Florida officials set up the commission in 1998 to improve the river’s dismal condition, and a crucial task, Mr. Aguirre said, was to haul the sunken wrecks and other junk out of the putrid water. In 2004, workers embarked on a four-year dredging operation that deepened the river by three feet and cost $89 million, a tab shared by federal, state and local agencies. Once that was done, developers, who had begun to run out of parcels elsewhere in South Florida, took a fresh look at the Miami River.

Although some new buildings along the waterway went up as far back as 2000, and several condo towers were built near its mouth more than a decade ago, most construction ground to a halt during the recession. With few impediments now, a burst of fresh projects are either being planned, under construction or completed, their crowns blending into the skyline of downtown and the Brickell neighborhood.

Just beyond the south side of the river, the $1 billion Brickell City Center — a massive complex that includes a shopping center, offices, luxury condos and a hotel — opened in November 2016 and inspired a slew of projects in its vicinity.

Across the river, the New York developer Shahab Karmely spotted a large empty lot, once a shipyard, while he was prospecting in the area in 2013. The result will be One River Point, a two-tower, 60-story condominium designed by the Uruguayan architect Rafael Viñoly that will be topped off by a pair of 14,000-square-foot “sky villas” costing about $30 million each. Spanning the gap between the towers, 800 feet in the air, a three-level private club will be encased almost entirely in glass. Construction is scheduled to start in early 2019.

Mr. Karmely, the principal at KAR Properties, said he had seen similar growth along rivers in London, Frankfurt and other cities, and regretted not diving in. “I didn’t take advantage of it,” he said while cruising the Miami River in a motorboat. “But I said to my partner: ‘This is undiscovered country. You can’t go wrong with a river. It’s dilapidated, but filled with potential.’”

Paul S. George, a history professor at Miami Dade College and the author of “Along the Miami River,” which begins its narrative with Spanish troops being entertained by Tequesta Indians on the river’s banks in 1568, said the development in recent years was nothing short of astonishing.