Juneau, Alaska — Residents near the Mendenhall Glacier are facing a heightened risk of flooding as water from a large glacial basin begins to surge downstream. Following recent warnings from officials, some areas of Alaska’s capital have been urged to evacuate in anticipation of significant floodwaters.

The National Weather Service has issued a flood alert for regions around the Mendenhall River, specifically near Auke Bay. This release of water, known as a glacial outburst, poses serious threats to homes situated along the river’s edge. As of Tuesday afternoon, local water levels measured 9.85 feet; major flooding is classified at 14 feet, with forecasts predicting a possible crest between 16.3 and 16.8 feet on Wednesday, threatening to set new records.

“This anticipated crest will establish a new record based on our current data,” meteorologist Nicole Ferrin stated at a news briefing, highlighting the urgency of the situation.

Local officials have been proactive in alerting residents about the risk of flooding. This morning, they confirmed the onset of water flow from the ice dam, which had begun to breach, with flooding expected to escalate into Wednesday. Authorities have advised those in flood-prone zones to evacuate at their earliest convenience, emphasizing the importance of safety without inciting panic.

The Mendenhall Glacier, located roughly 12 miles from Juneau, remains a popular destination for tourists, with accessible trails and breathtaking views. Homes in nearby neighborhoods are just miles away from Mendenhall Lake, which sits below the glacier, with many properties directly adjacent to the Mendenhall River.

This phenomenon occurs as the glacier, which has been shrinking over the years, serves as a dam for the Suicide Basin. In spring and summer, rainwater and snowmelt accumulate in the basin. When water pressure builds sufficiently, it flows over or around the glacier, entering Mendenhall Lake and ultimately the Mendenhall River, which traverses several neighborhoods in Juneau.

Officials have noted that the water in the basin had risen rapidly, sometimes by up to 4 feet on especially warm or rainy days, before the outburst began. The threat of flooding linked to glacier dynamics has been a recurring issue for Juneau, with reports of limited flooding affecting local roads and properties since 2011.

In the past, flooding from the basin has caused significant damage, prompting government agencies to implement temporary levees this year to mitigate potential impacts. Destructive outflows have swept away homes and inundated properties, illustrating the recurrent nature of this environmental threat.

Alaska Governor Mike Dunleavy declared a disaster for the state on Sunday due to the “imminent threat of catastrophic flooding” in Juneau, following coordinated efforts from local government agencies and tribal organizations seeking assistance.

As the situation continues to unfold, residents are advised to remain vigilant and heed official guidance as they monitor the changing water levels and possible further developments.