA 2011b, Rensel 2003) 

Station Information Port Angeles 

Sta. ID 9444090 

Port Townsend 

Sta. ID 9444900 

Inner 

Dungeness Bay 

(05/2000) 

Mean Higher High Water (MHHW) (ft) 7.07 8.52 7.55 

Mean High Water (MHW) (ft) 6.52 7.84 6.89 

Mean Tide Level (MTL) (ft) 4.23 5.17 N/A 

Mean Sea Level (MSL) (ft) 4.25 4.99 4.59 

Mean Low Water (MLW) (ft) 1.93 2.50 2.30 

North American Vertical Datum 1988 

(NAVD88) 0.43 N/A N/A 

Mean Lower Low Water (MLLW) 0.00 0.00 0.00 

Table 3-7. Historic Tidal Data Summary for Port Angeles and Port Townsend, Washington 

(NOAA 2011c, NOAA 2011d) 

Station Information Port Angeles 

Sta. ID 9444090 

Port Townsend 

Sta. ID 9444900 

Mean Range (ft) 4.60 5.34 

Diurnal Range (ft) 7.06 8.52 

Mean Tide Level (MTL) (ft) 4.23 5.17 

Minimum Water Level 

(ft below MLLW) 

-4.83 

(06/13/1982) 

-4.22 

(12/12/1985) 

Maximum Water Level 

(ft above MHHW) 

10.52 

(01/02/2003) 

11.73 

(12/10/1993) 

Tides are semidiurnal in Dungeness Bay, with higher high low, lower high and lower low tides 

generally occurring within a 24 hour 50 minute period. The mean tidal range, which relates to 

flushing ability, within the inner bay is approximately 4.4 feet. The water residence time in the inner 

bay averages about 40 hours. Details on tidal circulation can be found in Appendix A of Dungeness 

Bay Bathymetry, Circulation and Fecal Coliform Studies (Rensel 2003). 

It is anticipated that the warming of Washington’s temperate climate will contribute to fundamental 

changes along the coast, including but not limited to shifts in the timing and intensity of coastal 

storms, changes in precipitation and the delivery of freshwater inputs, sea level rise, and increased 

inundation of the shallow tidal basins. Regional coastal climate change may also result in changes in 

the intensity and timing of coastal upwelling, shifts in temperatures and dissolved oxygen 

concentrations, and alteration of the carbonate chemistry of nearshore waters. The combination of 

these changes will alter chemical concentrations in tidally influenced areas (Ruggiero et al. 2010). 

Dungeness Bay may experience changes in the salinity regime in response to changes in precipitation 

and snow melt in the watershed (resulting in changes in freshwater inflows) and increased intrusion 

of seawater associated with rising sea levels. However, the effect of climate change on salinity will 

vary with location and the magnitude of the relative sea level rise rate. 

3.2.3 Sea Level Rise 

Sea level rise on the Washington coast is the result of three major forces: global mean sea level rise 

driven by the melting of land-based ice, local dynamical sea level rise driven by changes in wind 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

3-14 Chapter 3. Physical Environment 

which pushes coastal waters toward or away from shore, and localized vertical land movements 

driven primarily by tectonic forces (Mote et al. 2008, McKay et al. 2011). Mean sea level is defined 

as the average sea level over a 19-year period, about which other fluctuations (e.g., tides, storm 

surges, etc.) occur (Smerling et al. 2005). Global mean sea level rise has been in the range of 1.3 to 

2.3 millimeters per year (0.05 to 0.09 inch/year) between 1961 and 2003 (IPCC 2007a). But since 

1993 the rate has increased about 50% above the 20th century rise rate to 3 millimeters/year (0.12 

inch/year) (Bromirski et al. 2011), and the latest global satellite sea level observations have risen to 

3.19 millimeters/year (0.13 inch/year) (NASA 2012). This acceleration is primarily the result of ice 

field and glacier melt-off (McKay et al. 2011). For example, the total global ice mass lost from 

Greenland, Antarctica and Earth’s glaciers and ice caps between 2003 and 2010 was about 4.3 trillion 

tons (1,000 cubic miles), adding about 0.5 inch (12 millimeters) to global sea level in a seven year 

period (Jacob et al. 2012). 

