Payette Lake Study Yields Disturbing Signs

Scientists say recent studies showing declining water quality in one of Idaho’s most popular recreation waterways, Payette Lake, should serve as a “wake-up call” to looming problems.

Summer studies showed higher levels of nitrogen, phosphates and chlorophyll, and less dissolved oxygen, than were present before a closed sewer system was installed around the lake in the early 1980s. The Big Payette Lake Water Quality Council presented the findings.

Scientists believe runoff from widespread forest fires in the area last year is a major contributor to the pollution. Council members say a number of corrective projects already are under way.

Summer sampling turned up high levels of nitrogen and record levels of chlorophyll. That can lead to choking algae blooms, further deteriorating water quality.

In the deepest parts of the lake, samples indicate oxygen is gone. That condition never has been seen in the lake before and can contribute to an internal fertilization process. The same thing is happening in the downstream Cascade Reservoir.