Backwater is a section of a river that is away from the main flow and therefore moves more slowly than the rest. This term is also used for a town or village where time seems to flow more slowly, where there is minimal activity or modernization. This can be used pejoratively for places where the laws or thinking is outdated.
As long as backwater has been around, backwaters has existed as a less common variation. The actual term is backwater, but backwaters is the plural form if one is discussing two or more backwaters. This is common when referring to a region and all the slow-moving places within said region.
Examples
Take Reuters’ obituary on Mr. Lee, which said that he had overseen “the island’s transformation from a malaria-infested backwater.” [The Christian Science Monitor]
The urban dead zone known as 105th Avenue has long been an Edmonton backwater, even though it’s just a stone’s throw from the city’s rapidly changing downtown core. [Edmonton Journal]
“The real harm, to all Hoosiers, is that it makes us all look like backwater hicks,” Councilman Zach Adamson, a Democrat, told The Indianapolis Star. [The Indianapolis Star]
Kerala Tourism, on March 8, 2015, bagged the Golden Gate Award at the Internationale Tourismus-Borse Berlin (ITB-Berlin) 2015 for its popular multimedia campaign to promote the backwaters. [India Today]
So 19 states including such cultural backwaters as Connecticut, Rhode Island and Illinois followed with copy-cat legislation, and Indiana is the 20th. [The Wall Street Journal]