Juneau Braces for Glacial Outburst Flooding: A Growing Threat to Alaskan Communities
Juneau, Alaska is facing a recurring adn escalating threat: glacial outburst flooding from teh Mendenhall Glacier. Residents are preparing for potentially record-breaking water levels as an ice dam continues to build, raising concerns about property damage and community safety. This article provides a complete overview of the situation, the risks involved, and the ongoing efforts to mitigate the impact.
Understanding the Phenomenon
The Mendenhall Glacier acts as a natural dam, containing a growing basin of meltwater. as water accumulates, pressure increases. Eventually, this pressure forces the water to flow under or around the ice dam, surging into Mendenhall Lake and then the Mendenhall River.
This isn’t a new concern. The threat of these outburst floods has been present as 2011, with varying degrees of impact each year. However, recent years have seen a dramatic escalation.
recent History of Flooding
Recent years have brought unprecedented levels of flooding to the Mendenhall Valley.
2023 saw record flooding,with the river cresting at 4.9 meters (over 16 feet).
2024 is predicted to exceed even those levels, potentially reaching between 4.96 and 5.12 meters.
Last year’s flood damaged nearly 300 residences.
The water level has been rising rapidly, sometimes as much as 1.22 meters (4 feet) per day during periods of sunshine or rain. This rapid increase underscores the urgency of the situation.
The Scale of the Potential Outburst
The potential volume of water released during a major outburst is staggering.Researchers from the University of Alaska Southeast and the Alaska climate Adaptation science Center estimate a single event could release approximately 15 billion gallons of water.
To put that into viewpoint:
That’s equivalent to nearly 23,000 Olympic-size swimming pools.
During last year’s flood, the Mendenhall River‘s flow rate was roughly half that of Niagara Falls.
Protective Measures in Place
City officials have responded to resident concerns by implementing temporary flood defenses. They’ve collaborated with state, federal, and tribal entities to install a temporary levee along 2.5 miles of riverbank.
This levee consists of approximately 10,000 barriers, each 1.2 meters high, designed to protect over 460 properties from flood levels similar to those experienced last year. You can rest assured that these measures are a proactive step to safeguard your community.
Long-Term Solutions and Ongoing Studies
Recognizing the need for a more permanent solution, the U.S. Army Corps of Engineers has initiated a multi-year study. This study will assess the conditions in the region and explore options for long-term flood mitigation.
However, the timeline for this study has drawn criticism from residents eager for a faster resolution. They feel the years-long process is unreasonable given the immediate and recurring threat.
The Future Outlook
Unfortunately,these outburst floods are expected to continue for decades. Researchers predict the Mendenhall Glacier will continue to act as an ice dam for another 25 to 60 years.Therefore, ongoing monitoring, preparedness, and adaptation strategies are crucial for protecting Juneau and its residents. You should stay informed about the latest updates and heed any warnings issued by local authorities.
Staying Informed and prepared
It’s vital to stay informed about the evolving situation. Here are some resources:
National Weather Service: For real-time water level updates and forecasts.
City of Juneau: For details on emergency preparedness and flood mitigation efforts.
Local news Outlets: For the latest news and updates on the situation.
This is a challenging situation, but through proactive measures, community collaboration, and continued research, Juneau can work towards mitigating the risks associated with glacial outburst flooding and protecting its future.
