# NONPOINT SOURCE ASSESSMENT REPORT

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/tribal%3Ahoh%3Ad0a93f75e970ef32

## Record

- **Collection:** Tribal code
- **Document type:** Tribal code

## Text

NONPOINT SOURCE ASSESSMENT REPORT
HOH RIVER WATERSHED
JEFFERSON COUNTY, WASHINGTON WRIA 20

Submitted to:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION 10 TRIBAL ASSISTANCE PROGRAM
1200 Sixth Avenue, Suite 155
Seattle, Washington 98101

Submitted by:
July 2026
Hoh Indian Tribe Natural Resources Department
2269 Lower Hoh Rd, Forks, Washington 98331
In cooperation with: WESTECH CONSULTING, LLC
937 Boathaven Drive, Port Angeles, Washington 98363
Trevor Shea, CEO
Copyright 2025 by Trevor Shea, Westech Consulting, LLC – All Rights Reserved

CONTENTS
OVERVIEW ................................................................................................................................. 34
INTRODUCTION ........................................................................................................................ 45
METHODOLOGY ....................................................................................................................... 67
Water Quality Monitoring Data ................................................................................................ 78
Equipment ............................................................................................................................... 910
Quality Assurance/Quality Control Protocols ........................................................................1011
Geospatial Data Sources ....................................................................................................... 1415
Historical Documentation ..................................................................................................... 1516
Limitations & Assumptions .................................................................................................. 1617
LAND USE SUMMARY ......................................................................................................... 1617
Forest Lands .......................................................................................................................... 1617
Developed Lands .................................................................................................................. 1920
Residential............................................................................................................................. 1920
Commercial ........................................................................................................................... 1920
Transportation ....................................................................................................................... 2021
Agricultural and Open Lands ................................................................................................ 2223
Other Land Cover Categories ............................................................................................... 2223
SURFACE AND GROUND WATER QUALITY .................................................................... 2829
Hoh Indian Reservation ........................................................................................................ 2829
Historical Monitoring Program ............................................................................................. 2830
Wetlands and Aquatic Features ............................................................................................. 3637
Ground Water Standards ....................................................................................................... 3637
Pollutants............................................................................................................................... 3738
RESULTS ................................................................................................................................. 3738
Nonpoint Source Assessment ................................................................................................ 4445
Data Gaps in Historical Record ............................................................................................ 4748
Results Assessment ............................................................................................................... 4748
DISCUSSION ........................................................................................................................... 4849
Temperature Impairments ..................................................................................................... 4849
Dissolved Oxygen Patterns ................................................................................................... 4951
pH Depression ....................................................................................................................... 5052
Sediment Sources .................................................................................................................. 5152
SELECTION OF BMPS ........................................................................................................... 5556
Selection Process .................................................................................................................. 5556
NPS CONTROL PROGRAMS ................................................................................................ 5860
EPA Programs ....................................................................................................................... 5860
Bureau of Indian Affairs Programs ....................................................................................... 5860
USDA Natural Resources Conservation Service Programs .................................................. 5860
NOAA Fisheries Restoration Programs ................................................................................ 5961
U.S. Fish and Wildlife Service Programs ............................................................................. 5961
Washington Department of Ecology Programs ..................................................................... 6062
Washington State Salmon Recovery Funding ....................................................................... 6062
Jefferson County Conservation District ................................................................................ 6062
North Pacific Coast Lead Entity ........................................................................................... 6163
Olympic Peninsula Conservation Organizations .................................................................. 6264
2

Regional Foundations and Funding Organizations ............................................................... 6365
Academic and Research Partnerships ................................................................................... 6365
Volunteer and Community Organizations ............................................................................. 6466
Coordination Mechanisms .................................................................................................... 6466
CONCLUSION ......................................................................................................................... 6567
Meeting EPA Section 319 Requirements .............................................................................. 6567
REFERENCES ......................................................................................................................... 6769
APPENDICES .......................................................................................................................... 7570
ACRONYMS AND ABBREVIATIONS .................................................................................. 7570
Lists of Tables and Figures
Table 1. Calibration and maintenance requirements for water quality equipment. 1314
Table 2. Current Land-Cover Composition in the Hoh River Watershed. ............................... 2526
Table 3. Hoh River Watershed hydrologic unit descriptions. ................................................... 2829
Table 4. List of monitoring sites conducted by the Hoh Tribe’s water quality monitoring program
and their frequency and parameters. ......................................................................................... 3233
Table 5. List of monitored rivers and creeks in the Hoh River Watershed as outlined in the Hoh
River monitoring program.. ...................................................................................................... 3536
Table 6. Existing or potential pollutants throughout the Hoh River Watershed. ...................... 3738
Table 7. Historical DO and pH impairments at high-risk creeks. ............................................ 3940
Table 8. Monitoring sites in rivers and creeks of the Hoh River Watershed with impaired water
quality from FY 2021-2025 that did not fully support designated uses.................................... 4243
Table 9. Impaired waterbodies within the HRW according to the Washington Department of
Ecology’s 2022 Waterbody Assessment Cycle. ........................................................................ 4344
Table 10. Summary of results of NPS category assessment for water quality monitoring sites.
................................................................................................................................................... 5455
Table 11. Summary of potential contributors of NPS program implementation. ..................... 5556
Table 12. Summary of previous or active BMPs addressing NPS pollution sources in the Hoh
River Watershed. ....................................................................................................................... 5759
Table 13. Summary of potential NPS funding sources. ........................................................... 6466
Figure 1.The Hoh Indian Reservation is located on the mouth of the Hoh River by the Pacific
Ocean. ........................................................................................................................................... 56
Figure 2. Hoh River Watershed Land Uses with potential for NPS pollution along water quality
monitoring site waterways. ....................................................................................................... 2425
Figure 3. Land coverage of the Hoh River Watershed. ............................................................ 2627
Figure 4. Land Coverage surrounding the Hoh Indian Reservation. ....................................... 2728
Figure 5. Water quality monitoring sites in the Hoh River Watershed. Site numbers correspond to
those found in Table 4. .............................................................................................................. 3132

3

Figure 6. Noxious Weed Detections throughout the HRW with monitoring sites waterways
labeled. ...................................................................................................................................... 4647

4

OVERVIEW
This assessment report aims to evaluate nonpoint source pollution throughout the Hoh River
Watershed (HRW), which runs from multiple glaciers on Mount Olympus to the Pacific Ocean.
The Hoh Tribe’s Reservation is located off the mouth of the Hoh River. Its land base in trust and
fees only comprises approximately 1% of the entire watershed, however, the Hoh Tribe aims to
restore and protect Hoh River waterways in its entirety. The Hoh Indian Tribe retains treatyreserved hunting, fishing, and gathering rights within the Tribe’s Usual and Accustomed (U&A)
area, which includes approximately 400 square miles of land and thousands of square miles of the
Pacific Ocean. Within the U&A, the Hoh Tribe co-manages natural resources with the state of
Washington. Members of the tribe depend on natural resources within their U&A for their cultural
and economic values. Protecting and responsibly managing natural resources, such as fish,
wildlife, cedar, and berries, in the Hoh River Watershed is of the utmost importance to the Hoh
Tribe to ensure that resources are available for current and future generations to hunt, fish, and
gather, as is their treaty-reserved right.
The Hoh Tribe’s water monitoring program has collected water quality data for decades. This data
provides the basis for establishing baselines, assessing nonpoint source (NPS) pollution, and
understanding waterway impairments. HRW’s top pollutant sources are temperature, dissolved
oxygen (DO), pH, and turbidity. Potential NPS categories contributing to these water quality
impairments include forestry, roads and highways, hydromodification, atmospheric deposition,
invasives species, and natural resource extraction. These NPS categories are contributing to
pollution that are slowly reducing the river or creek’s ability to support aquatic life. This
assessment will provide evidence of our pollution through historical water quality data collection,
cultural knowledge, GIS analysis of landscape patterns, and review of historical documentation.
By documenting current conditions, identifying pollution sources, and establishing selection
criteria for management practices, this assessment creates the roadmap for transitioning from
documentation to action. The widespread and persistent impairments revealed through monitoring,
from chronic temperature exceedances to severe acidification in some streams, demonstrate that
natural recovery processes alone cannot restore water quality within timeframes necessary to
protect treaty resources. This assessment provides the scientific justification and strategic
framework for the comprehensive management program needed to restore and protect water
quality from nonpoint source pollution throughout the Hoh Watershed.
INTRODUCTION
The Hoh Indian Reservation encompasses 960 acres (1.5 square miles) is located at the mouth of
the Hoh River on the western coast of the Olympic Peninsula in Jefferson County, Washington.
The reservation lands, established by Presidential Executive Order on September 11, 1893, sit
where the Hoh River meets the Pacific Ocean, containing 5.30 miles of rivers and streams, 1.76
miles of coastline, 2.97 acres of lakes and ponds, 19.6 acres of estuary, and 17.1 acres of swamps
and marshes. Beyond the original reservation boundaries, the Hoh Tribe has attained over 2,269
5

acres in trust landsbrought over 1300 additional acres into trust status. These trust lands include
the developing Highlands area near Highway 101, which represents the Tribe's commitment to
meeting housing needs while maintaining environmental stewardship. Additionally, over 400 acres
in fee lands have been added that expand tribal management authority within the watershed.

Figure 1.The Hoh Indian Reservation is located on the mouth of the Hoh River by the Pacific Ocean.

The Hoh River Watershed, a subset of the Tribe’s Usual and Accustomed Area, encompasses 298.5
square miles (191,360 acres) of the Olympic Peninsula's temperate rainforest ecosystem. The Hoh
River itself extends 56 miles from its glacial origins at Mount Olympus within Olympic National
Park to its terminus at the Pacific Ocean. The river's largest tributary, the South Fork of the Hoh
River, joins the mainstem at river mile 31, approximately 0.5 miles upstream from the Olympic
National Park boundary. Throughout the watershed, a dendritic network of 1,299 miles of mapped
streams and rivers creates critical habitat for Pacific salmon and other culturally significant species.
The watershed's landscape reflects its position on the western slope of the Olympic Mountains,
receiving between 94 and 125 inches of annual precipitation. This extreme rainfall, among the
highest in the continental United States, drives a dynamic hydrologic regime characterized by
frequent winter flooding and summer low flows. Peak runoff occurs from October through March
during intense Pacific storms, while minimum flows typically occur in late summer. The glacially

6

fed nature of the Hoh River and several headwater tributaries contribute year-round flow and
naturally elevated turbidity from glacial flour.
Major tributaries within the reservation boundaries monitored by the Tribe include Chalaat,
Fletcher, and Braden Creeks. These tributaries range from small, spring-fed streams to substantial
rivers draining extensive sub-basins, each contributing unique water quality characteristics shaped
by local geology, land use, and management history.
The Hoh Tribe’s nonpoint source program’s goal is to identify and control nonpoint source
pollution in the Hoh Watershed to protect water quality of waterways in their usual and accustomed
area (U&A). The primary objectives implemented to achieve this goal are to comprehensively
document current water quality conditions throughout the Hoh River Watershed, identify nonpoint
source pollution categories affecting those conditions, and establish the framework for selecting
management practices to address identified problems.
Synthesis of water quality data collected through the Tribe’s CWA 106 monitoring program from
FY 2021-2025 enables identification of both persistent impairments requiring restoration and highquality waters needing protection from future degradation. By documenting baseline conditions
across 60 monitoring sites representing diverse stream types, land uses, and management histories,
the assessment provides the scientific basis for prioritizing management actions where they will
produce the greatest water quality improvements.
Nonpoint source categories in the watershed include forestry and forest roads, hydromodification
and bank erosion, roads and highways, atmospheric deposition, natural resource extraction, and
invasive species. The wide variety of pollution sources and land use ownerships will require
collaboration and support from public outreach and partnering organizations.
This assessment provides the technical foundation for the companion Nonpoint Source
Management Program Plan, which will establish specific goals, implementation schedules, and
funding strategies for addressing identified water quality problems. Together, these documents
fulfill EPA requirements while serving the Tribe's broader mission of protecting and restoring water
quality for current and future generations. The assessment represents not just regulatory
compliance but a comprehensive evaluation of watershed health that will guide management
decisions affecting treaty resources fundamental to tribal culture, economy, and identity.
METHODOLOGY
This assessment synthesizes multiple data sources to characterize water quality conditions and
identify nonpoint source pollution throughout the Hoh Watershed. Primary data derives from the
Hoh Tribe's water quality monitoring program, supplemented by spatial datasets, field
observations, and historical documentation to provide a comprehensive watershed assessment. The
current monitoring network provides sufficient data for nonpoint source assessment with several
key strengths reinforcing assessment reliability.
7

