Does the State Revolving Fund (SRF) do infomercials for its Clean Water Loans? I think they should because SRF Sponsored Projects are a classic case of “buy-one-get-one-free.”
We usually focus on conservation efforts by farmers but today let’s give some credit to the municipal wastewater departments—they do a lot to keep our rivers clean. As a nation, we’ve generally been more successful in regulating and treating the pollutants coming out from sewage treatment plants and factories than we have been in dealing with the pollutants that wash off of farm fields, turf grass and parking lots. We’ve now reached a point where the water coming out of the local sewage treatment plant is cleaner in some respects than the water in the backyard creek. I’m not kidding: Ames Water and Pollution Control can’t exceed 126 E. coli colonies per 100mL in their treated effluent—E. coli levels in Squaw Creek for 2016 were eight times higher.
Repairing an aging sewer system or installing a UV disinfection system to meet permit requirements isn’t cheap. This year, the City of Gilbert will be borrowing $3.8 million from the State Revolving Fund (SRF) to upgrade its lagoons and the City of Ames will be borrowing $21 million to prevent inflows to its sanitary sewer system. With that necessary expense comes an additional opportunity to clean up Squaw Creek. A city can apply to do SRF Sponsored Project of up to 10% of the wastewater loan principal, and have the project cost offset by reduced interest rates. Eligible projects include “green infrastructure” in town, conservation practices on farmland in the watershed, or erosion control and ecological restoration along the stream.
Ames has done SRF Sponsored Projects before, so on Monday I joined staff from Gilbert, Fox Engineering, and IDALS to hear from Ames Stormwater Specialist Jake Moore and get some ideas for projects. Paved surfaces like parking lots can contribute to erosion, flooding, and water quality problems, because the rain that falls on them rushes via storm sewer to our waterways. Modern ordinances require that more stormwater be detained and treated on site, or allowed to soak into the ground rather than running off the surface. Ames rebuilt the city hall parking lot last year to absorb water. The parking stalls are permeable pavers. Up to 27 inches of stone underneath provides storage space for water after big storms to mitigate flooding. Compost amendment to the landscaped areas around the building increase soil permeability and promote healthy vegetation. The site was recently planted with the help of Ames High School students, so check back—over time the moisture-tolerant native plants in the bioswales should fill in and bloom, attracting butterflies.
Cool project, right? Prairie Rivers of Iowa is eager to partner with Gilbert, Ames, and other towns in the Squaw Creek and South Skunk watersheds to help facilitate water quality practices both in town and on farmland.
How do we reconcile good recreation with poor water quality? How can we work together to improve water quality in the South Skunk River? These are some questions I hope you will discuss with me at McFarland Park this Friday (Feb 9) at 5:30PM
The good: paddling! The portion of the South Skunk River that flows through Story County* will be dedicated as a water trail this year. Story County is lucky to have a river with so many acres of protected natural areas and with such well-marked public access points. A lot of work over the years by a lot of dedicated conservationists has made that possible.
Skunk River Paddlers trip in 2015
The bad: water quality! This stretch of the South Skunk is on the impaired waters list due to high levels of E.coli bacteria, an indicator for fecal contamination.
The ugly: rivers in the rest of the state aren’t any better. There are over 400 river/stream segments on the Iowa Impaired Waters List due to E coli. That understates the problem—thanks to budget constraints, our state’s abundance of rivers, and a state law that limits what data can be used for regulatory determinations, 1040 river/stream segments weren’t assessed by the DNR at all.
Here’s a classroom analogy. Of the 426 stretches of river that sat the test in 2016, only 9 passed. Under a proposed change to the scoring, 31 more could have passed, prompting misguided** concerns about grade inflation. The South Skunk River would have failed either method, but graded on a curve, it would have been in the cleaner half of the class. Squaw Creek was not allowed to sit the test because of Iowa’s Credible Data Law, but would have scored in the dirtiest quartile.
As a paddler, I have to say that getting sick from something in the water is not a big safety concern for me—when I’m on the river I’m more concerned about strainers and low-head dams. I don’t want to over-react to the water quality data and deny my kids the canoeing, fishing, and frog catching experiences that I enjoyed when I was growing up. Based on the data I’ve seen, the E. coli levels in the South Skunk haven’t gotten worse since then.