In addition, vertical land movements are occurring as the North American plate and the off-shore 

Juan de Fuca plate collide. Uplift, which may offset local sea level rise, occurs along the Washington 

coast, while subsidence occurs off-shore. For example, while tide gauge data in Seattle reflect the 

global trend of about 2 millimeters/year (0.08 inch/year), at Neah Bay at the western end of the Strait 

of Juan de Fuca, relative sea level is falling because rapid uplift of the Olympic Peninsula outpaces 

global sea level rise. An interpolation of regional uplift rates based on an analysis of 29 tide gauges 

and 113 pairs of level lines provides an estimate of approximately 1-1.5 millimeters/year (0.04-0.06 

inch/year) uplift in the vicinity of Dungeness NWR (Verdonck 2006). 

Based on monthly mean sea level data from 1975 to 2006, the mean sea level trend at Port Angeles is 

0.19 millimeter/year (0.007 inch/year) with a 95% confidence interval of ±1.39 millimeters/year 

(±0.054 inch/year), which is equivalent to a change of approximately +0.06 feet per century (NOAA 

2011e). Data for Port Townsend were recorded from 1972 to 2006 and indicates a mean sea level 

trend 1.98 millimeters/year (0.077 inch/year) with a 95% confidence interval of ±1.15 

millimeters/year (±0.045 inch/year), which is equivalent to a change of +0.65 feet per century 

(NOAA 2011e). 

Future Trends 

The IPCC Special Report on Emissions Scenarios (SRES) forecasted that global sea level would 

increase by approximately 12 inches (30 centimeters) to 39 inches (100 centimeters) by 2100 (IPCC 

2001). However, more recent analyses (Chen et al. 2006, Monaghan et al. 2006) indicate that the 

eustatic rise in sea levels is progressing more rapidly than was previously assumed, perhaps due to 

the dynamic changes in ice flow omitted within the IPCC report’s calculations. Vermeer and 

Rahmstorf (2009) suggest that, taking into account possible model error, a feasible range by 2100 

might be 30 inches (75 centimeters) to 75 inches (190 centimeters) (Vermeer and Rahmstorf 2009). 

Tebaldi et al. (2012) show that even seemingly low increases in sea level will have impacts in the 

short term when storm surges are taken into account. An analysis of historic data is combined with 

future projections of sea level rise to estimate future return periods for what today are considered 50-

year and 100-year events. This magnifies sea level rise by a factor of five, on average, and 

dramatically increases the occurrence, or return periods, of storm surge events. 

Rising sea levels may result in tidal marsh submergence (Moorhead and Brinson 1995) and habitat 

migration as salt marshes transgress landward and replace tidal freshwater and brackish marsh (Park 

et al. 1991). Changes in tidal marsh area and habitat type in response to sea level rise were modeled 

using the Sea Level Affecting Marshes Model (SLAMM 6), which accounts for the dominant 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-15 

processes involved in wetland conversion and shoreline modifications during long-term sea level rise 

(Park et al. 1989, Clough et al. 2010, Clough and Larson 2010). Within SLAMM, there are five 

primary processes that affect wetland fate under different scenarios of sea level rise: inundation, 

erosion, overwash, saturation, and accretion. There are currently several active projects involving the 

use of SLAMM 6 to estimate the impacts of sea level rise on the coasts and salt marshes of the 

Pacific Northwest (e.g., Glick et al. 2007). 

For Dungeness NWR, SLAMM 6 was run using mean and maximum estimates from scenario A1B 

from the SRES. Under the A1B scenario, the IPCC AR4 (IPCC 2007a) suggests a likely range of 

0.21 to 0.48 meter (0.7 to 1.6 feet) of sea level rise by 2090-2099 “excluding future rapid dynamical 

changes in ice flow.” The A1B-mean scenario that was run as a part of this project falls near the 

middle of this estimated range, predicting 0.40 meter of global sea level rise by 2100. The A1Bmaximum scenario predicts 0.69 meter of sea level rise by 2100. To allow for flexibility when 

interpreting the results, SLAMM was also run assuming 1 meter, 1.5 meters, and 2 meters (3.3 feet, 

4.9 feet, and 6.6 feet) of eustatic sea level rise by the year 2100. Pfeffer et al. (2008) suggests that 2 

meters (6.6 feet) by 2100 is at the upper end of plausible scenarios due to physical limitations on 

glaciological conditions. Model results through 2025 for Dungeness NWR are presented in Table 3-8 

(Clough and Larson 2010). All model results are subject to uncertainty due to limitations in input 

data, incomplete knowledge about factors that control the behavior of the system being modeled, and 

simplifications of the system. 

