Update: Suicide Basin release breaks previous record, causes evacuations

Saturday, August 5, 2023 at 11:16 AM

By Jasz Garrett and Jordan Lewis

Juneau, Alaska (KINY) - Water has receded throughout the morning. The flood warning has expired as of 10:00 AM.

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The flood warning expired at 10 AM Sunday according to National Weather Service Juneau (NWSJ).

Update 08/06/2023 1:00 PM

The City and Borough of Juneau have issued a local declaration of emergency following the Aug. 5 Mendenhall River flood event.

Although river levels continue to fall, at least two structures have been lost to the river and others are at risk and/or have been evacuated.

CBJ has stood up an emergency operations center and is coordinating with state and federal officials to respond.

At this time, the Mendenhall River banks remain highly unstable. All members of the public are strongly advised to stay away from the river to ensure safety and avoid obstructing response efforts.

CBJ has communicated with all residents impacted by evacuation orders to confirm they have shelter options available. If someone is in need of shelter due to the flood event, please contact [email protected] to coordinate.

CBJ has begun assessing structures damaged by flooding and bank erosion Sunday, Aug. 6.

CBJ will be in contact with owners and residents of buildings that are determined not safe to occupy as soon as possible.

Impacted residents in need of support should contact (907) 586-0600 if immediate assistance is needed from JPD dispatch or [email protected] for questions about resources and long-term response needs.

Please be aware that neighborhoods adjoining the river may see increased activity from local and state officials while a response is underway.

AEL&P confirmed most power has been restored, except for the section of condos that are in danger of falling into the river.

An Assembly meeting is at 6 pm Monday, Aug. 7 and as usual, the public can attend in Assembly Chambers or over Zoom.

Robert Barr, Deputy City Manager for CBJ, gave more details on the 11:40 a.m. update of a declaration of local emergency. He explained what the declaration means for Juneau.

"A local declaration of emergency really, simply allows us to modify our procurement rules. So, to the extent that we need to publicly purchase services or goods, normally we have a set of rules that govern how we do that to make sure that we're getting the best price, getting the best vendor, that sort of thing," he said. "And the declaration of emergency allows us to purchase things speedily, right? Because there's an emergency."

This is another step the City will take.

"We also intend to have a conversation with our colleagues at the State Emergency Operations Center next week to discuss whether or not it makes sense from their point of view to elevate this to a Statewide Declaration, which may — want to emphasize the word may — be able to enable us to seek state and federal funding to support private and public individuals and entities that were impacted by the disaster," Barr said.

This is what the assessment efforts look like as of Sunday afternoon.

"We continue to have teams out in the field. Right now, one of the things we're doing is visiting residences and making assessments about whether or not they're occupiable or not. So, we've got teams out there doing that. And then our street crews as the waters recede are also out and about cleaning and clearing off our local rights of way," Barr shared. "So, that work is ongoing as well and just sort of general collaboration with other partner agencies that are out there to help people."

He also responded to a question about impacts to utilities.

"We did experience some damage to some of our wastewater infrastructure which we are still assessing. We are not experiencing any performance issues that would impact the public - from the public perspective, there are no water or sewer restrictions," Barr said. "People can use their toilets, drains, etc like normal and drinking water has not been compromised."

A number of fuel tanks and hazardous materials containers have been affected by the floodwaters.

If someone sees a loose fuel tank/hazmat container or needs assistance disposing of one on their property, please contact the Alaska Department of Environmental Conservation Spill Prevention and Response (SPAR) hotline at 1-800-478-9300.

Kathy Shea, Interagency Coordinator in the Spill Prevention and Response Program at the Department of Environmental Conservation, shared what details are most helpful to include while reporting.

"We have received reports of sheen in the area and of paint floating. So, we do have spill responders who are out, and we are coordinating with the U.S. Coast Guard our response activity," she said. "We do have an online reporting tool. And so, that allows people to take photos of what they're seeing and upload those. And it also allows them to do geolocation so we know exactly where they're seeing the spill or the paint. But any information that they can provide about location and what they're seeing at the time is very helpful for us."

She added to only do these reports while in a safe location. Shea said right now they are trying to figure out if it is possible to recover these containers or even feasible to recover them as the situation is evolving.

