Background and Purpose
According to the Tillamook Estuaries Partnership, “Holden Creek is one of the most polluted creeks on the Oregon Coast based on bacterial counts.” Holden Creek begins in a pasture about 4 miles north of Tillamook, Oregon and runs between Hampton’s Tillamook Lumber and Tillamook High School. It crosses 5 major roads, runs behind the county shops, public utilities district, and Les Schwab. It eventually empties into the Trask River.
Holden Creek has serious water quality problems ranging from low oxygen, low pH, high sediments, high turbidity, high zinc and high organic input from greases, oils and other automotive liquids. The pollutants originate from roads, private property and the log yard at the Tillamook Lumber. Roads add hydrocarbons and some metals in high temperature greases. The log yard adds tannic acid for Hemlock bark, sediments from the gravel/dirt yard and zinc from the galvanized sheet metal.
Project purpose: to improve water quality and function while reducing flooding in Holden Creek. The Ag 1 classes at Tillamook High School embarked on the task of improving water quality in Holden Creek as an AgriScience project.
Holden Creek has serious water quality problems ranging from low oxygen, low pH, high sediments, high turbidity, high zinc and high organic input from greases, oils and other automotive liquids. The pollutants originate from roads, private property and the log yard at the Tillamook Lumber. Roads add hydrocarbons and some metals in high temperature greases. The log yard adds tannic acid for Hemlock bark, sediments from the gravel/dirt yard and zinc from the galvanized sheet metal.
Project purpose: to improve water quality and function while reducing flooding in Holden Creek. The Ag 1 classes at Tillamook High School embarked on the task of improving water quality in Holden Creek as an AgriScience project.
Survey Protocols
The Bio-Swales
Groups of Tillamook High School students researched and brainstormed ideas for mitigating the problems of Holden Creek. It was decided to create experimental bioswale, landscape ditches designed to maximize the time water flows through the swale to catch pollutant runoff (before it reaches the Trask River), for the purpose of testing various treatments that might improve water quality on Holden Creek.
Once a treatment was decided upon, groups dug 50 foot bioswales between Tillamook High School and Holden Creekwith a slope between 1% and 2%. They used a transit to get the correct slope. The bioswale were lined with plastic and the treatment medium was set in place. Water was pumped from Holden Creek and run through bioswales for several hours before testing began. Water quality was tested at the beginning of the bioswale and at each point where it changed medium.
Once a treatment was decided upon, groups dug 50 foot bioswales between Tillamook High School and Holden Creekwith a slope between 1% and 2%. They used a transit to get the correct slope. The bioswale were lined with plastic and the treatment medium was set in place. Water was pumped from Holden Creek and run through bioswales for several hours before testing began. Water quality was tested at the beginning of the bioswale and at each point where it changed medium.
Research History
2006-2007
Began water quality testing in creek by high school
Temperature, oxygen, pH, turbidity, conductivity, zinc, copper, water velocity, sludge
Ag 1 students created 8 research bioswales, testing their efficiency for improving water quality in Holden Creek
THS students plant hundreds of conifers and shrubs to improve riparian area and complete with willows that are restricting stream flow in many areas
Project presented at National FFA Agriscience Fair
Began water quality testing in creek by high school
Temperature, oxygen, pH, turbidity, conductivity, zinc, copper, water velocity, sludge
Ag 1 students created 8 research bioswales, testing their efficiency for improving water quality in Holden Creek
THS students plant hundreds of conifers and shrubs to improve riparian area and complete with willows that are restricting stream flow in many areas
Project presented at National FFA Agriscience Fair
2007-2008
Expanded Holden Creek water quality surveys to include the entire creek Expanded surveys to include bacteria counts and shade surveys Bioswales continue to be modified and tested by Ag 1 students Independent science researchpeoject comparing land use and stream quality began Survey of pinch points and water quality conducted Projects presented at regional, state, and national science fairs |
2008-2009
Bioswale research continues on two of the most effective designs
Project comparing stream flow, water quality, and pinch points conducted
Independent science research project using stream table models water quality changes if pinch points removed
Effect of shrub and tree litter on stream velocity and water quality investigated
THS seniors work on improving riparian area in East forest behind East Elementary School
Projects presented at regional, state, and national science fairs
Bioswale research continues on two of the most effective designs
Project comparing stream flow, water quality, and pinch points conducted
Independent science research project using stream table models water quality changes if pinch points removed
Effect of shrub and tree litter on stream velocity and water quality investigated
THS seniors work on improving riparian area in East forest behind East Elementary School
Projects presented at regional, state, and national science fairs
2009-2010
Permanent bioswales created by year's end incorporating all previous vioswale research
The correlation between water flow and water quality continue to be studied
East Elementary students plant conifers in riparian area to compete with willows
Independent science research investigating the role of oyster shells in reducing creek acidity and removing copper from creek
Projects presented at regional, state, and national science fairs
Permanent bioswales created by year's end incorporating all previous vioswale research
The correlation between water flow and water quality continue to be studied
East Elementary students plant conifers in riparian area to compete with willows
Independent science research investigating the role of oyster shells in reducing creek acidity and removing copper from creek
Projects presented at regional, state, and national science fairs
2010-2011
Continue monitoring water quality along Holden Creek
Students at East elementary take over water quality monitoring in the East Forest
Begin community outreach effort.
Produce a video on Holden Creek highlighting student research and including ideas for homeowners to improve riparian functions while reducing flooding.
Train and organize student groups to help landowners improve their riparian areas.
Continue monitoring water quality along Holden Creek
Students at East elementary take over water quality monitoring in the East Forest
Begin community outreach effort.
Produce a video on Holden Creek highlighting student research and including ideas for homeowners to improve riparian functions while reducing flooding.
Train and organize student groups to help landowners improve their riparian areas.