The St. Charles Avenue streetcar line is expected to resume full service Sunday following a three-month interruption caused by drainage work on three major Uptown thoroughfares.

Since May, the Regional Transit Authority has been offering only bus service along much of St. Charles, from just above Lee Circle to Webster Street near Audubon Park.

For most of the time since then, passengers would have to switch from a streetcar to a bus and then to another streetcar to travel the full 6.6-mile length of the St. Charles line between Canal Street and the line’s upriver end at South Carrollton and South Claiborne avenues. For about a month, the streetcars were removed entirely, and buses ran the full length of the line.

Crews working on the Southeast Louisiana Urban Flood Control Project, known as SELA, had to tear up streetcar tracks at Louisiana, Napoleon and Jefferson avenues to make way for the installation of new, underground box culverts, which form part of the Uptown drainage system.

U.S. Army Corps of Engineers spokesman Ricky Boyett said work still needs to be done on the culverts along some areas of St. Charles. But the construction won’t affect streetcar service or cause additional traffic delays, he said.

Eventually, the giant culverts will run the length of Louisiana, Napoleon and Jefferson avenues from Constance Street to South Claiborne Avenue, tying into the city’s existing drainage lines.

The $2 billion project is supposed to leave the drainage system capable of handling up to a 10-year rainfall event, meaning a rainstorm that has a 10 percent chance of happening in any given year. Right now, 11 of the 20 planned SELA projects are underway in New Orleans, each at various stages of completion.

Limited streetcar service was slowly reintroduced along the St. Charles track starting Thursday, following a test of the track’s safety on Wednesday.