Water Quality Monitoring in Story County

Understanding water quality in Story County lakes and rivers is a big job with many components and involving many partners:

Lab Testing

Staff from Prairie Rivers, the City of Ames, and volunteers collect monthly water samples from 15 sites around the county which the City of Ames Water and Pollution Control Laboratory tests for nutrients, sediment, and bacteria.  Results are posted here and updated within two weeks of sampling.

Archived results from 2020, 2021 and 2022.  Almost every stream we tested exceeded the primary contact recreation standard for E. coli!


How’s the water quality now?  This widget is updated hourly with data from a nitrate sensor in Ioway Creek installed by the IIHR Hydroscience and Engineering and a stream gage maintained by the USGS.  If a number for nitrate isn’t shown, it’s probably because water levels are too low or the sensor has been removed for the winter Walnut Creek near Kelly also has a pair of nitrate sensors.

Volunteer Programs

Story County Conservation has assembled water testing kits that it is making available for volunteers to do regular monitoring of streams around the county.  The program has grown!

The volunteers use training materials and a portal for data entry that were developed by the Izaak Walton League for it’s Save Our Streams program. Nitrate Watch and Salt Watch are easy ways to get started.

Since 2020, Prairie Rivers of Iowa has organized supplies and volunteers in order to continue the Ioway Creek Watershed Coalition’s tradition of twice-a-year volunteer “snapshot” events, testing many creeks on the same day.  Recently, we have been coordinating our events with Polk County Conservation and chapters of the Izaak Walton League, in order get a snapshot of water quality across more of the state.

Making Sense of the Data

Is water quality improving?  If it’s improving, is it because of conservation efforts or just the weather?  Those are a harder question to answer than you might expect!

We presented a conference poster illustrating some of the issues involved, and it’s a common topic on our blog.

But we’re developing some tools and tricks to make sense of our findings!

nitrate trend in south skunk river above Ames


Each year, we put out a report summarizing data from both volunteer testing and lab testing.  Long periods of drought have made comparisons between years and across sites less reliable, so the reports also break out the findings based on weather conditions and water levels.

The 2022 annual report is available here.

The 2021 annual report is available here.

Nitrate levels during conditions suitable for paddling.

Coordination and Planning

Prairie Rivers partnered with Story County and 8 other organizations to develop a ten-year Water Quality Monitoring & Interpretation Plan for Story County.  Regular communication between the various groups testing water helps avoid duplication and leads to new opportunities to improve water quality.  Planning for how data can be used over the long-term ensures that we get the most value from our time and effort.   Read the plan here

Story County Water Monitoring & Interpretation Plan 2021-2030

Questions about the plan, the data or how you can get involved?

Contact Dan Haug at Prairie Rivers of Iowa