Table 3-8. Predicted Change in Acreage of Land Categories at Dungeness NWR by 2025 Given 

SLAMM-modeled Scenarios of Sea Level Rise (Clough and Larson 2010) 

Sea Level Rise Scenarios* 

Initial 

Condition

A1B 

Mean 

(0.39 m 

by 

2100) 

A1B 

Maximum

(0.69 m 

by 2100) 

1 m by 

2100 

1.5 m 

by 2100 

2 m by 

2100 

Open Ocean 249.8 257.3 296.4 411.9 469.9 476.8 

Tidal Flat 620.9 611.2 606.5 598.7 584.2 568.4 

Undeveloped Dry Land 394.7 306.1 299.3 287.6 271.1 258.0 

Estuarine Beach 145.5 146.6 146.5 146.4 146.2 145.9 

Ocean Beach 130.1 204.0 170.1 62.9 16.7 19.6 

Brackish Marsh 25.0 25.0 25.0 25.0 25.0 25.0 

Salt Marsh 18.6 18.9 19.0 19.0 19.2 19.5 

Swamp 7.8 7.8 7.8 7.8 7.8 7.8 

Developed Dry Land 6.8 6.8 6.8 6.8 6.8 6.8 

Estuarine Open Water 2.5 12.3 17.0 25.1 39.9 55.9 

Inland Open Water 0.7 0.7 0.7 0.7 0.7 0.7 

Transitional Salt Marsh 0.0 5.7 7.3 10.5 15.0 18.1 

* 0.39 m = 1.3 feet, 0.69 m = 2.3 feet, 1 m = 3.3 feet, 1.5 m = 4.9 feet, and 2 m = 6.6 feet. 

 
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3-16 Chapter 3. Physical Environment 

3.3 Ocean Chemistry 

The ocean will eventually absorb most carbon dioxide released into the atmosphere as a result of the 

burning of fossil fuels and other sources. Current rates of carbon dioxide emissions are causing and 

an increase in the acidity of ocean surface waters and a decrease the saturation of calcium carbonate 

(CaCO3), a compound necessary for most marine organisms’ development of shells and skeletons 

(Hönisch et al. 2012). Oceanic absorption of CO2 from fossil fuels may result in larger acidification 

changes over the next several centuries than any inferred from the geological record of the past 300 

million years (with the possible exception of those resulting from rare, extreme events such as meteor 

impacts). In the past 300 million years, three analogous ocean acidification events have been 

identified and these events coincided with mass extinctions of marine organisms, however it should 

be noted that warming and corresponding oxygen depletion co-occurred during these events and 

contributed to the extinctions (Hönisch et al. 2012). 

Virtually every major biological function of marine organisms has been shown to respond to 

acidification changes in seawater, including photosynthesis, respiration rate, growth rates, 

calcification rates, reproduction, and recruitment. Much of the attention has focused on carbonatebased animals and plants which form the foundation of our marine ecosystems. An increase in ocean 

acidity has been shown to impact shell-forming marine organisms from plankton to benthic mollusks, 

echinoderms, and corals (Doney et al. 2009). Many calcifying species exhibit reduced calcification 

and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also 

causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and 

noncalcifying) (Doney et al. 2009, Smith and Baker 2008, OCBP 2008). These potential impacts to 

the marine food web may obviously negatively affect Refuge resources such as seabirds, shorebirds, 

and salmonids. Localized acidification rates within Dungeness Bay have not been evaluated. 

3.4 Topography and Bathymetry 

The topography of Dungeness and Graveyard spits is largely flat, with most areas below 15.0 feet 

North American Vertical Datum 1988 (NAVD88) in elevation (PSLC 2001). The spits are comprised 

of series of shallow dune ridges and troughs with accumulation of drift logs on the surface. The 

narrowest portion of Dungeness Spit measures only approximately 50 feet wide, and intermittent 

overwash events have been documented during and after large storms. 

Tidelands of the second class located within Dungeness Bay and surrounding the spits are managed 

by the Service under a perpetual easement with the Washington Department of Natural Resources 

and include mud and sand flats exposed only at low tide. The average depth of the inner Dungeness 

Bay is 8.3 feet (Rensel 2003). Shallower areas occur at the north part of the inner bay, while the 

deepest areas are located just west of Graveyard Spit and northwest of Cline Spit. A comparison of 

bathymetry, between 1967 and 2000, shows that the bay became shallower during that time period 

(Rensel 2003). 

Bluffs at the base of Dungeness Spit are approximately 90-100 feet high while bluffs west of the spit 

rise to about 130 feet. The forested areas within the Dungeness Unit are primarily between 90 to 130 

feet (NAVD88). 

