WATERBURY (AP) - Three years after flooding from Tropical Storm Irene made most of the Vermont state office complex in Waterbury unusable, construction is underway on a replacement complex.

The $125 million office complex is the largest state building project in Vermont history.

The project includes a new 86,000-square-foot office building, a 20,000-square-foot central plant and the renovation of 13 buildings that were on the site before the flood.

Irene made most of the buildings on the site unusable.

The new buildings are being constructed above the flood zone and the basements of the old buildings that are being renovated are being filled in so they won't flood in the future.

Project Manager Mike Stevens says the project is on time and on budget. It's due to be finished by late 2015.