{"id":35060,"date":"2026-09-05T07:55:46","date_gmt":"2026-09-05T11:55:46","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=35060"},"modified":"2026-09-05T07:55:46","modified_gmt":"2026-09-05T11:55:46","slug":"juneau-flood-suicide-basin-glacial","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/juneau-flood-suicide-basin-glacial\/35060\/","title":{"rendered":"An Alaska glacial lake burst free on August 13, sending Juneau\u2019s river to 14.7 feet almost exactly a year after the city\u2019s previous record flood"},"content":{"rendered":"

Water started flowing out of Alaska’s wilderness on August 12, creating yet another major flood in Juneau<\/strong> and pushing the Mendenhall River toward a crest of 14.71 feet on August 13.<\/p>\n

The resulting flood peaked almost exactly a year after Juneau saw its highest recorded flood ever.<\/p>\n

According to the National Weather Service, Suicide Basin has produced annual glacial lake outburst floods since 2011<\/strong>.<\/p>\n

Residents living near the river have now experienced another year in which rising water levels created renewed concerns about flooding. Forecasters and emergency officials closely monitored conditions as the river once again began rising toward major flood stage.<\/p>\n

What continues to cause these floods to return year after year<\/strong>?<\/p>\n

Yet another year of flooding for Juneau<\/h2>\n

As water fills Suicide Basin, it will eventually either drain beneath or through the glacial ice. This causes significant amounts of water to flow downstream into Mendenhall Lake and ultimately into the Mendenhall River.<\/p>\n

These events have become a recurring worry for neighborhoods and communities<\/strong> along the river corridor due to rapid increases in river water levels.<\/p>\n

As conditions were unfolding during early August, forecasters were tracking the basin and associated rivers very closely.<\/p>\n

The National Weather Service noted that the river’s water levels increased<\/strong> as the outburst flood traveled downstream. This prompted continued monitoring by all involved federal, state, and local agencies.<\/p>\n

On Aug. 13, the NWS stated that the Mendenhall River had crested at approximately 14.71 feet at about 2:15 p.m.<\/p>\n

The elevation placed the event in the major flood category<\/h3>\n

Forecasters estimated the river could potentially reach elevations of anywhere between<\/strong> 15.8 and 16.3 feet before cresting.<\/p>\n

However, the final peak was slightly lower than these predictions.<\/p>\n

Following the point when the river had started to fall back down, officials declared that the initial flood threat had passed<\/strong>.<\/p>\n

As waters continued to decrease, officials allowed evacuated areas to open again once the river had dropped below flood stage.<\/p>\n

Why Suicide Basin is different from many mountain lakes<\/h2>\n

It is formed adjacent to the Mendenhall Glacier, creating an environment where the water<\/strong> becomes trapped behind glacial ice.<\/p>\n

Eventually, this trapped water can accumulate to massive volumes prior to being released.<\/p>\n

When a release does occur, it is called a glacial lake outburst flood (GLOF). Large volumes of water are dumped into the river system<\/a> quickly upon release from Suicide Basin.<\/p>\n

They produce quick increases in river stages downstream.<\/p>\n

Due to Suicide Basin’s past experience with these types of releases, it receives continuous monitoring annually<\/strong>.<\/p>\n

Monitoring devices including cameras, river gauges, and basin observations allow forecasters to evaluate conditions and determine whether there are indicators of a release occurring.<\/p>\n

Monitoring also occurs long after a flood event has ceased. After the August 13 release, National Weather Service<\/a> officials stated that Suicide Basin had already commenced refilling with water.<\/p>\n

Less severe than last year’s flood<\/h2>\n

While the 2026 event was categorized as a “major” flood and exceeded flood stage, it did not exceed the previously established record high-water mark<\/a> from last year.<\/p>\n

The National Weather Service explained that the August 13, 2025, flood was a record flood event<\/strong>, whereas the 2026 release was the fourth-highest crest on record, reaching 14.71 feet.<\/p>\n

Within several days of the event, water levels on Mendenhall Lake and the Mendenhall River had both dropped below flood stage.<\/p>\n

According to the National Weather Service, river levels had returned to near normal<\/strong>, and additional analysis of the 2026 flood would continue in the coming weeks. Additional information from the 2026 flood event is expected to be reviewed in the weeks ahead.<\/p>\n

The findings may provide further insight into how future releases from Suicide Basin develop.<\/p>\n

Annual glacial lake outburst floods have occurred<\/a> at Suicide Basin every year since 2011.<\/p>\n","protected":false},"excerpt":{"rendered":"

Water started flowing out of Alaska’s wilderness on August 12, creating yet another major flood in Juneau and pushing the Mendenhall River toward a crest of 14.71 feet on August 13. The resulting flood peaked almost exactly a year after Juneau saw its highest recorded flood ever. According to the National Weather Service, Suicide Basin … Read more<\/a><\/p>\n","protected":false},"author":27,"featured_media":35163,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"Juneau,flood","rank_math_title":"","rank_math_description":"A glacial lake release from Alaska's Suicide Basin pushed the Mendenhall River to 14.7 feet on Aug. 13, one year after Juneau experienced its record flood.","footnotes":""},"categories":[24],"tags":[],"class_list":["post-35060","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-climate"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35060","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/27"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=35060"}],"version-history":[{"count":1,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35060\/revisions"}],"predecessor-version":[{"id":36420,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35060\/revisions\/36420"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/35163"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=35060"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=35060"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=35060"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}