Lake’S Oxygen Levels Double During Year

Big Payette Lake’s level of dissolved oxygen, a sign of - and necessary for - healthy aquatic life, has doubled during the past year, a U.S. Geological Survey limnologist said.

Paul Woods said the news raises hopes that an earlier trend of declining dissolved oxygen levels has been arrested in the scenic western Idaho lake.

Woods began monitoring the lake’s water quality in 1993 for levels of phosphorous, chlorophyll-A and dissolved oxygen.

A series of five tests conducted this year found phosphorous and chlorophyll-A levels at or below the limits established by the Big Payette Lake Water Quality Council, which was established by the Legislature almost seven years ago.

The level of dissolved oxygen measured near the lake’s bottom rose this year to 6.2 milligrams per liter from a low of 3.1 milligrams per liter measured in 1998. That was barely above the council’s minimum water quality objective of 3 milligrams per liter.

“This improvement is likely the result of the ongoing implementation of the council’s water-quality plan,” council Chairman Peter Johnson said.