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
Six Tips to Enjoy Iowa Lakes

Six Tips to Enjoy Iowa Lakes

lake at sunset

There is no better way to relieve stress and get an attitude adjustment than spending time by a lake, whether you’re fishing, swimming, paddling, watching wildlife, or watching the sunset.  But it’s hard to enjoy a lake if it’s choked with toxic blue-green algae. Cleaning up Iowa lakes so we can enjoy them will require some shifts to our attitudes.

1. Don’t Panic

I’m sure you’ve all heard about the “brain-eating amoeba” Naegleria fowleri. Iowa and Nebraska both had their first cases in 2022 (both fatal), contracted at the Lake of the Three Fires and the Elkhorn River, respectively. While scary, cases are also extremely rare. Nationwide there have only been 157 cases in the past 60 years, concentrated in the South. And even where the amoeba is known to be present, there are ways to enjoy the water while minimizing risk.

2. Check Where the Beaches are Cleanest

Iowa Environmental Council maintains a map and puts out a weekly report showing where there are beach advisories. The map also shows many lakes with no advisories (the blue umbrellas). For example, in Story County, the beach house at Hickory Grove Lake is sometimes closed due to high E. coli levels, but at Peterson Park, E. coli has been consistently below the detection limit. Not every lake in Iowa is hopelessly polluted, and even the most troubled lakes will have their good days.  Take advantage of them!

map of beach advisories
Peterson Park Lake
The beach at Peterson Park in Story County

3. Help clean up dirty lakes at the local level

Having spent some time enjoying a clean lake, hopefully, you are in a better frame of mind to tackle the not-so-clean lakes. There are lake improvement efforts all over the state that need the support of taxpayers or the help of landowners in the watershed. For example, Story County is planning a complete renovation of McFarland Park Lake, which recently suffered an algae bloom and fish kill.

“The renovation will: remove sediment, stabilize shoreline, increase lake depth, and improve lake habitat for aquatic plants and animals. Work will increase overall health of the lake, reduce the number of fish die offs in the future, and improve recreational opportunities.”

4. Keep clean lakes clean at the state and national level

It does no good to dredge out a lake if farmers in the watershed are going to plow up the hillsides around it. This is what happened to Lake of the Three Fires, as related by Chris Jones.  When a third of the county was converted from pasture to corn ground, the lake gradually returned to its former shade of brown. We can’t do much about naturally occurring amoebas, but we can take a hard look at the policies, business and purchasing decisions, and attitudes that shape farming practices across Iowa.

5. Think globally, act locally

The warmer the water, the more cases of Naegleria fowleri. The same goes for harmful algae blooms, a much more common problem in Iowa that is getting even more common. If we don’t reduce our greenhouse gas emissions fast, hotter temperatures and more intense spring rainstorms will continue to worsen our water quality woes. Fortunately, there are opportunities to reduce greenhouse gas emissions in Iowa while at the same time improving water quality in the short term by planting more deep-rooted perennials and cover crops, building up organic matter in the soil, and using less nitrogen fertilizer.

6. Share your favorite water memories

A friend was visiting from out-of-state when I wrote this article. A family vacation to Iowa of course included time with the grandparents and a visit to the Iowa State Fair, but he also set aside time to take his kids wading in Ioway Creek, where they caught minnows and marveled at the weirdness of dragonfly nymphs. For my friend, time spent outdoors in creeks and lakes was an essential part of growing up in Iowa, and he wanted his children to share that experience.

What a wonderful mindset to cultivate as we work to improve water quality!

The Community Academy explores Ioway Creek
Green Stuff in the Water

Green Stuff in the Water

I got a good look at a cyanobacteria “bloom” over Labor Day weekend, at a lake in Wisconsin.  Cyanobacteria can produce toxins, and this proliferation of green gunk had done so earlier in the month, causing a large number of fish to go belly up.  Cyanobacteria toxins can also be dangerous for people and dogs.

There were warning signs posted but they were wordy and left some doubt about whether it was okay to go in the water. Some kayakers were ignoring them.  This has been an issue in Iowa as well.  The Iowa Environmental Council is working with Iowa DNR to make the warning signs simpler and more visible.  The Environmental Working Group recommends that midwestern states do more frequent testing for microcystins, the most worrisome class of cyanobacteria toxins.  I support these steps, but I also think it’s important to let the public know what to look for, as its not always possible to run tests and post warnings in a timely manner.   How about this rule of thumb, illustrated in the graphic above?  If it looks like paint, stay out! 

Not every cyanobacteria bloom can be so easily identified, and not all cyanobacteria produce toxins, but enough of the toxin-producing species do look like spilled paint or “pea soup,” that it seems like a good starting point.

When I first arrived at the lake, it was streaks of green and brown in the water, like the rinse station for a child’s art project. The next day, more had been blown to our side of the lake and it formed a thick surface scum with bubbles, like latex paint left out for too long, and had a nasty smell.  The color was a bright green mixed with brown but cyanobacteria blooms can also be bluish green, blue, brown, or red.

Some of the harmless green things more commonly growing in lakes, streams, and ponds look completely different, as pictured above.

Duckweed looks like confetti scattered on the water surface.  There’s a few different species ranging from dots (the 1 cm Spirodela) to specks (the 2 mm Wolffia).  They are large enough you see the individual round leaves with the naked eye, and they sometimes have trailing roots. Surprisingly, it’s actually a flowering plant related to peace lillies, with tiny, wind-pollinated flowers. As the name implies, they are an important food source for waterfowl.

Green algae are a huge assortment of plant relatives, some single-celled and microscopic (until there are enough to turn the water green), some joining together into spheres, nets, or filaments.  Filamentous green algae look like slimy hair when they grow on rocks, and like drain clogs when they are dislodged and float on the surface or wash up on beaches.

And then there’s a variety of aquatic plants (pondweeds, coontail, and others) that can be found rooted to the bottom.  While dense “weeds” can be a nuisance for motor-boaters, a plant-dominated lake is better for fish than an algae-dominated lake, or one with nowhere to hide and nothing to eat.

If the lake looks like paint, stay out! Experts, can I say that?  It’s an over-simplification, but not everyone has the patience to read a more complicated message, or the good sense to take it seriously.

For more on harmful algae blooms and how to keep yourself and and your dog safe, the Iowa Public Health Department has some good resources.