Still, if you’ve heard from people who have gotten badly ill from a waterborne illness, you know it’s something to take seriously. The milder cases are under-reported; who’s to say the stomach distress I attributed to a bad burrito wasn’t really a case of Campylobacter that I swallowed when I tipped my canoe.
Unfortunately, there doesn’t seem to be a good way to put those health risks into perspective. The state standard of 126 E. coli colony forming units (CFU)/100mL is based on solid epidemiological studies of freshwater beaches, and corresponds to a defined level of risk: 36 people per 1000 swimmers will get a diarrhea after spending the day at the beach. However, the experts I spoke to said you can’t extrapolate those water quality-illness relationships into truly dirty water. Squaw Creek had a geometric mean almost ten times higher than the standard in 2016. Does that mean that your risk of getting sick from swimming in it is ten times higher? Definitely not. Twice as high? I have no idea.
If you want some good bedtime reading to understand why this stuff is so complicated, check out this EPA study on Quantitative Microbial Risk Assessment. Here are some takeaway points.
E. coli isn’t usually what makes you sick. It’s an easy-to-measure proxy for other pathogens carried in contaminated water, like Cryptosporidium, Campylobacter, E. coli 157, and Salmonella.
Whether you get sick depends on what kind of feces are in the water. You are more likely to get sick from ingesting water contaminated by a human waste (i.e. a leaky septic system) than you are to get sick from water contaminated by cattle manure. Swine manure is less dangerous than cattle manure, but there’s a lot more of it spread on the land. You are unlikely to get sick from poultry manure or geese droppings, since these animals are not as closely related to us.
Whether you get sick depends on the dose you ingest—a child swimming is more likely to swallow water than an adult fishing. You are more likely to swallow water while rolling your kayak than splashing yourself while canoeing.
Whether you get sick depends on your body’s response to the pathogen. Children, the elderly, and people with a compromised immune system may be at higher risk.
The good news is that it is possible to clean up water impaired by bacteria. Can we do it for the Skunk River? Let’s talk about it! Hope to see you on Friday.
*As Alan Spohnheimer proved in a recent talk, the Hamilton County portion of the South Skunk is also fun to canoe, you just have to be more adventuresome when it comes to access points and portages.
**All opinions expressed in this blog post are those of the author and do not reflect the views of Prairie Rivers of Iowa or its funders. But seriously, if you consider how easy it is for a river to exceed the single sample limit (i.e. a raccoon in a culvert near the sample site), how long it takes for a river on the impaired list to get a TMDL completed, and how little power regulatory agencies have to control non-point sources of bacterial contamination, the DNR’s proposed change did not merit the outrage.
I’ll take some cover crops with a prairie filter strip on the contour, a side-dressed nitrogen application, a grassed waterway, and riparian buffer strip. Hold the soil, please.(more…)
HUC12 watersheds in Story County. Can you locate your watershed?
We’re used to thinking of nested levels when it comes to our home addresses. You live in a city or township within a county within a state within a nation.
Jackson Township, Boone County, Iowa, USA
In the same way, you have a watershed address. Your land probably drains to a creek that drains to a river that drains to a larger river. The further downstream you go, the larger the watershed.
Onion Creek watershed, Ioway Creek watershed, South Skunk River watershed, Mississippi River basin
The US Geologic Survey’s Watershed Boundary Dataset is a good way of representing this watershed address. The entire United States is divided up into a nested six-level hierarchy of drainage areas. At each level, two digits are tacked on to the Hydrologic Unit Code (HUC). When we talk about a “huck twelve” (HUC12), we mean a small hydrologic unit with a twelve-digit code, on the order of 10-40 thousand acres.
Level
Hydrologic Unit Code
Rivers included
Size
HUC8
07080105
South Skunk
1,840 square miles
HUC10
0708010503
Ioway Creek
146,932 acres
HUC12
070801050305
Onion Creek
12,741 acres
Having a unique code and uniform coverage is essential for computer-based work—so there’s no confusion about which “Clear Creek” we are talking about—so you’ll see hydrologic units used as an organizing framework for a number of exciting mapping tools. These include the Agricultural Conservation Planning Framework (which maps good sites for practices like grassed waterways and saturated buffers), the Iowa BMP Mapping Project (which maps some existing conservation practices), the CarbonScapes Atlas (which shows the climate benefits of healthy soils), and the Iowa Daily Erosion Project (used to estimate topsoil loss for any day of the year).
