Construction is expected to start Monday on seawall projects to shore up eroding bluffs in two locations in Shell Beach.

Pismo Beach officials plan to spend about $2.3 million to install seawalls in two locations. One would protect a sewer pumping station at Vista del Mar and Ocean Boulevard, south of Eldwayen Ocean Park. The other would fortify a section of Ocean Boulevard between Wawona and Capistrano avenues.

The projects are expected to be completed in eight to 10 weeks, city Public Works Director Dwayne Chisam said. City officials say the work is necessary to protect the sewage pumping station — failure of which would cause 500 to 600 homes to be without sewage services — and prevent further erosion beneath part of Ocean Boulevard.

Since December, a section of Ocean Boulevard has remained closed between Wawona and Capistrano avenues after an inspection revealed that parts of the coastal bluff had become unstable and were believed to be in danger of collapsing.

City officials issued an emergency permit in December, prompting the California Coastal Commission to question whether there was “a sudden and unexpected occurrence that allows for issuance” of the emergency permit. A Coastal Commission planner could not be reached for additional comment.

Coastal commissioners would have an opportunity to appeal the project after the city’s Planning Commission has approved a coastal development permit for the work. Planning commissioners will consider the project at a future meeting sometime in the next few months, Chisam said.

Issuance of the emergency permit allowed the city to start working on a project immediately, instead of going through a longer process to solicit competitive bids for the work.

On Tuesday, the Pismo Beach City Council approved a final $2.2 million contract for design and construction services with San Diego-based TerraCosta Consulting Group and Carlsbad-based J.C. Baldwin Construction.

The seawalls will be sculpted and stained to fit in with the natural bluffs. They will be anchored into bedrock at the base of the bluff.

The project will be funded through a variety of sources, including $865,000 from the state Department of Boating and Waterways, as well as money from the city’s general fund, water and sewer funds.