Although Seattle‘s Big Bertha—the giant tunnel boring machine powering the Alaskan Way Viaduct replacement tunnel alongside Seattle’s waterfront—will be delayed until next March for repairs, the nearby Seattle Aquarium is moving steadily ahead with its plans for a major expansion.

The institution has just brought in San Francisco–based EHDD principal Marc L’Italien, who will lead concept designs for the project. A veteran of aquarium, museum, and zoo design, his firm helmed the Monterey Bay Aquarium design and renovated a dormant pier along the San Francisco Embarcadero into the new home for the Exploratorium.

The Seattle Aquarium plans to grow by 70percent, to a total of 184,500 square feet. The additional space would provide room for new exhibits and educational facilities, building upon the draft concept program by Seattle firm Mithun.

The aquarium is working with L’Italien to assemble a design and engineering team. In September, the team will present their plans to the Seattle City Council for review. Construction and fundraising for the aquarium expansion will take place over several phases, with anticipated completion by 2020, to coincide with the opening of the new waterfront.