Analyzing water quality data from Fish Creek and Twin Lakes

PFHS students, it’s time to use the data we collected and try to figure out the water quality status of Upper Twin Lake and Fish Creek! On Google Drive, check out the final data in “Twin Lakes_Fish Creek” to help you do this or check out the charts below. Comment on this post with your responses.

WQ Charts for Twin Lakes_Fish Creek

Screenshot 2014-10-15 14.59.53Screenshot 2014-10-15 14.56.18 TASK 1:

Select one variable, such as DO, pH, water temperature, clarity, or PTI to assess and write the following in a comment on this post, with all the names of who helped write it:

  • What variable are you analyzing?
  • Explain any variation in the observed data throughout the day (i.e., temporal variability). How does it change (or not), and why do you think that is? **You can easily compare data over time by creating a chart. To do so, highlight the time column and the column with your variable in it. In the “Insert” menus, select “Chart.” Click on the “Charts” tab, then select a scatterplot. Now you have a graph over time of the data so that you can visualize what’s going on!
  • Did we record different values at the creek and the lake (i.e., spatial variability)? Please explain any spatial variation, or lack thereof.


Since we collected data at the same time of year in 2013 and 2014, let’s see how that compares:

  • Overall (glancing at all the data), does it seem that water quality has improved, stayed the same, or gotten worse in this watershed from 2013 to 2014?
  • What limitations exist to determining the change in water quality from 2013 to 2014?

22 thoughts on “Analyzing water quality data from Fish Creek and Twin Lakes

  1. We picked dissolved oxygen. It did not change during the day or at Fish Creek or Twin Lakes. The temperature was hotter when we tested at Twin Lakes, but it might have better tree coverage, so the dissolved oxygen would be the same. Last year, the dissolved oxygen was better at Fish Creek than it was this year, but worse at Twin Lakes. The temperature was hotter at Twin Lakes than Fish Creek last year, so that might be why Twin Lakes had less dissolved oxygen.

    • Sonya, Jena, Rylee and Colleen, I like your hypothesis that the higher temperature in Twin Lakes than Fish Creek last year may have led to a lower dissolved oxygen level in the lake. What other factors do you think could have impacted dissolved oxygen?

  2. I am comparing dissolved oxygen (D.O). Last year the average D.O. was an 8.5, this year our average at both Twin Lakes and Upper Twin Lakes was an 8. The quality of the water seems to be the same, but has improved by a little. I got this theory based on that the pH of the water is a lower number last year and that their is a higher number of D.O.

    • Myrisa, the D.O. last year was actually 6.9 mg/L at Upper Twin Lake and 9 mg/L at Fish Creek. You are right that the average this year for both sites was around 8 mg/L. How might we explain the higher number in the lake and the slightly lower number in the creek?

  3. Our group selected the parameter of temperature, and analyzed the difference between the time periods during the day. We found that the temperature was much colder in the morning than in the afternoon, because of the placement of the sun. My group found that the water in the creek was much colder than the water in the lake. These are the results that we recorded.

    • Justin, Tariq, Chase, Kaden and Jayden, you make a good point that the water will warm up throughout the day. Our data didn’t fully show that because of some measurement problems, but that does make sense. Why do you the creek was much colder than the lake? How do you think the water quality compares between 2013 and 2014?

  4. dissolved oxygen in our data was 10 at 1003 in the morn.acording to another group, it was 8 at 1230 in the afternoon.the dissolved oxygen levels decreased by two in 2.5 hrs.last year the dissolved oxygen average was around seven .this shows that more oxygen is dissolving because the water is cooler….maybe due to the shade from the restoration projects at fish creek. kristen anne lowe ,olivia meuyer,alexis surber,rebecca starlsky

    • Hi Kristen, Olivia, Lexi and Rebecca. You are correct in that cooler water can hold more dissolved oxygen. But when are you saying that it was cooler? Last year? This year? In the morning? The water was actually warmer this year than last year. I don’t think there has been a lot of shade created yet by the restoration project because the trees planted need to grow more. But hopefully we will see in the future that shade created by the restoration project lowers water temperatures! Also, in the future please make sure to use proper capitalization and punctuation in your response.

  5. I checked out the different water temperatures within all the data. At Upper Twin Lakes the temperatures ranged from 10-17 C. At Fish Creek the temperatures ranged from 7-15 C. The variations of the data could have many reasons why, but some of the following may be: time of day, location on the water, and how long the thermometer was placed in the water. I think these factors may make the data vary because water temperature can change throughout the day, and not everyone took their measurements in the exact spot. The values between the creek and lake varied. The reasons the two could have varied was because of the different locations and the amount of water and movement in the two areas.