The network's temporal depth, with a 30+ year temperature record, captures long-term trends
beyond natural variability cycles, enabling detection land use impacts. Spatial coverage of all
major tributaries and mainstem segments ensures no significant source areas remain
uncharacterized. The parameter suite addresses core indicators of forestry impacts, the watershed's
primary nonpoint source category. EPA- compliant QA/QC procedures ensure defensible results
suitable for regulatory decisions. Sampling frequency exceeds minimum requirements for
statistical power, providing robust conclusions about designated use attainment. The five-year
dataset (FY 2021-2025) provides robust assessment of current conditions and recent trends,
meeting EPA requirements for NPS assessment while identifying specific waters needing
restoration and informing BMP selection.
Water Quality Monitoring Data
The primary dataset consists of water quality measurements collected through the Hoh Tribe's
EPA-approved monitoring program from FY 2021 through FY2025. This comprehensive dataset,
documented in annual CWA Section 106 reports to EPA, includes continuous temperature
monitoring at approximately 60 sites recording measurements every 15 minutes year-round,
instantaneous measurements of dissolved oxygen, pH, turbidity, and specific conductivity
collected monthly at 20 sites, continuous dissolved oxygen monitoring at 7 sites with 15-minute
recording intervals in the summer, benthic macroinvertebrate sampling at 5 sites during low flow
conditions since 2023, storm turbidity monitoring when events arise, low-flow measurements
collected during summer conditions, and water chemistry sampling in 2024 at 8 sites. Historical
monitoring data extending back to 1991 provides temporal context for assessing long-term trends
and persistent impairments, with particular emphasis on temperature records that span over three
decades at core monitoring sites. Secondary datasets provide insight into temperature, DO, pH and
low flow since the early 2000s at several different creek locations.
Instantaneous Water Quality
The Hoh Indian Tribe Water Quality Monitoring Program (HWQP) has measured instantaneous
water temperature, turbidity, DO concentration, and pH in the Hoh River mainstem and selected
tributaries each month since 2005 (excluding February 2020 through June 2021; monitoring was
discontinued during this time due to COVID-19 Pandemic restrictions). Instantaneous sites were
originally chosen by finding locations with the most historical data available at the time. In 2021,
water quality parameters of DO saturation and specific conductivity were added to monthly
monitoring.
Continuous Water Temperature
The Hoh Tribe’s Department of Natural Resources has monitored water temperature continuously
in the Hoh River mainstem and its tributaries since 1991. Sites for continuous temperature
monitoring include major tributaries, minor creeks, and the Hoh River mainstem.

8

The network captures the range of conditions present in rivers and streams in the watershed, from
the pristine waters to the severely impaired conditions where multiple stressors create harsh
conditions for aquatic life. This comprehensive monitoring network, maintained through decades
of tribal commitment despite funding uncertainties and physical challenges, provides the
foundation for understanding and ultimately reversing nonpoint source pollution impacts
throughout the Hoh River Watershed.
Continuous Dissolved Oxygen
In summer 2020, the HWQP began continuous monitoring of DO concentration in the Hoh River
above Anderson Creek. Since then, we have added six more continuous DO sites: the Hoh River
above Barlows, the Hoh River at ONP Boundary, Lower Braden, Lower Chalaat, Hell Roaring,
and Lower Nolan Creeks. Most of these waterways were chosen because results from
instantaneous monitoring indicated that they have low DO concentrations in summer months and
may be areas of concern.
Base Flow
The HWQP has monitored summer low flow in Hoh River tributaries since the early 2000s.
Monitoring varies by year depending on staff structure, availability, and weather conditions. The
low flow period varies slightly each year in the HRW but typically occurs from late-July to lateSeptember. This work is being carried out in cooperation with the Northwest Indian Fisheries
Commission, USGS, and other contributing Western Washington Tribes. Flow data are used in
conjunction with temperature data being collected by the tribes to assess the impacts of land use
practices, water withdrawal, and landscape changes.
Water Chemistry & Total Suspended Solids
Eight creeks, Chalaat, Braden, Nolan, Owl, Elk, Winfield, Hoh Oxbow, & Hell Roaring, were
selected to conduct surface water chemistry and total suspended solids testing in 2024. These
waterways were chosen because they are suspected to have elevated water chemistry or total
suspended solids concentrations and/or they are known to be used by salmon and steelhead for
spawning, rearing, and/or migration. Grab surface water samples from rivers and creeks were
collected once a month for twelve months following methods adapted from WDOE’s Standard
Operating Procedure EAP015, version 1.4: Manually Obtaining Surface Water Samples.
Benthic Macroinvertebrates
We sample 5 creeks for benthic macroinvertebrates during baseflow conditions in August and
September 2024. Samples were taken from Anderson, Owl, Elk, Nolan, and Winfield Creeks.
These creeks were chosen because they are used by salmon and steelhead for spawning, rearing,
and migration. We also collect a replicate sample from one creek, which is randomly chosen, to
assess the within-site variability of the samples. The replicate sample was collected right after the
primary sample and within the same sampling reach.

9

Samples were collected on days without any rain events. Eight digs were completed in each reach
(two per riffle, total kick area of eight-square feet per sample) using a surber sampler with a 500micron (μm) mesh size. Samples were subsampled to 500 individuals and identified to lowest
practical taxonomic level by Aquatic Biology Associates, a taxonomic laboratory.
Equipment
Current monitoring employs EPA-approved methods with standardized equipment ensuring data
quality and comparability across programs. To get meaningful data, it is necessary to use
equipment with the proper sensitivity, or the lowest detection limit for each measurement type. For
data to be used for Washington state’s Water Quality Assessment process, sensors must have a
sensitivity below the applicable water quality criterion. Benthic macroinvertebrate samples must
be subsampled and identified in a manner that provides meaningful information about the
community assemblage and water quality of the waterway. The equipment and methods used by
the HWQP are as follows:
Instantaneous water quality: The YSI ProDSS serves as the primary field instrument for monthly
monitoring with advanced features that improve both data quality and field efficiency. It consists
of a handheld meter, a cable, and a connected bulkhead with temperature/conductivity, optical
dissolved oxygen (ODO), pH, and turbidity sensors. The YSI ProDSS multimeter has sensors with
sensitivities of:
• Temperature: -5 ºC
• DO: 0 mg/L
• pH: 0
• Specific conductivity: 0 mS/cm
• Turbidity: 0 FNU
Continuous water temperature: The Onset HOBO TidbiT MX Temperature 400 and Temperature
Pro v2 are used to monitor continuous temperature every 15 minutes throughout the year. The
Onset HOBO TidbiT MX Temperature 400’ logger has a sensitivity of -20 °C in air or water. The
Onset HOBO Temperature Pro v2 logger has a sensitivity of - 40 °C in air or water.
Continuous dissolved oxygen: The Onset HOBO DO logger measures dissolved oxygen between
0-30 mg/L with an accuracy of ± 0.2 mg/L up to 8 mg/L; ± 0.5 mg/L from 8 to 20 mg/L.
Low Flow: The OTT MF Pro calculates flow measurements according to USGS and ISO methods.
The electromagnetic velocity sensor has an accuracy velocity range of 0 - 10 ft/s: ± 2 % of reading
± 0.05 ft/s Reading 10 - 16 ft/s: ± 4 % of reading.
Benthic Macroinvertebrates: Benthic macroinvertebrates are collected from wadable creeks
following methods from the Streamkeepers of Clallam County Field Procedures (2018) manual.
Equipment includes 500 micron sieves, denatured alcohol and surber sampling set.

10

Water chemistry and total suspended solids concentrations: Sensitivity of water sample analyses
methods is reported with the method detection limit, or the minimum concentration of an analyte
in a sample that can be reported with 99% confidence. The method detection limits for water
samples analyzed for water chemistry and total suspended solids concentrations are:
• Total Kjeldahl nitrogen: 0.2 ppm
• Nitrate + nitrite-N: 0.1 ppm
• Ammonia-N: 0.01 ppm
• Total phosphorus: 0.01 ppm
• Ortho-phosphate: 0.01 ppm
• Dissolved organic carbon: 0.095 ppm
• Total suspended solids: 4 ppm
Quality Assurance/Quality Control Protocols
To be considered usable, water quality data must conform to certain quality requirements presented
in the Hoh Tribes EPA-approved QAAP. Below are a list of objectives the equipment and sampling
undergo to maintain proper quality control measures.
•

Data are precise, with measurements being repeated consistently.
o Instantaneous water quality: Duplicate measurements of each water quality
parameter are taken at each site. If it appears that measurements are not precise,
then the YSI ProDSS multimeter will be recalibrated.
o Benthic Macroinvertebrates: Each year, a replicate sample will be taken from one
randomly chosen site to assess within-site variability.
o Water chemistry and total suspended solids concentration: Duplicate water samples
for analysis of each water quality parameter are taken at each site.

•

Bias of data is reduced as much as possible.
o Instantaneous water quality and storm turbidity: Instantaneous water quality is
measured each month at sites across the Hoh River watershed to capture a wide
range of conditions. Sites include those with relatively pristine (in the ONP) and
degraded (out of the ONP) water quality to reduce bias towards either type of site.
o Continuous water temperature: Continuous water temperature is recorded at sites
across the Hoh River watershed to capture a wide range of conditions. Sites include
those with relatively pristine (in the ONP) and degraded (out of the ONP) water
quality to reduce bias towards either type of site. In the Hoh River, loggers are
sometimes placed in side channels, which may result in main channel temperatures
being missed.
o Continuous dissolved oxygen: Continuous dissolved oxygen is recorded at sites
outside of the ONP (more degraded). Sites were chosen because results from
instantaneous water quality monitoring indicated that they had low DO
concentrations. Data are likely skewed. In the Hoh River, loggers are sometimes
11

placed in side channels, which may result in main channel DO concentration being
missed.
o Low Flow: Low flow is measured in creeks outside of the ONP and at a small
number of sites. Data are likely skewed and not representative of the entire Hoh
River watershed.
o Benthic Macroinvertebrates: Benthic macroinvertebrates are sampled at a small
number of sites. Data are likely skewed to reflect localized conditions instead of
the entire Hoh River watershed.
o Water chemistry and total suspended solids concentration: Grab samples for water
chemistry and total suspended solids concentrations are mainly located outside of
the ONP (more degraded). Most sites were chosen because results from
instantaneous water quality monitoring indicated that they may have elevated water
chemistry and/or total suspended solids concentrations.
•

Data are representative of the area from which they are measured.
o Instantaneous water quality and storm turbidity: Instantaneous water quality and
storm turbidity are measured at sites across the Hoh River watershed to capture a
wide range of conditions. Sites include those with relatively pristine (in the ONP)
and degraded (out of the ONP) water quality. Instantaneous water quality is
monitored once a month to capture conditions throughout the year.
o Continuous water temperature: Continuous water temperature is recorded at sites
across the U&A to capture a wide range of conditions. Sites include those with
relatively pristine (in the ONP) and degraded (out of the ONP) water quality to
reduce bias towards either type of site. At select sites, water temperature is
monitored through the entire year to capture seasonal variation in temperature. Sites
where monitoring is only done during the summer do not properly reflect conditions
throughout the entire year.
o Continuous dissolved oxygen: Continuous dissolved oxygen is recorded at sites
outside of the ONP (more degraded). Sites were chosen because results from
instantaneous water quality monitoring indicated that they likely had low DO
concentrations. Data are likely not representative of conditions throughout the
entire watershed. Results do not capture conditions throughout the year because
continuous dissolved oxygen is only monitored in the summer.
o Low Flow: Low flow is measured in creeks outside of the ONP (more degraded)
and at a small number of sites. Data are likely skewed and not representative of the
entire U&A.
o Benthic Macroinvertebrates: Benthic macroinvertebrates are sampled at a small
number of sites. Data are likely not representative of the entire Hoh River
watershed.

12

o Water chemistry and total suspended solids concentration: Grab samples for water
chemistry and total suspended solids concentrations are collected outside of the
ONP (more degraded). Most sites were chosen because results from instantaneous
water quality monitoring indicated that they may have elevated water chemistry
and/or total suspended solids concentrations. Data are likely not representative of
the entire Hoh River watershed.
•

Data are collected in a manner that they are comparable to other datasets.
o Instantaneous water quality and storm turbidity: The YSI ProDSS multimeter is
calibrated and maintained following QAPP protocols and the manufacturer’s
recommendations.
o Continuous water temperature: Onset Hobo temperature loggers are maintained
following QAPP protocols and the manufacturer’s recommendations. The accuracy
of each logger is checked using the QAPP protocol prior to deployment.
o Continuous dissolved oxygen: Onset Hobo DO loggers are calibrated and
maintained following QAPP protocols and the manufacturer’s recommendations.
o Low Flow: The MF Pro flow meter and velocity sensor are calibrated and
maintained following QAPP protocols and the manufacturer’s recommendations.
Data are collected following QAPP protocols.
o Benthic Macroinvertebrates: Benthic macroinvertebrates are sampled following
QAPP protocols.
o Water chemistry and total suspended solids: Water samples are collected following
QAPP protocols.

