ST. AMANT — Window panes dusted with dirt up to a sharp line of demarcation, two-tone porch screens with a clear line separating the two shades, bits of dark grit on the white columns of a front porch, and sheds and AC units turned on their sides.

Signs of how high the water rose two months ago at the end of Phillips Road in St. Amant — where a calm Bayou Francois now meanders within its banks — are both subtle and obvious.

Contractors working for the Federal Emergency Management Agency having been taking in all the clues, house by house, to make the same critical judgment that the agency and their parish contemporaries have been making for weeks now across the Baton Rouge region: how much water got in the house?

These signs, the contractors say, tell the tale.

"The water mark does not lie," said Seth Bradley, an engineer with Dewberry who is part of a joint venture working with FEMA. 

Bradley, a St. Amant native who now lives in New Orleans, and his partner, Jason Schneider, make up one of 20 two-person teams conducting what's known as damage assessments of homes across the parish for the past few weeks. Earlier this week, they were on Phillips Road.

They work for Starr II, a joint venture of three common FEMA contractors, Dewberry, Stantec and Atkins, that is handling the assessments in Ascension, and previously worked in Pointe Coupee, Tangipahoa and Acadia parishes and in Central.

These assessments will be used by Ascension Parish government to determine which homes have "substantial" damage and will, if the house is low enough and in the most high-risk areas, also be required to be elevated or demolished and rebuilt.

For a few hours on Phillips Road, Bradley and Schneider showed how, even two months after the floods and as some residents were well into their repairs, having replaced doors and windows, there's always a way to find a water mark showing the height of flood water.

The height of the water is an important factor in the software FEMA contractors and the parish use to determine how much damage a house has received. Greater heights, generally speaking, generate greater percentages of damage.

Homes with a total damage that is more than 50 percent of its market value, exclusive of land, are considered to have "substantial damage" and could face elevation requirements.

While the hunt for water marks is a big part of the job, there's also some subjective consideration that comes into play based on each home's context, the contractors said.

Some homes are two stories or split level, so water damage is less extensive, for example. 

Phillips Road happens to be just upstream from the Marvin J. Braud Pumping Station, a bank of six massive pumps that drain a large part of East Ascension.  

In many parts of Ascension, flood water gradually rose — what FEMA calls "ponding" — but that causes less damage than faster moving water that rushes down a creek or bayou. 

Part of Bradley and Schneider's consideration on Phillips Road, so close to those powerful pumps, is whether fast-moving water being drained by the pumps could have damaged the foundations of homes. Homes with that kind of damage could end up above the 50 percent threshold much more quickly.

At one house, a backyard shed was turned on its side, an indication the water was moving, but Bradley and Phillips said there was no other sign the foundation was damaged.

Each day, the teams are given a new batch of houses to inspect from data at their back office in Maryland and, each day, the parish gets a new data dump of assessments from the contractors from which to make determinations. 

Earlier this week, Bradley and Schneider took a few minutes on each home; teams have between 20 and 40 to finish each day.

As of Thursday, FEMA has evaluated 1,562 homes. The parish, which started evaluations before the FEMA teams arrived and has continued to do so, has evaluated 562 homes for a combined total of 2,124 homes, said Jerome Fournier, the parish planning director.

Of those homes, 423, or about 20 percent, have been deemed to have more than 50 percent damage.

While the total number of flooded homes has been a bit of moving target in Ascension, ranging from 6,500 to 16,000, Andres Luna, a field manager for Starr II in Louisiana, said the teams will end up assessing something fewer than 10,000 structures.   

In East Baton Rouge Parish, which has had FEMA contractors on the ground for about a month, 27,262 homes have had damage assessments conducted. The city-parish has gotten the data from about 17,000 of those assessments, city-parish officials said.

Of that number, Building Official Justin Dupuy said, only about 50 homes so far have been deemed as substantially damaged. Dupuy said that when the city-parish gets the data from FEMA, officials then double check those logging between 40 percent and 60 percent damage.

The city-parish and homeowner essentially go through an appeal process on each one to check the estimates, cost of repairs, market value and the height of the home to see if elevation is needed, Dupuy said. 

"We are going to explore every possibility before we make that final call," he said.

Dupuy said the city-parish has done many of the assessments on its own when homeowners come in for permits. 

He said about 60,000 homes have flooded, but about half were eliminated from damage assessments because they are not in the most high-risk flood areas where elevation requirements apply.

Dupuy said he believes the FEMA teams could finish their assessments within a week. 

In unincorporated Livingston Parish, the pace is a bit slower. The parish is not relying on FEMA contractors — it has that option according to FEMA officials — but a single building official has been conducting assessments and meeting with homeowners one on one.

Mark Harrell, parish director of homeland security, said Livingston Parish officials could not see having contractors go by people's homes without them knowing and then sending them letters in the mail about having substantial damage. 

Harrell did not have a tally of how many homes have gotten damage assessments so far but he said 146 have been deemed to have substantial damage.

"It is slow, but there's no time frame we have to do it in," Harrell said.

He said residents are being encouraged to do temporary repairs and move back in until the assessments can be conducted. The parish is currently training another official to help with the assessments, he said.

Meanwhile back in Ascension, Charles Nelson, 53, and Christine Nelson, 50, were doing finish work on new wall board in their father's flooded slab home on Phillips Road while he stays with family.

Christine Nelson said the water reached about 6 feet high in their old family home.

"The water was over my head," she said.

Charles Nelson said they are trying to get the house back up and running for their dad — the Shelter at Home program had already been through and made some improvements.

He figures there's little chance the house will hit the 50 percent threshold since they have only spent $15,000 so far fixing it up; also, he resists the whole idea of raising the old brick house.

"You can't elevate this house," Nelson said.

Bradley and Schneider estimated, based on water marks along windows in the back, that about 5 feet of water got in the house, though the depth hit 5.5 feet just outside the house.

It will be up to the parish to decide if that's enough to require elevation.

Follow David J. Mitchell on Twitter, @NewsieDave.