Rising Waters

Last June, 13-year-old Gracie Pryor stood atop one of the floodwalls that snaked around her community and marveled at the power of nature. The overflowing Mississippi River had completely swamped the landscape around the tiny town of Kimmswick, Missouri. “There was water as far as my eye could see,” says Gracie. “Muddy water full of debris. It covered the roads, the ground, everything.”

Gracie, along with most of her neighbors and the town’s mayor, were pitching in to keep the river at bay. “Everyone pulled together to save the town,” she says. They did so by strengthening the levee built along the river to hold back rising waters. They added clay, rocks, and gravel to raise the wall, then covered it with sheets of plastic and sandbags. The levee grew higher and wider until it was big enough to withstand floodwaters nearly 15 meters (49 feet) high.

The flooding around Kimmswick crested at 14 m (46 ft), just shy of the top of the reinforced levee. The town’s efforts had paid off! The levee held, keeping the water at bay. Fighting the flood cost Kimmswick nearly $150,000 and tested the tight-knit community’s mettle as they labored around the clock for weeks on end to stay dry.

Last June, 13-year-old Gracie Pryor stood on top of one of the floodwalls that surrounded her town. The power of nature amazed her. The overflowing Mississippi River had completely covered the land around the tiny town of Kimmswick, Missouri. “There was water as far as my eye could see,” says Gracie. “Muddy water full of debris. It covered the roads, the ground, everything.”

Gracie was helping to keep the river at bay. So were most of her neighbors and the town’s mayor. “Everyone pulled together to save the town,” she says. A levee had been built along the river to hold back rising waters. Now everyone worked to strengthen the levee. They added clay, rocks, and gravel to raise the wall. Then they covered it with sheets of plastic and sandbags. The levee grew higher and wider, until it was big enough to hold back floodwaters nearly 15 meters (49 feet) high.

The flooding around Kimmswick reached 14 m (46 ft). It stopped just below the top of the strengthened levee. The town’s efforts had paid off! The levee held, keeping the water at bay. Fighting the flood cost Kimmswick nearly $150,000. It also tested the spirit of the tight-knit town, as people worked around the clock for weeks to stay dry.

Kimmswick was just one of thousands of towns along the Mississippi that battled what’s been dubbed “The Great Flood of 2019.” The catastrophe, which spanned a total of nine months, was the longest period of flooding ever recorded in U.S. history. It caused $2 billion in damages throughout the Mississippi watershed. The watershed is made up of all the rivers and their smaller tributaries that flow into the Mississippi River (see The Mississippi Watershed). The river basin covers 40 percent of the continental U.S.

Flooding on the heels of spring snow melt has long been a problem in the American Midwest (see Key Moments: 5 of the Mightiest Mississippi Floods). But in recent decades, it’s become more frequent and severe. Now, as the 2020 flood season looms, the question on everyone’s mind is: What does Mother Nature have in store for us this year? “No one can say for sure,” says Kevin Low of the National Weather Service. “But the outlook suggests it’s going to be another tough season. We need to ask ourselves ‘Is this the new normal?’”

The disaster has been called “The Great Flood of 2019.” Kimmswick was just one of thousands of towns along the Mississippi that battled it. The flooding lasted nine months. That’s the longest period of flooding ever recorded in U.S. history. It caused $2 billion in damages throughout the Mississippi watershed. The watershed is made up of all the rivers and their smaller branches that flow into the Mississippi River (see The Mississippi Watershed). The river basin covers 40 percent of the continental U.S.

Flooding can happen after snow melts in spring. That has long been a problem in the American Midwest (see Key Moments: 5 of the Mightiest Mississippi Floods). But in recent decades, it’s become more common and severe. Now the 2020 flood season is nearing. The question on everyone’s mind is: What does Mother Nature have in store for us this year? “No one can say for sure,” says Kevin Low of the National Weather Service. “But the outlook suggests it’s going to be another tough season. We need to ask ourselves ‘Is this the new normal?’”

The Mississippi River is the longest river in America. It flows 3,780 kilometers (2,350 miles) from its source, Lake Itasca in Minnesota, down the center of the continental U.S. to the Gulf of Mexico. More than 30 million people—nearly a 10th of the U.S. population—live along the river or one of its offshoots.