•

Data are measured with sensors with the appropriate sensitivity to answer the questions
that are being posed.
o To get meaningful data, it is necessary to use equipment with the proper sensitivity,
or the lowest detection limit for each measurement type. For data to be used for
Washington state’s Water Quality Assessment process, sensors must have a
sensitivity below the applicable water quality criterion. Benthic macroinvertebrate
samples must be subsampled and identified in a manner that provides meaningful
information about the community assemblage and water quality of the waterway.

Equipment is calibrated to ensure accuracy and precision of respective parameters frequently to
ensure quality data. Calibration standards are purchased directly from the instruments supplier and
are regularly verified for expiration and reliability. Along with routine calibration by the Water
Quality Specialist, Onset HOBOware, YSI ProDSS multiparameter and MF Pro Flow meters are
sent to the manufacturer service center for inspection and, if necessary, replacement of parts and
calibration (Table 1).

13

Table 1. Calibration and maintenance requirements for water quality equipment.

Instrument/
Equipment
Onset HOBO
Pro V2
temperature
logger
Onset HOBO
TidbiT MX
temperature
400’ logger
Onset HOBO
DO logger

YSI ProDSS
multimeter
with fourport cable
assembly

OTT MF Pro
flow meter
and velocity
sensor

Calibration/ Verification
Method
• Temperature verification
against a NIST-certified
thermometer in an ice
bath and in room temp
water
• Temperature verification
against a NIST-certified
thermometer in an ice
bath and in room temp
water
• Replace sensor cap yearly
and calibrate 100%
saturation in watersaturated air and adjust
for elevation and pressure
• 3pt calibration using pH
4, 7, 10 buffer solutions
• Temperature verification
against a NIST-certified
thermometer
• Calibration with 1000
µS/cm conductivity
standard
• 2 or 3 pt calibration using
0, 12.4,124, or 1010 FNU
turbidity standards
• DO saturation calibration
using in water-saturated
air
• Send to OTT Repair
Center once a year for
calibration of sensors.

Calibration Frequency

Maintenance
Requirements
Per manufacturer’s
instructions

•

Check accuracy of logger
prior to summer
deployment.

•

•

Calibrate sensor after
replacing DO cap prior to
summer deployment.

•

Per manufacturer’s
instructions

•

Check accuracy of logger
prior to summer
deployment.

•

Per manufacturer’s
instructions

•

Check accuracy of
temperature sensor on day
of monitoring prior to use.
Calibrate pH and DO
sensors on day of
monitoring prior to use.
Check accuracy of turbidity
and specific conductivity
sensors on day of
monitoring prior to use. If
needed, calibrate sensors.
Send to YSI Repair Center
once a year for calibration
of sensors.
Send to OTT Repair Center
once a year for calibration
of sensors.

•

Per manufacturer’s
instructions.
Send to YSI
Repair Center once
a year for
inspection for
malfunctions and
repairs, including
replacement of
ODO cap and pH
module.

•

•

•

•

•

•
•

Per manufacturer’s
instructions.
Send to OTT
Repair Center once
a year for
inspection for
malfunctions and
repairs.

Data collection methods follow strict protocols outlined in the Tribe’s Quality Assurance Project
Plan (QAPP). This ensures standard operating procedures are in place to attain quality and avoid
14

data errors. Protocols are based on known and effective methodologies from NWIFC, USGS,
neighboring Western Washington Tribes, WDOE, WDNR, and Streamkeepers of Clallam County.
To ensure proper data management, data are recorded in field notebooks or the appropriate field
form when any measurement is conducted. When field data are collected, the site name, date, time,
and GPS location are also recorded. When paper field forms are used, they are scanned to pdf
format. Data are then entered into Excel files. When data are initially saved as digital forms on an
electronic device (e.g., continuous data in a HOBOfile downloaded from an Onset data logger),
the data are automatically converted to Excel files. All files containing data are stored in an
electronic project folder. Copies of this folder are kept on the Water Quality Specialist’s PC, the
Hoh Tribe’s centralized computer system, and a removable hard drive. After data have been
reviewed for anomalies and transcription errors, data are imported into the Hoh Tribe’s Tribal
Water Quality Database (TWQD) and the Water Quality Time Series (WQTS) database in
Microsoft SQL server. Backups of the TWQD and WQTS are saved onto the Water Quality
Specialist’s computer and external hard drive whenever changes are made to the databases.
Finalized data in TWQD are submitted to the EPA Water Quality Exchange (WQX) using the
Tribal Water Quality Exchange Client, an exchange network node developed by the NWIFC.
The Hoh Tribe does not have water quality standards for fresh surface waters. Therefore, tribal
goals for rivers and creeks in the watershed are based on Washington State fresh water designated
aquatic life uses (WAC 173-201A-200 freshwater designated uses and criteria, 2020). Designated
aquatic life uses describe the ways in which a waterbody is used by aquatic organisms during their
life cycles. Each designated use has limits, or “criteria”, for certain water quality parameters (i.e.,
temperature, DO, pH). If a water quality measurement of a waterway exceeds criteria, then the
water quality is degraded enough to hinder aquatic life growth, reproduction, and/or survival.
Geospatial Data Sources
Spatial analysis employed federal and state datasets to characterize watershed features and land
use patterns. The National Wetlands Inventory supplied wetland mapping including type,
hydrogeomorphic classification, and regulatory status. Rivers and streams data came from the
National Hydrography Dataset, offering complete stream network topology with flow direction
and stream order attributes.
Roads data from Topologically Integrated Geographic Encoding and Referencing (TIGER)
Shapefiles provided transportation network geometry including road classification and surface
type. Elevation data from the Washington State Geospatial Open Data Portal enabled derivation of
slope, aspect, flow direction, and flow accumulation, supporting complete watershed delineation.
The WADOE Water Quality Atlas supplied 303(d) impaired waters listings with parameter-specific
impairment designations.
Geospatial analysis employed ArcGIS Pro with Spatial Analyst extension to integrate diverse
datasets, identify pollution sources, and quantify landscape-water quality relationships. Land use
and land cover data from the Jefferson County Public Land records.
15

All spatial data were projected to NAD 1983 State Plane Washington North FIPS 4601 (US Feet)
to maintain geometric accuracy and enable precise overlay analysis. This projection minimizes
distortion across the watershed while maintaining compatibility with state and regional datasets.
Transformations between datums employed the NAD 1927 to NAD 1983 NADCON
transformation for historical data integration.
The watershed was delineated using 10-meter Digital Elevation Model (DEM) data through
systematic terrain processing. Flow direction was calculated using D8 algorithm identifying
steepest descent from each cell. Flow accumulation quantified upstream contributing area for
stream network definition. Stream networks were extracted at 25-acre accumulation threshold
calibrated to match NHD flowlines. Watershed boundaries were delineated from the Hoh River
mouth pour point, capturing all contributing drainage. Sub-watershed boundaries at HUC-12 scale
enabled localized analysis of pollution sources and impairment patterns.
Spatial overlay analysis identified potential nonpoint source pollution delivery pathways by
intersecting land use, infrastructure, and water resources. Analysis parameters included roads
within 100 feet of streams on slopes exceeding 10%, harvest units from 2015-2025 within 300 feet
of fish-bearing streams, residential parcels lacking 50-foot riparian buffers, and stream crossing
locations. While comprehensive GIS quantification exceeded the scope of this assessment, the
methodology established the framework for identifying pollution delivery pathways.
Despite these assumptions, the assessment provides sufficient information to identify priority
waters needing restoration, characterize major nonpoint source categories, and establish a
framework for BMP selection. The combination of long-term monitoring data, comprehensive
spatial analysis, and extensive historical documentation creates a robust foundation for the
Nonpoint Source Management Program. Acknowledged uncertainties are addressed through
adaptive management approaches that incorporate effectiveness monitoring and periodic
reassessment as additional information becomes available.
Historical Documentation
Historical documents reviewed included the Environmental Assessment for the Highlands
Development (2024) documenting pre-development conditions and infrastructure plans, multiple
Phase I Environmental Site Assessments identifying potential contamination sources including
historical land uses, wetland delineations and stream assessments establishing baseline habitat
conditions and regulatory jurisdictions, diesel spill response monitoring following incidents near
Chalaat Creek and Highway 101, and the Upper Hoh Road water quality assessment with monthly
sampling at six stations. The Hoh Tribe's Non-Expiring Forest Management Plan and
accompanying Environmental Impact Statement provided forest management standards and
harvest projections affecting water quality. Regional assessments including WRIA 20 watershed

16

planning documents and Olympic National Park monitoring reports offered watershed-scale
context for local observations.
Limitations & Assumptions
This assessment acknowledges inherent limitations in data availability, analytical methods, and
jurisdictional constraints that influence conclusions and recommendations.
The dynamic nature of the Hoh River system presents significant monitoring challenges that affect
data completeness and program costs. Seasonal access constraints affect data collection throughout
the year. Winter storms make roads impassable from December through February, snow blocks
upper elevation sites from November through April, and high flows prevent safe wading from
November through May. These limitations create temporal bias, with summer data overrepresented
relative to winter conditions when different water quality dynamics occur. Headwaters above
3,000 feet in elevation remain largely unmonitored due to access constraints and snow limiting
deployment windows. Non-fish tributaries receive lower priority given limited resources, though
they contribute flow and potentially pollutants. Wetlands require different protocols than stream
monitoring, remaining largely uncharacterized despite their influence on pH and dissolved oxygen.
LAND USE SUMMARY
The Hoh River Watershed encompasses diverse land cover types that collectively influence
nonpoint source pollution generation and transport pathways. Forest lands dominate the landscape,
comprising 81.6% of the total watershed area. This forested landscape creates both the watershed's
exceptional baseline water quality and its primary nonpoint source challenges through forest
management activities.
Forest Lands
Coniferous forest represents the watershed's dominant land cover, with evergreen forest
comprising 112,742 acres (58.89% of the watershed), extending from sea level to alpine zones
across multiple ownership categories. Within Olympic National Park's (ONP) 109,888 acres
(57.4% of the watershed), intact old-growth forests that create headwater conditions that maintain
exceptional water quality in the upper watershed. These protected forests, some containing trees
exceeding 1,000 years in age, provide an ecological benchmark against which downstream impacts
are measured.
A large portion of the Hoh River flows through a temperate rainforest. Dominant tree species are
western hemlock (Tsuga heterophylla), Sitka spruce (Picea sitchensis), black cottonwood (Populus
trichocarpa), big-leaf maple (Acer macrophyllum), red alder (Alnus rubra), willow species (Salix
spp.), western red cedar (Thuja plicata), Pacific silver fir (Abies amabilis), and Douglas fir
(Pseudotsuga menziesii). Obligate wetland plant species often found in the watershed include
slough sedge (Carex obnupta), water parsley (Oenanthe sarmentosa), and western skunk cabbage
(Lysichiton americanus). Invasive plant species, such as spotted jewelweed (Impatiens capensis),
Japanese knotweed (Fallopia japonica), scotch broom (Cytisus scoparius), and reed canary grass
17

(Phalaris arundinacea) persist within floodplain and riparian zones. Spread of invasives is
associated with reduced river bank stabilization and loss of water from the channel, which pose
major threats to instream ecosystems.
Outside the park boundaries, managed forests on state and private lands display a complex mosaic
of harvest units and regenerating stands at various stages of succession. Timber harvest operations
are extensive throughout the watershed, with clearcuts of varying ages along Highway 101, the
Hoh Mainline Road, and Oil City Road. These harvest units displayed distinct age classes that
reflect decades of continuous forest management: fresh clearcuts less than one year old with
exposed soil and logging debris, recent harvests between one and five years old showing early
regeneration (including a documented 5-year- old clearcut observed near the Elk Creek monitoring
station), mid-rotation stands of five to fifteen years displaying closed canopy conditions, and
maturing second growth exceeding fifteen years approaching commercial thinning age. A recently
harvested clearcut was documented immediately adjacent to the west side of Anderson Creek,
demonstrating the proximity of active forest management to water quality monitoring sites.
Spatial distribution of these harvest units correlates strongly with documented water quality
impairments. Washington Department of Natural Resources manages 46,464 acres (24.3% of the
watershed) as state trust lands, while private industrial and non-industrial forest lands encompass
33,600 acres (17.6%), including 10,315 acres under management by The Nature Conservancy
(Figure 2). The 960-acre Hoh Indian Reservation (0.5% of the watershed) maintains limited forest
management primarily for cultural uses. These actively managed forests outside the park, while
providing economic benefits through timber production, create the primary source areas for
sediment delivery, thermal pollution, and invasive species establishment affecting downstream
waters. The intensity of management varies by ownership, with industrial forests typically
harvested on 35–45-year rotations while state lands follow longer 60-80 year rotations, creating a
patchwork of forest conditions across the landscape.
Recently harvested and regenerating areas display clear successional patterns across the landscape.
GIS analysis reveals that shrub/scrub vegetation representing the most recent clearcuts (0-5 years
old) encompasses 10,620 acres (5.55% of the watershed), while deciduous forest dominated by
red alder colonizing older harvest units (5-20 years old) covers 38,962 acres (20.35% of the
watershed). Combined, these early successional stages total 49,582 acres (25.9% of the watershed)
(Figure 3), confirming field observations of extensive recent timber harvest activity. Disturbance
of these areas opens opportunities for invasive species to develop in place of native, large growth
trees.
These areas concentrate along major transportation corridors where access facilitates timber
extraction. Harvest rotation ages have evolved significantly from traditional practices, with
maximum ages now ranging from approximately 90 years on high-quality sites to 117 years on
lower-quality sites based on US Forestry Service (USFS) Pacific Northwest Research Station

