Environment

It rained a lot this year. So much so that 2018 is now the wettest year on record since the National Weather Service began keeping track in late 19th century.

2018 surpassed 2011 as the wettest year on record Monday morning —  the last day of the year.

As of 9:05 a.m., rainfall totals in Louisville reached 68.05 inches beating the old record of 68.02 inches.

National Weather Service Meteorologist Ron Steve said much of the moisture came from tropical systems coming up from the Gulf of Mexico.

“Well we had a wet spring and we had a couple of decaying tropical systems give us a pretty wet start to fall,” Steve said.

Heavy rains this spring caused the worst river flooding since 1997, forcing the Metropolitan Sewer District to release billions of gallons of sewage into Louisville waterways.

This fall, rains contributed to the death of a Abdinasir Siyat, a taxi driver whose car stalled in flood waters at a railroad underpass.

Heavy rain and flooding even cancelled day two of the Bourbon and Beyond festival in Champions Park.

This year’s Kentucky Derby was also the wettest on record, beating a hundred-year-old record from 1918.

Parts of the city usually flood for one of two reasons: either long-term rains saturate the ground and raise river levels, or heavy storms inundate the city causing flash flooding.

All that water has further revealed the vulnerabilities of Louisville’s aging sewers and flood protection system.

In several instances this year, the sewers were not able to cope with the amount of rainwater entering the system, resulting in sewage overflows in some parts of the city and causing MSD to release sewage into public waterways in others.

The city’s concrete and asphalt also increases the risk of flooding. With no way for the water to saturate the earth, much of it runs off. Louisville has 32 flood-prone viaducts where water gathers during heavy storms.

Meanwhile, the city’s aging flood pump stations have had trouble keeping up with the volume of water during some of the year’s heavy storms.

Climate change researchers anticipate Louisville will continue to see heavy downpours that test the limits of the city’s infrastructure as the weather warms. Increasing temperatures are also expected to cause more weather variability, including more hot summer days and a higher likelihood for droughts.

Ryan Van Velzer is WFPL's Energy and Environment Reporter.