Excuse the delay in posting the data. I had shared this with the participating volunteers but not with a broader audience. I was distracted by the dramatic change in water quality a week later. However, the results from the spring snapshot event is more typical of what we’ve been seeing this year–clear and drying up!
On the weekend of May 15, fifteen volunteers tested 25 sites on Ioway Creek and its tributaries.
Volunteers practice testing phosphate and dissolved oxygen.
Like most of 2021 so far, water levels were way below normal, and light rains Saturday afternoon did little to change things. A few volunteers tested their sites Sunday, but water levels had dropped back down by the time.
Water levels (blue) in Ioway Creek are below normal (triangles).
With streams running low and tiles not flowing at all, most sites were as clear as we can measure (transparency greater than 60 cm), had low nitrate (2 mg/L or less) and low phosphate (0.1 or less).
But there were a few interesting exceptions.
Nitrate concentrations were a little higher (5 mg/L) in the middle reaches of Ioway Creek, starting at Hwy E18 in Boone County and continuing to Moore Park in Ames. The upstream reaches in Hamilton County and the downstream reaches in Ames had low nitrate levels.
“Gilbert Creek” had higher nitrate (5 mg/L) and much higher phosphate (1 mg/L) than other sites. When streams are running low, effluent from wastewater treatment plants can make up a significant portion of streamflow and can have a big influence on water quality. When streams are running high, effluent becomes a small fraction of streamflow compared to runoff from cropland. Wastewater plants in Iowa are only beginning to install technology to improve nitrogen and phosphorus removal.
The upper reaches of Ioway Creek in Hamilton County. Good water quality on May 15, but warm, not much shade.
Some urban streams showed elevated chloride levels (125 mg/L), but still within Iowa standards for aquatic life (389 mg/L thresholds for chronic exposure). Road salt dissolves and makes its way into groundwater, so we can see it’s influence in spring and summer, but testing before and after winter storms can give us a clearer picture.
The little creek below Ames High School (SC23) had muddy water (transparency of 32 cm) and dissolved oxygen low enough to harm aquatic life. We know that when it does rain this creek gets a lot of stormwater runoff (the video we produced with City of Ames shows this in action) and construction could also be an influence.
I don’t have a good explanation for lower dissolved oxygen and transparency at other locations.
Filling a transparency tube in Montgomery Creek, one of the murkier sites this year.
Thanks to our volunteers for spending a morning testing water! Our next event will be in October.
“If it never rained, we’d have great water quality in Iowa.”
-Jim Richardson
“If it never rained, we’d have great water quality in Iowa,” joked a volunteer at our May 15 water quality snapshot. 15 of us spent the morning testing Ioway Creek and its tributaries in Boone, Hamilton, and Story County and were marveling at the low nitrate levels and crystal clear water at the majority of our sites.
I wish more creeks in central Iowa were like this spot in Boone County. Cows fenced out the creek, a CREP wetland upstream keeping nitrate levels low, orioles and a kingfisher flitting between the trees.
Well, we’ve had some much-needed rain in the week since, and water quality has gone from good to bad. I’ve written before about “weather whiplash” that explains some of the big swings in nitrate over the past decade and here’s an early hint of it. Here’s data from a nitrate sensor in Ioway Creek installed by IIHR-Hydroscience and Engineering. A five-fold increase in nitrate concentrations in just one week! The water has gone back down but the nitrate levels are still above the drinking water standard.
And here’s some water samples I collected on Friday May 21. No, that’s not my coffee thermos, that’s some of the world’s best top soil washing down the Skunk River!
Four samples collected May 21, after a 3/4 inch rain
That’s not to blame the weather. It does rain in Iowa and if your farming practices let a plume of topsoil, manure, or fertilizer wash off the field every time that happens, you’re doing it wrong! Some farmers are doing it right (I saw some cover crops this spring near Nevada and lots driving on I-80) but not enough, especially in the Ioway and South Skunk River watersheds.
Water quality monitoring has been top of mind for Prairie Rivers of Iowa lately and I see an challenge and an opportunity. It’s a challenge to interpret data and track our progress when one good rain can cause water quality to go from clear to coffee-colored overnight! There’s an opportunity to be more strategic about how and where we test, so we notice and communicate more eye-opening moments like this one, and hopefully persuade a few more people to protect soil and water.
Update: June has been abnormally dry and Hamilton, Boone and Story County are experience severe drought. Droughts stress is impacting crops and smaller streams are drying up.
When snow melts, salt applied to melt snow on sidewalks, roads, and parking lots can make its way to streams. Freshwater critters don’t like living in saltwater. Are we getting to a point where they’d have trouble? Not quite, the chronic levels of concern for Iowa is 389 mg/L of chloride, and this sample (from a creek near Ames High School) and some others in our area were just shy of that last weekend. But be mindful of how much salt you’re scattering if we get some more icy days this month–people often apply more than what’s needed for safety!
The Izaak Walton League’s Winter Salt Watch is a good way for people to check on water quality during the winter and learn more about the issue.
What else is being carried in snowmelt? Our lab tests from late February are showing higher nitrate and bacteria levels than January’s tests. Check back in mid-March and we’ll get that data organized.