18

extended rotation research. This evolution toward longer rotations reflects growing recognition of
the multiple values forests provide beyond timber production.
Mixed forest areas occupy 4,516 acres (2.36% of the watershed), occurring primarily in riparian
zones and transitional areas between coniferous and deciduous stands. Red alder (Alnus rubra)
dominates the deciduous component, particularly in riparian areas and recently disturbed sites
where its nitrogen-fixing capability accelerates soil development. Bigleaf maple (Acer
macrophyllum) occurs as a subdominant species, providing rapid shade recovery along stream
corridors critical for temperature regulation. These hardwood-dominated stands, while
representing a smaller portion of total forest cover, provide disproportionate ecological benefits
through nitrogen fixation, rapid growth rates that quickly restore canopy cover, and high-quality
leaf litter that supports aquatic food webs.
Commercial timber harvest has persisted as the dominant land use activity affecting water quality
throughout the watershed's state and private forest lands over the past decade. While tribal forest
lands continue to be managed under sustained yield principles that prioritize cultural values and
salmon habitat protection, the surrounding industrial and state forests have maintained active
harvest programs that create ongoing nonpoint source pollution challenges.
The Olympic Experimental State Forest's 270,000 acres on the western Olympic Peninsula has
emerged as a living laboratory for evolving forest management approaches that may influence
practices throughout the Hoh watershed. Research conducted there has documented a fundamental
shift in silvicultural philosophy, with harvest rotation ages extending from traditional 45–60-year
industrial cycles to 90-117 years under extended rotation strategies developed by the USFS Pacific
Northwest Research Station. Maximum rotation ages now range from approximately 90 years on
high-quality sites to 117 years on lower-quality sites, with peer-reviewed studies demonstrating
that rotations can be "considerably extended without reducing long-term timber production”
(Curtis 1995). This paradigm shift reflects growing recognition that forests managed for multiple
values, including wildlife habitat, carbon sequestration, and water quality protection, can maintain
economic viability while reducing environmental impacts.
Post-harvest regeneration throughout the watershed follows predictable Olympic Peninsula
succession patterns, though specific stocking levels and species composition data remain
proprietary to individual landowners. Natural regeneration by red alder (Alnus rubra) dominates
riparian-adjacent harvest units, providing nitrogen fixation and relatively rapid canopy closure that
partially mitigates temperature. However, the conversion from complex old-growth and mature
second-growth forests to simplified even-aged plantations represents a fundamental alteration of
watershed processes that affect water quality for decades following harvest.
The spatial distribution of harvest activity over the past decade may contribute with persistent
water quality impairments documented through the Tribe's monitoring program. The FY25
monitoring found 26 sites across the Hoh River, South Fork Hoh River, and 22 tributaries impaired
due to elevated temperatures, affecting 35.8 river miles or 47.2% of the total monitored stream
19

length (Hoh FY25 Water Quality Assessment Report, 2025). This represents a troubling expansion
from earlier assessments. Current aerial imagery available through Google Earth and NAIP reveals
visible harvest patterns that align with these temperature-impaired drainages, suggesting a
relationship between canopy removal and thermal pollution.
Developed Lands
Development within the watershed concentrates in specific zones that create localized but
significant water quality impacts. GIS analysis of 2021 NLCD data reveals that developed areas,
including residential, commercial, and transportation infrastructure, comprise 7,463 acres (3.90%
of the watershed). Despite this relatively small footprint, the concentration of impervious surfaces
and human activities in these areas can generate disproportionate pollutant loads that affect
downstream water quality, especially with heavy traffic stemming from the ONP.
Residential
The Lower Hoh community represents the primary concentration of development within tribal
lands, encompassing the 960-acre Hoh Indian Reservation at the river mouth where tribal members
maintain their ancestral connection to the watershed. This community benefits from modern
wastewater infrastructure, which serves tribal homes and administrative buildings. The Tribe’s
municipal-style treatment system represents a significant investment in water quality protection,
preventing the nutrient and pathogen loading that would occur from individual on-site septic
systems.
Residential growth within the watershed has proceeded at a modest but steady pace, though at rates
significantly lower than broader Jefferson County trends would suggest. While Jefferson County's
population increased from approximately 30,000 residents in 2014 to 34,000 in 2025 (USA Facts
2026), representing a compound annual growth rate of 1.1%, most of this growth occurred on the
eastern side of the Olympic Peninsula in communities like Port Townsend and Quilcene. The Hoh
Watershed on the western slope contains only a small fraction of the county's population, with
most residents concentrated in the Lower Hoh community and scattered rural properties along
transportation corridors. The watershed's geographic isolation and limited services, suggests
development pressure remains minimal compared to many Pacific Northwest watersheds.
However, the cumulative effects of even modest development in a largely undeveloped watershed
create water quality impacts that persist for decades.
Commercial
Tourism infrastructure has experienced dramatic growth pressure, with Olympic National Park
visitation at 3.5 million annual visitors generating 565,706 vehicle trips along Highway 101 in
2025 (National Park Service, 2026). This tourism surge creates seasonal stress on transportation
systems, with one-to-two-hour entrance delays during peak periods indicating infrastructure
capacity limitations. The economic importance of tourism drives pressure for infrastructure
improvements that may conflict with water quality protection goals.
20

The emergency repairs needed on Upper Hoh Road exemplify how increasing storm intensity
overwhelms infrastructure designed for historical conditions. Projected increases in atmospheric
river events, rain-on-snow occurrences, and peak flow magnitudes suggest that existing
infrastructure will face accelerating stress, potentially creating new pollution sources as systems
fail. The observed bank stabilization challenges, requiring massive dolosse structures and ongoing
multi-mile armoring projects, indicate that geomorphic changes are already exceeding
infrastructure adaptive capacity.
Transportation
The watershed's transportation network continues to serve as a chronic source of sediment and
toxic chemicals while providing essential access for local residents, the annual visitors to Olympic
National Park and the forest management activities that support regional economies.
Highway 101 serves as the watershed's primary transportation artery and most significant linear
source of nonpoint pollution, extending 366 miles through Washington State while bisecting tribal
lands to provide the only year-round access route to the outer Olympic Peninsula coast. This
heavily traveled corridor generates continuous water quality impacts through multiple mechanisms
that compound across its length. Many river and stream crossings, such as the Highway 101 old
trestle bridge over the Hoh River, have no stormwater control infrastructure, resulting in traffic
and road stormwater flowing directly into the waterways. This complete absence of treatment
infrastructure allows road runoff contaminated with tire particles, petroleum hydrocarbons, heavy
metals, and winter de-icing materials to discharge directly into waters that support threatened
salmonid populations. Emissions from vehicle exhaust or hazardous material combustion can
reach waterbodies through proximity and aerial dispersal. High mercury concentrations, attributed
to vehicle emissions, have already been detected in snow and fish in the Olympics (Eagles-Smith
et al. 2014). Waterbodies are directly affected through rainwater runoff; however, particulates also
get distributed to soil through lichen absorption or forest debris (Maynes 2008). This insinuates
long-term adsorption from soil, even if roads are no longer in use. Elevated mercury concentrations
pose hazards to aquatic life species and human health.
Upper Hoh Road exemplifies the escalating challenges of maintaining essential transportation
infrastructure in a dynamic river environment while attempting to minimize water quality impacts.
It provides the critical access route from Highway 101 to Olympic National Park's Hoh Rainforest
visitor center and represents another significant infrastructure corridor. This road serves the
460,000 annual visitors who entered the park in 2024, with 176,566 vehicles sometimes creating
one-to-two-hour entrance wait times during peak periods (National Park Service, 2026).
In 2021, Western Federal Lands Highway Division built a massive erosion control barrier along
the north bank between the road and the river to protect Upper Hoh Road from the river's erosive
force. This barrier incorporates traditional riprap and logs but relies primarily on dolosse—
specialized concrete erosion control structures typically used in coastal engineering—placed in
large piles along the bank between the river and road. The presence of these massive concrete
21

forms, each weighing several tons, indicates erosion pressures that exceeded conventional
engineering solutions. The current 12-mile bank stabilization project underway through the
Western Federal Lands Highway Division represents a multi-million-dollar investment attempting
to protect the road into the Olympic National Park from destruction, though the long-term viability
of armoring approaches remains questionable under the extreme migration of the Hoh River. The
Tribe’s Natural Resource Department is aiding in long-term research monitoring to assess the
effectiveness of this project. This project demonstrates the ongoing challenge of maintaining
transportation infrastructure in this dynamic river environment while minimizing water quality
impacts. The road's importance to both tourism and emergency access was highlighted by the need
for $650,000 in emergency repairs at milepost 9.9 in May 2025, funded through Washington State
Strategic Reserve funds.
The Hoh Mainline Road, anchored at its Highway 101 intersection where a former lumber mill
once processed the watershed's timber harvest, continues providing access to extensive forest lands
and rural properties throughout the middle watershed. While receiving less traffic than Upper Hoh
Road, this route's proximity to active forest management areas creates chronic sediment delivery
at numerous stream crossings. The road's gravel surface generates fine sediment during dry
conditions and concentrated erosive flows during storms, creating year-round water quality
impacts that affect downstream beneficial uses.
Jefferson County's maintenance responsibility for 400 center-line miles of secondary roadway plus
8.4 miles of multi-use trails creates an extensive secondary transportation network that generates
cumulative water quality impacts through distributed pollution sources. Secondary roads within
the watershed primarily serve residential properties and provide natural resource access, creating
moderate but persistent traffic that mobilizes pollutants year-round.
Forest roads constructed primarily for timber harvest access create the watershed's most extensive
transportation infrastructure, forming a dendritic network throughout the approximately 70,864
acres of state and private commercial forest lands. These roads, while essential for forest
management operations, represent chronic sediment sources that persist long after harvest
activities cease. Many forest road stream crossings, including single-lane wooden bridges at Maple
Creek and Owl Creek Upper monitoring stations, act as nonpoint sources of sediment runoff during
precipitation events.
Washington Department of Natural Resources road management has shifted from expansion
toward strategic decommissioning and maintenance optimization, reflecting recognition that road
density correlates directly with water quality degradation. Regional studies indicate that properly
functioning watershed conditions require road densities below 2 miles per square mile, with
sensitive species like bull trout often absent where densities exceed 1.5 miles per square mile (Lyon
& Maguire, 2008).

