Water Quality Improvement Project
Upper Humptulips River Watershed:


The Humptulips River is located in the southwestern portion of the Olympic Peninsula in Washington State. Its drainage area includes the entire area of the East Fork Humptulips and West Fork Humptulips watersheds.

The U.S. Forest Service (USFS) manages approximately 65% of this land base, which is part of the Olympic National Forest (ONF). The remaining 35% of the area outside of the ONF is under county and private ownership. Commercial forestry is the dominant land use throughout the upper Humptulips watershed. The USFS manages the ONF under the Olympic National Forest Land and Resource Management Plan and the Northwest Forest Plan. Commercial forestry outside of the ONF is subject to forest practice rules under the Washington Forest Practice Act.

Salmon, steelhead, and cutthroat trout occur throughout much of the Upper Humptulips watershed. Excessive summer water temperatures in some of these streams reduce the quality of rearing habitat for chinook, chum, and coho salmon, as well as for steelhead and cutthroat trout.

Water quality issues

The Humptulips river and several of its tributaries are considered impaired due to high instream temperatures. Water temperatures influence the types of organisms that can live in a waterbody. Cooler water can hold more dissolved oxygen which fish and other aquatic life need to breathe. Warmer water holds less dissolved oxygen. Salmon need cold, clean water for spawning and rearing.

Monitoring found that the Humptulips River showed water temperatures warmer than the state water quality standards. The Humptulips River was listed on the 1996 and 1998 Water Quality Assessments (303[d]) list for temperature. Excessive summer water temperatures may reduce the quality of rearing habitat for coho salmon, as well as for steelhead and cutthroat trout.

Primary watershed disturbance activities that contribute to surface water temperature increases include forest management within riparian areas, timber harvest in sensitive areas outside the riparian zone, and road construction and maintenance. The watershed is still recovering from historical logging practices (during late 19th and early 20th centuries, splash dams for example) that destroyed a lot of instream and riparian habitat.


TMDL implementation: getting to clean water

Ecology conducted total maximum daily load studies (TMDL) in the lower and the upper watersheds. The TMDL boundary begins at the confluence of Humptulips River with Stevens Creek and extends upstream to the headwaters of the Humptulips River. EPA approved the TMDL for temperature in 2001.

A detailed implementation plan was completed and submitted to EPA in 2003. Implementation of the TMDL relies in large part on forest practice rules which establish prescriptive standards and guidelines that should be protective of natural resources, including water quality, when implemented correctly.

WA Department of Natural Resources (DNR) and Ecology has foresters that routinely inspect areas that are being actively logged or managed to ensure that forest practice rules are followed. If logging companies are not following the rules, they are subject to enforcement.

A follow-up study was conducted during the summer of 2010 to continuously monitor water temperature at five stations to determine if water quality temperatures are meeting state water quality standards. Instream temperatures at two stations were slightly cooler than the numeric criteria (7-day average of the daily maximum [7DADMax] temperature of 16°C) while three stations were warmer than the criteria. Further monitoring and assessment is needed to determine if the listings can be delisted (meets Category 1 criteria).

Ecology and DNR foresters visit this watershed on a routine basis to make sure that forest practice rules are being followed.

Technical information

TMDL reports are submitted to the U.S. EPA for approval. These documents are also called WQ Improvement Reports (WQIRs). Sometimes the study on which these reports are based is published separately as a TMDL study, or technical report, that describes the results and analysis of the study. The precursor to a study is a Quality Assurance Project Plan (QAPP). The QAPP describes the study design, data collection and data quality objectives. Important follow-up studies to a TMDL are also included in the following table. Unless otherwise specified, the following documents are Ecology publications.

Document Type Pollutant Title Publication #
TMDL Reports Temperature Upper Humptulips River Watershed Temperature Total Maximum Daily Load (Water Cleanup Plan) Submittal Report 01-10-022
TMDL Implementation Plan Upper Humptulips River Temperature Total Maximum Daily Load: Detailed Implementation Plan 03-10-042
TMDL Study Upper Humptulips River Temperature Total Maximum Daily Load -- Technical Report 01-10-056
Follow-up Studies Quality Assurance Project Plan: Humptulips River Temperature Monitoring 10-10-034
Humptulips River Temperature Monitoring 2010 11-10-045


Related information

WRIA 22: Lower Chehalis Watershed Information (Water web site)




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Last updated October 2016
  Map for water resource inventory area (WRIA) 22, Washington State.


WRIA: #22 (Lower Chehalis)
County: Grays Harbor

Water-body Name:
Humptulips River


# of TMDLs: 11

TMDL approved by EPA

Contact Info:
Brett Raunig
Phone: 360-690-4660
Email: Brett.Raunig@ecy.wa.gov

Southwest Region
Department of Ecology
P.O. Box 47775
Olympia, WA 98504-7775