It's possible that fish and shellfish could be exposed to the sheen. Shea said any gear someone is using like a net or fishing rod could be exposed to sheen on the water.

"We ask people if they see or smell sheen, not to collect any of those resources in that area," Shea said.

Below: CBJ and Alaska Department of Transportation & Public Facilities engineers have determined that the Mendenhall River Bridge on Back Loop Road is safe to reopen to the public. DOT&PF Maintenance removed hazardous trees that were falling on the structure. The pedestrian footbridge at Dimond Park remains closed while it is being evaluated. (Photo provided by DOT&PF)

Below: A photo taken from the bridge after it reopened Sunday. (Photo credit Jasz Garrett/KINY)

Update 08/06/2023 10:00 AM

The flood warning is now expired according to National Weather Service Juneau (NWSJ).

Local historian Jim Geraghty explained why this outburst occurred.

"It hasn't been very long in the past that this Suicide Basin jökulhlaup has been having glacial outburst floods, but we've had ones in previous years. And in the early valley, they were just called unexplained floods because people didn't understand the source of the outburst," Geraghty said. "The glacier is taller in the center of the glacier than it is on the edges. So, you have sort of an arc shape to the flowing river of ice. And off to the side, you can get little alcoves that are now free of ice because of the shrinking of the glacier. And since there's no ice in there, they fill up full of water, and the glacier blocks it from flowing down until it gets to a certain depth. Then you have an outburst event where it breaks through the ice. Once you've started a small stream of water through there, it's just like running hot water onto a block of ice in your sink. It bores a hole right through it. And then all the entire Suicide Basin jökulhlaup empties in a very short time."

Andrew Park, a meteorologist with NWSJ, said while flooding is no longer expected to pose a threat, hazards persist in and near the Mendenhall River.

"The main issue or the main story we want to push is stay out of the river, stay out of the area. Give resources plenty of space to respond. There's already been people river rafting and going down the river and it's a dangerous situation. There are trees, there's hazards, there's homes in the river," Park said. "So, stay out of the river. That's the main story. You know, give the resources plenty of time to work and respond. Don't become part of the problem."

Roald Pope, the main operator for Capital Transit, notified News of the North bus routes are changed for Sunday.

He said service to Mendenhall Back Loop will only include the Dredge Lake bus stop and Mint Way, and then Capital Transit buses will continue left down Mint Way and down Riverside. These route changes are in effect for Sunday while the road bridge is closed on Back Loop.

Below: A photo from NWSJ illustrates what historian Geraghty describes.

Below: Data from NWSJ updated at 9:15 AM. (Courtesy of NWSJ)

Update 08/06/2023 8:45 AM

AEL&P Executive Director Debbie Driscoll gave News of the North an update on affected areas without power.

"There were multiple streets involved. We've been working basically around the clock to assess areas and determine if an area had to be de-energized or not for safety reasons. 19 hours ago, we cut power to Mendenhall Campground. That was the first location that we cut power to. We were keeping a close eye on View Drive because the water levels were rising pretty quickly. At 3:25 pm yesterday afternoon, floodwaters continued to rise, so we had to cut power to View Drive," she summarized. "Then 11 hours ago, we had to cut power to Meander Way and Stream Court. And then seven hours ago, we had to de-energize Long Run Drive, River Court, and Meander Way."

At about 7:00 a.m. Sunday., AEL&P was able to restore power to Meander Way and View Drive.

At approximately 8:00 a.m., they were able to restore Mendenhall Campgrounds and the CBJ lift station. The crew is currently assessing the condominium that is next to the home that was lost to the river. The condos are partially restored.

Below: AEL&P workers restore power to View Drive Sunday morning at about 7:00 AM. (Photo credit Jasz Garrett/KINY)

Below: A before and after of the road near Skater's Cabin. Saturday morning vs Sunday morning. (Photo credit Jasz Garrett/KINY)

Update 08/06/2023 7:16 AM

The Department of Transportation has advised residents to continue avoiding the road bridge, more commonly referred to as the bridge on Mendenhall Loop Road as it has been closed due to safety concerns with trees falling onto the bridge as the bank has eroded due to the flood.

DOT will continue to clear the bridge and assess its safety as the water continues to recede.

