The native village of Shishmaref, Alaska, is located on tiny Sarichef Island about 100 miles south of the Arctic Circle. The Inupiaq Inuit—about 600 of whom currently live in Shismaref—have been here for more than 4,000 years but lately have seen the ground literally wash away from under their feet.

The village was built on permafrost tundra, a ground surface that is composed of peat moss, silt, and other soil held together by ice. The ice on the top few feet of permafrost typically thaws out during the arctic summer, but over the past 10 to 20 years the vulnerable thaw-out period has grown longer and longer. The sea that surrounds the community freezes over during the winter, but it doesn’t stay frozen as long as it used to. Storms batter the quarter-mile wide island, causing significant seaward erosion. Hunting and fishing, primary ways of life in Shishmaref, are now dangerous tasks. The village continues to seek a long-term safe haven on the mainland, and funding to continue the relocation planning, design, and engineering.

In 2005, under contract to the U.S. Army Corps of Engineers (USACE), Tetra Tech started looking at how Shishmaref might relocate to more stable ground. Under a separate task order, Tetra Tech also considered the possibility of relocating another native Alaskan community called Newtok.

Since then, USACE and Congress have taken on a statewide assessment to look at erosion, including the impacts of melting permafrost, late forming coastal ice. Tetra Tech, under contract to USACE, completed an "Alaska Baseline Erosion Assessment" of 162 communities and assisted with developing a prioritization methodology. Because of the expenses involved in relocation, Congress is asking USACE to look at alternatives, including measures to slow down the impact of erosion. These solutions include revetment walls, short-distance relocation of structures to get them out of harm’s way, or restricting development in certain areas.

Tetra Tech is participating on a multi-dimensional front, by helping with short-term solutions and relocation planning. Along with USACE and the Alaska Department of Transportation, Tetra Tech has conducted feasibility studies on the potential relocation sites.

Tetra Tech's Anchorage program manager made a presentation on Alaska Erosion: Assessing Vulnerability of Alaska's Coastal and Riverine Communities at the American Water Resources Association (AWRA) Conference "Managing Water Resources and Development in a Changing Climate" in Anchorage in May 2009.