The historic storm that struck Houston on Monday may have caused as much flooding in some areas as Tropical Storm Allison did 15 years ago, suggesting the possibility of billions of dollars in economic and insured losses.
While it will take days for flood waters to recede and the damage to become clear, some figures are beginning to emerge. Ratings agency A.M. Best, citing the Insurance Council of Texas, said insured automobile losses alone could top $200 million.
Catastrophe modelers Aon Benfield described the flooding in some parts of the city as a 1-in-200-year event.
While Aon said it was too soon to know the actual economic losses for the event, it noted that in some areas the flooding was as bad as or worse than Allison, which caused $7 billion in economic losses in 2001.
"A preliminary tally suggested that a minimum of 1,000 homes were damaged, though it is expected that the final total will be far higher," Aon said.
NBC affiliate KPRC reported that more than 240 billion gallons of water fell on the Houston area, with some parts of town breaking daily and monthly rainfall records before lunchtime.
Catastrophe modeling company AIR Worldwide, whose data is used by insurers to project losses, noted in a Tuesday report that two dams in the Houston area were in an "extremely high risk" condition, with the potential for tens of billions of dollars in losses if they breached.
The floods, and whatever damage they may have caused, come on top of more than $1 billion in destruction last month from two hail storms in other parts of the state.
By comparison, for all of 2015 the entire state had about $3.2 billion of insured catastrophe losses, according to the Insurance Council of Texas.
The greater Houston area has a relatively high concentration of federal flood insurance policies, which could increase the size of the insured loss relative to the economic loss.
According to Federal Emergency Management Agency (FEMA) data, at the end of February there were more than 120,000 flood insurance policies in force in the city of Houston, representing $31.9 billion in coverage.
Since 1978, the National Flood Insurance Program has paid out more than $6.1 billion in flood losses in Texas, with $1.4 billion of that in the city of Houston proper.