Paddling While Impaired

Paddling While Impaired

For safety’s sake, I wish people would not mix boats and alcohol, but I’m writing about the other type of impairment that can get in way of having a fun and safe experience on Iowa’s lakes and rivers: water quality.  Every two years, the Iowa Department of Natural Resources takes stock of which lakes and rivers have water quality good enough to fully support recreation, fishing, drinking water supply, and other beneficial uses.  Those that don’t go on the Impaired Waters List.  The draft 2024 Impaired Waters List has been published and you can make public comment through April 12.

Kayaker with impaired waters message

Understanding the numbers

Most of the op-eds and news stories about the impaired waters list focus on the numbers.  There are 572 rivers and streams, 137 lakes, and 12 wetlands on the impaired list.  If you had forgotten that Iowa has water quality problems, here’s your biennial reminder!

This year, there are fewer impaired waters than in the 2022 cycle.  Much will be made of that, and will be much ado about nothing.  The Impaired Waters List is not very useful for evaluating water quality trends, because the number of waters assessed and the methodology used to assess them is always changing.  It’s also worth noting that the assessment period (2020-2022) included long stretches of drought, which means less runoff, so it’s possible that some of the 97 waters removed from the list will go back on the impaired list when we get some wetter weather.

Missing data

Not too long ago, the biggest category in the integrated report was waters not assessed.  This year, it has dropped to 49% of rivers, 44% of lakes, and 21% of wetlands.  We can claim a little bit of credit for this.  Eight stream segments formerly in the not assessed category were tested for E. coli as part of the Story County water monitoring program and are now in a category called Waters in Need of Further Investigation (WINOFI).  There’s a state law that prevents IDNR from using third-party data for regulatory decisions, but I still appreciate that they reached out and included our data in the report!

An example of Waters in Need of Further Investigation (WINOFI)
Seasonal E. coli averages for West Indian Creek, from our local monitoring program.

Finding clean waters

I’m most interested in which waters are impaired and why.  For rivers, the leading cause of impairment is E. coli bacteria, an indicator of fecal contamination and a proxy for other pathogens that could potentially make people sick if they swallow some water while recreating. 

I am sometimes asked where to go in Iowa to find clean water for paddling, swimming, floating in an inner tube, or just letting the kids splash and catch crayfish in the creek.  A map or list of impaired waters is not very helpful for this, because the waters that aren’t included might be clean, or they might not have been assessed.  So I made an interactive map, color-coded to show which lakes and rivers met or exceeded the primary and secondary contact recreation standards, in the last four recreational seasons.  Hopefully this a just a prototype for something even better and more comprehensive.

Interactive map of E. coli in Iowa

Improving Impaired Waters

We don’t want to just avoid the impaired waters, we want to know how to clean them up.  The Impaired Waters List is also a waiting list for a water quality improvement plan, or Total Maximum Daily Load (TMDL).  IDNR has studied swimming beaches at several lakes (including Hickory Grove Lake in Story County), and found that E. coli is highest in the wet sand at the beach, and lower in the lake and tributaries.  For these lakes, that suggests that the biggest sources of contamination are located at the beach, things like geese and diaper malfunctions.  For rivers impaired by E. coli, we don’t know the cause.  Many rivers have been waiting decades for a TMDL in a low priority tier, and a TMDL that was written in 2017 for the Iowa River seemed incomplete.

However, after attending the Raccoon River Watershed Association’s annual conference on March 9, I no longer feel like Iowa has given up on recreational water quality in rivers.  Robin Fortney shared reminiscences of many river trips.  Jon Wenck (IDNR) and Pat Boddy (ICON) talked about Iowa’s growing network of water trails.  It’s clear there are people who care about our rivers and see how they can benefit quality of life and economic development.  Claire Hruby (Drake University) shared some early results from microbial source tracking and microbial risk assessment research in Polk County.   With these approaches, can find out which pathogens are present in the water (not as many as we feared) and whether waste is coming from livestock, wildlife, or humans or a combination!

My contribution to the conference was a nuanced look at exactly how CAFOs (big feedlots) impact water quality.  I hope to share a video of the presentation and a report in our April newsletter.  There are far too many spills and leaking manure storage structures, and manure management plans don’t prevent over-application of nitrogen and phosphorus.  However, the claim that waste from factory farms is responsible for most of Iowa’s impaired waters is just not supported by the data.  Here is one figure from my presentation.  Notice that Iowa has many rivers with extremely high E. coli levels but fairly low livestock densities in the watershed.  To understand E. coli contamination, you have to consider not just the amount of feces produced, but how it likely it is that feces will reach the water before the bacteria die off.

