After all the furore, it’s hard to remember now that Donald Trump’s combative press conference earlier this month was supposed to be about infrastructure. Holding two flowcharts, the president explained how his latest executive orders would slash the time it takes to get new buildings improved and that the permitting process would “go very, very quickly”.

History will remember that he immediately went on to “very quickly” deal with another issue , blaming parties on “both sides” for the fatal clashes during the white supremacist march in Charlottesville, Virginia.

However, although his infrastructure reforms were lost in that controversy, his regulatory slashing may yet have a long-term, and controversial, impact of its own.

As tropical storm Harvey spins slowly over the Gulf coast, catastrophic flooding has forced tens of thousands from their homes in and near Houston. And with the storm moving into Louisiana, officials only expect the number of people whose lives are upended by it to increase.

An executive order issued by Trump earlier this month revoked an Obama-era directive that had established flood-risk standards for federally funded infrastructure projects built in areas prone to flooding or subject to the effects of sea-level rise – like many of those now sinking in Texas.

Houston already has some of the laxest building regulations for structures in potential flood zones and the president wants to spread that policy across the US.

“It makes no sense,” said Steve Ellis, vice-president of Taxpayers for Common Sense. “Taxpayers deserve to have the assurance that if they provide assistance to a community to build or rebuild, it’s done in a way that isn’t going to cost taxpayers money in the future.”

Storms and flooding are generally becoming costlier and more frequent and data suggests climate change is a leading culprit.

Many towns are located in coastal areas and riverine floodplains, where the National Oceanic and Atmospheric Administration (NOAA) says “building codes are often insufficient in reducing damage from extreme events”. The number of “billion-dollar events” – natural disasters ranging from flooding to wildfires that incur more than $1bn in damage – has risen over the past few decades, increasing in cost from a roughly $10bn five-year average in 1985 to more than $50bn in 2015.

Obama signed executive order 13690 in 2015 in response to rising sea levels and surface temperatures and more frequent storms, particularly tropical cyclones. The Obama order, with its references to sea-level rise and climate change, became an instant target for an administration eager to expunge those terms from the political lexicon.

“That executive order was meant to help Fema pressure communities to rebuild in a smarter, more resilient way,” said Ellis. “This removes that pressure.”

The regulations associated with 13690 had not yet gone into effect when it was revoked, but several federal agencies – including Fema (the Federal Emergency Management Agency) and Housing and Urban Development (HUD), which funds and oversees public housing projects – had already initiated the rule-making process.

The flood standard, which among other things would have required structures built within a 100-year floodplain – an area where a major flood statistically has a 1% chance of occurring in any given year – to be elevated by two feet to prevent flood damage, had its detractors.

The National Association of Homebuilders was a staunch opponent of the standard, and argued that more stringent regulations would reduce working-class people’s access to affordable housing due to its effect upon federal home insurance programs.

Rob Moore, a senior policy analyst with the Natural Resources Defense Council, countered that NAHB may have been less concerned about the standard’s impacts upon private development than they were about the limits it could place on development in general.

“If the federal government isn’t going to support the infrastructure that supports a development – roads and water treatment plants and that sort of thing – it could make it impossible for development to occur,” he said. “If private entities want to go in and develop a flood-prone area on their dime, that’s their prerogative, but I don’t see why the federal government should foot the bill for that.”

NAHB did not respond to a request for comment.

In the days after Hurricane Sandy – which ravaged the New York City metropolitan area in the fall of 2012 – federal, state and municipal government agencies poured billions into repairs for flood-damaged public transit, public housing and other types of infrastructure. The New York governor, Andrew Cuomo, estimated that repairs cost the state nearly $33bn. New Jersey’s bill was close to $30bn. With no standard in place, much of the federal money spent on rebuilding ended up supporting projects in flood zones.

Public housing, which often stands upon flood-prone land that was inexpensive for housing authorities to purchase, is particularly vulnerable. According to HUD, more than 11,000 public housing buildings – 5% of the total – are in flood zones. In total New Orleans has 1,944 buildings in flood zones; Miami and Jacksonville, Florida, have another 1,157, according to HUD.

“In the wake of Hurricane Sandy, a number of public facilities were knocked out that could have been better protected had they been subject to more stringent regulations,” Moore said. “In part, this is what pushed the Obama administration in that direction, so that they could avoid having to spend federal dollars to rebuild risky structures.”

Although the Obama-era executive order has been revoked, there is still a chance that the regulations it spurred could stand on their own. Fema, HUD and the Environmental Protection Agency (EPA) all had regulations pending to implement the standard set forth by the executive order, and all those agencies had completed public review and were awaiting final adoption of the new rules.

“It’s possible they could still be adopted absent the president’s action,” Moore said. “For Fema and HUD, it’s vitally important to do so, as all the post-Harvey rebuilding would have to be done to the more protective standard.”

The consequences of making it easier to build in flood zones are likely to be severe. So far 30,000 people are projected to have been displaced by flooding from Hurricane Harvey. This is the third major flood in the US this year, and the third the Houston area has seen since March of last year. Catastrophic flooding, whether on the coast or in the river-hashed central plains, is a given.