“The soil is saturated and there is very little capacity to absorb anything along the Mississippi River,” he said, pointing out that his city is still recovering from a massive 2016 flood that caused $10 billion in damage in and around Baton Rouge. “And we even have spring rains to come.”

The 1993 floods caused at least $15 billion in damage and claimed 50 lives in St. Louis. Its duration on the Mississippi, from May to September, prolonged the misery.

The mayors said one of the reasons they are here is to urge Congress to maintain the $7.9 billion flood mitigation spending. The group also is pushing for the establishment of a revolving loan fund that would allow localities to help get financing elsewhere.

In addition, the mayors this week came to an agreement with a company called Quantified Ventures, aimed at creating “environmental impact bonds” to help cities finance local disaster mitigation. The company bills itself as an “investing advisory firm that simplifies the process of financing innovative and evidence-based environmental, health and educational outcomes.”