Graph of E. coli vs livestock density in 58 Iowa watersheds

The Fine Print

If you explore the Impaired Waters List and the rest of the assessment database, you will likely run across some things that don’t make sense.  I share your frustration!  This pair of short videos from our “Clean Water Act: 50 Years, 50 Facts” series contrasts how Section 305(b) and 303(d) of the Clean Water Act should work in theory, and how it can go wrong in practice.  However, I continue to see improvements in the assessment database (ADBNet) and water quality database (AQuIA) and want to express my appreciation to IDNR for the data they collect and their efforts to be make it available to the public.

Thumbnail for Clean Water Act Fact 44
Thumbnail for Clean Water Act Fact 45
The Impaired Waters List is a Missed Opportunity

The Impaired Waters List is a Missed Opportunity

Many Iowans would like to know which lakes and rivers are safe for recreation and good for fishing because that affects how they’ll engage with the outdoors. They would like to know whether water quality is improving, and if not, what kinds of changes on the land would make a difference. Regardless of whether you think the right way to improve water quality is through voluntary projects, legislation, or some combination, we need good information to guide our efforts. However, for all the attention it gets, the 2022 Impaired Waters List does not really tell us which waters are safe for recreation or the direction of statewide trends. We think that’s a missed opportunity.

By the Iowa Department of Natural Resources (IDNR) own admission:

“An increase or decrease in impaired waters does not necessarily mean that the water quality in the state is worsening or improving. It could be a reflection of the additional monitoring we are conducting, changes in water quality standards, and changes in assessment methodologies. Impaired segments are often used for recreation and fishing, among other uses, so impairment doesn’t mean that the segments are unusable.”

-Roger Bruner, Supervisor, Water Quality Monitoring and Assessment section, IDNR

While there’s a lot of good science that goes into Iowa’s water quality assessment database, the list of impaired waters is not a scientific study of water quality status and trends. (The United States Geological Survey actually does that through a national program you’ve probably never heard of). 303(d) lists are legal documents written by state natural resource agencies for the Environmental Protection Agency, as required by Section 303(d) of the Clean Water Act. Even if the IDNR wanted to make things clearer for the public, many of the terms and categories are defined by federal rules and linked to other regulatory processes.

In other words, the Impaired Waters List is part of a Rube Goldberg machine! If you’d like to comment on the draft list before March 19 — either to ask questions about particular water bodies or to express your opinion on Iowa’s larger approach to water quality — you may benefit from the following explanation of the machine.

Disclaimer: I am not an environmental lawyer or policy expert, and am probably not treating the subject with the seriousness it deserves wink.

I don’t mean to throw shade on the staff at environmental agencies or the Clean Water Act. The 1972 law is the reason why American rivers mostly don’t burst into flames anymore. Some lakes and rivers in Iowa have benefited from the process described above, which results in technical information, stakeholder engagement, and grant funds that can help improve water quality. One example I’m familiar with is Hickory Grove Lake in Story County, which is now on its way to recovery. However, many other water bodies have gotten stuck somewhere in the process. I’ll share some examples from Central Iowa.

Step One: If the water was clean, could you swim or fish in it?

The goal of the Clean Water Act was for our waters to be swimmable and fishable by 1983 (yes, we missed that deadline). “Designated uses” for each lake and stream segment clarify what kind of recreation or aquatic life is possible, and these affect which water quality criteria are applied. For example, the Iowa River at Eldora has plenty of water for fishing, swimming, and paddling (so is designated A1 B-WW1). The South Skunk River at its headwaters near Blairsburg is too shallow for any of these uses, regardless of water quality (so is designated A2 B-WW2). As a result of this difference in designated uses, the Eldora Wastewater Treatment Plant must meet stricter E. coli and ammonia limits than the Blairsburg Sewage Treatment Plant.

However, perhaps one-half of the waters in the database have an asterisk next to the designated use. Most smaller creeks in Iowa are presumed to support primary contact recreation until the IDNR determines otherwise, through on-site investigation and surveys of residents. For example, Long Dick Creek in Hamilton County does not have enough water to float a canoe, but since no permit is affected by this determination, Iowa DNR has never been asked to find out. If they did a use attainability analysis, Long Dick Creek would probably not be on the Impaired Waters List — it has E. coli levels exceeding the primary contact standard, but below the secondary contact standard. For this creek, both the impairment and the protections provided by the Clean Water Act are hypothetical.

