The federal government has proposed a $1.8 billion plan to help protect Norfolk, Virginia, from rising seas and increasingly powerful coastal storms by ringing the city with a series of floodwalls, storm surge barriers and tidal gates.

The low-lying city is among the most vulnerable to sea level rise, and it's home to the nation's largest naval base. The combination has made protecting the region a matter of national security for the federal government.

The draft recommendations, which the United States Army Corps of Engineers published Friday, said "the project has the potential to provide significant benefits to the nation by reducing coastal storm risk on the infrastructure including all of the primary roadways into the Naval Station."

While the proposed measures are designed to shield thousands of properties from flooding by major storms and to protect critical infrastructure and utilities that serve the naval station, the base itself is outside the scope of the project. Three years ago, the Defense Department identified about 1.5 feet of sea level rise as a "tipping point" for the base that would dramatically increase the risk of damage from flooding. The military has not funded any projects specifically to address that threat, however, as detailed in a recent article by InsideClimate News.

The new Army Corps report found that "the city of Norfolk has high levels of risk and vulnerability to coastal storms which will be exacerbated by a combination of sea level rise and climate change over the study period," which ran through 2076. By that point, the report said, the waters surrounding Norfolk will likely have risen anywhere from 11 inches to 3.3 feet. (The land beneath Norfolk is sinking, exacerbating the effects of global sea level rise.)

In addition to physical barriers like tidal gates and earthen berms, the report outlined several other steps that the city should take, including elevating existing structures and buying out landowners in flood zones so they can relocate elsewhere.

"This is a great plan and a great start," said retired Rear Adm. Ann Phillips, who has worked on flooding and climate adaptation in the region and is on the advisory board of the Center for Climate and Security, a nonpartisan think tank. "It starts to outline the extreme costs we're going to deal with, because $1.8 billion is probably low."

The draft recommendations are now open for public comment, with the final report not expected to be finalized until January 2019. Only then would Congress begin to consider whether it would fund the project. The draft says the federal government would cover 65 percent of the costs—almost $1.2 billion—with the rest coming from local government.

"The road to resilience for Norfolk is a long one measured over years and decades," George Homewood, Norfolk's planning director, said in an email.

Similar studies and work will need to be conducted for the cities that surround Norfolk and collectively make up the Hampton Roads region. The cities are interconnected in many ways, Phillips noted.

"Until you look at the whole region as one piece, you don't fully recognize what the needs are," she said. "Until we do that, we're really selling ourselves short."