By Sean Breslin -- Every year at Oregon's Lost Lake, something unusual happens. At the end of a long winter, snow melts into a lake, and the water level rises.
Then, in a matter of days, all that water just disappears.
According the Bend Bulletin, which captured the video above, the water is being drained into two hollow lava tubes underneath the lakebed, sucking all the water down below the surface until Lost Lake is totally dry. The lake is 9 feet deep and drains annually, the report added.
The lava tubes formed naturally underneath Willamette National Forest, and it's believed that the water flows through these tubes to become groundwater once again to supply springs and even drinking water sources, Jude McHugh, a spokesperson for the forest, told the Bulletin.
People have tried to plug the hole with all kinds of foreign objects, such as car parts and other debris, McHugh told KCRA.com. But that's discouraged, she told Live Science, because it not only interferes with the natural processes but could flood areas nearby if the water isn't allowed to drain.
It's unknown whether water levels were lower this year than in past years at Lost Lake, but Willamette National Forest has been bordering on severe drought, according to the U.S. Drought Monitor. At the last survey, 67 percent of Oregon is in severe drought or worse.
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