However, when using this framework, there’s caveat you need to keep in mind: not all hydrologic units are watersheds. James Omernik et al. pointed out the issue this month in a new paper in the Journal of Environmental Management:
The problem is that it is impossible to map watersheds, basins, or catchments of relatively equal size and cover the whole country. The hydrologic unit framework is in fact composed mostly of watersheds and pieces of watersheds. The pieces include units that drain to segments of streams, remnant areas, noncontributing areas, and coastal or frontal units that can include multiple watersheds draining to an ocean or large lake. Hence, half or more of the hydrologic units are not watersheds as the name of the framework “Watershed Boundary Dataset” implies. Nonetheless, hydrologic units and watersheds are commonly treated as synonymous, and this misapplication and misunderstanding can have some serious scientific and management consequences.
We encountered this issue with a watershed planning project. About 210,622 acres drain into the South Skunk above Ames. However, that watershed is too big for a HUC10, so the section that includes Keigley Branch was separated from two headwater areas near Ellsworth and Jewell. 33,385 acres drain to Keigley Branch, but that watershed is too big for a HUC12 so it was split between the headwaters and the lower section. Rain that falls on Little Wall Lake and its tiny watershed probably stays in the lake until it evaporates, but those acres were lumped into a HUC12 with land that drains to the South Skunk above Story City, the “Miller Creek-South Skunk River Watershed”.
Level
Hydrologic Unit Code
Rivers included
Size
HUC2
07
Upper Mississippi River*
189,000 square miles
HUC4
0708
Upper Mississippi-Iowa-Skunk-Wapsipinicon*
22,800 square miles
HUC6
070801
Upper Mississippi-Skunk-Wapsipinicon*
10,200 square miles
HUC8
07080105
South Skunk
1,840 square miles
HUC10
0708010504
Keigley Branch- South Skunk*
116,137 acres
HUC12
070801050405
Lower Keigley Branch*
15,265 acres
*Not a true watershed
After successfully working with the Ioway Creek Watershed Management Authority to write a management plan and get funding for education and conservation practices in the Ioway Creek Watershed, tackling another HUC10 was a logical next step. We hope to add additional watershed projects in the future to further improve water quality in the South Skunk River. However, the hyphenated names make it confusing to talk about. Bear with us.
So what’s a HUC, again? HUC stands for the Hydrologic Unit Code of a watershed (or part of a watershed) in the national Watershed Boundary Dataset. The number of digits in the code indicates the scale of the hydrologic unit. A ten-digit hydrologic unit (HUC10) is a bit smaller than a county, a twelve-digit hydrologic unit (HUC12) is a bit smaller than a township. Add digits to specify a smaller watershed within a larger river basin. Think of it as the zip code for your watershed address.
I spent Sunday hiking along Clear Creek in the company of a curious herd of six deer, who came within 20 feet of me. Bigger rivers may afford more opportunities for boating. Cold-water trout streams in the northeast part of the state may have better fishing. But the warm-water creeks in Central Iowa have their own charms.
Deer by Clear Creek in Munn Woods
Clear Creek starts in Boone County and passes through Munn Woods and Pammel Woods in Ames before joining Squaw Creek. As a boy, the woods along this creek was one of my favorite places, full of interesting rocks and animal tracks and birds and crayfish, the site of both noisy stick battles with my friends and quiet contemplation.
As my environmental consciousness grew, I would go to the woods to pick up litter. At the time, I had no idea the storm drain emptied to creek, or else I would have stopped my friends from throwing pop cans down there. A recent survey showed that 37% of Iowans imagine that storm sewers go to the wastewater treatment plan or soak into the ground, so labels like this one below are a valuable reminder.
Labeled storm drain in Ames: “No Dumping. Drains to Creek”
In revisiting Clear Creek, I was struck by what a marvelous thing a creek can be if given some space to roam. (Thank you Iowa Natural Heritage Foundation.) I’ve heard from many people in both the city and the country who share my fond memories of time spent by the creek near where they grew up. Not every Iowa creek has hills and woods this dramatic, but if we treat them as something more than drainage systems for our convenience, any local creek can instill in a child the same sense of wonder and discovery that this one did for me.