When a use attainability analysis is done, the conclusions can be confusing. I had understood secondary contact recreation to mean “shore-fishing” but is often paired with a designated use for aquatic life that implies there are no fish worth catching. I had understood primary contact recreation to mean “deep enough for canoeing”, but IDNR uses it to mean “deep enough to accidentally go swimming if you tip your canoe”.

Step 2: How clean does the water need to be for fishing and swimming?

Here’s an example of how the factual questions about the condition of Iowa’s waters get tangled up in economic and legal questions about how to address it. We know that algae blooms can kill fish and become a nuisance (or a safety issue) for swimmers and boaters. We know that phosphorus and nitrogen contribute to algae blooms in Iowa waters. We have lots of data about nitrogen and phosphorus in Iowa waters. We even had a study by IDNR staff examining the relationship between nutrients and aquatic life. What we still don’t have is numeric criteria to translate nitrogen and phosphorus data into “fully supporting”, “partially supporting” or “not supporting” for fishing and recreational uses of lakes and rivers.

Why? Because water quality criteria are not just used to make sense of the data; they are also used to regulate wastewater treatment plants. Iowa’s Environmental Protection Commission has rejected calls to establish numeric nutrient criteria because they were concerned it would put too heavy a cost on municipalities. It’s a valid concern — one that other states have dealt with through permit variances and nutrient trading systems.

Step 3: Is the water clean enough for fishing or swimming?

Assessments are done every two years using recent (but not current) data. The 2022 cycle uses data from 2016 to 2020.

Don’t expect a comprehensive list. Iowa has many lakes and streams and Iowa DNR does not have the resources to monitor them all. Almost one-half of the waters (49% of the river segments, 48% of lakes and reservoirs, and 18% of wetlands in the database) were not assessed for the 2022 cycle.

Even this is overstating how much we know. Most waters are assigned a designated use reflecting what kind of recreation is possible (Class A) and what kind of aquatic life is possible (Class B). The IDNR has conclusive enough data to say whether or not aquatic life uses are supported for 21% of river segments and 33% of lakes and wetlands. IDNR has conclusive enough data to say whether Recreational Uses are supported for 19% of river segments and 57% of lakes and wetlands.

Step 4: Oh no, the water is too dirty for fishing or swimming!

Local groups are doing water quality monitoring and could help the IDNR assess more water bodies. For example, Prairie Rivers of Iowa and our partners documented E. coli levels in Ioway Creek that were 18 times higher* than the standard! However, since our data was not collected under an IDNR-approved quality assurance plan (and since IDNR rarely approves such plans), the most they can do is put Ioway Creek on a list of “Waters in Need of Further Investigation” (WINOFI). If not for a state law (the Credible Data Law), the Impaired Waters List might be much longer and more worrisome.

*The South Skunk River between Story City and Ames is still on the Impaired Waters List because in 2014, the average (in this case, a geometric mean) E. coli count for the season was 223 colonies per 100mL, almost twice the primary recreation standard (126 colonies/100mL). In Ioway Creek in Ames, Prairie Rivers and our partners documented an E. coli geometric mean of 2,280 colonies/100mL in 2018.

Step 5: How can we clean up the water?

The 303(d) list is not just an embarrassment for the state of Iowa. It’s also a waiting list for a water quality improvement plan. These plans are time-consuming to write, so the IDNR has to prioritize. Bacteria impairments in rivers are considered a lower priority, so the South Skunk River between Story City and Ames has been on the waiting list since 2004. It’s in good company: there are 594 stream segments, lakes, and wetlands that need a Total Maximum Daily Load (TMDL).

Step 6: Let’s clean up the water!

Some lakes and rivers have water quality improvement plans that were written over a decade ago and haven’t been implemented. I’ve read a few. In the case of the Little Wall Lake plan (2005), the report did not offer any good solutions, and maybe there aren’t any–it’s a shallow lake with a lot of phosphorus in the muck that gets stirred up when it’s windy. In the case of the Raccoon River plan (2008), solutions are recommended, but there are many obstacles to implementing them: both social (many farmers don’t want to) and legal (the Clean Water Act can’t make them).

How to get involved

You can comment on the Draft Impaired Waters List through March 19, 2022, by mailing a letter to:

Iowa Department of Natural Resources
Attention: IR Comments
Water Quality Monitoring & Assessment Section
Wallace State Office Building
502 East 9th Street
Des Moines, IA 50319

Or send an email to:

As I’ve said, we think the Impaired Waters List represents a missed opportunity to communicate with the public about threats and opportunities to recreation and fisheries in Iowa waters. We would welcome a discussion about how this gap could be filled.

