Why do ice jams keep water levels high on the Yenisey River in winter?

On the Yenisey River, winter water levels remain high primarily due to the formation of ice jams.12

While the river's overall runoff is reduced sharply during the winter months, these ice jams act as physical blockages within the river channel. When ice accumulates—often where the river's slope changes from steeper to milder or where moving ice encounters an intact ice cover—it restricts the flow of water. This obstruction causes water to build up behind the jam, maintaining higher levels than would otherwise occur during the low-runoff winter season.1234