Water Quality Improvement Project
Hangman Creek Area:


The Hangman Creek (also known as Latah Creek) watershed drains approximately 431,000 acres and spans across two states and four counties. More than 60 percent of the watershed resides in eastern Washington State (WRIA 56) while the remaining portion, including the headwaters, originates in the western foothills of the Rocky Mountains near Sanders, Idaho. The major tributaries to Hangman Creek are Marshall Creek; California Creek; Spangle Creek; Rock Creek; Rattler Run Creek; and the Little Hangman Creek.

Water quality issues

Streams in the Hangman Creek watershed currently do not meet Washington state’s water quality standards for several reasons. Land use influences, (agriculture, impervious surfaces, timber harvest, roads, etc.) as well as stream channel and flood plain alterations over the last 100-years have contributed to “flashy” flow conditions, unstable stream banks, and substandard water quality.

Hangman Creek is also a majority tributary to the Spokane River. Ecology developed a plan to address low oxygen and high nutrients (phosphorus) in the Spokane River and Lake Spokane (Long Lake). Hangman Creek's contribution of nutrients and sediment to the Spokane River is important to this process. Efforts to reduce nutrients, especially phosphorus, in the Hangman Creek watershed will be necessary to address water quality issues in the Spokane River and Lake Spokane.


Status of the project

To address the water quality problems in the Washington portion of the watershed, Ecology and the Spokane County Conservation District worked together on a project called a Total Maximum Daily Load (TMDL). A TMDL, also known as a water quality improvement plan, is a common-sense, science-based approach to cleaning up polluted water so that it meets water quality standards. TMDLs established today also can help manage water quality on a watershed scale to prevent the loss of beneficial uses in the future. Beneficial uses can include irrigation, fishing, habitat, recreation (swimming, wading, and boating) and other uses.

In 2004, the Spokane County Conservation District (SCCD) applied for and was awarded a grant to develop the water quality improvement report or total maximum daily load (TMDL) for the Hangman Creek watershed. Since then, the SCCD and Ecology have worked together to study the watershed, work with the local community, and develop the improvement report. This effort addresses high levels of fecal coliform bacteria, high water temperatures, and high turbidity.

In 2004-2005, SCCD conducted monitoring to fill the data gaps needed to complete the TMDL analysis. The SCCD also formed a watershed advisory group to work on strategies to reduce the amount of pollution reaching the streams. The advisory group consists of people representing many different interests in the watershed, including agriculture; forestry; livestock production; and entities such as Spokane County; the city of Spokane; and the Coeur d’Alene Tribe. The advisory group met regularly to work on the water quality improvement plan (TMDL).

Ecology published the water quality improvement report for fecal coliform bacteria, high water temperatures, and turbidity in the Spring of 2009. Ecology and the SCCD reviewed all comments, revised the report, and published the final report in June 2009. The Environmental Protection Agency approved the report on September 29, 2009.

After EPA approval of the TMDL, Ecology and the SCCD worked with agencies and organizations to develop an implementation plan outlining what needs to occur to meet water quality targets in the watershed and various commitments to the effort. The draft implementation plan was available for public review and comment from February 15 to March 18, 2011. After addressing the comments received, Ecology published the final plan and sent a copy to EPA on May 13, 2011.

In 2015, a group of agencies and interests groups formed a partnership committed to reducing pollutants from nonpoint sources in the Greater Spokane River Watershed. This watershed includes the Spokane River, Hangman Creek, and the Little Spokane River watersheds in both Washington and Idaho. The partnership of over 20 entities submitted an application to the Natural Resource Conservation Service’s (NRCS) Regional Conservation Partnership Program (RCPP) for funding to provide agricultural producers and foresters with financial and technical assistance to install practices that reduce pollutant delivery to area waterways. In 2016, the partnership was award $7.7 million which will be equally matched by the partners to provide a funding program for agricultural and forestry conservation practice implementation. The Hangman Creek Watershed is a priority area for this funding. More information about the Greater Spokane River Watershed RCPP is available on the Lead Partner’s (Spokane Conservation District) website.

In 2017, Ecology initiated a new study in the Hangman Creek watershed with two primary objectives. The first objective is to conduct a receiving water study of the stretch of the river where the City of Tekoa’s wastewater treatment plant discharges. This portion of the study will provide Ecology with the information needed to provide the City with nutrient permit limits to ensure the discharge does not impair the creek for dissolved oxygen and pH.

