After four years of work by planners, thousands of public comments, at least three drafts and a final seven-hour discussion, the City Council late Thursday night approved a massive overhaul of the law that has governed zoning in New Orleans for more than 40 years.

The council’s unanimous vote to adopt the new comprehensive zoning ordinance came after a number of residents made final pleas for and against various provisions and reprimanded the council for even considering several proposed last-minute changes.

Neighborhood and preservation leaders lost a number of battles, such as over proposed “height bonuses” for some structures along the riverfront, but they won a few, such as the addition of language on the role of the Vieux Carre Commission in land-use decisions in the French Quarter.

In all, the council considered about 70 amendments, half of which were drafted in the last week and received their first public airing Thursday.

Amendments still were being submitted late into the night Wednesday, and some were even written during Thursday’s meeting.

The new law is likely to continue to be amended over the coming months and years. The city’s last zoning law, passed in the 1970s, has been amended hundreds, perhaps thousands, of times over the decades.

The last-minute changes drew a rebuke from the Bureau of Governmental Research. The nonprofit watchdog agency’s president, Janet Howard, said the public deserved more time to read, digest and comment on the new proposals, particularly given that the ordinance has been years in the making.

“We have gone to meetings at night, on weekends. We have gone to charrettes,” said Meg Lousteau, executive director of Vieux Carre Property Owners, Residents and Associates, summing up the frustration of residents who objected to the large number of new amendments.

“It is insulting to every citizen who has taken part in this process for you to be asked to vote on something that has not had a public vetting,” she said. “This is not a vetting. This is a sneak attack.”

Several City Council members defended the amendments, saying the items introduced Thursday had been discussed at some point over the years even if they had not been written down until this week.

“It’s not something some dictator sent to us at the last moment,” Councilman James Gray said.

Still, City Planning Commission staff members, the City Attorney’s Office and even some council members expressed reservations at various points during the meeting about approving some of the 11th-hour changes, such as one to raise height limits along Canal Street from Claiborne Avenue to North Dorgenois Street from 50 feet to 85 feet in most areas. That amendment was approved 6-1.

In the end, the council approved most of the amendments before it, the majority of them unanimously.

The new CZO is intended to give legal force to the guidelines and principles set forth in the city’s master plan for long-term development. It governs development on all property in New Orleans and includes lists of permitted land uses for each zoning classification, as well as height limits, building sizes, setback requirements, urban design standards, operational rules and other regulations.

The Planning Commission held 20 meetings across the city in 2011 and 2013 on the proposed new rules, which drew more than 1,000 comments. The council also held an earlier public hearing on the measure.

Among the amendments receiving approval Thursday was one adding a definition for “cigar bar” to the zoning law — a change that effectively clears the way for La Habana Hemingway Cigar Bar on Toulouse Street to continue operating. The bar, which began as a restaurant and morphed into its current use, would have been prohibited otherwise.

The amendment defines a cigar bar as a bar that generates at least 35 percent of its income from the sale of cigars and related products, excluding cigarettes; it permits such establishments to operate in the French Quarter despite an existing ban on new cocktail lounges there.

Critics said the change will mean a proliferation of cocktail lounges disguised as cigar bars in the Quarter.

Mayor Mitch Landrieu’s administration opposed the amendment, saying the Habana Hemingway bar’s fate should have been decided by the Planning Commission as a conditional-use issue, not a zoning matter. However, the amendment passed 6-1, with Councilwoman Susan Guidry opposed.

The council also voted to reinstate Section 8.1 of the current zoning law into the new CZO. That section prohibits the Department of Safety and Permits from issuing a permit for any change in use of a building in the French Quarter without permission of the Vieux Carre Commission, unless the change in use would involve no change in the building’s exterior appearance.

The section also establishes four broad standards by which the VCC should evaluate projects, including that new structures and designs should not “injuriously” affect the historic character of the French Quarter and that they should “be in harmony” with the neighborhood’s traditional architecture.

That language often is cited by French Quarter residents and preservation organizations in opposing proposed new developments in the city’s most historic district.

The Landrieu administration opposed the amendment on the grounds that it would give zoning power to the VCC, authority that should be reserved for the City Planning Commission.

The council deferred action on a handful of proposed amendments, including ones that would have provided an incentive for developers citywide to include affordable housing in residential buildings, raised the maximum height for fences from 7 feet to 8 feet and prohibited additional hotel developments in the French Quarter along the riverfront, near where an Iberville Street hotel is under construction.

The deferred amendments will go to the City Planning Commission for consideration.

Several of the recently introduced amendments were contentious, including one that removes language requiring commercial developers to be respectful of residential uses and the overall quality of life in a mixed-use area of the French Quarter. The measure passed 4-3 over the opposition of French Quarter residents and council members Guidry, Stacy Head and LaToya Cantrell.

Also drawing the ire of French Quarter residents was an amendment from Councilwoman Nadine Ramsey, backed by the French Quarter Business League and the Louisiana Restaurant Association, that, among other things, would have allowed standard restaurants to sell packaged liquor for off-site consumption. That provision ultimately was referred to the City Planning Commission for study.

Despite the many amendments, what over recent months has proved to be the most contentious issue in the new ordinance went untouched: The creation of an “overlay district” along the riverfront remains in the ordinance.

The Riverfront Design Overlay District would allow structures to qualify for a 25-foot “height bonus” to bring a residential building’s maximum height to 75 feet if it incorporates “superior design elements.”

The affected district includes lots along the Mississippi River uptown from Jackson Avenue to the Pontchartrain Expressway, in Algiers from Powder Street to Alix Street, and downtown from Esplanade Avenue to the Industrial Canal, excluding the Marigny neighborhood.