Hangman (Latah) Creek
Water Quality Improvement/Total Maximum Daily Load (TMDL) Project

Hangman Creek, also known as Latah Creek, is the heart of a watershed that begins in the foothills of northern Idaho and extends over the southeastern portion of Spokane County in Washington State. The watershed encompasses over 689 square miles (approximately 430,000 acres). (map)

Project Overview

The Spokane County Conservation District, in cooperation with the Washington State Department of Ecology and local residents, is conducting a planning process to address water quality concerns in Hangman Creek, also known as Latah Creek.

The planning process is known as a Water Quality Improvement or Total Maximum Daily Load (TMDL) project. The project involves identifying the type, amount, and source of water quality problems, and recommending practices to reduce the impacts of pollutants and improve the water quality of the Hangman Creek watershed.

This project is funded by a Centennial Clean Water Fund grant from the Department of Ecology to the Spokane County Conservation District (Grant Number G0400196) .

The Conservation District is also facilitating a watershed planning process in Hangman Creek. The watershed planning process is focused on water quantity issues, such as water rights, storage, habitat and instream flows. The watershed planning process will involve an assessment of water supply and use in the Hangman Creek watershed and will result in the development of strategies to manage water use in the future. While there is a relationship between the water quality issues addressed in the TMDL process and the water quantity issues addressed in the watershed planning process, the water resource issues in the Hangman Creek watershed are being addressed in the two separate projects.

The TMDL Process

A TMDL is required under the federal Clean Water Act (CWA) for all waters identified as not meeting federal or state water quality standards. Section 303(d) of the CWA requires Washington State to prepare a list of all surface waters in the state for which beneficial uses - such as agriculture, drinking, recreation, and aquatic habitat - are impaired by pollutants. Section 303(d) also specifies pollutants of concern under the Clean Water Act. Waters failing to meet water quality standards for any or all of these pollutants are placed on a 303(d) list by the Washington State Department of Ecology.

The sediment load in Hangman Creek is obvious in this photo of the confluence of Hangman Creek into the Spokane River. The need to address the water quality concerns in Hangman Creek expand beyond just the creek and the watershed.

Hangman (Latah) Creek has been identified by the Department of Ecology as not achieving state water quality standards for several factors, including fecal coliform, dissolved oxygen, turbidity, ammonia, pH and temperature. Recent monitoring has identified several other water quality problems not specifically addressed under Section 303(d) of the Clean Water Act, including sediment load, low flows and total phosphorus. In addition, there are pollution issues with Little Hangman Creek, Rock Creek and Rattlers Run Creek. The pollution levels in Hangman Creek are also significant because of their contribution to the water quality concerns in the Spokane River. Ecology is also in the process of conducting a TMDL for the Spokane River and Lake Spokane. The contribution of pollutants and sediment from Hangman Creek is an important consideration in the development of the TMDL for Spokane River watershed.

Initial analyses show there are various factors leading to water quality problems on Hangman Creek. Agricultural practices are impacting the watershed as fertilizers and other chemicals find their way to the creeks, erosion washes sediment into the waters, riparian vegetation is removed, and water channels are altered. While the area is dominated by farming, the watershed is also experiencing increases in urbanization and changes in land use practices. The result is increased run-off and drainage of pollutants into the water systems. The removal of native riparian vegetative buffers by landowners throughout the watershed has reduced the natural filtering function and increased stream bank erosion.

Improvements are already being made by some landowners in the area, including the adoption of new agricultural practices. But more remains to be done throughout the watershed. The TMDL process will build upon the prior successes and identify additional steps to improve water quality.

A phased process will be utilized for Hangman Creek TMDL project. The process will identify and evaluate pollutant causes and develop recommendations to allow landowners to voluntarily select the practices that work best for them.

Project Status

The Hangman Creek Water Quality Improvement Report (TMDL) was approved by the U.S. Environmental Protection Agency on September 29, 2009.

See report at http://www.ecy.wa.gov/biblio/0910030.html.

Project Contact

If you would like to learn more about the watershed planning process in the Hangman Creek watershed, please contact Rick Noll, Water Resources Project Coordinator - Hydrologist at (509) 535-7274 ext. 26 or rick-noll@sccd.org.

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