The water levels in the Kuskokwim River at Napaimute dropped 10 feet on Sunday night.
Hydrologist Celine Van Breukelen has been flying the river with the National Weather Service’s annual River Watch program, and she spoke with KYUK on Monday morning about what she saw over the weekend.
“Either the jam significantly weakened, or it may be gone altogether. We won’t know until we fly,” Van Breukelen said. “And talking to folks at Aniak and Kalskag that the water level remained pretty steady or came up a little bit overnight, but it didn’t look like there’s any flooding associated with it so far.”
The NWS was concerned that communities downstream would flood when the ice dam below Napaimute broke, but that does not appear to have happened.
“Because that ice jam remained in place for a couple more days until at least Sunday night [May 3], that gave a chance for that downstream ice to move out with just a little flooding, but really to clear the way,” Van Breukelen explained. “And it also gave the water behind the Napaimute ice jam some time to bleed off into the tundra a little bit. We were noticing as we were flying that water was flowing into the tundra and then back into the Kuskokwim a little bit farther downstream.”
On Sunday, the river flowed ice-free between Napaimute and Kalskag, but downstream of Kalskag, an ice jam was holding at Coffee’s Bend. That section of the Kuskokwim has two quick horseshoe bends, making it tough for large ice sheets to make it through. When Van Breukelen flew over the ice jam on Sunday, she noticed that one of the two large ice sheets stuck in the bend had cleared.
“Talking to folks at Kalskag, their water levels have dropped nine inches overnight. That would make me think that that ice jam moved out, which is not surprising because it didn’t look like it was all that strong last night [May 3] when we flew over,” she said.
Also on Sunday, the ice was moving between Kalskag, Tuluksak, and Akiak, indicating that breakup had made its way farther downstream, away from the high mountains to more flat and open ground where the river has more side channels and sloughs.
“Which allows the water to spread out. And even if you have a larger wave, it disperses out that flood wave,” Van Breukelen explained.
Van Breukelen said that between Kalskag and Bethel, there were some smaller ice jams and minor flooding. Below Bethel, she reported that the ice is patchy, and that there is not a whole lot of ice left.
Van Breukelen said that when she flies the river on May 4, the National Weather Service may revise the flood watch for communities along the Kuskokwim.