“There’s little question the earth is warming,” he said, adding as a qualifier: “Regardless of whether it’s a natural cycle or human-induced, hotter air holds more moisture. And so for Harris County that means the potential for more extreme events.”

Mr. Lindner’s concern, he said, is that “by the time policy is in place it will already lag behind the latest information.”

Considering that most people whose homes flooded had no flood insurance, getting everyone to buy it might solve one problem — but would increase another. “We ought to call federal flood insurance what it actually is,” as Phil Bedient, an engineer and colleague of Mr. Blackburn’s at Rice, put it. “It is subsidized floodplain development.” The Netherlands — the global gold standard for water management — does not offer a national flood insurance program for just this reason.

Mr. Blackburn tells a story about a local hero, Jesse Jones, the former secretary of commerce, who helped secure federal funds for the ship channel. In 1929, Mr. Jones convinced fellow Houston bankers to put aside reserves of cash that prevented city banks from failing in the Depression. What may save Houston today, Mr. Blackburn said, is another common-sense strategy involving stricter controls and infrastructural investments that somehow lets state Republicans acquiesce behind closed doors but beat their chests in public.

“The worst flood has not yet occurred,” Mr. Blackburn noted. A hurricane that pushes a massive storm surge from the Gulf of Mexico into Galveston Bay, up the ship channel, could overwhelm refineries and unleash a toxic tsunami, killing many and rattling the national economy.

The judge and mayor are among those talking about a so-called Ike Dike, named after Hurricane Ike in 2008, which killed dozens in Texas. It would be a massive sea-gate that could block a surge. The scale and engineering would be Texas-size. The cost would be, too.

It’s hard to imagine that happening in the current political climate, Washington’s included, when so little gets done. “Looking back, should we have spent more to avoid some of the flooding?” Judge Emmett asked, rhetorically, when we met in his office. “Sure. Did taxpayers want to pay more to do those things? No.