Throughout history, the Mississippi River has naturally altered its course many times, shifting its banks and route as it flowed south to the ocean. Then people stepped in. They tried to shape the waterway to meet their needs: to transport goods and people, to provide drinking water, and to lessen the impact of floods on property and communities. Over the years, the river has been heavily engineered to contain and redirect its waters (see Flood Control). In the wake of a devastating flood in 1927, the U.S. Army Corps of Engineers began building levees to confine the river to its current banks.

But people have never been able to completely tame the mighty Mississippi. Even today, whenever too much water pours into the river, from melting snow or heavy rains, it overflows, swamping nearby towns and farms. So engineers have built in additional safeguards, like spillways, that allow for the regulated release of water from the river into nearby basins or lakes. Dozens of massive dams within the Mississippi River basin also help hold back or release water to help with flood control.

The Mississippi River is the longest river in America. It starts at Lake Itasca in Minnesota. From there, it flows 3,780 kilometers (2,350 miles) down the center of the continental U.S. to the Gulf of Mexico. More than 30 million people live along the river or one of its branches. That’s nearly 10 percent of the U.S. population.

Throughout history, the Mississippi River has naturally changed its course many times. Its banks and route shifted as it flowed south to the ocean. Then people stepped in. They tried to shape the waterway. That’s because they needed it to transport goods and people and to provide drinking water. They also wanted to lessen the damage of floods on property and communities. Over the years, the river has been heavily engineered to contain and shift its waters (see Flood Control). A devastating flood struck in 1927. After that, the U.S. Army Corps of Engineers began building levees to hold the river to its current banks.

But people haven’t been able to completely tame the mighty Mississippi. Even today, it overflows and covers nearby towns and farms. This happens when too much water pours into the river, from melting snow or heavy rains. So engineers have built in more safeguards, like spillways. They allow the controlled release of water from the river into nearby basins or lakes. Dozens of massive dams were also built in the Mississippi River basin. The dams hold back or release water to help with flood control.

The first six months of 2019 were among the wettest on record in much of the Mississippi Valley, Plains, Ohio Valley, and Great Lakes. Many scientists think the increased rainfall is a consequence of climate change. Warmer air absorbs more water from the ocean, and that water eventually falls onto the land. Several factors magnified the effects of precipitation leading up to the 2019 flood, which inundated the nation’s most expansive river basin for most of a year.

“Last year, the worst of three situations came together,” says Kevin Stamm, an engineer with the Army Corps’s Missouri River Basin Water Management Division. First, as spring approached, the basin was buried in deep snow. Additionally, the ground had already become saturated, so it wasn’t able to absorb additional precipitation and melting snow. “Before we even got to spring, there was a lot of moisture in the ground,” says Stamm. “It caused the ground to freeze very deeply, and when that happens it turns into an impermeable layer. It’s like concrete.” That frozen barrier blocked additional water from seeping into the ground. “Then on top of that, a big storm system came through, and heavy rain and snow fell on the frozen ground,” Stamm adds.

The first six months of 2019 were among the wettest on record in much of the Mississippi Valley, Plains, Ohio Valley, and Great Lakes. Many scientists think the increased rainfall is a result of climate change. Warmer air absorbs more water from the ocean. Sooner or later, that water falls onto the land. Several factors increased the effects of precipitation last year. Then the 2019 flood covered the nation’s largest river basin for most of a year.

“Last year, the worst of three situations came together,” says Kevin Stamm. He’s an engineer with the Army Corps’s Missouri River Basin Water Management Division. First, the basin was buried in deep snow as spring neared. Plus the ground had already become saturated. It couldn’t absorb more precipitation and melting snow. “Before we even got to spring, there was a lot of moisture in the ground,” says Stamm. “It caused the ground to freeze very deeply, and when that happens it turns into an impermeable layer. It’s like concrete.” That frozen barrier blocked more water from soaking into the ground. “Then on top of that, a big storm system came through, and heavy rain and snow fell on the frozen ground,” Stamm adds.

The excess water began to flow south across the land into waterways. As it journeyed from South Dakota to Nebraska to Iowa, rising waters quickly deluged communities. High waters from the Missouri River and other tributaries poured into the Mississippi, causing it to swell to record-breaking levels. By late June, the flooding was so severe and widespread that at least 11 states sought disaster funds from the federal government.

The extra water began to flow south across the land into waterways. It traveled from South Dakota to Nebraska to Iowa. Along the way, rising waters quickly flooded communities. High waters from the Missouri River and other branches poured into the Mississippi. The river swelled to record-breaking levels. By late June, the flooding was severe and widespread. At least 11 states asked the federal government for disaster funds.