Water Quality Monitoring
Water quality monitoring is necessary to raise awareness of water quality issues in our streams and to track the progress of conservation efforts. Over the past five years, Prairie Rivers of Iowa has supported the water monitoring of Squaw Creek and its tributaries through organizing volunteer events, sharing monthly lab data, and developing educational materials and presentations to help interpret it.
Establishing a Story County 10-Year Water Monitoring Program
We are currently working on a project to begin monitoring additional streams in Story County, work with stakeholders to develop a plan to sustain monitoring efforts over 10 years, and make sure the data collected can be used for education and to guide water quality improvements. The project is supported by funding from Story County, the City of Ames, the Leopold Center, and the Story County Community Foundation.
How is the water quality in Squaw Creek and its tributaries? We have several ways to answer that question.
Today’s conditions in Squaw Creek
We can see real-time nitrate data from a sensor installed at Moore Park in Ames by IIHR Hydroscience and Engineering at the University of Iowa, and compare that to other sites in their network on the Iowa Water Quality Information System.
7/18/2020 update: The sensor is currently off line for maintenance. Based on monthly sampling, nitrate-N concentrations in Squaw Creek dropped back below 10 mg/L in July after rising to 15 mg/L in June.
5/18/2020 update: After last week’s rains, we saw nitrate concentrations in Squaw Creek jump from 5 mg/L to 15.2 mg/L, well over the drinking water standard (10mg/L). May and June are when we typically when we see the highest nitrate levels in Iowa streams.
Drain tiles (like this one, in Story County) provide an easy path for nitrogen to “leak” from crop fields. Cover crops, bioreactors, saturated buffers, or wetlands are a good way to plug the leak!
Nitrate concentrations in Squaw Creek average around 6 mg/L. Before the widespread use of commercial fertilizer, they would have been closer to 2 mg/L. The drinking water standard is 10 mg/L.
Prairie Rivers of Iowa helped the Squaw Creek Watershed Coalition organize two water quality monitoring “snapshots” in 2019, continuing a long tradition of citizen science. In October 2019, 28 people tested 30 sites on Squaw Creek and tributaries in Ames, Story County, and Boone County for nitrate, orthophosphate, transparency, chloride, and pH. Snapshot results going back to 2006 are available here.
Our “Watershed Matchup” series can help you interpret that data. Looking at two creeks that were tested on the same day, you can begin to see the influence of different land uses and conservation practices.
Biweekly Lab Tests
- Squaw Creek at Lincoln Way in Ames
- East Indian Creek at S27 north of Maxwell
During the growing seasons of 2016, 2017, and 2018, City of Ames and Story County Conservation staff collected biweekly samples for these two sites and used automated sampling equipment to collect samples during storm events. The City of Ames Laboratory Services tested these samples for nitrate, phosphorus, total suspended solids, and E. coli. Our handout explains what those things are!
There’s poop in the water, so use caution and hand sanitizer when fishing or wading in the stream. Squaw Creek has levels of fecal indicator bacteria (E. coli) that regularly exceed the primary contact recreation standard. In a large watershed, it can be difficult to tell where it’s coming from, but testing of multiple sites by volunteers has helped us find and address sewer and septic issues in the past. Some of our partners are exploring some intriguing new techniques for microbial source tracking that may help us distinguish human, livestock, and wildlife influences so we can better direct our efforts.
It turns out to be quite difficult to measure trends in nitrogen, and very difficult to measure trends in phosphorus (which tends to shoot up after a rainstorm). You need a lot of data and a big improvement to pick out a signal from the noise of day-to-day and month-to-month variation. Now that we have a baseline, we may come back and monitor again once we have a few more thousand acres of cover crops in the watershed, but for now we’re working with Story County and other partners to develop a comprehensive, locally-led water quality monitoring strategy.