Cranberry, Johns, and Mill Creeks are too warm to meet the state water quality standards for temperature. These three creeks are on the Washington state 2004 and 2008 303(d) lists of impaired waterbodies. We are developing a total maximum daily load (TMDL) project for these creeks to protect the beneficial uses of fish migration, rearing, spawning, and shellfish harvesting.
Water quality issues
Cranberry and Johns Creeks are tributaries to Oakland Bay, a short, narrow bay angling abruptly northeast from its connection with Hammersley Inlet to the south. Mill Creek is a tributary to Hammersley Inlet. Hammersley Inlet is one of the shallowest and narrowest of all inlets in South Puget Sound. Land use in the watershed is primarily commercial forest, with a smaller percentage dedicated to residential development and agriculture. Shorelines of both the marine area and the lakes in the watershed are heavily developed. Agricultural lands are dominated by small non-commercial farms.
All three of these creeks are characterized by lakes or large wetlands at their headwaters. The large surface area exposed to sunlight may cause the relatively high water temperatures. Elevated water temperatures may also be the result of land use. We plan to re-activate the Total Maximum Daily Load (TMDL) project and work with local partners to find ways to reduce water temperatures and protect the beneficial uses such as fish migration, rearing, spawning, and shellfish harvesting.
What we have done
We began a cleanup process in spring 2003. The first step was a water quality study. Starting with an evaluation of existing water quality data, we and a technical advisory group designed a study plan to fill information gaps.
Status of the project
The temperature study will evaluate sources of heat and cooling, determine how much heat the creeks can handle naturally, and make recommendations for returning water temperature to healthy levels. We plan to re-activate the TMDL project and work with local partners to find ways to reduce water temperatures, protect aquatic life, and identify implementation actions needed to improve water quality in the study area.
Our partners in this project
Why this matters
Temperature may be the most influential factor limiting the distribution and health of aquatic life. Cooler water can improve the growth and development of fish, reduce the risk of disease, improve fish migration, and help native fish compete with non-native species. Human activities can greatly influence temperature in water bodies.