White River Algae Study update

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RBC | The White River Conservation District and Douglas Creek Conservation District (Districts) are pleased to report that the White River Algae Study is on course for completion as anticipated. We expected significant algal growth this summer with warm temperatures and low flows. However, all reports indicate algae levels were much less than expected. United States Geological Survey (USGS) staff found plenty of algae but there is not an overabundance of Cladophora as seen a few years ago. We look forward to seeing if there are any significant differences in nutrient levels relative to past years.

The Districts continued working with volunteers to take pictures of the river at weekly and then daily intervals to determine the peak of algae growth which was predicted to be about the first week of August. Rio Blanco County Planner Leif Joy also captured images along the river with a drone during early August to compare with images from the last two years.

The White River Technical Advisory Group (TAG) added a couple of tasks to the USGS scope of work this year including taxonomic identifications and supplementing stream flow measurements. These additional tasks were covered by a matching grant and allowed USGS to spend a week longer in the basin making observations and taking more notes. While community members reported potentially more algae in the South Fork, USGS staff indicated there didn’t appear to be Cladophora growth during their observations. We will have good data to compare at each site over the past three years for verification

The USGS crew sampled during high flow and in early August. Their final sampling event was in October during low flow, steady state conditions. This effort focused on nutrient levels while stream flows were stable, and algae was primarily dormant. The hope is to clearly identify any areas where nutrient levels are elevated and potentially identify any sources and source areas.

Additionally, the Districts are working with Colorado Parks and Wildlife (CPW) and Trout Unlimited (TU) to conduct an analysis of the White River benthic macroinvertebrate data, which has been collected for several years. To expedite the results of these studies, the Districts contracted with a third party to analyze the data and finalize a report by year-end to ensure the information will be included in the USGS final report.

The Algae Technical Advisory Group (TAG) will be hearing an update from the USGS in early December. The Districts are working with USGS to provide a recording of the status update in January that would be available to the public on the Districts’ website.

The three-year White River Algae Study will wrap up by the end of 2020 and USGS will finalize their analysis and provide a report in 2021. The Districts and the Technical Advisory Group (TAG) appreciate the community’s support in this effort and look forward to providing the final report in late 2021.

Please contact the District office at 970-878-9838 with any questions.

Special to The Herald Times