Gilbert Sebenste remembers when Watson Creek flooded on June 16, 1999.

“I was at the intersection of Locust and Carroll streets,” NIU’s staff meteorologist told audience members at “Hazards From the Sky,” a weather safety seminar for students and staff Tuesday. “There was 6 inches of water flowing down it. The entire NIU visitor’s parking lot was flooded, which reinforced the reason why people shouldn’t park there.”

Sebenste warned of the dangers of flash floods — a significant threat to campus because Watson and Kishwaukee creeks frequently spill over their banks.

When Watson Creek flooded two years ago, 3 inches of rain fell in three hours.

“Neptune Hall was at the greatest risk for damage, but the groundskeepers were informed,” Sebenste said. “They put sandbags up, and the hall didn’t suffer any damage. NIU has dredged the creek since 1999, which has helped substantially. There is also talk of putting in retention ponds upstream. By putting up sand bags, we can stop the damage, but not the flood.”

Sebenste warned people to get away from rivers and streams when there is a flash flood alert.

“It is especially dangerous to drive across water-covered roads at night,” he said. “I learned my lesson one night when I did just that. I found my car in 6 inches of rushing water. The water was so powerful that it began to move my car across the road. Luckily, the tires hit dry land before the car was swept away. I thought I was dead, but it made me learn to take my own advice.

“I am trained in this, and I couldn’t even tell that the water was that deep,” he added.

Sebenste also spoke Tuesday about tornadoes, known to develop in Illinois beginning in the spring. They are usually less than a half-mile wide but strong ones can cause significant damage, with winds up to 300 mph, Sebenste said. He warned that early action is essential to survival.

“You should seek shelter in a sturdy building during a tornado warning,” he said. “The taller the building, the more secure it is, but go to the lowest level possible. Get under a piece of sturdy furniture. A person caught outside should seek shelter in a river valley, ditch or ravine and lie flat. Under any circumstance, use your arms to protect your head and neck.”

Sebenste added that just like with most weather phenomena, tornadoes strike all over Illinois.

“Tornados are equal-opportunity destroyers,” he said.

Flash floods and tornadoes aren’t the only weather that affects DeKalb. Thunderstorms, lightning and wind storms also can cause serious damage and even death, Sebenste said.

Lightning is the most dangerous form of weather and kills the most people, 50 percent of whom are golfers, he said. The other half are mostly campers, hikers and outdoorsmen.

If caught outdoors with no shelter in a lightning storm, stay low to the ground and avoid tall objects like utility poles and trees, Sebenste said. Get off the phone, too, because lightning can strike phone systems and travel miles through the cables.

Thunderstorm watches and warnings and strong wind advisories should be taken seriously, too, he noted. Take shelter during thunder- and windstorms and stay away from windows. If caught outside, lie on low, flat ground and stay away from objects that could be blown around.