The northeastern portion of the Dawley Unit fronts Sequim Bay. The topography then generally 

slopes upward from northeast to southwest. Dean Creek flows from south to north through the 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-17 

southeastern corner of the unit. Maximum elevations within the Dawley Unit are approximately 650 

feet (NAVD88). 

3.5 Geology and Geomorphology 

3.5.1 Regional Geologic Context 

Dungeness NWR is located on the northeast coast of the Olympic Peninsula along the Strait of Juan 

de Fuca. South of the Refuge, the jagged peaks of the Olympic Mountains loom over a deep, forested 

labyrinth of canyons. The Olympic Mountains originated from subduction of the denser Juan de Fuca 

Plate of oceanic crust underneath the North American Plate of continental crust in an area known as 

the Cascadia Subduction Zone. This subduction caused the superficial rocks of the descending 

oceanic plate (an accretionary wedge) to be progressively scraped off and accreted to the continental 

margin (Tabor and Cady 1978). Due to the subduction and the accretionary wedge, there are two 

lithologic assemblages that can be found on the Olympic Peninsula: the peripheral and core rocks. 

The peripheral rocks, part of the Coast Range Terrane, consist of oceanic crust that was accreted onto 

the continent by either the collision of an intra-Pacific seamount province or by backarc or forearc 

rifting at the North American plate margin (Wells et al. 1984, Clowes et al. 1978, and Babcock et al. 

1992 cited in Brandon et al. 1998). The Coast Range Terrane is composed of a basal unit called the 

Crescent Formation and an overlying Eocene to lower Miocene marine clastic sequence known 

informally as the Peripheral sequence (Brandon et al. 1998). The Crescent Formation consists of 

thick basalt flows such as pillow lava that are cut by dikes and interbedded with pelagic limestone 

and mudstone (Brandon et al. 1998). On the present day Olympic Peninsula, the peripheral rocks 

form a horseshoe shaped belt that rings the core rocks on the northern, eastern, and southern sides of 

the peninsula. 

The core rocks are known as the Olympic Subduction Complex and they encompass mélange scraped 

off the subducting Juan de Fuca plate and thrust, or underplated, on the bottom of the continental 

crust. This stacking of successive scrapes thus continually thickens and raises the older, top surface. 

As the subduction process at the Cascadia Subduction Zone continues, uplift occurs. At the same 

time, erosion eats away at the oldest, top sediments. Rocks of the Olympic Subduction Complex 

were first thrust above sea level about 12 million years ago and accretion and uplift presently outpace 

erosion in some parts of the range and so the Olympic Mountains are still rising, with the fastest rates 

occurring within the western part (Thackray and Pazzaglia 1994, Brandon et al. 1998). 

Extensive glaciation over time has greatly shaped the Olympic Peninsula. The latest glaciation, the 

Fraser, lasted from about 23,000 to 11,000 years ago. The last major advance during the Fraser 

Glaciation occurred during the Vashon Stade, roughly 14,000 to 17,000 years ago (Hellwig 2010). At 

its maximum during the Vashon Stade, the margin of the Cordilleran ice sheet that influences the 

Olympic Peninsula originated in British Columbia, moved down through Georgia Strait on a base of 

advance outwash sands and gravels, proceeded south through the Puget Lowland to below the present 

city of Olympia (the Puget Lobe), and extended out the Strait of Juan de Fuca to beyond Cape 

Flattery (the Juan de Fuca Lobe). 

The upper parts of watersheds draining into the Strait of Juan de Fuca were carved by alpine glaciers, 

which formed in the high mountain peaks of the Olympic Range and moved downstream. As the ice 

sheet retreated, widespread glacial deposits (outwash, drift, and till) were left behind. The lower 
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3-18 Chapter 3. Physical Environment 

watersheds were cut by glacial water outflows and formed gently sloping plains of glacial till and 

outwash. Since glaciation, landforms have been modified by mass wasting, surface erosion, and 

deposition. 

3.5.2 Refuge Geology 

Dungeness and Graveyard spits are elongate spits primarily composed of well-sorted sand, gravel, 

and cobble which originate from erosion of adjacent mainland bluffs, alongshore sediment transport 

(shore-drift), and from washover deposits where the spits are narrow enough for overwash processes 

(Schwartz et al. 1987). The feeder bluffs are typically composed of Holocene-Pleistocene 

undifferentiated surficial (clay, silt, sand, gravel, till, diamicton, and peat) and landslide deposits 

(clay, silt, sand, gravel, and larger blocks deposited by mass wasting) that are at the edge of 

Pleistocene glaciomarine drifts (Schasse 2003). Net shore-drift patterns at the Dungeness Spit are 

driven primarily by fetch exposure. Sediment eroded from the glacial bluffs to the west is transported 

to the east, around the end of Dungeness and then along the recurve of Graveyard Spit. On the 

mainland, shore-drift converges from the east and west upon Cline Spit (Schwartz et al. 1987). 

