Two years removed from the 2016 flood, the three worst-affected parishes in the Baton Rouge area have had mixed population changes, with East Baton Rouge falling and Ascension and Livingston growing or rebounding, new census data show.

East Baton Rouge Parish continued to see a small decline in population while Livingston's population came back after a fall in 2017. Ascension's population never stopped growing, though modestly, the new data show.

The U.S. Census Bureau released its latest population estimates for counties and parishes a minute after midnight Thursday. The data reflect the estimate as of July 1, more than nine months ago.

At that point, Ascension Parish was the fastest-growing parish in the nine-parish Baton Rouge metropolitan statistical area both since the flood and since last year. East Baton Rouge and East Feliciana parishes were in a virtual dead heat for the fastest population losses, though small.

Ascension was also the fastest-growing parish in the state between 2017 and 2018, slightly overtaking St. Bernard Parish by a hundredth of a percentage point. Livingston was slightly behind in third with growth of 1.1 percent, the data show.

Statewide, Louisiana's population fell slightly between 2017 and 2018, though it's still up from 2010, at 4.66 million, according to previously released data.

Across the Baton Rouge statistical region, population grew slightly over 2017 but is down slightly since 2016 at 831,411 people. Other parishes in the area are East Feliciana, Iberville, Pointe Coupee, St. Helena, West Baton Rouge and West Feliciana. 

East Baton Rouge Parish's population fell six-tenths of percentage point since 2017 and 1.1 percent since July 1, 2016, just more than a month before the August 2016 flood inundated tens of thousands of homes in the Baton Rouge and Lafayette areas and parts of the Florida Parishes. 

East Baton Rouge's population was 440,956 people as of mid-2018, the latest estimates show.

East Feliciana's population, with just 4 percent of East Baton Rouge's population, fell at very similar rates the past two years, standing at 19,035 by mid-2018. 

Meanwhile, Ascension's population grew 1.3 percent since mid-2017 and nearly 2.6 percent since July 1, 2016, rising to 124,672 people from 121,520 in mid-2016. 

West Baton Rouge and West Feliciana parishes were the only other parishes in the statistical area to show population growth since 2016, increasing by 2 percent and 1 percent, respectively.

West Baton Rouge had 26,427 people as of mid-2018, while West Feliciana had 15,460. West Baton Rouge grew last year by slightly less than a percentage point but that was enough to rank it seventh in the state in terms of rate of growth year to year.

Livingston, which had devastating flooding in Denham Springs, Walker and elsewhere, saw its population drop 1.4 percent between 2016 and 2017, falling from 139,970 to 138,038. In 2018, the parish recovered almost all of that loss, growing to 139,567 people, the new data show.

Hidden within the latest information were revisions of old population estimates from prior years. These new changes also had mixed effects on Baton Rouge-area parishes. In East Baton Rouge, the revision cut the parish's population figures further than they had been reported just a year ago.

One way of measuring those effects is to consider how the revisions have affected population estimates since the 2010. The new data show East Baton Rouge has grown only 0.7 percent between mid-2010 and mid-2017.

The old data had pegged that increase at 1.3 percent. The bottom line is the revisions lowered East Baton Rouge's previously reported population in 2017 by 2,661 people, falling from 446,268 to 443,607.

Then, the new estimates for 2018 cut the parish's population further, by another 2,651 people.

In contrast, the revisions served to boost Ascension's population for prior years compared with what had previously been reported, but only slightly.

In 2017, the original data had the parish's population at 122,948. With the revisions, the total for 2017 rose by 80 people to 123,028. The change had the side effect of slightly muting the rate of growth for 2018 that Ascension would have seen had the old 2016 or 2017 population totals remained. 

A census bureau spokesman said the agency sometimes makes revisions but did not offer a reason why those had been made for the Baton Rouge area or whether they were related to the flood in 2016.

Advocate reporter Jeff Adelson contributed to this report.


Follow David J. Mitchell on Twitter, @NewsieDave.