Hydrologist notes Ocean City wasn’t beach community 21,000 years ago - Ocean City Sentinel: News

Hydrologist notes Ocean City wasn’t beach community 21,000 years ago

By ERIC AVEDISSIAN/Sentinel staff | Posted: Wednesday, November 27, 2019 11:12 am

OCEAN CITY – Dr. Tom Harrington, a hydrologist from the Urban Coastal Institute at Monmouth University, said thousands of years ago, Ocean City wasn’t a beachfront community.

He also said the current flat nature of the island causes problems with runoff, but that Ocean City is among the few communities being proactive in the ongoing fight against flooding.

Harrington spoke Nov. 16 at an Ocean City Flooding Committee meeting and gave a background of the region’s geology and its relation to historic flooding.

In the distant past, the coastline was radically different than it looks today, he said.

“If we were here 21,000 years ago and we had a house in Ocean City we’d be commuting to the beach as if we lived in Philadelphia. The actual coastline was way out on the edge of the continental shelf. There are some archeological records that show there were forests out there on the shelf,” Harrington said.

Harrington said based on historic tide records, sea level in Atlantic City has risen at 4 millimeters per year and the island slowly sinking over the past 100 years. He noted the weather service’s analysis showed more rain events along the Mid-Atlantic coast. 

“Because we have the sea level inching up on us every year, we have a higher probability of rainfall occurring at high tides that are going to create flooding conditions,” Harrington said. 

He said a loss of wetlands also impacts flooding intensity. 

According to Harrington, ocean temperatures are increasing, with the expansion of the heated water elevating water levels. He added that ice sheets in Greenland, Antarctica and Canada are melting and adding water to the sea level. Watershed impermeabilities cause water runoff into the oceans, he said.

Harrington said hard rainfall and high tides can cause higher probability of serious flooding on barrier islands. 

“If you get a half an inch of rain and tide is at a higher high tide of the month, you get a lot of flooding. That’s not even minor flood levels … that’s just high tide,” Harrington said. “We’re seeing flooding occur below the minor flood elevation level when it rains. That’s something we want to understand in better detail.”  

Harrington presented a topographic map of Ocean City which showed a lack of sloping which facilitates water runoff.

“We’re very flat. There’s no pitch to get the water down and out of the streets very quickly,” Harrington said.

He said Ocean City has done notable flood mitigation work to their infrastructure by replacing outdated drainage pipes and built new pumping stations. 

“There are a few communities in New Jersey that are proactive. Yours is one of them,” Harrington said, adding OC Flooding Committee has pushed the city officials to action. “They have done things. Other communities have done nothing except sit there and say, ‘We’re going to get wet, just get used to it.’”