Using a comparison of historic maps of Dungeness Spit from dating 1855, 1926, and 1979 in 

conjunction with field surveys conducted in 1985, Schwartz et al. (1987) measured an eastward 

growth of the spit of about 1,900 feet (575 meters) over a period of record of 130 years. This 

elongation of Dungeness Spit was confined to that portion of the spit east of the junction with 

Graveyard Spit, as both Graveyard Spit and the west end of Dungeness Spit have remained relatively 

unchanged since the 1855 land survey. The study found an average elongation rate of 14.4 feet/year 

(4.4 meters/year) for the spit which agreed closely with 14.8 feet/year (4.5 meters/year) calculated by 

Bortleson et al. (1980). The volumetric increase in Dungeness Spit was estimated at about 

65,305,000 cubic yards (1,850,000 cubic meters) from 1855 to 1985. 

At the Dawley Unit, a portion of the unit adjacent to Dean Creek is underlain by Crescent Formation 

(middle and lower Eocene) basalt and basalt breccia. The lower part of Dean Creek, as it passes 

through the Refuge, is underlain with Vashon Stade advance glacial outwash, which is comprised of 

stratified, well-sorted sand, gravel, lacustrine clay, and silt deposited by meltwater during the glacial 

advance. The remainder of the unit occurs on Vashon Stade glacial till, which consists of unstratified, 

poorly sorted clay, silt, sand, gravel, and boulders directly deposited by the glacier (Schasse and 

Logan 1998). 

3.6 Soils 

All soil types and descriptions are mapped and described in the Soil Survey of Clallam County, 

Washington (USDA 2012). The principal soil types at the base of Dungeness Spit are Dick loamy 

sand (0 to 15 percent slopes) and Hoypus gravelly sandy loam (0 to 15 percent slopes). The Dawley 

Unit is made up of several soil types: Hoypus gravelly sandy loam (0 to 15 percent slopes, 15 to 30 

percent slopes, and 30 to 65 percent slopes), Dick loamy sand (0 to 15 percent slopes), and Clallam 

gravelly sandy loam (15 to 30 percent slopes). 

Dick loamy sand and Hoypus gravelly sandy loam are very deep, somewhat excessively drained soils 

formed in glacial outwash and found on outwash terraces. Permeability of these soils is rapid with a 

low water capacity. Consequently, runoff is slow. The effective rooting depth for both soils is 60 

inches or more. Below a mat of organic material, the surface layer of Dick loamy sand is grayish 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-19 

brown and dark brown loamy sand about 3 inches thick. The next layer is brown sand about 19 

inches thick. The upper 26 inches of the underlying material is light olive brown and yellowish 

brown, stratified sand to loamy sand, and the lower part to a depth of 60 inches or more is olive 

brown and dark yellowish brown, stratified gravelly sand to gravelly loamy sand. The surface of 

Hoypus gravelly sandy loam is typically covered with a mat of organic material 1 inch thick. The 

surface layer is very dark grayish brown gravelly sandy loam 3 inches thick. The upper 7 inches of 

the subsoil is dark brown gravelly sandy loam, and the lower 21 inches is dark yellowish brown very 

gravelly loamy sand. The upper 14 inches of the substratum is dark brown very gravelly sand, and 

the lower part to a depth of 60 inches or more is dark yellowish brown gravelly sand. 

Clallam gravelly sandy loam is a moderately deep, moderately well drained soil formed in compact 

glacial till and found on hills. Permeability of this soil is moderate to the compact glacial till and very 

slow through it. Available water capacity is low. Runoff is medium, and the hazard of water erosion 

is slight. The effective rooting depth is 20 to 40 inches. Water is perched above the compact glacial 

till from January through April. Typically, the surface is covered with a mat of organic material 2.5 

inches thick. The surface layer, where mixed to a depth of 6 inches, is dark brown gravelly sandy 

loam. The upper part of the subsoil is brown gravelly sandy loam about 4 inches thick, and the lower 

part is brown very gravelly sandy loam about 18 inches thick. Compact glacial till is at a depth of 28 

inches. Depth to glacial till ranges from 20 to 40 inches. 