22

Agricultural and Open Lands
Agricultural lands and pastures represent a minor land use within the watershed. GIS analysis
reveals that agricultural uses account for 765 acres (0.40% of the watershed), consisting primarily
of hay and pasture lands. Pastoral landscapes dot the Upper Hoh Road, including relatively large
areas of pastureland along the north side of the road with several large open fields enclosed by
grazing fences. These agricultural areas occur primarily in valley bottoms where gentler slopes
and deeper soils support pasture establishment, with most operations appearing to be small-scale
livestock grazing and hay production based on aerial imagery interpretation.
Grasslands and open areas not in active agricultural production comprise 5,128 acres (2.68% of
the watershed) according to GIS analysis. These areas include natural meadows maintained by
periodic flooding or poor drainage, utility corridors requiring vegetation management for power
line clearance, road rights-of-way maintained in herbaceous vegetation, and other open land types
visible in current aerial imagery. While individually small, these openings in the forest canopy
create edge effects and can concentrate surface runoff during precipitation events.
Other Land Cover Categories
Barren lands throughout the watershed, including exposed river gravels, landslide scars, and rock
outcrops, represent 670 acres (0.35% of the total area). The Hoh River's active channel migration
zone creates the most extensive barren areas, with dynamic patterns of gravel bar formation and
vegetation colonization visible in sequential aerial imagery. The river's characteristic milky slateblue coloration, produced by glacial flour from the Blue, White, and Lateral Glaciers in the upper
watershed, indicates active erosion of bedrock that maintains sediment supply to these depositional
features. These naturally barren areas, while appearing disturbed, represent essential components
of the river ecosystem, providing spawning gravels for salmonids and nesting habitat for
specialized bird species.
The distribution of land ownership within the watershed creates distinct management zones that
fundamentally influence water quality protection approaches (Figure 2). The majority of the upper
basin is under federal preservation status that prohibits commercial resource extraction, providing
better headwater protection compared to some Olympic Peninsula watersheds. The ownership
maps (Figures 2 - 4) illustrate the complex checkerboard pattern of state and private forest lands
in the lower and middle watershed that creates coordination challenges for implementing
consistent management practices, while the upper watershed's consolidated federal ownership
enables uniform preservation standards.
The Hoh Tribe has strategically expanded its land base through acquisition of additional trust lands
beyond the reservation boundary, enhancing the Tribe's capacity to implement comprehensive
watershed protection measures. These acquisitions, focused on culturally significant areas and
critical habitat, demonstrate the Tribe's long-term commitment to ecosystem restoration and
protection.
23

The current land cover composition, shaped by geology, landscape, and human management over
millennia, creates both the watershed's exceptional ecological values and its vulnerability to
nonpoint source pollution. The dominance of forest cover maintains base water quality conditions
superior to more developed watersheds, yet the intensity of forest management on portions of the
landscape generates chronic and acute water quality impacts. Understanding this complex mosaic
of land covers and their associated management regimes provides the foundation for developing
targeted strategies to protect and restore water quality throughout the Hoh River Watershed.

24

Figure 2. Hoh River Watershed Land Uses with potential for NPS pollution along water quality monitoring site waterways.

25

Table 2. Current Land-Cover Composition in the Hoh River Watershed.

Land Cover Type

Acres

Percentage

Primary Locations

Evergreen Forest

112,742

58.89%

Throughout watershed

Deciduous Forest

38,962

20.35%

Riparian areas, harvest regrowth

Mixed Forest

4,516

2.36%

Transitional zones

Shrub/Scrub

10,620

5.55%

Recent harvest areas

Grassland/Herbaceous

5,128

2.68%

Meadows, clearings

Pasture/Hay

765

0.40%

Valley bottoms

Woody Wetlands

7,425

3.88%

Throughout

Emergent Wetlands

631

0.33%

Lowland areas

Open Water

2,469

1.29%

Rivers and streams

Developed Open Space

6,257

3.27%

Lower Hoh area

Developed Low Intensity

1,072

0.56%

Rural residential

Developed Medium
Intensity

96

0.05%

Commercial areas

Developed High Intensity

38

0.02%

Dense development

Barren Land

670

0.35%

River gravels

Total

191,391

100%

-

Source: GIS analysis of 2021 National Land Cover Database (NLCD)

26

Figure 3. Land coverage of the Hoh River Watershed.

27

Figure 4. Land Coverage surrounding the Hoh Indian Reservation.

28

SURFACE AND GROUND WATER QUALITY
Hoh Indian Reservation
The 1.5-square mile (960-acre) Hoh Indian Reservation is located on the Olympic Peninsula in
Jefferson County, Washington (Figure 1). The reservation, which sits by the mouth of the Hoh
River on the Pacific Coast, contains a variety of freshwater and saltwater sources, including 5.30
miles of rivers and streams, 1.76 miles of coastline, 2.97 acres of lakes and ponds, 19.6 acres of
estuary, and 17.1 acres of swamps and marshes. Tribal residents receive potable water from one
major aquifer system. Wastewater is treated at a plant on the reservation that was installed in 2018.
The Hoh River originates at glacial terminuses on Mount Olympus in the Olympic National Park,
flowing 56 miles from its headwaters to the Pacific Ocean. Due to the glacially-fed nature of the
Hoh River and several of its headwater tributaries, glacial till gives the river high background total
suspended sediment concentrations. Numerous tributaries enter the river as it flows towards the
coast; in total, there are 1,299 miles of creeks and rivers within the HRW comprised of seven
different hydrologic units (Table 3). The South Fork of the Hoh River, the river’s largest tributary,
joins the mainstem near river mile 31, approximately 0.5 miles upstream from the ONP boundary.
Waterways within the Hoh Tribal trust and fees land include Chalaat, Braden, and Fletcher Creek.
Table 3. Hoh River Watershed hydrologic unit components and descriptions.

Name
Headwaters Hoh River
Hoh Creek-Hoh River
South Fork Hoh River
Mount Tom Creek-Hoh River
Maple Creek-Hoh River
Hell Roaring Creek-Hoh River
Nolan Creek-Hoh River

HUC12
Area (SqKm)
171001010701
120.59
171001010702
79.78
171001010703
139.04
171001010704
125.78
171001010705
67.2
171001010706
123.7
171001010707
115.38

Open water features, including the Hoh River mainstem, creeks, ponds, and small lakes, represent
2,469 acres (1.29% of the watershed) according to GIS analysis. The extensive stream network
totals 1,299 miles of mapped channels, creating an intricate drainage system that connects upland
areas to the Pacific Ocean. This network includes the Hoh River mainstem extending 56 miles
from its glacial origins to the ocean, plus numerous tributaries that support critical salmonid
spawning and rearing habitat.
Historical Monitoring Program
The Hoh Tribe has conducted systematic water quality monitoring throughout the Hoh River Basin
since the early 1990s, establishing the longest continuous water quality datasets for the watershed.
This multi-decade monitoring effort provides critical baseline data for assessing long-term trends,
documenting persistent impairments, and evaluating watershed responses to land management
changes and climatic variations.
29

The Hoh Water Quality Program (HWQP) began comprehensive monitoring in 1991 with
deployment of continuous temperature loggers in the Hoh River mainstem and major tributaries
(Hoh Tribe FY25 CWA 106 Report, 2025). This initial focus on temperature responded to observed
impacts from timber harvest activities, which had intensified throughout the watershed during the
1980s timber boom. Temperature was selected as the primary indicator based on its critical
importance to salmonid survival and its responsiveness to riparian canopy removal. The strategic
placement of loggers in creeks providing year-round flow, major tributaries, and the Hoh River
mainstem at multiple points established the foundation for understanding thermal dynamics across
the watershed's diverse habitats.
The Tribe has maintained continuous temperature monitoring at 22 year-round stations and up to
28 additional summer stations within the Hoh River Watershed monitoring network (Hoh Tribe
FY25 CWA 106 Report, 2025). Strategic placement of loggers captures longitudinal temperature
profiles through multiple mainstem sites documenting temperatures from headwaters to mouth,
tributary contributions via stations above and below major confluences to quantify thermal inputs,
thermal refugia, and hyporheic exchange zones identified through FLIR surveys, and land use
gradients through paired sites above and below harvest units and road crossings.
The program underwent significant expansion in 2000-2001 with a basin-wide Forward Looking
Infra-Red (FLIR) study conducted through ground-truth and helicopter surveys (Aerial Surveys in
the Hoh River Basin, 2001). FLIR technology detects thermal radiation emitted from water
surfaces, identifying cool water refugia critical for salmonid survival during summer months. This
thermal imaging assessment mapped groundwater inputs, documented thermal pollution sources,
and established priority monitoring locations that continue to be sampled today. The FLIR analysis
revealed previously unknown cold-water springs, identified reaches where riparian loss created
thermal loading.
Monthly instantaneous monitoring for multiple parameters commenced in 2005, adding dissolved
oxygen, pH, and turbidity measurements to the temperature monitoring network to 20 new or
existing sites in 2021 (Hoh Tribe FY25 CWA 106 Report, 2025). This expansion coincided with
increasing recognition that temperature alone could not fully characterize water quality impacts
from land use activities. The multi-parameter approach enabled detection of cumulative effects
from forest practices, road networks, and development, revealing complex interactions between
thermal pollution, oxygen depletion, and pH depression that single-parameter monitoring would
miss.
The channel of the Hoh River is highly complex and dynamic, with large migration zones. As
steep, glacially-carved valley walls near its headwaters transition to a wide alluvial floodplain
downstream, glacial sediments in the river are distributed across wide braided channels. The
watershed is especially rainy, with the annual mean precipitation in the watershed ranging between
94 and 125 inches (England, 2003). As a result, major flood events are frequent, especially in
winter months. During floods, the Hoh River often avulses into old, abandoned channels or carves
30

new ones into low terraces and gravel bars. According to the United States Geological Survey
(USGS) gauging station on the Hoh River at Highway 101, peak runoff occurs in the winter from
October to March due to large rainfall events, while low flow is recorded in the summer. The
maximum discharge recorded since 1960 was 62,100 cfs (gage height = 20.2 ft) on October 17,
2003; minimum discharge recorded since 1960 was 196 cfs (gage height = 1.89 ft) on September
21, 2024, (U.S. Geological Survey, 2025).
Fish distribution data from the Washington Department of Fish and Wildlife confirms the
watershed supports populations of chinook (Oncorhynchus tshawytscha), coho salmon
(Oncorhynchus kisutch), steelhead (O. mykiss), coastal cutthroat trout (O. clarkii), and bull trout
(Salvelinus confluentus). The presence of these sensitive species throughout the stream network
underscores the importance of maintaining water quality across all land cover types.
As most sites monitored by the Tribe are not located on Tribal Reservation, trust, or fee lands, the
Hoh Tribe applies Washington State's water quality standards (Chapter 173-201A WAC) to assess
attainment of designated uses within the Hoh Watershed. These criteria establish numeric standards
for protecting aquatic life uses, with particular emphasis on salmonid habitat given the watershed's
critical importance for salmon and steelhead populations.

31

Figure 5. Water quality monitoring sites in the Hoh River Watershed. Site numbers correspond to those found in Table 4.

32

Table 4. List of monitoring sites conducted by the Hoh Tribe’s water quality monitoring program and their frequency and parameters.
Site Name

Map #

Temp.

Alder, Lower

1

S

Alder, Middle

2

Alder, Upper

3

Anderson, Lower
Anderson, Upper
Braden, Lower

Turb.

DO

pH

Flow

Benthic macroin.

C

BF
M
Y

4

M, C

5

Y

M, SE

M

M

M, SE

M

M

BF

BF

C

S

124.229225

47.829815

124.226756

47.848982

124.241098

47.771694

124.323045

47.781444

124.333260

47.739340

124.349698

7

S

C

47.731540

124.324708

8

S

C

47.817024

124.063933

Canyon downstream of Upper Hoh Road

9

M

M, SE

M

M

47.812813

124.070669

Canyon upstream of Upper Hoh Road

10

M

M, SE

M

M

47.813726

124.070907

M

Chalaat, Lower

Y

11

M, C

47.744523

124.423781

12

Y

47.737172

124.414742

13

S

C

47.781977

124.293126

14

S

C

47.814196

124.024150

15

S

C

47.812624

124.098379

16

S

C

47.802086

124.039139

Elk, Lower

17

Y

C

47.809659

124.212923

Elk, Middle

18

M

47.798611

124.196944

19

Y

47.798958

124.172857

47.734321

124.383816

Chalaat, Upper
Cottonwood
Crippen Springs
East Pole
E. F. Iron Maiden

Elk, Upper
Fletcher
Hell Roaring
Hoh above Anderson
Hoh above Barlows
Hoh above Campground

20

M, SE

S

M, C

M

47.815885

M, C

Canyon Springs

M, C

Longitude (W)

6

Braden, Upper

M, SE

S

Latitude (N)

C

M, SE

M

M

C

S

C

S

M, C

47.840109

124.262493

22

Y

S

C

47.772739

124.314575

Y

S

47.748662

124.388057

47.856069

123.929961

47.821942

124.197176

47.820204

124.018508

23
24

C

M, C
C

Y

C

Y

Hoh above Willoughby

25

C

Hoh at ONP Boundary

26

CY

CS

M

BF

21

C

M, SE

S

BF

33

Table 4 (cont.): List of monitoring sites conducted by the Hoh Tribe’s water quality monitoring program and their frequency and parameter.
Site Name

Map #

Temp.

Hoh Creek

27

S

C

Hoh Oxbow

28

M

29

S

Jackson
Line

Hoot

Lost
Maple, Lower
Maple, Upper
McQuarry-Fisher
Mount Tom
N.F. Winfield

Turb.

Latitude (N)

Longitude (W)

47.879339

123.754112

47.812511

124.250506

C

47.790253

123.963615

30

Y

C

47.855163

123.925163

31

CS

47.791398

123.970043

32

S

C

47.781337

124.269993

33

S

C

47.803377

124.089971

34

S

C

47.770946

124.100010

35

S

C

47.799704

123.988497

36

S

C

47.866800

123.887510

37

Y

47.781535

124.196996

M, SE

DO

pH

M

Flow

Benthic macroin.