The second objective is to quantify sources of phosphorus to Hangman Creek throughout the year, in order to identify reductions needed to meet load allocations at the mouth of Hangman Creek set by the Spokane River and Lake Spokane TMDL. This portion of the study will provide information that will be used to prioritize where implementation will have the most effect on reducing phosphorus and sediment delivery to the Spokane River.

More information about the 2017-2018 study can be found in the Quality Assurance Project Plan.

Why this matters

Water quality standards are designed to protect the beneficial uses of our streams and lakes. Beneficial uses can include irrigation, fishing, habitat, recreation (swimming, wading, and boating) and other uses. When a water body does not meet state standards, it is placed on the federal Clean Water Act’s 303(d) list of impaired water bodies. Information about the 303(d) list can be found on our Water Quality Assessments page.

Fecal coliform is a type of “bacteria” common in human and animal waste. It indicates that sewage or manure is entering a water body. As the level of fecal coliform increases the risk of people getting sick from playing or working in the water increases. Bacteria can get into our waters from untreated or partially treated discharges from wastewater treatment plants, from improperly functioning septic systems, and from livestock, pets and wildlife.

People can help keep bacteria out of the water. Properly collect, bag, and trash dog poop. Check your on-site sewage system to make sure it is maintained and working properly. Ensure livestock and manure are kept away from the water.

Water temperature influences what types of organisms can live in a water body. Cooler water can hold more dissolved oxygen that fish and other aquatic life need to breathe. Warmer water holds less dissolved oxygen. Many fish need cold, clean water to survive.

One way to cool water temperature is to shade the water body by adding or retaining streamside vegetation.

Turbidity is a measure of the clarity of the water. In the case of Hangman Creek most of its elevated turbidity comes from high levels of suspended fine sediments. These elevated suspended sediment levels are the result of streambank erosion, agricultural runoff, and other sources that wash off during rain and snowmelt. Pollutants such as fecal coliform bacteria and nutrients, like phosphorus, can hitch a ride with suspended sediments. Turbidity can also make a river or stream less transparent, resulting in greater solar absorption and higher stream temperatures.

Stream turbidity can be improved by controlling stormwater and agricultural runoff and by adding or maintaining vegetation on stream banks.


For more information on these parameters please see our impairments information page.

Technical information

Unless otherwise specified, the files below are Ecology publications.

Bacteria, temperature, turbidity (total suspended solids)

Hangman (Latah) Creek Watershed Fecal Coliform, Temperature, and Turbidity Total Maximum Daily Load - Water Quality Implementation Plan

Hangman (Latah) Creek Watershed Fecal Coliform, Temperature, and Turbidity Total Maximum Daily Load - Water Quality Improvement Report

Hangman Creek Watershed Water Quality Sampling - Quality Assurance Project Plan (QAPP) (Spokane Conservation District)

Hangman (Latah) Creek Water Sampling Data Summary - March 2005 (Spokane Conservation District)

CDM's Final WARMF Model Report to Ecology

April 23, 2009 Public Meeting Presentation

Dissolved oxygen, pH (nutrients)

Quality Assurance Project Plan: Hangman Creek Watershed Dissolved Oxygen and pH Total Maximum Daily Load Water Quality Study Design

Quality Assurance Project Plan: Hangman Hills Nutrient Loading Groundwater Study (Ecology publication)

Hangman Creek Watershed Dissolved Oxygen, pH, and Nutrients Total Maximum Daily Load (TMDL) Study: Data Summary

Addendum to Quality Assurance Project Plan: Hangman Creek Watershed Dissolved Oxygen and pH Total Maximum Daily Load

Quality Assurance Project Plan: Hangman Creek Dissolved Oxygen, pH, and Nutrients Pollutant Source Assessment

Related information


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Last updated April 2016
  Water resource inventory area (WRIA) 56 map, Washington State.


WRIA(s): #56 (Hangman)

Water-body Names:
California Creek
Hangman Creek
Little Hangman Creek
Marshall Creek
Rock Creek
Rattler Run Creek
Spangle Creek

Fecal Coliform

# of TMDLs: 27

Implementation plan sent to EPA

Contact Info:
Elaine Snouwaert
Phone: 509-329-3503
Email: Elaine.Snouwaert@ecy.wa.gov

Eastern Region
Department of Ecology
4601 N Monroe Street
Spokane, WA 99205-1295