Thousands of people have been evacuated, some 15 have died and at least a dozen are missing across the US Midwest and northern Mexico, as a result of flash flooding and other extreme weather phenomena, including tornados, which struck the area over the weekend and on Monday. Similarly severe storms are expected to impact a much broader area of the American South and Central Plains in the coming days, according to the National Weather Service.

Rivers in some areas have surged by up to 30 feet virtually overnight, as all-time record levels of rain have fallen across Texas, Oklahoma, and a number of other central US states, drenching many areas which have suffered intense drought until recently. In scenes reminiscent of Hurricane Katrina, many Texans have been forced to navigate local roads using inflatable boats and other small watercraft.

Entire streets have been left with “maybe one or two houses left on them and the rest are just slabs,” local emergency coordinator Kharley Smith said in public comments.

In Oklahoma City, nearly 28 inches of rain have fallen in 2015, as compared to less than 5 inches in all of 2014. Residential areas have been completely inundated with water, stranding scores of residents who have been forced to evacuate via helicopter.

Teenager Alyssa Ramirez died after her vehicle was overwhelmed by surging floodwaters on the way home from her high school prom near San Antonio, according to reports Monday. Two other deaths were reported as a result of flooding in Texas.

At least two residents have been hospitalized as apartments near Houston, Texas, were struck by a tornado. An infant was reported to have been torn from its mother’s arms as a tornado struck across the border in Mexico’s Ciudad Acuna. As many as 13 other residents were killed and hundreds of homes were destroyed as a massive tornado ripped through the town in northern Mexico.

Large swathes of the central US have been placed on tornado alert. At least one first responder, an Oklahoma firefighter, died during rescue efforts over the weekend.

Emergency flood alerts were announced in Kansas, Missouri and Arkansas as the storm system continued to develop and began moving across portions of Colorado, where at least one city has been evacuated and several counties have appealed to the state government for emergency aid.

Rising water levels in Texas’ Lake Lewis, surpassing previous records from the 1920s, have raised fears that a major dam could be compromised and vastly intensify flooding in the surrounding area, prompting hundreds of evacuations.

In some US states, almost 50 percent of dams are insufficiently prepared to handle such a disaster scenario, according to recent data from the National Inventory of Dams. Hundreds of “high hazard” dams lack any substantial plan for dealing with the fallout of a dam failure, according to the NID. This is despite the fact that some 180 dams have failed or partially failed across the US during the past decade.

Steadily increasing temperatures in the Pacific Ocean are fueling the extreme and unusual rainfall patterns, climate and weather experts say.

At the same time, the increasingly decrepit condition of US infrastructure, including preventative infrastructure such as berms designed to contain floodwaters, ensures that any extreme weather events, whether hurricanes, tornados, floods or otherwise, will produce far greater damage than if these systems were in good repair. The American Society of Civil Engineers (ASCE) has warned repeatedly in recent years of dangers posed by inadequate investment in public flood control projects.

Across the US, waterways and dams now regularly receive near-failing grades from ASCE maintenance scorecards. Nationwide, US infrastructure received an average score of D+ in the ASCE’s 2015 report.