With a "very dangerous," "powerful" Hurricane Ida fast approaching, East Baton Rouge Mayor-President urged residents to make their final preparations before it lands.

Ida is expected to drop 8 to 16 inches of rain on the Baton Rouge area between Saturday and Tuesday and bring hurricane-force winds that could knock out power for days.

The heaviest downpour in the capital region is expected Sunday and Monday. Rain bands could arrive mid-to-late-Sunday morning, according to the latest forecast.

"This is a very dangerous storm and … it will possibly bring life-threatening impacts," Broome said at a late morning press conference Saturday. "It's powerful storm."

"Please," she added, "take this seriously and use this time to prepare."

The mayor-president said those preparations should include a three-day supply of food and medicine for family and pets, plus masks and other protections against COVID-19 should people have to leave their homes.

Broome said Baton Rouge is dealing with two emergencies: Hurricane Ida and the pandemic: "So please prepare for both."

City-parish officials said they were arranging for pandemic-conscious shelters of last resort to open before Ida arrives Sunday. But they did not announce the locations or opening times during Saturday's news conference at Mayor's Office of Homeland Security and Emergency Preparedness building near the Baton Rouge airport.

Clay Rives, parish homeland security director, said one of the local shelters would be able to hold 200 people; another, about 250. Both were being staged Saturday morning, he said.

Evacuation orders along the Louisiana coast, where Ida is expected to make landfall Sunday as a potent Category 4 storm, have sent traffic chugging through greater Baton Rouge as people flee the coming storm. 

Because of the amount of wind Ida is expected to bring to the state and Baton Rouge, outages could last as long as two weeks, though typically for storms as strong as Ida, power can be restored in a week to 10 days, Entergy officials said.

In an interview, Will Johnson, region customer service manager for Entergy, said utility officials had to go back to Hurricane Betsy in 1965 for historical parallels to measure the potential impact of a Category 4 storm hitting this part of the southeast Louisiana's power grid.

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Because so much has changed in the region since 1965, though, the utility could not really do a full projection of power loss for Ida based on historic trends, but applied a more standard two-week time frame associated with Category 4 storms.

"Now it doesn't reach that. We always get them in before that, maybe seven days, eight, nine, but never two weeks, but that's the possibility," Johnson said.  

Cheri Ausberry, Entergy customer service manager for the Baton Rouge area, added the power utility has about 3,000 workers ready and more from other states are already headed to Louisiana to help restore power if outages happen.

"We're going with the worst-case-and-hoping-for-the-best scenario, so we're going to be prepared for whatever that may be," Ausberry told the new conference Saturday.

Earlier on Saturday, Assumption Parish issued a mandatory evacuation order for its more than 21,000 residents as Ida's eye is expected to pass through the Lake Verret basin and near Pierre Part on Sunday, a Weather Underground compilation forecast shows.

The order appears to the first mandatory one for the greater Baton Rouge area.

Rives and Broome explained that the city-parish was coordinating with the state on its sheltering plans but said state highway and Louisiana State Police were coordinating the evacuation traffic flow. 

Broome said parish crews have been clearing obstructions in waterways and lowered the water level in the Capitol Lake by two feet for flood storage.

Part of a $20 million drainage program has cleared more than 2 million pounds of sediment from 1,400 storm drains over the past nine weeks, but Broome said the amount rainfall projected still could overwhelm drainage systems.

The city-parish has also asked for 15 high-water vehicles from the Louisiana Army National Guard, Broome said.

Broome said demand for sand and sandbags is high, but the parish has set up locations throughout the parish. Residents who are elderly or disabled and are unable to make their own sandbags and can call 211 for assistance.

Likewise, people seeking a ride to a state or local shelter can call 211 for help.

Email David J. Mitchell at dmitchell@theadvocate.com

Follow David J. Mitchell on Twitter, @NewsieDave.