The geology around Port Heiden is largely composed of unconsolidated volcanic deposit, much of it pumice. This makes the bluff vulnerable to erosion, especially during significant storm events. In the absence of sea ice that can prevent waves and shore ice that armors and protects the land, erosion can be greatly accelerated. Historically, the coast around Port Heiden was protected by a series of small islands, which washed away in the late 1950's during a storm.
Observers have submitted observations to LEO documenting the rate and impact of the erosion. In an LEO Network post from March 2013, Shannon Matson wrote that the erosion, occurring during a severe storm, was impacting the public roads, electrical transformers, and water wells. She explained that if the erosion continued, it would be expensive to repair the roads. She notes that associated flooding may also ruin the electrical transformers and seep into the water wells. Additionally, an area of coast where a tank farm stood has now eroded, along with a safe boat harbor (documented in an LEO Network post in December of 2016), as well as the land surrounding the fuel header. Documented in an LEO Network Post by Port Heiden resident Linda Anderson, the city decommissioned the fuel header for the bulk fuel farm in January of 2014. In an LEO post from May 23, 2017, Port Heiden residents and scientists with UAF and DGGS comment on the potential breach of Goldfish Lake.
The Alaska Department of Geological and Geophysical Surveys (DGGS), Coastal Hazards Program Stakes for Stakeholders project is working with the Port Heiden environmental program to measure the rate of erosion along the Port Heiden coast. According to their measurements, the bluff between Goldfish Lake and the coast has eroded 30 feet towards the north and 20 feet at the towards the south between 2016-2017. Pictured below are images from Google Earth, sourced by DGGS, and a ShoreZone image, documenting land loss since 2004.