Attorneys representing nearly 100 oil and gas companies told a federal judge Wednesday that a sweeping lawsuit accusing the companies of destroying coastal wetlands in southeast Louisiana should be thrown out.

The hearing before U.S. District Judge Nannette Jolivette Brown was the first real legal test of the case brought by a New Orleans-area levee authority last year.

Brown did not issue a ruling after the hearing, which packed her courtroom with dozens of lawyers representing energy firms and the Southeast Louisiana Flood Protection Authority-East.

While she gave few hints about where she might come down on the issues, she suggested attorneys representing the oil and gas industry need to clear a high bar to get the case tossed out before it goes to trial.

“Dismissal is a harsh remedy,” Brown said.

Wednesday’s hearing, the first of two that will determine whether the authority’s suit can move forward, focused on arguments by the defendants that it should not.

Those arguments fall into three general categories: that the levee authority is barred from pursuing the suit by a state law passed after the case was filed, that the issue should be handled by federal regulators and not the courts, and that the levee authority was not the proper body to sue over any damages that may have occurred.

Brown said she did not expect to have a written ruling on those issues by Dec. 10, when the levee authority’s lawyers will have their chance to strike back in a hearing before Brown that will center around the state law — known as Act 544 — aimed at killing the case. The authority’s lawyers say the law does not apply to their suit and is unconstitutional in any case.

A state judge already has ruled in the authority’s favor on both those issues in an unrelated case. While that decision is not binding on the federal courts, it is expected to be appealed to the state Supreme Court, whose opinion could carry more weight with the federal bench.

Attorneys did not spend much time on Act 544 during Wednesday’s more than two-hour hearing, though each side laid out familiar arguments about it. Lawyers for the energy companies said state lawmakers clearly intended for the law to stop the suit. Jim Swanson, an attorney for the authority, countered that the law was poorly drafted and, as passed, applies only to the state government or parish governments and not to multiple-parish entities with a specialized focus like the levee authority.

Robert Meadows, an attorney for Chevron, argued that the lawsuit also would interfere with federal laws and regulators because it calls for the oil and gas companies to repair the damage allegedly done to wetlands by decades of dredging and drilling. Should the authority win its case, such activities would require permits from the U.S. Army Corps of Engineers, and the court cannot force that agency to grant those permits, Meadows said.

Swanson replied that the suit also allows for monetary damages — estimated to add up to billions of dollars — which he said would provide an alternative approach for the court. One of the laws cited by the defendants in their argument, the federal Clean Water Act, also specifically includes language that it will not stop legal claims, he said.

He also noted that the permits issued by the Corps when the projects were started required the companies to maintain them and repair damage from them and that many of those permits specifically included language allowing for lawsuits related to the projects.

ExxonMobil attorney Martin Stern also argued that the levee authority’s suit did not make a convincing case that the oil and gas companies’ activities could be shown to have caused coastal erosion. While the suit includes attachments describing all the wells, canals and other structures built by the energy companies, it does not show how specific projects contributed to wetlands loss, Stern said.

“Nowhere do they say what any defendant has done wrong,” he said.

That argument could be made in an amended petition that more clearly assigns blame, or it could be done at trial, said Gladstone Jones, an attorney for the authority.

Lawyers for the oil and gas companies also challenged the suit by arguing the levee authority didn’t have legal standing to file it. Attorneys for the authority countered that wetlands damage has led to more significant storm surge in the New Orleans area, that the law creating the levee authority specifically gave it responsibility for handling some coastal erosion and that even though the wetlands in some case are far from the levees themselves, their loss still has an effect on the authority’s structures.

Follow Jeff Adelson on Twitter, @jadelson.