3.7 Fire 

3.7.1 Presettlement Fire History 

Dungeness NWR is in the driest area in western Washington (please refer to the Precipitation section 

for further discussion). Consequently, prior to Euro-American settlement, the predominant vegetation 

on lowlands west of the Cascades, from the Willamette Valley of Oregon north to the Georgia Basin 

of southwest British Columbia, was a mosaic of grasslands, oak and conifer forests, savannas, and 

various types of wetlands (Chappell and Crawford 1997). These forests, savanna, grassland, and 

herbaceous bald ecosystems generally rely on fire to maintain their vegetative structure and species 

composition. In addition to lightning-caused fires, historical accounts have also established that 

Native Americans used prescribed burning to create habitat for game animals and to promote the 

growth of weaving materials and food (Agee 1993, Chappell et al. 2001). The historic frequency with 

which a given area burned depended directly upon the number of natural and human ignited fires. 

Other factors affecting fire frequency and fire intensity include plant community types, changes in 

topography (i.e., slope and aspect), varying fuel accumulations, and variation in seasonal 

precipitation. The advent of Euro-American settlement interrupted Native American land 

management practices and altered the natural fire regime by eliminating prescribed fires and 

suppression of natural fires. 

The watershed of the Dungeness River has experienced repeated large, intense wildfires 

prehistorically as a result of a number of climatic patterns, including long-term temperature cycles, a 

rain shadow effect from the adjacent Olympic Mountains, jet stream patterns, and prevailing west-toeast winds (DAWACT 1995, BOR 2002). Large, intense, stand-replacement wildfires have swept 

across the watershed at intervals of approximately 200 years with surviving older trees generally 

restricted to higher elevations and along riparian corridors. Present data indicate that large, standreplacing fires occurred in A.D. 1308, 1508, and 1701 in the Dungeness watershed (DAWACT 
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3-20 Chapter 3. Physical Environment 

1995). The intervals between these fires were long enough to permit growth of a replacement stand 

and accumulation of both ground and ladder fuels within the forest (BOR 2002). 

3.7.2 Postsettlement Fire History 

In the areas dominated by Douglas-fir, such as on the mainland portion of Dungeness NWR and the 

Dawley Unit, the natural fire regime was probably similar to that described by Agee (1993) in coastal 

Douglas-fir forests. The majority of fires in the region are human-caused and starts occur during the 

dry summer months. A large, human-caused fire occurred in 1890 in the foothills between Port 

Angeles and Sequim, smoldered over the winter, and flared up again in 1891. Although not as 

extensive as the prehistoric fires, the 1890-1891 fire burned large areas of the lower Dungeness 

watershed. Numerous smaller fires have also occurred in the watershed with significant ones reported 

in 1860, 1880, 1896, 1902, 1917, and 1925. Few fires have occurred in the watershed since 1930, 

largely as a result of improved fire prevention techniques and increased levels of summer 

precipitation (DAWACT 1995, BOR 2002). 

All known fires at Dungeness NWR were human-caused. The 1969 Dungeness Annual Narrative 

related the investigation of a fire started on June 3, 1969 when U.S. Coast Guard personnel were 

burning their garbage dump behind the residence. High winds caused the fire to quickly spread into 

the dry grass and driftwood affecting a total of 17 acres. Driftwood logs tend to smolder for weeks 

after the initial burn. The 1971 Dungeness Annual Narrative reported a fire at the junction of the 

main spit and Graveyard Spit on June 27 and 28, of that year. The 1983 Dungeness NWR Fire 

Management Plan states that between 1980 and 1983, two small unwanted fires originated on the spit 

from Native American campfires. In June 1989, the Ravine Fire burned 0.1 acre near the eastern 

boundary of the mainland portion of the Refuge. In June 1999, the Dungeness Fire burned 1 acre on 

Dungeness Spit, and a month later, the Lighthouse Fire burned 50 acres at the extreme end of the 

spit. The latter fire burned around New Dungeness Light Station with no damage. 

3.8 Environmental Contaminants 

3.8.1 Air Quality 

The air quality may be affected by various activities on and adjacent to the Refuge including: marine 

vessels, industrial facilities, automobiles, and other human caused activities such as outdoor burning, 

wood stoves, and operation of various vehicles and machines (e.g., gasoline powered equipment, 

motorboats). The Refuge staff uses various types of equipment and transportation methods to achieve 

the Refuge habitat conservation projects and research. Habitat improvement projects and monitoring 

activities may include the use of tractors, heavy equipment, and/or the operation of trucks, boats, or 

other transport. Refuge visitors generally drive their automobiles to visit the various units of the 

Refuge and others operate motor boats within Dungeness Bay to fish or access the lighthouse. 

