Watershed Monitoring

From 2003 to 2006, volunteers and graduate students from Washington State University’s Department of Natural Resource Sciences monitored Thompson Creek and the eight other inlets that discharge into Newman Lake. Parameters monitored included Discharge (cubic feet per second), Dissolved Oxygen, pH, nutrient levels and temperature. Cross-sectional and longitudinal profiles were surveyed to note geomorphologic conditions and channel stability. In addition, the stage/discharge relationships at Thompson Creek Bridge and Temple Creek at West Newman Lake Road were used to create rating curves. Once such curves are established, discharge can be calculated by pairing staff gage readings with the respective points on the graph. Periodic flow measurements and channel geometry surveys (profiles) are needed to ensure that the stage discharge relationship has not been altered by changes in the channel configuration.

Stream Profiles

• Lower Temple Ck at Lindgren's Culvert, 32.3' upstream from culvert , 4-26-06



• Lower Temple Ck at Lindgren's, 137' upstream from culvert, 4-26-06



• Temple Ck at West Newman Lake Rd., 31.7' upstream from culvert, 4-17-06



• Temple Ck at West Newman Lake Rd., 75.4' upstream from culvert, 4-14-06



• Thompson Ck at Gate, 0.0' upstream from beginning of reach (flagged rebar) 4-21-06



• Thompson Ck at Gate, 50.0' upstream from beginning of reach (flagged rebar) 4-21-06



• Upper Thompson Ck, 0.0' upstream from beginning of reach (flagged rebar) 4-20-06



• Upper Thompson Ck, 114' upstream from beginning of reach (flagged rebar) 4-20-06

Rating Curves

Temple Creek Rating Curve

Thompson Creek Rating Curve

Stream Monitoring

2003

2004

2005

2006

Inlet Total Phosporus

2003

2004

• 2004 TP Inlets
• 2004 Thompson Creek Data
• 2004 Thompson Creek Chart

2005

• 2005 TP Inlets
• 2005 TP Thompson Creek Data
• 2005 TP Thompson Creek Chart

2006

• 2006 TP Inlets
• 2006 TP Thompson Creek Data
• 2006 TP Thompson Creek Chart
• 2006 TP Mtn View Creek/Temple Creek

There are opportunities for further analysis of existing data sets as well as future samples as they are gathered. The following suggestions outline methodologies that can be employed to utilized field data to the highest and best extent:

Channel Geometry: While cross-sectional and longitudinal profiles are measurements that will not generally change significantly over short periods of time, these surveys should be conducted at a minimum every five years or after extreme flooding events. This is especially relevant at sites that have rating curves developed centering upon the stage/discharge relationship. If channel morphology is altered, then these relationships need to be established using the new channel geometry.

Discharge Measurements: Accurate flow measurements are of vital importance for many research and management actions in relation to given water body. In addition to channel geometry, discharge can be used in the appropriate sizing of culverts and other crossing and conveyance structures. When paired with water quality parameters, analysis can be conducted to determine minimum flows in which temperature and dissolved oxygen are negatively impacted. Discharge is also useful in nutrient loading data, where further research may demonstrate a relationship between flow and nutrient concentrations.

Water Quality Parameters: The data derived from discharge measurement is useful when paired with temperature, dissolved oxygen, and pH. Not only do these parameters demonstrate the overall health of a body of water, they also establish relationships between seasonal variations.

Nutrient Measurements: Newman Lake is on the 303(d) list as being impaired due to elevated phosphorous concentrations, a significant portion of which are due to influx from the lake’s tributaries. As a result, data collection has and will continue to focus on measuring total phosphorus. These measurements are crucial in examining the relationship between changing management practices and nutrient loading.

Though the information gathered by the volunteers and WSU graduate students has proven invaluable for watershed analysis, new data collection/monitoring will be vital in assessing current and future watershed conditions. If you are interested in joining in the volunteer monitoring effort, please contact Jacob McCann at jmccann@spokanecounty.org or call 509/477-3600.