M

C

Y

Nolan, Lower

38

M, C

47.751175

124.324632

Nolan, Middle

39

CY

47.744451

124.281750

40

Y

47.742364

124.240451

Y

47.804241

124.079039

47.798555

124.079222

47.779911

124.079742

47.770711

124.291886

Nolan, Upper
Owl, Lower

41

Owl, Middle

42

Owl, Upper
Pins

44

S.F. Hoh

BF

BF
Y

S

S.F. Hoh at Campground

M

BF

C

M, C

45

M, C

C

43

Rock

M, SE

S

M, SE

M

M

C

S

BF

M, C

M, SE

M

M

47.817483

124.138163

46

M

M, SE

M

M

47.806054

123.996233

47

CY

47.807991

123.998023

48

S

C

47.765486

124.347220

Snider

49

S

C

47.847710

123.971624

Snider at Upper Hoh Road

50

M

47.844104

123.966624

51

S

C

47.797040

123.983418

Taft

52

S

C

47.860354

123.946815

Taft at Upper Hoh Road

53

M

47.860084

123.940811

Six Mile

Split

M, SE

M, SE

M

M

M

M

34

Table 4 (cont.): List of monitoring sites conducted by the Hoh Tribe’s water quality monitoring program and their frequency and parameters.
Site Name
Tower
Twin, Lower
Twin, Upper
West Pole

Map #

Temp.

Turb.

DO

pH

54

S

M, C

M, SE

M

55

S

M, C

M, SE

M

56

S

C

57

S

Flow

Latitude (N)

Longitude (W)

M

47.817857

124.119303

M

47.832780

123.990266

47.835370

124.002435

47.813405

124.105330

47.801612

124.040714

47.822138

124.198055

47.798882

124.229283

47.771304

124.198823

C

58

S

M, C

M, SE

M

M

Willoughby

59

Y

M, C

M, SE

M

M

BF

Winfield, Lower

60

M, CY

M, SE

M

M

BF

61

Y

W.F. Iron Maiden

Winfield, Upper

Benthic macroin.

C

BF

35

Table 5. List of monitored rivers and creeks in the Hoh River Watershed as outlined in the Hoh River
monitoring program. Sites highlighted green represent creeks within Hoh Tribal Trust and Fees lands.
Sites with * have additional salmonid spawning protections.
Site
Alder, Lower; Middle; Upper
Anderson, Lower
Anderson, Upper
Braden, Lower; Upper
Canyon Springs
Canyon upstream & downstream
of Upper Hoh Rd
Chalaat, Lower; Upper
Cottonwood
Crippen Springs
East Pole
E. F. Iron Maiden
Elk, Lower; Middle; Upper
Fletcher
Hell Roaring
Hoh above Anderson
Hoh above Barlows
Hoh above Campground
Hoh above Willoughby
Hoh at ONP Boundary
Hoh Oxbow
Hoot
Jackson
Line
Lost
Maple, Lower
Maple, Upper
McQuarry-Fisher
Mount Tom
N.F. Winfield
Nolan, Lower
Nolan, Middle
Nolan, Upper
Owl, Lower & Middle
Owl, Upper
Pins
Rock
S.F Hoh
Six Mile
Snider & Snider at Upper Hoh Rd
Split
Taft
Taft at Upper Hoh Rd
Tower
Twin, Lower
Twin, Upper
West Pole
W.F. Iron Maiden

Water
Type
Creek
Creek
Creek
Creek
Creek
Creek

Waterbody
length (mi)
3.57
2.99
0.47
5.51
0.51
2.91

Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
River
River
River
River
River
River
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
River
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek
Creek

1.22
0.04
unknown
0.42
1.04
2.15
0.70
1.38
1.11
1.68
1.05
0.85
1.74
1.45
1.51
4.36
1.96
0.97
1.82
1.55
1.25
2.43
0.82
2.73
1.65
2.86
0.83
2.58
2.73
2.00
1.32
1.97
1.84
0.36
1.72
0.15
0.44
0.53
2.79
0.26
0.66

Usage Information
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat*
Char Spawning and Rearing
Core Summer Salmonid Habitat*
Char Spawning and Rearing
Core Summer Salmonid Habitat*
Char Spawning and Rearing
Char Spawning and Rearing
Char Spawning and Rearing
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Char Spawning and Rearing
Char Spawning and Rearing
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat
Char Spawning and Rearing
Core Summer Salmonid Habitat
Char Spawning and Rearing
Char Spawning and Rearing
Char Spawning and Rearing
Char Spawning and Rearing
Core Summer Salmonid Habitat*
Char Spawning and Rearing
Char Spawning and Rearing
Core Summer Salmonid Habitat
Core Summer Salmonid Habitat

36

Site
Willoughby
Winfield, Lower
Winfield, Upper

Water
Type
Creek
Creek
Creek

Waterbody
length (mi)
0.44
3.59
1.16

Usage Information
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat*
Core Summer Salmonid Habitat*

Wetlands and Aquatic Features
Wetland complexes throughout the watershed provide critical water quality functions. GIS analysis
identifies 8,056 acres (4.21% of the total area) of wetlands, including 7,425 acres of woody
wetlands and 631 acres of emergent herbaceous wetlands (Figure 5). The National Wetlands
Inventory (NWI) database maintained by US Fish and Wildlife Service (USFWS) likely
underrepresents actual wetland extent due to the challenges of mapping wetlands beneath dense
forest canopy. Recent LiDAR research by Stewart et al. (2024) reveals that traditional satellite
mapping significantly underestimates forest complexity within the watershed. Their discovery of
extensive "cryptic" wetlands hidden beneath the forest canopy indicates that forested areas provide
greater ecological functions than previously understood. Using Wetland Intrinsic Potential (WIP)
mapping tools, researchers found that including these hidden forested wetlands increases
watershed carbon-storage capacity estimates by fivefold, suggesting the watershed's forests play
an even more critical role in landscape regulation and water quality protection than recognized in
earlier assessments.
The Tribe is actively developing a wetland inventory in cooperation with University of Washington
using a new wetland mapping tool by Monika Moskal’s lab. The WIP Tool creates a map of
probabilities of wetland location. With traditional methods of mapping analysis, it is difficult to
locate wetlands that exist under forest canopies. The WIP is not meant to be regulatory and is not
a replacement for, but a supplement to, the NWI, which will be beneficial for addressing gaps in
the watersheds nonpoint pollutant sources.
Ground Water Standards
Washington's groundwater quality standards under Chapter 173-200 WAC establish protection
criteria for subsurface waters that influence surface water quality through baseflow contributions.
While groundwater provides baseflow critical for maintaining summer stream temperatures and
dissolved oxygen, the interaction between groundwater and surface water in the Hoh watershed
remains poorly characterized. Groundwater quality monitoring is not currently conducted as part
of the Tribe's water quality program, though individual domestic wells exist within the reservation
boundaries.
The HWQP was temporarily suspended from February 2020 through June 2021 due to COVID-19
pandemic restrictions (Hoh Tribe FY23 CWA 106 Report). This unprecedented disruption created
a data gap during critical seasonal transitions but also demonstrated the program's resilience and
importance to tribal resource management. Monitoring resumed in July 2021 with addition of
dissolved oxygen saturation and specific conductivity parameters, providing more complete water
quality characterization. Specific conductivity serves as a surrogate for total dissolved solids,
37

indicating groundwater inputs, road salt applications, or other ionic pollution sources, while DO
saturation helps distinguish temperature-driven oxygen loss from biochemical oxygen demand.
Pollutants
The Tribe’s water quality monitoring program, cultural accounts, and historical landscape records
provide insight into existing and potential pollutants. The greatest threats to the watershed are
temperature, dissolved oxygen, pH, and sedimentation delivery. Pollutants stem from various
categories of sources like forestry, hydromodification, roads, invasives, atmospheric deposition,
and gravel mining.
Table 6. Existing or potential pollutants throughout the Hoh River Watershed.
Pollutants
Temperature
Dissolved Oxygen
pH
Stormwater Runoff
Turbidity/Suspended Solids
Toxic Chemicals
Undersized Culverts
Invasives
Large woody debris

RESULTS
The Hoh River and its tributaries are often described as a relatively pristine, intact habitat for
salmonids and other native fish species. Nevertheless, our monitoring efforts point to persistent
and long-standing forms of water quality impairments in the Hoh River and tributaries. Warm
water temperatures in the summer are the most apparent threat to salmon and char. From long-term
monitoring efforts by the Hoh Tribe and others, it has been shown that warm waters which threaten
salmonids and char have been present in the Hoh River and many tributaries for more than a
decade, with additional tributaries being listed since then. From our efforts, we identified that more
than half of the waterways that we monitor in the HRW were not achieving tribal goals or the State
of Washington’s water quality standards.
In the face of environmental fluctuations and impending loss of the glaciers that feed the
watershed, existing cold water refugia will likely be further diminished in the future. Moreover,
we have found low dissolved oxygen concentrations in the Hoh River and some creeks, which may
be linked to warm temperatures and/or dissolved organic carbons in some sites. Finally, our
monitoring program has identified tributaries of the Hoh River that have very low pH, although it
is yet to be determined if this is from anthropogenic influences or natural conditions. Given the
Hoh Tribe’s dependence on salmon and steelhead, the identified water quality issues are of tribal
concern. Efforts should be made to protect waterways that we identified as fully supporting
designated aquatic life uses and restore those with poor water quality.
38

The Hoh Tribe’s water quality monitoring program is responsible for assessing approximately 60
sites each year for a specific set of parameters including:
•
•
•
•
•
•
•

Temperature
DO
pH
Turbidity
Specific conductivity
Flow
Benthic macroinvertebrates

The frequency of monitoring these parameters varies by site but includes continuous and discrete
records (Table 4). Because the Tribe’s monitoring network is so expansive, data shows that sites
are located and exposed to various pollutants covering the watershed lands. The Tribe assesses
water quality data on a yearly basis, which is useful for establishing most recent water quality
conditions. However, the water quality program hasn’t yet established baselines or long term
parameter “normals”. The following section provides insight into 2025’s monitoring results.
Although the program has not established numerical normals, the program tracks narrative
conclusions like creek impairments by year and pollutant.
Instantaneous monthly monitoring showed four creeks/rivers were impaired due to temperatures
outside of their respective criteria. The impaired sites included Lower Nolan, Lower Winfield, and
Middle Elk Creek, and the SF Hoh River. Nolan Creek claimed the highest average site
temperature, 10.92°C, and maximum temperature overall, 19.15°C (Hoh FY25 CWA 106
Assessment Report, 2025).
Continuous temperature monitoring in FY 2025 yielded twenty-one impairments throughout the
watershed. Impairments were observed at four sites within the Hoh River mainstem, twelve of the
Hoh River's tributaries, the SF Hoh River, and three of the SF Hoh River’s tributaries (Hoh FY25
CWA 106 Assessment Report, 2025). The Hoh River and nine tributaries did not fully support
core summer salmonid habitat based on our continuous temperature monitoring. Additionally, the
Hoh River, the SF Hoh River, and seven tributaries did not fully support char spawning and rearing
either.
Hoh River above Barlows had the highest monthly 7-DADM average temperature, 20.02°C, in
June; the maximum 7-DADM calculated for a single day, 22.01°C in August; and the maximum
temperature occurrence, 23.97°C in August. Upper Nolan Creek held the lowest monthly 7DADM average temperature. Middle Nolan Creek recorded the lowest daily 7-DADM
temperature, 2.02°C, and the lowest recorded temperature, 0.4°C, in February (Hoh FY25 CWA
106 Assessment Report, 2025).
Of the 48 sites monitored over the summer, 30 sites experienced their hottest monthly 7-DADM
average in August and 12 sites in July. This is likely due to warmer than usual temperatures in
39

August across the state. Temperatures recorded at Quillayute’s weather station were 2.0°F above
normal (Genuise, 2025).
Waters designated for general salmonid use showed extensive impairments affecting spawning and
rearing success. Fifteen tributaries consistently exceeded the 16°C criterion during summer
months, including Alder, Anderson, Elk, Line, Lost, McQuarry-Fisher, Mount Tom, Owl (lower),
Split, Snider, Tower, Twin, Willoughby, and Winfield Creeks. Many of these streams have
remained on the 303(d) list since 1996, indicating chronic impairment persisting nearly three
decades.
Low pH in Lower Braden and Hell Roaring is longstanding. Monthly instantaneous pH
measurements have shown pH impairment since 2018 in Lower Braden Creek and since 2005 in
Hell Roaring Creek. HWQP historical instantaneous data from 2005-2025 shows pH impairments
at Lower Braden Creek for 16 out of 21 years, at Lower Chalaat Creek for 10 out of 20 years, at
Hell Roaring Creek for 21 years, and at Lower Nolan Creek for 6 out of 21 years. Historical
monthly data from Hell Roaring Creek dating back to 2005 indicates that the site hasn't recorded
a pH above 6.5 since 2018. Lower Chalaat Creek has had pH issues since 2020.
Three of the four sites with pH impairments also had accompanied DO impairments. Lower
Braden, Hell Roaring, and Lower Nolan Creek failed to maintain DO concentrations above 9.5
mg/L for less than the 5% of allowable exceedance days. Braden and Nolan Creek were below the
criterion from June to August and Hell Roaring in October 2024 and from June to September 2025
(no measurement in July). Hell Roaring led in lowest average DO concentration this year, 9.83
mg/L, and lowest single event occurrence, 7.74 mg/L. The maximum average DO concentration,
11.84 mg/L, occurred at Snider Creek. The maximum DO concentration, 12.9 mg/L, occurred at
Lower Willoughby Creek (Hoh FY25 CWA 106 Assessment Report).
Table 7. Historical DO and pH impairments at high-risk creeks.

