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The December 2020 Landslide Events in Haines, Alaska
Describing the distribution and timing of landslides caused by the historic 2020 weather event
INTRODUCTION
In December 2020, a record-breaking rain-on-snow event caused flooding and dozens of landslides in the Haines, Alaska area. Damage in the community was widespread, including washed-out roads, disrupted utilities, and damage or destruction of property. One of the landslides caused two fatalities.
This story is based on results from an NSF-funded project , on a journal article analyzing the Beach Road landslide , and on the generous contributions of photographs and insights of Haines residents.
2020 STORM EVENT
Southeast Alaska is wet and its residents are used to substantial rainfall, but the December 2020 storm was unprecedented. It was caused by an atmospheric river that affected many communities in Southeast Alaska . Take a short map tour of the Haines area weather station data associated with the December 2020 atmospheric river...
01 / 04
1
Ripinsky Ridge Weather Station (RRWA2)
The weather station at Ripinsky Ridge recorded significant precipitation as increased snow depth. Multiple snowfalls are indicated by the arrows.
2
Flower Mountain Station (SNTL 1285)
The graphs above summarize temperature, snow depth, and snow-water equivalent (SWE) for early December 2020. Temperatures were well above freezing during the event. Although not all of the snow melted at this site, the SWE increased considerably between December 1 st and 3 rd .
3
Haines Downtown COOP Station (ANHA2)
The precipitation recorded in downtown Haines (16.8 cm on December 2) broke the station's all-time daily record.
4
Haines Airport Station (PAHN)
The same trend was recorded at the Haines airport, with 26.1 cm of precipitation in two days. These data represent a one-in-500 year weather event.
TIMELINE OF IMPACTS
The storm broadly impacted the Haines area. This map tour illustrates how varied and widespread the impacts were, and provides a timeline of how the events unfolded and residents responded to them during the course of a few days.
01 / 19
1
Rain all through the night (December 1-2)
The 2020 atmospheric river hit the Haines area hard. This short video captures what the significant rainfall sounded like. Video by W. Slate taken around 2 am on December 2
2
Slopes start to fail (December 2, ~12-1 am)
Along Lutak Spur, residents experienced the first landslide events in the early hours of December 2, as sandy slopes forming the bluff started to fail and impact their homes. Photograph by E. Stevens taken on December 8
3
Debris flows in backyards (December 2, early morning)
Some residents were awoken by debris and water hitting their houses. These pictures compare a backyard before and after multiple pulses of debris covered the property. Photographs by S. Maust
4
Water makes new channels (December 2, early morning)
The tremendous rainfall and snowmelt caused many streams to jump their banks, with runoff occurring in unexpected locations, such as across this field. Photograph taken on December 5 by E. Stevens
5
Landslides break the ice (December 2, early morning)
A landslide came down the steep slopes adjacent to Chilkat Lake, broke through the lake ice, and caused a small wave that prompted the evacuation of residents. The red arrow in this photograph points to where the landslide may have started. Photograph by E. Stevens taken in early 2021
6
Washed out roads throughout the community (December 2, 8:35 am)
After significant rainfall throughout the night and a fitful night’s sleep, residents woke up to find many of their local roads impassable due to extreme erosion. Photograph by E. Stevens
7
Flooding along Lutak Road (December 2, ~9 am)
All the precipitation and snow melt made significant runoff throughout the community, overwhelming some roads. This photograph illustrates water covering Lutak Road, the community's only access to the ferry terminal. Photograph by W. Slate
8
Torrents in Ditches (December 2, 10:28 am)
The runoff caused considerable erosion of ditches, such as this one along Beach Road. The trees in the background behind the brown house with white trim is where the Beach Road Landslide occurred hours later. Photograph by M. Balise
9
Lutak Spur (December 2, morning)
This video captures some of the tremendous volume of runoff that changed typically small stream channels into raging torrents. Video by A. Myren
10
Debris-clogged bridge (December 2, morning)
Water, sand, and gravel unexpectedly flowed out and onto the bridge over the Chilkat River, making travel difficult. Photography by L. Campbell
11
Debris on the Haines Highway (December 2, morning)