2018 Impaired Waters List

The Iowa Department of Natural Resources is seeking public comment on the newly released draft impaired waters list.  Prairie Rivers of Iowa will be recommending that Squaw Creek and East Indian Creek be added to “Waters in Need of Further Investigation.”  We’ll also take this opportunity to try to demystify a topic that can be confusing, using examples from the South Skunk River watershed.

Every two years, the DNR is required to assess the available data to determine whether Iowa’s lakes, rivers, and wetlands are meeting their designated uses.  About half the rivers, and a bit more of the lakes have enough data to assess.  Since new waters are considered each cycle, the length of the impaired waters list doesn’t really tell us whether water quality is getting worse.  Since nutrients aren’t considered for most uses and the data used for the 2018 assessment is from 2014-2016, it doesn’t tell us whether the Iowa Nutrient Reduction Strategy is working.  What it tells us is the extent and severity of local water quality problems that have been officially vetted.

Recreational Uses

A river segment, lake, or reservoir that gets use by paddlers or where children play would be designated A1 (primary contact recreation use) or A3 (children’s recreational use).  To determine whether the water quality is good enough to support these uses, the DNR compares E. coli bacteria to the state standard (a geometric mean of 126 organisms per 100mL).  If the stream consistently exceeds the standard, that means there could be enough human or animal waste in the water to pose a health risk to anyone that swallowed some–a child splashing in the creek, or a paddler who tipped their canoe might get exposed to a waterborne illness.

Fully supporting:  None of the lakes or rivers in our watershed appeared on this list

Partially supporting: The South Skunk River above Ames was slightly impaired with high E. coli levels in one of three years.  Indian Creek near Maxwell, the upper part of Long Dick Creek in Hamilton County, Montgomery Creek in Boone County, Hickory Grove Lake in Story County, Lake Keomah and White Oak Lake in Mahaska County all have moderate E. coli problems.

Not supporting:  Prairie Creek in Boone County has consistently high E. coli levels.  The data was collected through an agreement between Iowa DNR and volunteers with the Squaw Creek Watershed Coalition.

Not assessed:  This includes Squaw Creek, East Indian Creek, McFarland Pond, and many others.

Wait a minute, Squaw Creek and East Indian Creek?  Didn’t we work with City of Ames and Story County Conservation to collect three years of monthly E. coli samples, starting during the assessment period?  Wasn’t the 2016 geometric mean ten times higher than the standard? Yes, but DNR never approved a quality assurance plan, so under Iowa’s Credible Data Law, they can’t use our data.  However, we will write to DNR to recommend that they add those streams to Iowa’s list of waters in need of further investigation (WINOFI).  We’re aware that bacteria cleanup plans for large rivers are difficult to do and are a low priority for the department, but we want people to be more aware of the health risks.

Aquatic Life Uses

The South Skunk River is  a warm water stream with a smallmouth bass fishery, so is designated B(WW-1).  Most of its perennial tributaries don’t have enough water or habitat for gamefish so are designated* B(WW-2) for other aquatic life.  Fish kill reports, biological monitoring of fish and invertebrates, and monitoring of dissolved oxygen and some toxic chemicals are used to assess whether water quality is good enough to support these uses.

*Adding to the confusion, smaller creeks are given a presumptive A1 B(WW-1) designation until a Use Attainability Assessment proves otherwise.  This change supposedly gives them extra protection, but I don’t see how that would work in practice.

Fully supporting: A lower segment of the South Skunk River in Mahaska County, Little Wall Lake, Hickory Grove Lake, lower Squaw Creek, and Montgomery Creek appear to have good enough water quality for a healthy aquatic community.  FYI: Fish aren’t bothered by high nitrate or E. coli.

Partially supporting:  The South Skunk River above Amesthe upper part of Squaw Creek, Long Dick Creek, upper Ballard Creek, and Walnut Creek are on the impaired waters list due to fish kills or a low quality fish or invertebrate community.

Waters in Need of Further Investigation:  Onion Creek, Worrell Creek, and College Creek had some low scores for fish or invertebrates, but DNR hasn’t worked out an appropriate threshold for these headwater creeks.  The lower part of Ballard Creek was removed from the impaired waters list and placed in this category when DNR discovered an error in the previous assessment.

Not Assessed: This includes several segments of the South Skunk River, Dye Creek, Clear Creek, Keigley Branch, West Indian Creek and many others.

Takeway message:

If a river was added to the impaired waters list, don’t assume it’s gotten dirtier.  Maybe it was always polluted and we hadn’t bothered to look.  And by the same token, if a river is not on the impaired waters list, don’t assume it’s clean.