3.8.2 Water Quality 

A state is required to identify waters that do not meet that state’s water quality standards under 

Section 303(d) of the Clean Water Act (CWA). These waters are considered “water quality limited” 

and placed on the state’s 303(d) impaired waters list. Section 303(d) requires the state to develop 

Total Maximum Daily Loads (TMDLs) for impaired water bodies. TMDLs are the amount of each 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-21 

pollutant a water body can receive and not exceed water quality standards. Water quality standards 

for Washington include beneficial uses, narrative and numeric water quality criteria, and 

antidegradation policies. The Washington Department of Ecology (WDOE) assesses water segments 

according to parameters including bacteria, bioassessment, contaminated sediments, dissolved 

oxygen, pH, total phosphorus in lakes, temperature, total dissolved gas, toxic substances, and 

turbidity. 

Dungeness Bay was listed as impaired in the 2008 303(d) reporting cycle for the following 

parameters: fish habitat and fecal coliform bacteria. A TMDL for fecal coliform was established in 

2004 to address elevated fecal coliform levels that were impairing water quality and shellfish harvest. 

The Dungeness River has been identified as a source for nutrient loading and elevated fecal coliform 

problems from agricultural and residential runoff. Fecal coliform bacterial contamination and 

nutrient loading from animal waste were found on both commercial and small farms with high 

livestock concentrations and poor management. Existing on-site sewage disposal systems continue to 

have the potential to contribute bacterial contamination and nutrients to both surface and 

groundwater due to soil conditions and inadequate maintenance. Terminating near the Dungeness 

River delta and in several locations along the shoreline of the southern side of Dungeness Bay are 

outfalls for approximately 97 miles of irrigation ditches that divert water from the Dungeness River 

to agricultural and residential lands. These ditches are also likely contributing to the elevated fecal 

coliform problems in Dungeness Bay. Within 10 miles of the Refuge, there are five additional major 

subdrainages within the Dungeness River area watershed. These include McDonnell, Siebert, Bagley, 

Cassalery, and Gierin Creeks. There are approximately 546 miles of streams and tributaries in the 

overall watershed as identified in the 1993 Dungeness River Area Watershed Management Plan. 

Similar agricultural/residential runoff issues are likely associated with these drainages and are likely 

contributing to the existing problems with elevated fecal coliform bacteria. 

Because of the shallow depth to groundwater, the lack of a confining layer in many areas, and porous 

soils, groundwater in this area is highly susceptible to nonpoint chemical contamination. In 1990, 

wells sampled by Clallam County showed levels of nitrate, although generally well below the 

drinking water standard, were elevated in some areas, and it was concluded that this was an upward 

trend. The source or sources for this contaminant is likely attributable to failing septic systems, 

livestock waste and agricultural/residential fertilizer usage combined with the presence of highly 

permeable soils and nearly 100 miles of irrigation ditches. 

3.8.3 Contaminants 

Considering the historical uses of Dungeness NWR and the Dawley Unit, environmental assessment 

studies have revealed some threats to the Refuge from contaminants. Some of these contaminant 

issues have already been addressed while others remain. Jurisdiction issues and other factors (e.g., 

exposure risks, funding, location, concentration, potential for movement of the hazard, and 

accessibility) influence the timing of remediation. Historical uses included military, navigational aids 

(lighthouse), residential, and commercial. 

In 1857, prior to the establishment of the Refuge, a lighthouse station was constructed on the 

terminal end of Dungeness Spit. The United States Coast Guard (USCG) operated and maintained 

this facility in accordance with acceptable laws and practices during their years of operations. In 

1974, the station was automated with aids to navigation. In March of 1994, the Coast Guard stationed 

the last keeper; then from March–September the USCG auxiliary staffed the lighthouse. September 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

3-22 Chapter 3. Physical Environment 

of the same year the lease for the maintenance and operation of the historical structures transferred to 

the newly formed New Dungeness Chapter of the U.S. Lighthouse Society (Society). In 2003, the 

New Dungeness Chapter separated from the Society and formed the New Dungeness Light Station 

Association. The agreement between the USCG and the New Dungeness Light Station Association 

was modified to reflect this change and continues today. As identified in this CCP, in the event that 

the USCG declares the light station property excess to its needs, the Service will work with the 

USCG to bring the lighthouse and surrounding land into the Refuge System. As part of that transfer 

the Service would work with the USCG on any unresolved contaminants issues concerning the 

lighthouse site. Several known issues have already been identified by the USCG through their own 

investigations. 

