Abercrombie Creek receives upgrades to stream embankments

As part of Alyeska’s River and Flood Plains project, Abercrombie Creek stands to receive flood-mitigation repair work this year.

In 2006, massive flooding occurred in Valdez and all along the southern portion of the TAPS corridor. Consequently, Abercrombie Creek — typically a small stream that weaves a gentle path through the Chugach Mountains to the Port of Valdez — overran its banks, breached a containment bank, and threatened Alyeska’s metering facility that supplies North Slope crude oil to the Petro Star refinery.

The flooding on Abercrombie Creek also overflowed onto Dayville Road, briefly closing the only road that connects the Valdez Marine Terminal to the City of Valdez. In the interim, Alyeska’s Ship Escort/Response Vessel System ferried essential personnel across the port to the VMT during the closure.

The 2009 work at Abercrombie Creek will strengthen and extend the current guide bank that was breached in 2006. The new guide bank will be approximately 730 feet long with class three and class four riprap used as foundation to strengthen the containment structure.

Riprap is typically large chunks of rock or other material such as blocks of concrete that is used to armor shorelines, streambeds, and other shoreline structures against scour or water erosion. The size and mass of the riprap at Abercrombie Creek will absorb the impact of future floods, with the gaps between the riprap trapping and slowing the flow of water, thus lessening its ability to erode or breach the new guide bank.

In addition to riprap, Alyeska crews are also installing logs at regular intervals along the guide bank. These logs will further interrupt water flow and create shaded areas, providing ideal fish sanctuaries and habitat.

Wildlife and environmental concerns were primary drivers for the design of the project. However, safety was also at the forefront of the 2009 planning.

“Every morning we have a safety briefing and discuss all of the potential hazards associated with that day’s work and how to mitigate those hazards,” said Mark Lafon, general foreman with Ahtna Construction. “No one’s allowed on the site without reviewing the Site Specific Safety Plan, and we all look out for each other. Safety’s our first priority.”

Click here to watch a short video of Mark Lafon, pictured at right along the new river guide bank, giving a tour of the Abercrombie Creek worksite.