What "Lake No Lake" is, and why the Taku is running cold and full of debris

The name is the first clue. Up the Taku River, behind the Tulsequah Glacier just across the Canadian border, sits a basin that's a lake only part of the time. Meltwater pools against the ice until the pressure forces a path underneath, and then the whole thing drains at once — a glacial outburst flood. When it empties, there's no lake. Hence Lake No Lake.

One of those releases began overnight June 30, and it's what the National Weather Service is now warning boaters about. The Taku is running toward bankfull, forecast to crest near 42 feet — just under its 43-foot flood stage, so no flooding is expected. But the water carries the signature of these events: a surge more than 10 degrees colder than normal, and debris — ice, wood, sediment — washing down the river and out into Taku Inlet and Stephens Passage, at least through Wednesday.

It's the same phenomenon behind the glacial floods that have battered Juneau from Suicide Basin — just on the wilder Taku south of town, where it threatens boats, not homes. These releases come every year or so and run their course in one to three days.