In 2003, the USCG contracted Tetra Tech, Inc., to conduct a Phase I environmental site assessment 

also called an Environmental Due Diligence Audit (EDDA). The purpose of this audit was to 

“evaluate a particular property for potential environmental contamination and liabilities from past or 

present use of the site” in this case the New Dungeness Light Station. There were two underground 

storage tanks, and one above ground tank, on site which were removed in 1998 and soils tested for 

total petroleum hydrocarbons. The results were below the Model Toxic Control Act concentrations 

and no remediation was required. 

The USCG, in 2009, contracted with Engineering/Remediation Resource Group, Inc. to conduct a 

Phase II (EDDA). The objectives were to evaluate (1) the presence and concentrations of lead in 

paint on the interior and exterior walls of the present site structures; (2) the concentrations of lead in 

soil around structures compared with background concentrations; (3) the presence of asbestoscontaining material (ACM) inside site structures; (4) the presence and concentrations of petroleum 

hydrocarbons quantified as total petroleum hydrocarbons (TPH) and metals in the cisterns at the 

station; (5) the presence and concentration of petroleum hydrocarbons quantified as TPH in soil 

associated with former aboveground storage tanks (ASTs), former underground storage tanks 

(USTs), former fuel lines, and the present and former oil houses; (6) the concentrations of metals in 

soil around the current and former paint locker compared with background concentrations; (7) the 

presence and concentrations of polychlorinated biphenyls (PCBs) in soil in the vicinity of the 

transformer building; (8) the presence of mercury in the lighthouse lantern room; and (9) background 

metal concentrations. Based on the findings and recommendations of this report further sampling and 

remediation actions would be required. 

In 2006, the Dawley rental house, located on the south side of Highway 101 and the mobile home 

west of the main residence, were sampled for Asbestos Containing Material (ACM) and Lead Based 

Paint (LBP). The test results were negative for all samples. The beach house along Sequim Bay, 

northwest of the Dawley main residence, was also sampled for ACM and LBP with test results 

showing positive for ACM but negative for LBP. There was an UST removed, also in 2006, near the 

garage west of the Dawley main residence and a vehicle oil changing rack. From both of these there 

was soil contamination by petroleum products that required the removal of 26 tons of soil from the 

UST and 5 tons from the rack areas. The Mellus Cabin, located in the Dungeness Unit, was surveyed 

for Asbestos Containing Material (ACM) and Lead Based Paint (LBP) in 2010 by the USFWS 

Regional Environmental Compliance Coordinator. A small area of interior floor tile contains low 

levels of ACM and there was no detection for LBP on any surface. The Dawley main residence was 

also surveyed at the same time for ACM and LBP. These compounds were detected at various levels 

and locations in and around the structure. For any of the structures that tested positive for either 

survey, the Service would be required to contract remediation services prior to any construction 

work. 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-23 

The Dawley forest unit contains several small dump sites of waste construction material, household 

appliances, and other miscellaneous debris. In 2006, the Service conducted a Phase I and Phase II 

Environmental Site Assessment of the Dawley Unit revealing ACM in two locations. These sites 

were cleaned up by a contractor in 2009. No other containments, other than personal structural debris 

remains on the site. 

Creosote pilings and rogue creosote logs are also a source of contamination on the Refuge and 

removal is an on-going management activity. Contamination by creosote is a concern because of the 

presence of toxic polycyclic aromatic hydrocarbons (PAHs) that can leach into water and sediments 

where they accumulate and impact marine and nearshore organisms. Sometimes levels of these 

compounds can reach above Washington State Department of Ecology sediment quality standards 

(Holman et al. 2009). In 2006, the Service partnered with the Washington State Department of 

Natural Resources and removed 150 tons of these logs from the Refuge. In 2011, a survey was again 

conducted for creosote rogue logs accumulation levels and locations. The U.S. Navy removed 

creosote treated sight target pilings from Dungeness Bay in 2010 that were on Refuge tidelands. 

The threat of oil spills is another concern that can affect all of the Refuge’s nearshore habitats. 

According to the Washington State Department of Ecology over 41 million gallons of oil are 

delivered over sensitive waterways every day in Washington. The Strait of Juan de Fuca is one of the 

most critical maritime highways for both the United States and Canada. Tanker traffic alone through 

this area carries over 15 billion gallons of oil each year (WDOE 2009a). The Refuge works with 

many partners on oil spill prevention, preparedness, and response programs to protect the natural 

shoreline and marine resources. 

 
Dungeness National Wildlife Refuge Comprehensive Conservation Plan 

3-24 Chapter 3. Physical Environment 

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