    The water clarity in Fish Creek was about the same as last years data, but the water clarity in Upper Twin Lakes was slightly more clear. The change in this could be because of the restoration project and all the means people are putting in to try to restore the water. There are limitations to our data though because the weather may have changed and the times the data was captured may not exactly measure up.

    • Hailey, you make great points as to why the water temperature varies spatially and temporally, and because of potential human error involved in taking the measurements. You are right, time of day and weather will affect our ability to do determine if we are really seeing water quality improvements. It would probably be best to keep monitoring for awhile to see how things continue to change.

  6. In comparing the temperatures of Fish Creek and Upper Twin Lakes at the different times, I found a couple things. For Upper Twin Lakes, the temperatures were mostly the same, except for a couple rising later in the day as it warmed up. However, the temperatures at Fish Creek were way lower and changed much more because of the running water instead of Upper Twin Lake’s mostly still water, which gathers and holds heat easier. Not every group went to the exact same places in the lake or creek, but that information was not recorded, which could’ve been why some temperatures were different and yet taken at the same time.
    In comparing the water quality from last year to this year, it has slightly improved. For Fish Creek, the air temperature, water temperature, and dissolved oxygen increased, but the PH and clarity remained the same. For Upper Twin Lakes, everything increased, including air and water temperature, dissolved oxygen, PH, and clarity. The limitations, however, are that some of the circumstances were different between last year and this year. For example, it rained last year, increasing the sediments in the creek, but it didn’t this year. Overall, it seems to already be improving.

    • These are great observations, Kaytlyn. It does appear that the water quality is slightly better this year than last year, but you’re right, the rain last year could have had a big impact by eroding sediment into the creek. We need to keep monitoring to see how it continues to change!

  7. I chose water temperature to compare to the rest of the data. The water temperature at Upper Twin Lakes was approximately 14 degrees C in the morning. In the afternoon, the average temperature was 16 degrees C. This change could be due to the temperature of the air, time of day, location of lake, etc. At Fish Creek, the average morning temperature was 9.5 degrees C. In the afternoon, it was about 12 degrees C. The differences between the lake and the creek may be due to location, depth, or movement of water. Overall, the water quality has gotten better. In both the lake and the creek, the DO level had increased along with the pH level. Limitations include that the time of year the data was collected may vary and the weather/temperatures at the time of the data collecting may affect the overall data.

    • Mikayla and Makenzie, good job! You make a good point about the variability between the creek and the lake being related to the depth and movement of water. As we talked about in class, the data was collected at the same time of year both years, but yes, the time of day may have changed. What else impacts dissolved oxygen besides water temperature?

  8. Cierra Foster, Alexis Young, Hope Newman, Timmi Short, Gabby Edlund

    Our air temperature data at Fish Creek varied from 12.2 degrees Celsius to 24.4 degrees Celsius. This could be for various reasons such as; a broken thermometer, different times of the day, how long the thermometer was siting in the sun, and possibly if the thermometer was in the shade or direct sunlight. Our data may not be completely accurate due to these variables.

    The average air temperature data from last year at Fish Creek was 6.7 degrees Celsius. The difference between these air temperatures was 5.5 to 17.7 degrees Celsius. This difference between these again could be for the same reasons seen above ,but now including exactly what time/season this data was taken in.

    • That is a lot of variation in air temperature! You have some good ideas about why that may have happened. It shows that you have to be very careful when collecting data so that measurements are accurate. How would you fix this problem in the future?

  9. Reflection:
    1) The most valuable thing that I learned was that Twin Lakes and Fish Creek’s water quality is not unsafe
    2) The way that water quality affects me is the drinking water, the Spokane River, and the Rathdrum Prairie Aquifer
    3) How it compares is that we took data and used certain equipment, and how it is different is that we took data from the source of the problem
    4) My favorite part was that I got to help restore the creek and that I got to fish in my free time.
    5) Thursday’s experience made me understand that hydrologists use interesting pieces of equipment.
    6) Thursday’s work helped me understand that water can be dangerous if not taken care of.
    Analyzing data:
    I picked pH
    It did not change throughout the day. It changed from last year because the rain had something to do with the results.
    The lake and the creek were the same in pH. This was probably because the damage had already been done upstream (farther upstream than were we tested).

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