On San Antonio’s South Side, a group of about 20 parishioners hurry one by one from the parking lot into a tiny church that can’t hold more than several dozen. Their frilly dresses are quickly soaked with rain, their shiny shoes are instantly ruined in deepening puddles and the flowers that some are carrying whip out of their hands and disappear.

But Jessica Garcia has a very good reason to brave the wind and the rain. She’s holding her son Jacob in her arms.

“No matter what the weather, we know that God’s going to help him get baptized,” Garcia says.

Winds and downed trees aren’t the biggest problem for San Antonio: it’s the rain. (Kim Brunhuber/CBC)

Even if she can’t see Harvey yet, she can feel it building. Wind vanes are churning like propellers. The rain is saturating already soaked ground. Roofs are covered with tarps that look ready to rip off as though they were Band-Aids.

To those who live in San Antonio, Texas, the fact that Harvey has been downgraded from a hurricane to a tropical storm means little because the city lies in what’s called a flash flood alley.​ And those who live near this old mission may be directly in its path.

Many houses in San Antonio, Texas, are built on low-lying ground that could face flooding, like this one in the Mission Espada area. (Kim Brunhuber/CBC)

The community surrounding Mission Espada is built on flat, low-lying ground. Their next-door neighbour: the San Antonio River. Four years ago, Marco Longoria says the area was devastated by flooding.

“It’s kind of dangerous sometimes when it rains a lot,” he says.

One major flooding risk: the San Antonio River, which flooded during storms in 1998 and 2002. (Kim Brunhuber/CBC)

That’s why Andres Gallegos, the pastor at Mission Espada, says this will be the last service until further notice. He’ll have to turn to more secular matters in order to ensure that this 200-year-old church is still standing next week.

“We’re going to talk about this,” Gallegos says. “I think we need to make some decisions.”

There’s been a run on staples at many grocery stores, as San Antonio residents prepare for possible flooding. (Kim Brunhuber/CBC)

It’s not just the suburbs and outskirts that risk flooding. The San Antonio River snakes through the downtown core; its famed River Walk boasts a network of walkways with shops and restaurants on either side. The prospect of flooding has spooked many businesses and residents; some shops have chosen to close and spread tarps over their windows. Several grocery stores have seen runs on staples. At one H-E-B grocery store near downtown, an elderly woman brushes past, muttering to herself about how she was probably too late because “everyone bought up the water.”

Many San Antonio businesses have chosen to close for the weekend. (Kim Brunhuber/CBC)

“We’ve created additional flood control infrastructure that has helped us cope,” Mayor Ron Nirenberg told CBC News. “We’ve invested hundreds of millions of dollars, if not billions of dollars over the years, particularly in the last 20 years to cope with major flooding events,”

And that has given some residents who live in flood-prone areas like Eric Warner a sense of calm despite the storm.

Downtown San Antonio is full of canals, but experts don’t experts don’t expect them to flood. (Kim Brunhuber/CBC)

“We have a pretty robust flood system in San Antonio,” Warner said, smiling. “I think it’ll do its job.”

But those attending little Jacob’s baptism at Mission Espada are choosing to put their faith elsewhere. They feel the river is too powerful — their houses are too close.

The Garcias say they will rely on their faith to get them through the aftermath of Harvey. (Kim Brunhuber/CBC)

“I know God will help us get through this day, through this hurricane,” Garcia says, and takes her seat in the pew to pray.