Debris was deposited across many roads in the community, including the Haines Highway, the only land access in and out of the community. These images illustrate some of the damage along the road. Photographs by L. Campbell
12
Landslide along Mosquito Lake Road (December 2, mid-day)
One of the trees knocked down by the storm helped to plug a culvert, which caused water to overtop Mosquito Lake Road, resulting in a landslide downslope. Looking down the slope from the edge of the roadway. Photography by J. Korsmeyer
13
Beach Road Landslide (December 2, 1:17 pm)
By midday on December 2, the rain started to slow. Just when people were catching their breath during the storm, a devastating landslide occurred along Beach Road. Some residents heard a heavy explosion, followed by a rumbling or scraping sound. Tragically, the landslide took the lives of two people, and damaged or destroyed four residences. Photograph by E. Stevens taken on December 6, once the weather cleared enough to see its full extent
14
Beach Road Evacuation (December 2, 1:25 pm)
The residents to the south of the landslide were immediately evacuated. This evacuation remained in place for multiple weeks. Image taken from the Haines Borough website
15
Evacuation advisory (December 3, 8:11 pm)
Following reports of falling trees, an evacuation advisory was issued for the area around Cunningham Creek. Base map imagery from State of Alaska Open Data Geoportal
16
Continued movement on Lutak Spur sand flows (December 2 morning to December 3, 10 am)
While some landslides happened quickly, some took their time to finish. For example, the sand that started to flow from the bluff along Lutak Spur in the early morning of December 2, continued to build up all throughout the next day. Photographs by A. Myren
17
Debris piled up along Lutak Road (December 4)
Lutak Road was impacted by dozens of debris flows and landslides. This video illustrates some of the debris that subsequently had to be removed to restore safe travel. Video by T. Ganner
18
Considerable clean-up (December 5)
Road crews immediately started to restore access along state roads; this photograph taken on December 5 captures some of that effort. Photograph by E. Stevens
19
Lots of landslides on Lutak (December 5-9)
Lutak Road was probably impacted by the greatest number of landslides. These photographs from December 5-9 illustrate just a few of the landslides that needed to be removed to restore access. Photographs by E. Stevens
BEACH ROAD LANDSLIDE
The Beach Road Landslide was the biggest landslide event during the December 2020 storm. An estimated 187,000 cubic meters of rock and soil rapidly tumbled down the slope. For comparison, imagine one dump truck carrying 14 tons of debris. Now imagine 48 of those dump trucks hauling away that debris every day...for an entire year.
- A view up towards the head scarp of the Beach Road landslide
1 Looking up towards the top of the Beach Road Landslide (photograph by E. Stevens). 2 The landslide took everything with it, including the forest. Here, trees float on the inlet (photograph by W. Slate). 3 Reconnaissance of the head scarp area revealed a large crack in the bedrock (photograph by E. Stevens). 4 The landslide demolished Beach Road and disrupted utilities to residents for months (photograph by M. Balise).
The video below provides an overview of where Haines is located within Alaska and where the Beach Road Landslide is located related to Haines. It also provides an overview of related data sets and some different ways of looking at map data. For more information on the lidar differencing shown in the video, refer to this paper .
Beach Road Landslide overview video; produced using Google Earth, ArcGIS Pro, and Adobe Premier Pro.
TOTAL IMPACT
The impact from the December 2020 weather event was widespread. This map illustrates all of the landslide and flooding damage reported by the Alaska Department of Transportation and Public Facilities (ADOT&PF) as yellow dots, and all the damage reported by private individuals as red dots. Approximately 1/3 of all Haines residents were impacted by this storm.
This heat map illustrates the spatial density of reported damage in the immediate area around Haines. Maps like these can help in planning for future extreme weather events.
Thanks to all of the Haines residents who shared their experiences and photographs. Please do not use any of the photographs or videos without the express permission of the photographer.
This material is based upon work supported by the National Science Foundation (NSF) under Grant No. 2114015. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF.
To view and download existing lidar data of the Haines area, visit the Alaska Division of Geological & Geophysical Surveys Elevation Portal.
Contact for this Story Map content: Dr. Margaret M. Darrow at mmdarrow@alaska.edu