Monthly Archives: April 2020

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.

Upper White River Basin Featured at Crystal Bridges

by: Angela Danovi, Arkansas Projects Manager

A few years ago while I visiting Crystal Bridges, I came across a beautiful piece of art which depicted our basin, the Upper White River Basin. In a single sculpture, the artist depicted one main idea I have spent the last several years working to share with everyone living in or associated with our watershed: that we are all connected together through water and we all live downstream.

The beauty of this sculpture at Crystal Bridges is that we see the water which connects us and flows through our land. But, we don’t see state lines, county boundaries, cities, or other artificial barriers that we perceive and live with every day, but which are invisible and meaningless to the water.

The sculpture, “Silver Upper White River” by Maya Lin is made from recycled silver and represents the 722 miles of the Upper White River running through Arkansas and Missouri. Beaver Lake is depicted on the far left-hand side of the sculpture with the White River flowing into and forming Table Rock Lake, Lake Taneycomo, and Bull Shoals.

Beaver Lake portion of the sculpture

The descriptive panel with the piece explains that the artist chose the medium of silver because “when Europeans arrived in the Americas, there were so many fish in the streams that the reflections off of their backs gave rise to the term, ‘running silver.'”

In a public conversation held earlier this year with James Steward, Director of the Princeton University Art Museum, Lin was asked to explain why water has been an enduring feature in her artwork. “I’ve always been drawn to a very still use of water,” Lin said. “I’m in love with things that aren’t what you think they’re going to be. I want to ‘still’ the water down until it’s barely moving, and then you engage with the piece. Water has a propensity to be both very powerful and extremely calm. I love the fact that you have a language and materiality that can transform itself completely.”

Photo from Crystal Bridges Blog

It’s hard to capture the size and scale of Lin’s “Silver Upper White River” in a single photograph. The sculpture sits over the museum’s lower pond and can be seen from across the museum through the windows inside Eleven. The next time you are at Crystal Bridges, you can sit at a table in the restaurant and look across the water towards the museum’s lower galleries where you will see this sculpture or you can spend some time walking over to get an artistic birds eye view of our connected water.

Lake Atalanta and Prairie Creek see Phosphorus Reductions

by: Angela Danovi, Arkansas Projects Manager

Since 2012, volunteer citizen scientists have been conducting stream monitoring on Prairie Creek below Lake Atalanta Dam in Rogers with the StreamSmart Program.

Last year when I prepared our annual StreamSmart data report, I was surprised to see that the 2018 total phosphorus concentrations in Prairie Creek had decreased by half compared to 2016 and earlier. But, with only one year of data showing these reductions, I was reluctant to say it was a trend or even notable because with only four samples collected after the park re-opening, the lower total P values in 2018 could have been a coincidence rather than a trend.

Throughout 2019, our volunteer citizen science team continued to monitor Prairie Creek. This year, when I added the 2019 data to the existing dataset, I was excited to find that the lower phosphorus concentrations we had identified in 2018 had sustained throughout 2019 and even into our first monitoring of 2020.

Looking at the graph (above) and then plotting the data into two box plots, I realized there was in fact a noticeable difference in total P concentrations at Prairie Creek below Lake Atalanta Dam since 2018, which aligned with the timeline of the park undergoing the renovation and an extended closure due to the spring 2017 flood.

I wanted to be sure the data from 2012-2017 was actually statistically different from the 2018-2020 data. So, I conducted a statistical test called a t-test and assumed unequal variances between the two datasets. The results showed the means of the two datasets to be statistically significantly different (p-value = 0.0000269). P-values that are less than .05 are generally considered significant.

Looking only at the stream data, I thought one reason Prairie Creek may have decreased total P concentrations since 2018 was because Lake Atalanta had been dredged during the construction and renovations. Therefore, I thought we may find total P concentrations in lake Atalanta to be increasing because of the increased capacity of the lake to capture and retain sediments and particulates. Surprisingly, when I looked at the volunteer lake monitoring data at Lake Atalanta, I found a decreasing total P trend which aligned with the same decreasing total P trend in Prairie Creek below Lake Atalanta Dam, during the same years.

Total Phosphorus Concentrations from volunteer Lake monitoring at Lake Atalanta 2017-2019

Unfortunately, we do not have lake monitoring data prior to the construction and dredging, so we cannot give you the total P concentrations in the lake prior to 2017.

After I identified the two aligned trends, one question arose in my mind: if phosphorus concentrations are decreasing, why does Lake Atalanta seem to have more algae growth during the summer, after the park renovation and lake dredging? I contacted an associate who helped prepare both monitoring reports this year and who is familiar with lake chemistry cycles, Tony Thorpe with the Lakes of Missouri Volunteer Program. One explanation he proposed was that prior to the renovation and dredging, Lake Atalanta may have been more turbid, due to the lower amount of time and capacity for sediment to settle out. This could have prevented light from penetrating the water column and prevented algae from growing. After the park renovations, which include a forebay that can capture tons of sediment and other low impact development features that slow sediment movement during rainfall in addition to the lake dredging, it’s possible that clearer water is allowing light to penetrate deeper into the water column, stimulating algae to grow in the lake during the warm summer months.

This is just one possibility as to why Lake Atalanta may have increased algae growth since the renovation. Although the monitoring data does not provide a definite answer or solution to the algae problem at Lake Atalanta, it does show that phosphorus, a major nutrient that stimulates algae growth, has declined over the last two years both in Lake Atalanta and in Prairie Creek. This is a positive trend for the environment and for water quality in Lake Atalanta and downstream.

In addition to the reduced phosphorus concentrations, Prairie Creek has also had consistently high ratings in StreamSmart macroinvertebrate surveys, achieving good and excellent scores in 2019 and rating as the overall highest site and only site exceeding an average composite score of 20 in 2019.

Looking upstream on Prairie Creek towards Lake Atalanta Dam

The overall story for both Prairie Creek and Lake Atalanta in a positive one, with phosphorus declining in both waterways while each is supporting and enhancing the aquatic environment.