The Story of our River
Hello Nishnabotna water defenders!
Last week Trevor Boyer, a friend of the Nishnabotna River and supporter of the Nishnabotna Water Defenders, kayaked from Atlantic Iowa, down the East Nishnabotna to the Missouri River and on to Brownsville Nebraska, a 117 mile journey in an effort to break the record for speed paddling. Along the way he tested the water using Nitrate Watch test strips. He did, in fact, break the record. Congratulations Trevor!
I want to talk about the results of those nitrate tests:
He tested the water several times along the way and I believe it tested at 4mg/L N03-N. Which everyone agreed wasn’t alarming. The Nishnabotna was running high because of recent rains and that can have a diluting effect on nitrate levels in the water.
So, ho hum right? At least it wasn’t above the 10 mg/L we are all focused on correct?
Well, let’s look at what that 4 mg/L might tell us about the health of the river:
A consistent long term level of four is significantly higher than what you might hope to find in a slow moving, warm water river like the Nishnabotna River. For our river, we might hope for something in the .05-1.0 mg/L range.
At that level, you would expect to find a high diversity of sensitive insects and their larva like mayflies, stoneflies and caddisflies.
You would also expect to see a diversity of mussels/amphipods, and midges/worms/snails.
Then you would see small insect eating fish, suckers and darters, minnows and carp.
If there is habitat for them there will be Bass and Crappie, and then large predators.
The overall character of the river would be a broad diverse food web.
A ScienceDirect study: Nitrate Toxicity to Aquatic Animals: A Review of New Data for Freshwater Invertebrates, recommends a level of 2mgL or below to protect the most sensitive freshwater species, with chronic adverse effects on sensitive invertebrates, fish and amphibians demonstrated at
10mg/l NO3-N
So, the 4 mg/L we find sits in the uncomfortable middle, and that is exactly what we see in our river. The most recent DNR sampling shows an acceptable number of fish as well as insects, but it also shows a decrease in the size of those fish and a decrease in the diversity of insects.
The 2026 Draft assessment by the DNR conducted above Red Oak FAILED because of “low aquatic macro invertebrate” life. The river is not listed as “Impaired”, only because the drainage area above Red Oak is larger than the criteria used to test it; a technicality.
The interesting part for me is that sampling has consistently failed because of low invertebrate numbers since 2007, a stretch of 19 years by my calculations.
So, what we have is a distressed river that can maintain “acceptable” fish numbers, but with significantly lower diversity.
We also have nitrate at levels that studies have been shown to play a role in higher cancer rates if consumed regularly.
If, or when the DNR gets around to making the adjustments needed to properly sample the Nishnabotna River and, it fails again they would list it as Category 5 - impaired.
This would put it on Iowa’s Clean Water Act Section 303(d) list.
Iowa would ultimately be required to establish a Total Maximum Daily Load (TMDL) for the pollutants responsible for the impairment.
Then it would develop a map of where the pollutants come from and a plan for lowering the pollution in an effort to restore the river.
Sounds good right? Everything is going to plan right?
Well, let’s see.
There are at least two places on the Nishnabotna river that are listed as impaired:
The East branch of the West Nishnabotna river near Avoca, first listed in 2022 because of low macro invertebrate numbers.
Also:
The East Nishnabotna River from the Fisher Creek to the Page/Montgomery County line.
The documented impairment there is E. coli bacteria affecting primary contact recreation, not nitrate or aquatic biology.
This stretch has been listed since 2008, 18 years on the impairment list.
The latest statewide number of waterways listed as impaired is 577 with 746 separate impairments. This number has been fairly flat for a number of years with one important catch: not all waterways in Iowa are tested. DNR explicitly says the impaired list is limited by where adequate monitoring exists.
Beyond that, even when all the work is done, with TMDL’s created, much of the work that needs done on private land is voluntary.
So the Nishnabotna River and the lakes and streams in our watershed that are listed as impaired will probably stay that way until priorities change in our state and clean water becomes a priority.
This is the time of year when Iowans like to be outside. Much of our activities are centered around our waterways.
Please don’t think that because today’s nitrate level in the water you want to visit isn’t a 10+, that everything is well with the lake or river just because it may not hurt you immediately.
The fact is that many of our waterways are not healthy even if you can catch a few fish and otherwise enjoy yourself on the water.
What can we do?
Educate yourself, be involved, use your voice.
We need more and better testing of our waters and actual teeth in our restoration plans.
This is a very important election year and water quality is on the lips of everyone.
We have a chance for change. VOTE.
Speaking of enjoying our river:
The Nishnabotna Water Defenders will host our first annual float trip and clean up effort on September 27th from 10:00 AM to 2:00 PM
We start at Bonds Landing (Stennett) to Coolbaugh Street boat launch in Red Oak.
Everyone is welcome. Bring your own boat, or there are a limited number of kayaks or canoes available. Find the announcement and RSVP on our website.
We have been very busy this month and most of it is documented on our Facebook page: Nishnabotna Water Defenders and Instagram: @nish2odefenders
Find us, follow us, and stay tuned!
Thank you everyone for paying attention, your support makes the hard work worth it.
Kevin
P.S. If you are with the DNR, or you have updated or more correct information about what I am talking about here, please e-mail me. I am interested.
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