Updated 2021-10-28 to include fall snapshots and better site descriptions

Introduction

The Ioway Creek (formerly Squaw Creek) watershed has a long tradition of citizen science by a volunteer Watershed Coalition. Formerly, the Department of Natural Resources supplied kits and training. After the IOWATER program was ended, Prairie Rivers of Iowa started ordering supplies and organizing the events. The change also brought some data management headaches, but we have now got the data in a consistent form so we can see the full scale of the effort in a few graphs!

Adopt a Stream

The graph shows which stream sites were monitored at least 6 times in a year.

Some dedicated volunteers sustained monthly or twice monthly monitoring for many years. Jean Dow monitored Clear Creek (SC27). Lloyd and Gaylan Crim monitored Montgomery Creek and Prairie Creek in Boone County (SC08, SC11, SC12, and SC13). Erv Klaas monitored Ioway Creek at 4th St (SC33) and South Duff Ave (SC39).

Regular monitoring can give us a good sense for baseline conditions in a stream, and if there’s cause for concern. For reasons I’ve discussed here, small changes may not be noticeable over the noise of weather variability, but regular monitoring can help us spot large trends. The Crims noticed a decline in nitrate in their creeks from 2002-2008 (it jumped back up again in 2013). Regular monitoring can also tell us if there is something unusual happening that needs followup. Erv brought an unusual E. coli reading in Ioway Creek to the attention of City staff, who found and fixed a cracked sanitary sewer main.

Story County Conservation is now providing chemical water monitoring kits to volunteers to do regular testing of streams around the county that haven’t been studied before. We encourage you to get involved and test your local creek.

However, when monitoring streams on different schedules it can be difficult to make apples-to-apples comparisons

Same-day monitoring (Snapshots)

In the early days of the IOWATER program, there were more volunteers testing sites regularly, but relatively few sites were tested on the same day. “Watershed snapshots” held in May and October began in October of 2006.

The value of monitoring multiple sites on the same day (or at least the same weekend) is that we can make comparisons between different streams tested under the same conditions. Wait a week, and we might get a storm, or the crops might be further along, or someone near the stream might start a construction project or spill something, but if we test on the same day we can rule out a lot of those chance differences.

These events are also a way for people to learn about water quality and get involved without a bigger time commitment.

The following section shows results for sites that were tested at 12 or more snapshots.

Results from May snapshots

Here are some results from sites that have been monitored at over a dozen spring snapshot events. The downstream most point on Ioway Creek (SC39, at South Duff Ave) is highlighted.

Nitrate

Nitrogen contributes to algae blooms and Gulf Hypoxia and is a drinking water concern. Nitrate is the most common dissolved form of nitrogen in rivers. Nitrate in Ioway Creek can be quite high in May. Most upstream and tributary sites are the same or lower. Worrell Creek (SC43) is especially high. Glacial Creek (SC04), College Creek (SC31) and some smaller urban tributaries (SC54, SC23) are especially low.

Phosphate

Phosphorus contributes to algae blooms and Gulf Hypoxia. Phosphate is the dissolved form. Ioway Creek has higher phosphate at its upper reaches in Boone and Hamilton Counties (SC02, SC03, SC14). Gilbert Creek (SC15) has unusually high phosphate. Clear Creek (SC27) and Montgomery Creek (SC08) have especially low phosphate.

Dissolved Oxygen

Low dissolved oxygen (especially below 5 mg/L) can affect sensitive critters like mayflies, and the fish that eat them. In spring, all sites average between 8 and 11 mg/L, but in fall, some sites average as low as 6 mg/L. Urban creeks such as College Creek, “Ames High” Creek and “Gilbert” Creek have especially low dissolved oxygen.

Transparency

Transparency is a measure of water clarity or sediment in the water. Some middle reaches of Ioway Creek (SC10, SC14, SC16) are especially muddy. Most tributaries were clearer during the snapshot events, including the aptly named Clear Creek (SC27), College Creek (SC31) and some other urban tributaries (SC23, SC41).

Chloride

Chloride can enter streams from de-icing salts, water softeners, and fertilizers. Salty water can harm sensitive fish and invertebrates–the standard for chronic toxicity is 230 mg/L. None of the sites averaged close to this threshold during spring or fall. Levels in winter may be higher.