Upside-down logging

One of the most amazing things I saw on a trip to Tasmania to speak at a forest education conference was underwater logging – an idea so foreign to me that when our hosts talked about it, I thought it was another Tasmanian slang term I didn’t understand.

Given my complete cluelessness about what underwater logging was, I had no idea what to expect when we traveled to Lake Pieman on the west coast of Tasmania to visit the Hydrowood logging operation.

We arrived at an area that reminded me of British Columbia. There were large stacks of logs on the ground. The Hydrowood employees told us the history of the area: Plans were made to dam the Pieman River to provide hydroelectricity in 1971, and the area where Lake Pieman would sit was opened up to logging to avoid wasting the timber. The region’s dense forests and inaccessibility made operations slow and difficult, so that by the time the dam was ready to be filled only a small portion of the area had been logged. The Reece Dam’s water filled up Lake Pieman in 1986, and the remaining forest was covered over by water.

Fast-forward to 2012, when a feasibility study was done. A dive team that was sent in found large quantities of rare Tasmanian timber, including Huon pine, sassafras and Tasmanian myrtle. In 2015 Hydrowood began using a custom-built barge fitted with a waterproof harvester designed to go down into the depths instead of up into the canopy, becoming one of the world’s first underwater forestry operations.

We were able to go out on the barge and watch the harvester up close, to get a taste of what it would be like to spend a shift “harvesting” underwater trees. The operator of an underwater harvester must have marine experience as well as machine-operator skills.

Hydrowood is harvesting trees that are more than 88 feet down and have been there for over 30 years. The company says logging is the same underwater as on dry land, except upside-down. They’re salvaging logs that would otherwise be left to decay. The harvested timber surfaces are in pristine condition, and the wood is desired by architects, craftsmen and builders to make boats, furniture and custom home features.

There are many underwater forests in Tasmania, and there are plans to use the technology and experience from Lake Pieman to harvest more. It was fascinating to observe such a unique form of logging and learn about how forestry is practiced in another part of the world. 

Norie Dimeo-Ediger
Director of K-12 Education Programs