WASHINGTON (Dow Jones)–The U.S. Senate unanimously agreed on Tuesday night to approve a popular flood insurance program for a year, taking a crucial step to ensure the federally-backed program isn’t allowed to run out when it expires on Sept. 30.

House lawmakers must still take up the measure before the continuation is finalized.

Without the program in place, it is doubtful that people who reside in areas of the country prone to flooding would be able to purchase insurance to safeguard against that risk. The program is several decades old and requires private property and casualty insurers to offer policies that include coverage against flood insurance.

The Property Casualty Insurers Association of America, a group that represents the property insurance industry, welcomed the Senate action, but urged the House to act quickly to take up the extension.

"Absent House action, this vital program that protects 5.5 million Americans will expire at the end of the month," said Marguerite Tortorello, senior vice president at the association.