Foster Creek Conservation District
Foster Creek Conservation District

Results of 2018 Water Quality Monitoring

We will continue to update this page as more data are collected through the season! Please contact Angie Knerl if you have questions at


We are measuring water quality to better understand long-term changes to the watershed. Water quality should improve over time as new farming techniques are implemented and as trees and shrubs within riparian restorations mature. What follows are the summaries of data collected from June to July 2018 at 4 sites in Douglas County. 


Here we define the water quality variables measured. Visit this site for more information.

Variable What is it Why it is important How to change it
Temperature Stream warmth Creatures living in the stream like specific ranges, changes rate of chemical reactions in water Plant shading vegetation

Specific Conductivity

Ability to pass an electrical current from minerals in the water Tells us if there is erosion into the stream and the streambed's minerals Prevent soil erosion
pH If water is acidic or basic (lemon juice vs. ammonia) Changes if the water can dissolve compounds or if creatures can uptake compounds Prevent pollution
Turbidity The clarity of water changed by fine organic or inorganic matter Fine particles can cover stream habitat or may contain pollutants Prevent soil erosion, have plants next to the stream to block erosion
Dissolved Oxygen Oxygen in water Creatures living in the stream breathe it Shade the stream
A TidbiT temperature logger in a PVC tube ready for the water.


There were 4 sites and there could be one or multiple sampling locations per site. Sampling locations at the sites were given a number, so sampling location 3 at site 4 is written 3_4. The numbering starting at 1 orders the sampling locations from upstream to downstream per site.


We collect data with 2 tools; the TidbiT and the HL4.


The TidbiT stays in the water as long as the stream is flowing and only measures temperature.


The HL4 is placed in the water for 8 days each month and measures water temperature, specific conductivity, pH, and dissolved oxygen. 


We logged the water temperatures with the TidbiT at 15 sampling locations starting June 7, 2018 at Sites 1, 2, and 4, and on June  21st Site 3. One logger was placed in a tree near the stream to measure air temperature. 

Two HL4 probes in the water connected to an instrument that reads the results

We logged water temperature, specific conductivity, pH, and dissolved oxygen with the HL4 at 3 of the sites. We logged sampling locations 2_7 and 4_4 from June 28th to July 5, 2018 and 3_1 from July 5th to July 12th


TidbiTs and HL4s measured 48 values each day because they took a measurement every 30 minutes. We averaged these (gray) and recorded the daily minimum (blue) and maximum (orange) values.  These values are graphed for the HL4s.


To see a smooth trend in TidbiT temperatures, we averaged 7 days of averages (gray), minimums (blue), and maximums (orange) and these are lines on the graphs below. 


Under Washington legislation (WAC 173-201A0600), West Foster Creek is designated as protected for “salmonid spawning, rearing, and migration.”  Salmonids are considered a “cold water” fish and, for healthy spawning, prefer the following parameters:

  • Water temperature (highest 7-day average) -  maximum no greater than 63.5° F
  • pH – between 6.5 and 8.5
  • Dissolved oxygen – not less than 8 mg/L

These limits are indicated by the straight red lines in the graphs below. If one or more of these parameters are not met, it may be detrimental to salmon and other aquatic life. Our ongoing monitoring program will help us understand the changes made by riparian restoration activities and land use, and help guide planning for future projects.



Sampling location and flow direction at Site 1

Site 1: The upper stream stretch 1_1 had the lowest maximum average temperatures and 1_2 the highest maximum average.

Seven day average maximum temperatures for Site 1 in Douglas County

Sampling location and flow direction at Site 2

Site 2: 

  • The stream had warmer and cooler stretches depending on conditions upstream.
  • 2_6 had the highest 7-day average maximum temperatures, while 2_7 a mile downstream had the lowest. 
  • All sites were above recommended maximum temperatures for salmon. 
  • Water was below pH 8.5 limit, clear except one time, and dissolved oxygen was below the desired 8 mg/L.

Seven day average maximum temperatures for Site 2 in Douglas County

HL4 for Site 2 in Douglas County

Sampling location and flow direction at Site 3

Site 3: 

  • The stream at the 3_1 was beneath the allowed maximum temperature except mid August.
  • The water was below pH 8.5 limit and dissolved oxygen was above the desired 8 mg/L. No further HL4 measuresments were taken in August as the water was too shallow for the tool.

Seven day average maximum temperatures for Site 3 in Douglas County

HL4 for Site 3 in Douglas County

Sampling location and flow direction at Site 4

Site 4:

  • 4_3 and 4_2, the upper reaches of stream, had the lowest maximum average temperature and the lower reach 4_4 had the highest maximum average.
  • All reaches climbed above the allowed maximum temperature by mid July.
  • The water pH dropped under the 8.5 limit, dissolved oxygen dropped below the desired 8 mg/L and water was cloudy at times.

Seven day average maximum temperatures for Site 4 in Douglas County

HL4 for Site 4 in Douglas County

Print Print | Sitemap
Foster Creek Conservation District 203 S Rainier Waterville, WA 98858 509-888-6372 © Foster Creek CD