Sales and property tax revenues for Ascension Parish government have been on an upward trend over the past five years as population growth and construction in the chemical sector have been strong.

But parish auditors said Monday that total sales tax revenue, which constituted about half of all parish revenue in 2015, plateaued and fell ever so slightly last year to nearly $54 million.

“It’s actually down about 0.01 percent from prior years, so it looks like things have pretty much leveled out over 2014, 2015,” said auditor Jacob Waguespack, a certified public accountant with the parish’s hired auditing firm Faulk and Winkler.

“You’ve seen some growth just with construction and other things, but it looks like that peak has finally been hit, and we’ll see where it goes from here. It’s still a very good number,” he said Monday.

Waguespack showed the Parish Council Finance Committee a five-year graph of revenues as part of a presentation on the parish’s annual audit.

Waguespack said sales taxes rose about $19 million between 2011 and 2015, while property taxes rose about $8 million over that period to nearly $30 million in 2015.

Parish officials have noted for months that, while some major projects may be on the horizon, the chemical building boom of the past few years has ebbed as big projects, like the $2.1 billion expansion of CF Industries in Donaldsonville, wind down.

The audit is a snapshot in time, at Dec. 31, showing what parish government finances were when the current council and new Parish President Kenny Matassa took over from the prior council and former Parish President Tommy Martinez.

Rising revenues with largely flat operational expenses over the five-year period, the auditors note, have allowed parish government to boost its combined surpluses to about $190 million by the end of 2015. The total surplus is a notable increase from 2011, when the parish had combined surpluses of a bit more than $140 million.

But auditor Tommy LeJeune was quick to point out that about $97 million of that surplus, or what auditors call a “fund balance,” is legally dedicated to specific uses.

Voters have made those dedications through the years as taxes have been approved and renewed. Almost half of that $97 million, or about $42.6 million, is dedicated to drainage.

“So, $190 million sounds like a significant sum of money, but you’ve got a lot restrictive types of dollars and general obligations in terms of where you can spend it,” LeJeune said.

Waguespack and LeJeune said about $31 million of the $190 million is discretionary.

Meeting separately as the East Ascension drainage board, Parish Council members agreed Monday to settle a financial dispute involving the Henderson Bayou floodgate and pump station in Galvez.

Though the project was finished in late 2014 and already has been credited with blunting the effect of high water on the Amite River last year, the drainage board and builder Cajun Constructors have been negotiating for more than a year on final payment for the $15.7 million structure over major rain delays several years ago.

The parish had brought liquidated damages against Cajun over the delays, but, in a change order approved Monday, the board agreed to add an extra $98,267 in work that was not in the original contract and also deduct $157,000 from the contract for liquidated damages.

In the end, Cajun Constructors will get its final payment of $785,466, and the project will remain about $218,662 under budget.

Follow David J. Mitchell on Twitter, @NewsieDave.