It is 4,139 feet above sea level and has two major tributaries, the Williamson and Wood Rivers, as well as many smaller springs and stream inflows, providing Klamath Lake with waters of exceptional purity.
The most recent work estimates the formation of the Klamath bed sediments at the Pliocene epoch, more than two million years ago.
Many of the lake’s characteristics are responsible for this unusual ecosystem, allowing for such abundant bloom of AFA:
- First, the lake is so old that it contains 30 feet of mineral-rich sediment at its bottom, much of it donated by the explosion of Mount Mazama. In their 1967 study of the lake, Miller and Tash estimated that the top one inch of the lake’s sediment alone contains enough nutrients to sustain a full algal bloom.
- Second, the average depth is less than tenfeet with a median depth of about five feet. In more than 50 percent of the lake, you can stand on the bottom.
- Third, the lake is nearly 25 miles long and five miles wide, providing a longitudinal shape that fosters strong winds and turbulence. When the wind blows, it applies pressure to the shallow lake’s surface, forcing the water to turn over. The turbulence grabs the mineral-rich sediment, bringing up into suspension a wealth of nutrients that further promote algae blooms. This cycle explains the exceptionally abundant growth of AFA in Klamath Lake.