Thirteen volunteers braved the cold on October 24 to test water quality in Squaw Creek, the South Skunk River, and their tributaries. For some, this was their 14th Fall Water Quality Snapshot. For others it was their first time doing stream monitoring. What we found defies easy categorization.
Update: The name “Squaw Creek” was officially changed to “Ioway Creek” in February of 2021, to be more respectful to native peoples. Over the next year, expect to see some changes to the names of the Squaw Creek Watershed Coalition and other groups that have formed to protect the creek, as well as maps and signs.
Volunteers Diane Birt, Paul Readhead, Liz Calhoun, and Rick Dietz take turns brushing off rocks to capture bugs in our net. The water was freezing!
By some indicators, water quality in Squaw Creek was good. Since I wasn’t sure how many creeks would be flowing when I planned this event, I added bug collection to the agenda to keep us busy. Excuse me. Benthic macroinvertebrate sampling. We were pleased to find tiny stoneflies and mayflies. They’re good fish food, ask any fly fisherman! Excuse me. An important part of the aquatic food web. These insects also act as a sort of canary in the coal mine. They need water with a lot of dissolved oxygen so will be rare or missing in streams with too much pollution, murky water, or not much in the way of habitat.
Fun fact: while the adult mayfly is notorious for living only 24 hours, the juvenile form (naiad) lives in the stream for several years. If you’re curious what adult mayflies and stoneflies look like, I found somephotos from our neighbors in Missouri.
By some indicators, water quality in Squaw Creek and it’s tributaries was bad. As in, there’s poop in the water. Excuse me, fecal indicator bacteria. This month, E. coli bacteria in Squaw Creek continued to exceed the primary contact recreation standard, and College Creek jumped above secondary contact standard. I wondered if this spike might be due to accumulated… debris… being washed out of the storm sewers and off the landscape by the 1.25 inch rain we received Thursday and Friday, but the lab samples were actually collected on Wednesday Oct 21, so I’m not sure. Anyway, covid-19 is not the only reason I bring hand sanitizer to these events!
By some indicators, water quality was unusually dry this fall. Nitrate was too low to detect at 13 of 16 sites we tested. Under wetter conditions, as we had this spring or last fall, nitrate in these same streams was higher and differences due to landuse or conservation practices in the watershed become more apparent.
Site
Watershed
Fall 2020
Spring 2020
Fall 2019
Squaw Creek @ Duff Ave
Rural and urban
0
10
5
Bluestem Creek @150th St
Rural
2
10
5
Glacial Creek @ U Ave
Rural (with a constructed wetland)
0
2
2
College Creek @ University
Urban
0
2
2
Nitrate-N concentrations, in mg/L
Water quality is rarely all good news or all bad news. Citizen science can us a more complete picture.
It turns out that stream monitoring is quite compatible with social distancing. 28 volunteers participated in the Squaw Creek Watershed Coalition’s 13th spring water quality snapshot on May 30 and 31. Together we tested water quality at 43 sites on Squaw Creek, its tributaries, and the South Skunk River! This time, Prairie Rivers of Iowa assembled the equipment, organized the event, and entered the data. We’re happy to support this dedicated group of citizen scientists in better understanding and drawing attention to our local rivers and creeks.
Update: The name “Squaw Creek” was officially changed to “Ioway Creek” in February of 2021, to be more respectful to native peoples. Over the next year, expect to see some changes to the name of the Coalition, as well as maps and signs.
Here’s a few selfies taken by participants, a mix of long-term volunteers and new faces.
The Kopecky family by the South Skunk River
Jeff White at Gilbert Creek
Kelly Nascimento Thompson at Glacial Creek
Kurt Plagge and Mary Burnet at Onion Creek
As the name implies, this is a snapshot in time. The water quality on one sunny weekend in May is not necessarily representative of the month, let alone the year. As described here and here, water quality can change dramatically in response to a big rainstorm. But for this moment in time, testing many sites gives us a very detailed picture of the Squaw Creek watershed.
For example, during May 30 and 31, nitrate in Squaw Creek at Moore Park and other locations in Ames was quite high (11-12 mg/L) exceeding the drinking water standard (10 mg/L). Where is that nitrate coming from? All over its 147,000 acre watershed, but in some tributaries more than others, as you can see in the color-coded chart below. Nitrate was especially high in the upper reaches of Squaw Creek, Gilbert Creek and Clear Creek and especially low in Glacial Creek (which has a series of constructed wetlands and a lot of pasture) and College Creek (which has an urban watershed). The upstream, rural parts of College Creek and Clear Creek have higher nitrate, which appears to be diluted they move through town.
For phosphorus some of the patterns are flipped. Glacial Creek has especially high orthophosphate (the dissolved form of phosphorus) while Clear Creek is especially low.
There’s lots of interesting patterns to explore, and more data from this and previous snapshot events here. If you’re curious about water quality, subscribe to our blog, I’ll be continuing to interpret data from this and other sources.
Thanks to all our volunteers for collecting it!
Questions about stream monitoring, or observations from our volunteers? Post a comment.
