Sammamish River Diel Dissolved Oxygen and pH Study September 21, 2005

STUDY AREA

Sammamish River Basins Big Bear Creek Little Bear Creek Swamp Creek North Creek

Study Goals Diel variation of DO and pH during summer low-flow period Focus on upper reach between Lake Sammamish and Woodinville Provide information for development of dynamic water quality model

CE-QUAL-W2 Model Vertically 2-D model Laterally averaged Hydrodynamics, temperature, algae/eutrophicaton kinetics Epiphyton and riparian shade model added recently

Sammamish River Model

Historical Data

Sammamish River routine grab ambient monitoring data DISSOLVED OXYGEN

Sammamish River routine grab ambient monitoring data DISSOLVED OXYGEN

Monitoring Locations

Reconnaissance Data

Sammamish River diel DO and pH data collected in 2000

Sammamish River diel DO and pH data collected in 2002

2003 Study Results

Photo Tour of Sampling Sites

Redmond Rowing Club

Between Bear Creek and Redmond Railroad Bridge

Redmond Railroad Bridge

Upstream of NE 116 th St Bridge

Upstream of NE 145 th St Bridge

Woodinville Railroad Bridge

I-405 Bridges

Upstream of Blyth Park (old Railroad Bridge)

Summer 2003 Flow and Precipitation Conditions

Daily maximum discharge and total daily precipitation recorded by local King County gauges in the Little Bear and Big Bear Creek basins during the 2003 study

Time Series Data

Sammamish River YSI EDS data, 2003

Sammamish River YSI data from the third deployment 7/22/03 through 7/30/03

Sammamish River YSI data from the fourth deployment 8/22/03 through 9/2/03

Longitudinal Summary Plots

Longitudinal profiles of Sammamish River maximum temperature, temperature range, minimum DO, and DO range for selected days in 2003

Longitudinal profiles of Sammamish River maximum pH, pH range, minimum DO percent saturation, and DO percent saturation range for selected days in 2003

Comparison to Water Quality Standards

Comparison of 2003 Sammamish River YSI continuous temperature, DO and pH data to water quality standards

Critical Period for DO?

Sammamish River routine grab ambient monitoring data DISSOLVED OXYGEN

Sammamish River routine grab ambient monitoring data DO SATURATION

Unintended Results Storm Event

Daily maximum discharge and total daily precipitation recorded by local King County gauges in the Little Bear and Big Bear Creek basins during the 2003 study

Temperature, specific conductance, DO and pH data recorded by the YSI EDS sonde 9/1/2003 through 9/14/2003

Unintended Results Conductance/Groundwater Linkages

Longitudinal trend in specific conductance, 8/22/2003 through 9/2/2003

Sammamish River YSI unqualified specific conductance data, 2003

Sammamish River YSI data from the third deployment 7/22/03 through 7/30/03

Modeling to Identify Cause of pH/DO Fluctuations QUAL2Kw

Model Segment below Bear Creek

Periphyton Photosynthesis Model Segment below Bear Creek

Reaeration Model Segment below Bear Creek

Periphyton respiration Model Segment below Bear Creek

Conclusions Continuous monitoring of DO and pH is feasible provided proper and well maintained equipment are available. Significant diel variation in DO and pH occurs in the Sammamish River particularly between Big Bear and Little Bear creeks Unintentionally, other phenomena were also observed

Recommendations Synoptic temperature/conductance study to identify significant surface and groundwater inputs to the river Quantify the distribution and biomass of aquatic plants and attached algae in the Sammamish River Conduct a time-of-travel study in the Sammamish River to support model development Confirm/investigate fluctuation of conductance in Big Bear Creek

THE END

Sammamish River YSI EDS raw data, 2003

Sammamish River YSI unqualified data from the first deployment 5/29/03 through 6/6/03

Sammamish River YSI unqualified data from the second deployment 6/24/03 through 7/2/03

Sammamish River YSI unqualified data from the fifth deployment 9/25/03 through 10/3/03

Model Setup