Water Quality Improvement Project
Clover Creek Area:


The Clover Creek watershed is located in Pierce County, central western Washington State, and flows through the city of Tacoma urban growth areas, the city of Lakewood, Joint Base Lewis-McChord (JBLM), and empties into Steilacoom Lake. (See Study Area map). Ecology recently finished a water quality study of Clover Creek and plans to have a report summarizing results completed by early 2016.

Water quality issues

Portions of the Clover Creek watershed and its tributaries do not meet the state criteria for dissolved oxygen (DO), fecal coliform (FC), and temperature and are on the Washington State 303(d) list of impaired water bodies. From 1991 to 1992, U.S. Geologic Survey (USGS) data showed that three out of five DO samples fell below criteria on Morey Creek. From 1991 to 1992, USGS data showed three excursions beyond the temperature criteria on Clover Creek at Gravelly Lake Drive. Furthermore, from 1993 to 2001, Ecology data showed four additional temperature excursions. Multiple FC excursions occurred throughout the watershed.

Status of the project

Given the small size of the watershed, the nature of the pollution sources, and our limited resources, we decided to use an alternative to the total maximum daily load (TMDL) approach. We are working to improve water quality directly by implementing fixes to address the pollution sources identified in the Clover Creek water quality assessment. This effort is similar to a straight to implementation (STI) process because we're focusing on implementation rather than planning, but it differs in that we are not the project lead. Pierce County has jurisdiction over much of the watershed and has elected to serve as the lead for implementation efforts.

We are working closely with Pierce County, other local governments, and stakeholders to identify priority river reaches and pollution sources, and develop a list of possible implementation projects to address these problem areas. Pierce County will conduct long-term water quality monitoring to assist with adaptive management efforts and track overall progress.

If water quality fails to improve we may decide to use the TMDL process at a later date.

Why this matters

Oxygen dissolved in healthy water is vital for fish and aquatic life to “breathe” to survive. It is more difficult to transfer oxygen from water to blood than it is to transfer oxygen from air to blood. Therefore, it is critical that an adequate amount of oxygen is maintained in the water for this transfer to take place efficiently and sustain aquatic life. Oxygen is also necessary to help decompose organic matter in the water and bottom sediments, as well as for other biological and chemical processes.

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.

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.


Status of the project

Field data were collected through March 2014 (sampling locations map [PDF]). A report summarizing the results was published in late 2016.


Technical information

Unless otherwise noted, the following are Ecology publications.

Clover Creek Dissolved Oxygen, Fecal Coliform, and Temperature: Total Maximum Daily Load (Water Quality Study Design)

Addendum to Quality Assurance Project Plan: Clover Creek Dissolved Oxygen, Fecal Coliform, and Temperature Total Maximum Daily Load Water Quality Study Design: Riparian Canopy Hemispherical Imagery Assessment

Clover Creek Watershed Fecal Coliform Bacteria, Dissolved Oxygen, and Temperature: Source Assessment Report

Related information

Clover Creek Dissolved Oxygen, Fecal Coliform, and Temperature Total Maximum Daily Load Study: 1st Quarterly Report

WRIA 12: Puyallup-White Watershed Information (Water web site)


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Last updated April 2017
  Map for water resource inventory area (WRIA) 12, Washington State.


WRIA: #12 (Chambers-Clover)
County: Pierce

Water-body Name:
Clover Creek

Dissolved Oxygen
Fecal Coliform Bacteria


Water Quality Assessment project under development

Contact Info:
Donovan Gray
Phone: 360-407-6407
Email: Donovan.Gray@ecy.wa.gov

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