Beaver Lake Water Quality Progress Uncertain in Secchi Day Results

Recent tests were inconclusive on whether the quality of the water in Beaver Lake is improving or degrading, said the manager of environmental quality for Beaver Water District.

Beaver Lake is cloudier than average this year, but results varied depending on the specific location, and making an accurate determination of the quality trend will require more data, Bob Morgan said in a press release from the water district.

The data was gathered during the district’s ninth-annual Secchi Day, which took place Aug. 16.

Twenty-seven teams gathered samples at 35 sites on the lake and took Secchi disk readings to determine water clarity. High Secchi depths indicate clear water, whereas low depths indicate cloudy water.

Overall, Secchi readings across the entire lake were less than average, 2.44 meters versus the long-term average of 2.68 meters, according to the press release.

However, in the upstream reaches of the lake, farthest from the dam, the water is slightly clearer than average, with a Secchi depth of 1.36 meters compared to 1.29 meters as the long-term average.

The mid-reaches of the lake, in an approximate area between Hickory Creek and Highway 12, were also better than average, according to the press release. However, north of Highway 12, practically all of the readings were lower than average.

Morgan said the results were “unexpected for a low-rainfall year.”

He also added that “Secchi results may have been skewed by the choppy conditions on the lake and the broken sunshine, making readings hard to obtain.”

The lack of chlorophyll in the water, however, reflected what would be expected for a dry year, Morgan said.

The samples were analyzed in the water district’s lab to determine levels of chlorophyll, phosphorous and nitrate.

The full Secchi Day report is available on the district’s website, bwdh20.org.

Beaver Water District supplies drinking water from Beaver Lake to 300,000 Arkansas residents.