Below: The bridge road closed on Mendenhall Back Loop. (Photo credit Jasz Garrett/KINY)

Update 08/06/2023 6:00 AM

Water levels on the Mendenhall are receding rapidly after reaching a record-high crest of 14.97 ft at 11:15 PM on Saturday night. Water is expected to recede throughout the morning at a rate of 0.7 ft per hour.

Update 08/05/2023 9:00 PM

The Mendenhall River continues to flood due to the release of Suicide Basin.

At least one structure has been lost to the river and others are at risk and/or have been evacuated.

The CBJ emergency operations center recommends residents of Marion Drive evacuate overnight due to concerns of potential bank failure that could result in quick overnight land wasting.

The road bridge at Back Loop is closed.

The footbridge at Dimond Park is closed.

For the sake of emergency teams and impacted residents, please stay away from the river throughout the duration of the event.

Members of the public impacted by flooding and in need of guidance should contact (907) 586-0600.

This is an evolving situation and more information will be released as it is available.

Update 08/05/2023 7:00 PM

The Mendenhall River has exceeded historic flood stages.

Mendenhall Lake reached a record level of 12.03 ft at 12:30 pm. The lake continued to rise and was at 12.28 ft at 1:15 pm. As of 7:00 p.m., the Mendenhall Lake gauge is at 13.09 ft. This breaks the previous record of 11.99 ft recorded in 2016.

NWSJ stated that as of 7:00 p.m., the rate of increase is three 10ths of a foot per hour. It is expected to crest sometime Saturday evening, but as for when they aren't sure. They are expecting it to reach 14.05 ft by 8:00 p.m. Saturday.

Capital City Fire Rescue received reports of sections of the riverbank sloughing off into the river and are warning residents to stay away from the river's edge as any river rescue will be "extremely hazardous" at this time.

The City and Borough of Juneau issued evacuation orders for specific structures. As of this update, all individuals impacted by evacuation orders have been contacted. CBJ staff are on-site, monitoring the situation, and standing up emergency operations.

CBJ asks for residents to avoid the area and to limit vehicle activity on the Mendenhall River bridge on Back Loop to essential travel only.

News of the North will provide an update once the flooding has reached its official crest.

Below: Due to the flooding, AEL&P is cutting power to Meander Way and Stream Court. (Photo provided by AEL&P)

Below: Photos of the historic flooding. (Photos provided by CCFR)

Original 08/05/2023 11:16 AM

Andrew Park, a meteorologist with National Weather Service Juneau (NWSJ), detailed the flood warning with News of the North Saturday morning. NWSJ is currently monitoring the situation on Mendenhall Lake due to the glacial release from Suicide Basin. The basin is a side basin of the Mendenhall Glacier above Juneau.

Since 2011, Suicide Basin has released glacier lake outburst floods that cause inundation along Mendenhall Lake and Mendenhall River.

These are the areas the warning currently covers.

"Mendenhall Lake and River. Basically, if you look at inundation maps and historical records, the main areas that could affect it are up by West Glacier, campgrounds, the visitor center...anywhere close to the lake. Historically speaking above 10.09 feet, View Drive is flooded, we were just out there. That's, you know, got about a foot of water on the road," Park said. "And then below the back loop bridge, we're going to see flooding in some yards and significant bank erosion is another problem. So, we will see some hazardous navigation in the river. So, for the communities like Whitewater, over the next couple of days, being really cautious on that river as you see tree debris flowing in."

The flood warning is in effect until 10 am Sunday, Aug. 6. There is a high chance flood levels could break a record this year.

"We're looking at water levels, new data suggesting water levels are going to crest near record levels," Park stated. "I think we're looking at around 12.03 feet and that's going to happen sometime between one or four o'clock. 11.99 feet is the current record."

The current record of 11.99 feet was recorded in 2016.

United States Geological Survey (USGS) is taking live measurements of the Mendenhall River and providing data to NWSJ. The last measurement was 11.03 around 10:30 a.m.

The rate of rise on the Mendenhall Lake gauge is around 0.4 ft-0.5 ft per hour and is in a moderate flood stage.

As soon as it hits the crest of 12.03 Saturday, Park said the water is estimated to decrease at the same rate. But that is subject to change.

It's a developing situation, and the public can continue to monitor it on Facebook, Twitter, or the NWSJ website. News of the North will update this article as the situation evolves.

Updates are also posted on the weather service’s website three times a day.