Long-term trends revealed in new data monitoring reports

by: Angela Danovi, Arkansas Projects Manager

The 2020 StreamSmart and Beaver Lake Watershed citizen science monitoring reports have been released.  The reports include all monitoring data through the 2019 monitoring year.

StreamSmart Citizen Science Report

This year’s StreamSmart report has been revised to concisely present data for each site. Graphical representations of data for each parameter across all sites allow readers to make comparisons between sites. The data has also been grouped by sub-watershed to easily make comparisons of sites within and between subwatersheds of the Beaver Lake watershed.

Total Phosphorus in Streams

Total Phosphorus Data for StreamSmart sites 2012-2019

Phosphorus is a nutrient we test for in StreamSmart because it is a contributor to algal growth and has the potential to cause harmful water quality conditions. Our 2020 data report reveals Holman Creek downstream of Huntsville to be the only site in the StreamSmart data to have an average total phosphorus above .10mg/L. The remaining 19 sites were below .05 mg/L and indicate they are less likely to have phosphorus concentrations which could cause harmful water quality conditions.

Macroinvertebrates and Stream Health

Data for one parameter do not serve as an exclusive indicator for stream health. Our volunteers have been conducting macroinvertebrate surveys during the spring and summer months as part of the monitoring protocol. One benefit of conducting a macroinvertebrate survey is the organisms that live in the stream serve as a good indicator of water quality because they must live in the environmental conditions where they are. Some macroinvertebrates are more tolerant of poor water quality than others. By conducting macroinvertebrate surveys, stream health is indicated by the presence and composition of the macroinvertebrate population.

To conduct macroinvertebrate surveys, citizen scientists kicked three times across a riffle at their stream. Then they sorted and identified all of the macroinvertebrates (insects, bugs, and crustaceans visible to the naked eye) they collected from the kicks. Macroinvertebrates are scored based on their sensitivity to pollution. Sensitive species are scored 3 points, somewhat sensitive are scored 2 points, and species tolerant of pollution receive 1 point.

Macroinvertebrate composite scores indicate water quality:

  • Excellent > 22
  • Good 17-22
  • Fair 11-16
  • Poor <11

StreamSmart macroinvertebrate survey results show site 306, Prairie Creek below Lake Atalanta Dam, had excellent water quality during the 2019 monitoring season. It was also the only site to exceed an average composite score of 20.

Five sites were found on average to have good water quality based on their macroinvertebrate composite scores:

  • Site 102 – West Fork at Brentwood Park (Upstream of the city of West Fork)
  • Site 303 – Clear Creek in War Eagle Watershed
  • Site 305 – War Eagle at the Mill
  • Site 103 – Baldwin Creek in the headwaters of the watershed
  • Site 300 – Brush Creek, which flows directly to Beaver Lake

The information we learn from the macroinvertebrate survey indicates sites where water quality is good and supports a diverse macroinvertebrate population. Sites with lower composite scores, especially 10 or below, indicate that aquatic environmental conditions are not supporting a diverse macroinvertebrate population. There are many factors that can contribute to low scores, including poor local site conditions which limit macroinvertebrates from populating the specific location. Sites with low scores should be further examined to gain a better understanding of the environmental conditions which could be adversely affecting macroinvertebrate populations and water quality.

Individual Site Trends

Beyond the first few pages of the StreamSmart report, which give us an opportunity to view the data as a whole and compare sites and subwatersheds, each site is given a page where it’s most recent data is made available along with the longer term trends at the site.

Conclusions from Stream Monitoring Report

Overall, we have good water quality in the Beaver Lake Watershed. Sites which show areas of concern are associated with more urbanized areas. Generally riparian zones at those sites are limited and less able to protect the waterway from urban runoff. Urban sites also tend to be more affected by high flows, higher nutrients, and more pollutants. Urban sites also tend to have less macroinvertebrate diversity. Some urban sites, such as prairie creek below Lake Atalanta can be celebrated for supporting diverse macroinvertebrate populations. That site should have increased focus on protecting the riparian zone by promoting native plants, which can protect streambanks, promote habitat and ensure the water quality remains good.

Sites that indicate overall better water quality are in our headwaters, such as the White River near St. Paul (Site 104) and Baldwin Creek (Site 103). These sites illustrate the good water quality we have when impacts to the stream are limited.

Citizen Science Lake Monitoring

The lake monitoring report continues in the same format as previous reports.