DO

pH

Total Years Total Years
Impaired
Monitored
Chalaat Creek
16
19
Braden Creek
17
21
Hell Roaring Creek
18
21
Nolan Creek
16
21
Chalaat Creek
10
20
Braden Creek
16
21
Hell Roaring Creek
21
21
Nolan Creek
4
21

Analysis of HWQP historical instantaneous data (2007-2025)
points to persistent DO impairment in Lower Chalaat Creek for
16 of the past 19 years of monthly monitoring (Table 7). This
year marks the first year since 2022 that Chalaat Creek will not
be listed for DO impairment. Braden Creek DO impairment has
returned after three years without measured impairments (not
including continuous data). Similarly, Nolan Creek was not
listed for DO impairment based on monthly monitoring last
year; however, this year the DO issues have returned. Hell
Roaring continues to have persistent DO issues marking the 18th
out of 21st year of impairment based on historical monthly
monitoring data (Table 7). Furthermore, analysis of HWQP
instantaneous data measured from 2005 through 2025 shows
40

that water quality, whether pH or DO, has been impaired in Braden Creek and at Hell Roaring for
the past 21 years (Table 7).
According to the FY23 CWA 106 Report, Hell Roaring Creek contained disconnected pools from
June through September, while Braden Creek experienced complete cessation of flow from July
through September, creating stagnant conditions where dissolved oxygen depletion becomes
inevitable regardless of temperature. This reality has occurred at various creeks in the past and is
not partial to just 2023. The FY25 CWA 106 Report also documented impairments in the Hoh
River at multiple sites exemplifying low oxygenation in larger channels where stagnation and
disconnection would not be an issue.
According to the U.S. Fish and Wildlife Service National Wetland Inventory, the sites with DO
impairments (Lower Braden Creek, Hell Roaring Creek, Hoh River above Anderson, and Lower
Nolan Creek) are located downstream of freshwater forested/shrub wetlands (U.S. Fish and
Wildlife Service, 2022). Data involving nearby wetland analysis would be useful to gather
baselines and a greater understanding of how these relationships cooperate with each other. We
continue to recognize, however, that elevated water temperatures could still be a cause of reduced
DO concentrations through decreased solubility.
The Hoh Tribe does not have benchmark goals for ambient turbidity, specific conductivity, or
instream flow because Washington State does not have aquatic life criteria for these water quality
parameters. Furthermore, setting criteria for ambient turbidity requires site-specific information
(i.e., baseline conditions for turbidity and conductivity, local geology and soils types) that is
currently not available for the Hoh River and its tributaries. However, baseline conditions can be
established by continuing to collect turbidity and conductivity data, which can then be used to set
tribal goals in the future.
Turbidity standards protect aquatic life from suspended sediment impacts including gill abrasion,
reduced feeding efficiency, and substrate embeddedness that eliminates spawning habitat.
Washington's criteria prohibit turbidity increases exceeding 5 NTU over background when
background is 50 NTU or less, or more than a 10% increase when background exceeds 50 NTU
during in-water work. These incremental standards recognize natural background variability while
preventing human-caused degradation that would impair designated uses. However, Washington
State does not have turbidity criteria for ambient conditions.
Field observations at Canyon Creek documented the physical sources of the watershed's most
severe turbidity impairment, with steep banks requiring riprap and netting installations from
ongoing instability due to clay deposits. The direct discharge of stormwater from Upper Hoh Road
observed flowing quickly into the creek without any treatment or velocity dissipation provides a
chronic clay sedimentation to be activated during every precipitation event. Similarly, at the Oil
City Road unnamed stream crossing, field crews documented failed erosion control infrastructure
where old riprap had fallen into the channel, creating both a sediment source and partial barrier to
flow.
41

Integration of USGS flow data with water quality monitoring reveals important relationships where
temperature exceedances correlate with low flow periods, DO sags coincide with reduced
velocities and reaeration, turbidity spikes follow rain-on-snow events, and seasonal patterns show
earlier spring runoff and extended summer baseflow periods. The August 2023 base flows
averaging 40-60% below long-term means demonstrate an accelerating trend toward summer flow
depletion that exacerbates all other water quality impairments.
Benthic macroinvertebrate sampling has occurred at Anderson, Elk, Nolan, Owl, and Winfield
Creeks during summer low flow conditions since 2021. All creeks monitored have held excellent
to excellent/good standards according to the Benthic Index of Biotic Integrity scoring system.
Although water quality impairments are present in these creeks, macroinvertebrate species still
show up in diverse populations compared to other Western Washington areas.

42

Table 8. Monitoring sites in rivers and creeks of the Hoh River Watershed with impaired water quality
from FY 2021-2025 that did not fully support designated uses.
Monitoring Site
Alder, Lower
Anderson, Lower
Braden, Lower
Chalaat, Lower
Chalaat, Upper
Elk, Middle
Elk, Upper
Hell Roaring
Hoh River above
Anderson
Hoh River above
Barlows
Hoh River above
Campground
Hoh River above
Willoughby
Hoh at ONP
Boundary
Hoh Creek
Hoot
Jackson
Line
Lost
Maple, Lower
McQuarry-Fisher
Mount Tom
N.F. Winfield

FY 2021
Temp
Temp
DO, pH
None
Temp
None
Temp
DO, pH, Temp

FY 2022
Temp
None
DO, pH
DO, pH
Temp
None
None
DO, pH
DO,
Temp

FY 2023
Temp
Temp
DO, pH
DO, pH
Temp
Temp
None
DO, pH

FY 2024
Temp
None
pH
DO, pH
Temp
None
None
DO, pH

FY 2025
Not monitored
None
DO, pH
pH
Temp
Temp
Temp
DO, pH

DO, Temp

Temp

DO

Temp

Temp

Temp

DO, Temp

Temp

Temp

Temp

Temp

None

Temp

Temp

Temp

Temp

None

Temp

Temp

Temp

Temp

Temp

Temp, DO

Not monitored
Temp
Temp
Temp
Temp
None
Temp
Not monitored
Temp

Temp
Temp
Temp
None
None
None
Temp
Temp
None
DO, pH,
Temp
Temp
Temp
Temp
Temp
Temp
None
Temp
Temp
Temp
Temp
None

Not monitored
Temp
Temp
Temp
None
Temp
Temp
Temp
Temp

Not monitored
Temp
Temp
Temp
None
None
Temp
Temp
None

Not monitored
None
Temp
Temp
None
None
Temp
Temp
None

Nolan, Lower

DO, Temp

DO, Temp

DO, Temp

DO, pH, Temp

Nolan, Middle
Owl, Lower
S.F. Hoh
Snider
Split
Taft
Tower
Twin, Upper
Willoughby
Winfield, Lower
Winfield, Upper

Temp
Temp
Temp
Temp
None
DO
None
Temp
Temp
Temp
Temp

Temp
Temp
Temp
Temp
Temp
None
Temp
Temp
Temp
Temp
Temp

Temp
Temp
Temp
None
Temp
DO
Temp
Temp
Temp
Temp
Temp

Temp
Temp
Temp
Temp
Temp
None
Temp
Temp
Temp
Temp
Temp

DO, Temp

Since expanding and maintaining our monitoring efforts in 2021, the Hoh Tribe’s water quality
data has determined that 34 locations have shown impairment for at least one parameter (Table 8).
Removing redundancies like “upper”, “lower” creeks and Hoh River sites at different mile markers
43

still leaves 26 total creeks/rivers with impairments. This list encompasses the Tribe’s assessment
of all monitoring including continuous and discrete temperature, pH, DO data.
The Wahington Department of Ecology recently updated their listings of the impaired waterways
(303(d)) in releasing their 2022 Assessment cycle data. This cycle added 8 new creeks to the list
of impairments and now includes impairments for parameters like dissolved oxygen and pH as
compared to the 2018 data cycle (Table 9).
Table 9. Impaired waterbodies within the HRW according to the Washington Department of Ecology’s
2022 Waterbody Assessment Cycle.
WATERBODY
ALDER CREEK

PARAMETER
Temperature

ALDER CREEK

Temperature

ANDERSON
CREEK
BRADEN
CREEK
ELK CREEK

Temperature

ELK CREEK

Temperature

FISHER CREEK
(MCQUARRY
CREEK)
HOH RIVER

Temperature

HOH RIVER

Temperature

HOH RIVER
HOH RIVER

Dissolved
Oxygen
Temperature

HOH RIVER

Temperature

HOH RIVER

Temperature

HOH RIVER

Temperature

HOH RIVER

Temperature

HOOT CREEK

Temperature

JACKSON
CREEK
LINE CREEK

Temperature

LOST CREEK

Temperature

MAPLE CREEK

Temperature

Dissolved
Oxygen
Temperature

Temperature

Temperature

DESIGNATED USE
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Char Spawning and
Rearing

ASSESSMENT UNIT ID
17100101000708_001_001

Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat

17100101013703_001_001

17100101000701_001_002
17100101012795_001_001
17100101000359_001_001
17100101023220_001_002
17100101023224_001_001
17100101013878_001_001

17100101000044_001_001
17100101000033_001_001
17100101013742_001_001
17100101023769_001_001
17100101000033_001_001
17100101000091_001_001
17100101000077_001_001
17100101000770_001_001
17100101000380_002_002
17100101046753_001_001
17100101013209_001_001
17100101000383_001_001

44

Table 9 (cont.): Impaired waterbodies within the HRW according to the Washington Department of
Ecology’s 2022 Waterbody Assessment Cycle.
WATERBODY
NOLAN CREEK

PARAMETER
Temperature

DESIGNATED USE
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Char Spawning and
Rearing
Aquatic Life - Core Summer Salmonid
Habitat

ASSESSMENT UNIT ID
17100101000766_001_001

NOLAN CREEK
NOLAN CREEK

Dissolved
Oxygen
Temperature

OWL CREEK

Temperature

POLE CREEK

Temperature

SNIDER CREEK

Temperature

SOUTH FORK
HOH RIVER
SPLIT CREEK

Temperature

TOWER CREEK

Temperature

TWIN CREEK

Temperature

UNNAMED
CREEK (TRIB
TO EAST FORK
HELL
ROARING
CREEK)
UNNAMED
CREEK (TRIB
TO EAST FORK
HELL
ROARING
CREEK)
UNNAMED
CREEK (TRIB
TO WINFIELD
CREEK)
WILLOUGHBY
CREEK
WINFIELD
CREEK
WINFIELD
CREEK

pH

Dissolved
Oxygen

Aquatic Life - Core Summer Salmonid
Habitat

17100101012968_001_001

Temperature

Aquatic Life - Core Summer Salmonid
Habitat

17100101000767_001_002

Temperature

Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat
Aquatic Life - Core Summer Salmonid
Habitat

17100101000699_001_001

Temperature

Temperature
Temperature

17100101000766_001_001
17100101000769_001_001
17100101000394_001_001
17100101000719_001_002
17100101000698_002_002
17100101013869_001_001
17100101020036_001_001
17100101000718_001_002
17100101000704_001_001
17100101012968_001_001

17100101000744_001_001
17100101000746_001_001

Nonpoint Source Assessment
Nonpoint Source categories were chosen based on factors affecting our waterways. Temperature,
DO, pH, and turbidity were prioritized given our extensive data and cultural priorities.

