Most coastal cities evacuated in the face of climate catastrophe. Houston, perhaps deep down accepting its role in the oil supply chain that wrecked the world, but more likely desperately protecting billions in infrastructure, decided to stay put and face the elements.
The Houston Levee Project was the most ambitious engineering project of its time, and to this date the structures still stand. The city sits entirely below sea level, behind massive mountain-scale levees that keep the city dry-ish.
One upside to this structure is that it keeps out much of the air pollution that terrestrial cities suffer, allowing a minimum of Carbon Macrofilters to keep the bowl of the city full of breathable air. Despite being one of the most breathable cities, the lack of air currents makes the city nonetheless incredibly humid (yes, even more than before). Any green areas in the city are usually quickly turned into swamps as the humidity encroaches.
Ironically, despite having one of the most livable environments remaining on Earth, Houston also boasts one of the most miserable ones. It is one of the most Arco-populated cities on earth, much of its sprawl being solid structure that sees no sunlight. As the core of the city develops, they build upward using the Levee walls as foundation-scaffolding (and they are designed to bear the weight). The result is a massive steep canyon spotted with nearly-as-massive facilities.
Due to its stability and wealth, Houston is a major maritime hub. The external docking structures are barnacled by ramshackle floating-city complexes of docks & shipping containers. Those are naturally prone to disasters, but the age of the Mega-Hurricane is fortunately past in 2420.
The design of Houston is arguably an example of an Eco-Arcology due to its open design where structures build modularly into an artificial landscape. It is considered one of the first Post-Fosterite Arcologies, but only because Homunculi had not settled in Houston at this point, so there was no foreseen need to adjust spaces according to racial apartheid.