45

Assessment findings derive from synthesis of five years of monitoring data (FY2021-2025), and
review of existing documentation. Seven major NPS categories were identified.
Forestry & Logging Roads
Forest management activities and associated road networks represent the most widespread
nonpoint source pollution category affecting water quality in the Hoh River Watershed. The
combination of timber harvest, road construction and maintenance, and log transport creates
multiple pathways for sediment delivery, thermal pollution, and hydrologic alteration. The spatial
distribution of these forestry impacts, which overlays active harvest areas and road networks with
documented water quality impairments.
Hydromodification & Bank Erosion
Hydromodification, the alteration of natural stream channels and floodplains, combines with
accelerated bank erosion to deliver substantial sediment loads while fundamentally disrupting
aquatic habitat. The Hoh River's dynamic channel migration, exacerbated by land use impacts,
creates both natural and anthropogenic sources of water quality degradation. Extensive erosion
control infrastructure exists throughout the watershed, including massive concrete dolosse
structures placed between the river and Upper Hoh Road, indicating the severity of bank erosion
challenges.
Invasive Species
Extensive invasive species have been identified by various organizations throughout Washington
like Washington Native Plant Society, Washington State Department of Agriculture (WSDA),
Washington Department of Natural Resources (DNR), 10K Years Institute (10K), and more. Their
presence contributes to species monoculture, limited nutrient and soil profiles, and replacement of
stabilizing vegetation. Mapping of invasives in the Hoh River Watershed is extensive because of
publicly available noxious weed reporting. However, mapping fails to represent noxious weeds
within Olympic National Park and at higher elevations (Figure 6).
Roads, Highways, and Bridges
Roads, highways, bridges, and associated infrastructure create concentrated sources of nonpoint
source pollution through increased impervious surfaces, altered drainage patterns, and introduction
of vehicle pollutants. While the Hoh watershed remains predominantly rural, extensive
transportation corridors generate measurable water quality impacts. Near development, there are
multiple pathways for untreated stormwater to reach surface waters, with no stormwater treatment
infrastructure observed at major discharge points.

46

Figure 6. Noxious Weed Detections throughout the HRW with monitoring sites waterways labeled.

47

Natural Resource Extraction
Historical gravel extraction has created disturbed areas throughout the watershed vulnerable to
erosion and potentially vehicle-related emissions. Unreclaimed pits contribute pollutants through
sediment mobilization at 100-1,000 tons/acre/year from exposed surfaces, hydrocarbon
contamination at 100-1,000 mg/kg TPH from equipment operations, pH impacts from exposed
minerals creating pH 4-5 or 9-11 extremes, temperature effects with shallow ponds reaching 2535°C in summer, and heavy metals including iron at 1,000-10,000 mg/L in acidic conditions
(Newton and Drenten, 2015). There are currently three gravel mining operations active within the
watershed, the Seton Construction Canyon Creek Quarry located by Canyon Creek, Winfield
Surface Mine DNR located near Elk and Winfield Creeks, and the St. Regis Gravel Pit located
near an unnamed creek and wetland.
Atmospheric Deposition
Chronic deposition from vehicle traffic creates distributed contamination along Highway 101 and
forest roads. Annual deposition rates include 0.1-1.0 kg/hectare/year of PAHs, 10- 100
g/hectare/year of heavy metals including copper, zinc, and lead, 1-10 kg/hectare/year of petroleum
hydrocarbons, and 0.01-0.1 kg/hectare/year of platinum group elements from catalytic converters
(Hwang et al., 2016). The Highway 101 bridge crossing, with its documented lack of stormwater
treatment, delivers these contaminants directly to the Hoh River.
Data Gaps in Historical Record
Temporal gaps include limited winter monitoring due to access and safety constraints, the COVID19 suspension from February 2020 through June 2021, and intermittent equipment failures during
extreme events. These gaps, while unavoidable, create uncertainty in annual assessments and may
underestimate impairment frequency.
Spatial gaps affect headwater areas above 3,000 feet elevation where snow and access limit
monitoring, non-fish bearing tributaries that receive minimal monitoring despite contributing flow
and pollutants, and wetland systems that require different sampling protocols than stream
monitoring. Private industrial forest lands often restrict access, creating gaps in understanding of
active harvest impacts.
Results Assessment
The consistency of degradation trends across parameters, sites, and years indicates that current
management approaches have failed to arrest, much less reverse, water quality decline. Despite
three decades of forest practice rules, salmon recovery efforts, and restoration investments, no
monitored parameter shows statistically significant improvement. Several sites show accelerating
degradation, suggesting threshold effects where initial impacts trigger cascading ecosystem
changes.
The persistence of temperature impairments since 1996 despite riparian replanting indicates that
passive recovery through vegetation regrowth cannot overcome landscape-scale changes and
48

landscape forcing. The emergence of new impairments in previously unaffected waters suggests
degradation is spreading rather than contracting. Most concerning is that reference sites within
Olympic National Park also show warming trends, eliminating upstream sources for recolonization
even if downstream conditions improved.
Recovery planning must acknowledge these trajectories and design interventions scaled to
observed degradation rates. The field observations of extreme conditions like streams drying
completely, pH below 5.0, temperatures exceeding 20°C indicate some waters have crossed deadly
thresholds where restoration may take years to show promise.
DISCUSSION
While many waterways have long-term water quality degradation, some stream reaches maintain
conditions meeting water quality standards or possess exceptional ecological and cultural
significance warranting protection from future degradation. These waters, though increasingly rare
within the watershed, provide critical refugia for sensitive species, serve as reference conditions
demonstrating potential recovery, and support treaty-reserved resources fundamental to Hoh Tribal
identity and subsistence. Protection of these high-quality waters represents an equally important
management priority as restoration of impaired reaches, particularly given projected landscape
change impacts that will intensify pressure on remaining functional habitat.
Temperature Impairments
The geographic distribution of water quality impairments reveals clear patterns corresponding to
land use intensity and channel position within the watershed. Temperature impairments
concentrate in tributaries draining actively managed forestlands, particularly those accessed by the
Hoh Mainline Road where DNR and private timber company lands undergo regular harvest
rotation. These streams—including Owl, Winfield, Elk, and Maple Creeks—show persistent
temperature violations dating to 1996, indicating that current forest practices rules have not
successfully restored thermal regimes.
Water temperature was the primary water quality parameter of concern. Twenty-two sites, four
within the Hoh River mainstem, fourteen of its tributaries, the SF Hoh River mainstem, and three
of its tributaries were impaired due to warm temperatures. In total, we found that 35.8 river miles,
or 47% of the total length monitored for water temperature, had temperatures that exceeded
criteria. In comparison, FY 2024 temperature impairments spanned 46.1 river miles or 47.8% of
total waters assessed for temperature (Hoh Tribe FY2025 Water Quality Assessment, 2025). Of
the total 76 river miles we assessed in the watershed in FY 2025, 43.8 river miles (57.68%) were
impaired because at least one water quality parameter did not meet water quality standards criteria.
This is an increase in impairments from last year's total extent of waters assessment.
Reports have linked canopy cover loss from logging with elevated water temperatures in Hoh
River tributaries. In the 1990s, large-scale timber harvests in the HRW were associated with
significant changes in water temperature. Hatten (1992) showed that daily maximum water
49

temperatures were two to three times greater for Hoh River tributaries in logged sub-basins (> 65%
timber removed) than in forested streams. Daily maximum temperatures also exceeded
Washington state’s water quality standards, creating unsuitable warm environments for salmon.
Additionally, the study found that logged streams had more variable day-to-day and diurnal water
temperatures than those in unharvested areas. Fluctuating temperatures hinder salmon’s ability to
adjust to warming temperatures (Coutant, 1977; Hokanson et al., 1977; Torgersen et al., 1999).
Hatten & Conrad (1995), Murray et al. (2000), and Pollock et al. (2004) supported Hatten’s (1992)
findings. In all three studies, daily average and/or maximum temperatures were significantly
greater in logged Hoh River tributaries.
Following the adoption of Washington State’s Forest Practices Habitat Conservation Plan in
2006, protections for aquatic species were greatly improved on state forest lands. The goal of the
plan is to protect endangered aquatic and riparian species under the Endangered Species Act. Prior
to the adoption of the plan, forests could be logged up to creek banks. Leaving a forested riparian
buffer along fish-bearing streams became a requirement when the plan was adopted. Although
logging practices are more protective of riparian zones and waterways now than they were in the
1990s, many waterways in the HRW have legacy effects from historical logging practices. The
Hoh River and many of its tributaries downstream of the South Fork Hoh River (ie., outside of
ONP) lack sufficient canopy cover and instream large wood debris because old-growth riparian
zones have yet to re-established (Smith, 2000). Loss of old-growth trees along waterways results
in widening of the channel and a loss of cold-water pools, which contribute to warm water. Of the
26 sites with impairments, 18 were located on designated forest land owned by a private entity (9
sites) or the State of Washington (9 sites).
Forest management and road networks fundamentally alter watershed hydrology. Road networks
intercept subsurface flow, concentrate surface runoff, and extend the drainage network, leading to
flashier hydrographs with higher peak flows and reduced base flows (Montgomery, 1994; Wemple
et al., 1996). These alterations manifest as increased peak flows during storms, with 10-30%
increases documented in similar Pacific Northwest watersheds. Runoff response times decrease by
50-70% in heavily roaded watersheds, concentrating flow in destructive pulses. Conversely,
summer base flows decline by 20-50% as intercepted subsurface flow and reduced infiltration
diminish groundwater recharge.
Field observations of log jams at Winfield Creek and debris accumulations at Nolan Creek
following flood events demonstrate how altered hydrology interacts with woody debris to create
complex channel blockages that exacerbate both flooding and low-flow conditions.
Dissolved Oxygen Patterns
Dissolved oxygen and pH impairments cluster in lower gradient reaches where reduced velocity,
accumulated organic matter, and extended residence time create conditions for biochemical
oxygen depletion and acid accumulation. The severe impairments in Hell Roaring and Lower

50

Braden Creeks occur where extensive upstream disturbance combines with channel modifications
that concentrate pollutants.
Lower Chalaat Creek has shown chronic DO impairment throughout the monitoring period, failing
to meet the 9.5 mg/L criterion in 19 years (Table 7). This persistent impairment suggests complex
interactions between biochemical oxygen demand from organic inputs, reduced reaeration due to
low gradient and velocity, potential groundwater inputs with naturally low DO, and cumulative
effects from upstream land uses. The consistency of this impairment across diverse weather
patterns indicates systemic rather than episodic causation.
Low dissolved oxygen concentrations in the Hoh River and Lower Nolan Creek are potentially
produced by warm water temperatures. Dissolved oxygen becomes less soluble in warmer water,
resulting in a loss of DO from the waterway. In addition to low DO concentrations, we measured
warm water temperatures that exceeded the applicable designated uses criterion in both Lower
Nolan Creek and Hoh River above Anderson, Barlows, ONP, and Willoughby.
Prior to 2024, we hypothesized that Lower Braden, Lower Chalaat, and Hell Roaring Creek DO
complications were influenced by nutrient pollution since these creeks did not have paired
temperature impairments. After receiving results from our yearlong assessment of nutrients
derived from nitrogen and phosphorus in FY 2024, we did not see relationships that would indicate
there was eutrophication occurring.
The next alternative reasoning we addressed was dissolved organic carbon influences originating
from nearby wetlands. Freshwater wetlands are known for having high dissolved organic carbon
concentrations which promote aerobic respiration, thereby reducing DO concentrations. According
to the U.S. Fish and Wildlife Service National Wetland Inventory, the sites with DO impairments
(Lower Braden Creek, Hell Roaring Creek, Hoh River above Anderson, and Lower Nolan Creek)
are located downstream of freshwater forested/shrub wetlands (U.S. Fish and Wildlife Service,
2022). Our 2024 DOC analysis of all creeks suggested an inverse relationship between dissolved
organic carbon concentrations and dissolved oxygen concentrations (R2 = 0.62 p = <0.001)
(Hernandez, 2025). This relationship corroborates our hypothesis that DOC from nearby wetlands
is affecting DO concentrations. More data involving nearby wetland analysis would be useful to
gather baselines and a greater understanding of how these relationships cooperate with each other.
We continue to recognize, however, that elevated water temperatures could still be a cause of
reduced DO concentrations through decreased solubility.
pH Depression
Hell Roaring Creek has exhibited consistently acidic conditions since monitoring began, with pH
values frequently below 5.5 (Hoh Tribe FY25 CWA 106 Report). Lower Braden Creek shows
similar chronic pH depression. These patterns reflect both natural factors including organic acids
from wetland drainage and coniferous forest leachates high in fulvic and humic acids, and

51

anthropogenic influences such as potential acid deposition from atmospheric sources and altered
hydrology concentrating natural acids.
First, cedar spaults, or waste cedar pieces left over from timber harvesting, may be leaching watersoluble tannins, which are natural acids, into the creeks. When cedar spaults are in the wetted
channel, the water can become acidified from the tannins. Cedar spaults are pervasive in certain
parts of the watershed due to unrestricted logging during the 1970s and 1980s (Jill Silver, personal
communication). In 1999 and 2000, the Hoh Tribe’s Natural Resources Department removed cedar
spault

[Text truncated at 120,000 characters. The full text is on the page linked above.]

---

Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/tribal%3Ahoh%3Ad0a93f75e970ef32. Public record. Not legal advice.