Ocean City engineers explain that the city is unable to handle severe rainfall amounts that led to drastic flooding in the area earlier in the month. The north end of the city’s topography and elevation puts additional stress on the city’s drainage systems which suffered from four to six inches of rain, with some reports of up to seven inches of water, in three hours.
The rainfall, unusual for the area, led to flooding that was “wheel deep” with many trucks having water up to the top of their wheels. The city is known for flooding with modest rainfall, and residents are used to roads being shut due to flooding, but the most recent rainfall was more severe.
Roads were closed and backed up further due to traffic jams as seniors flocked to the area to celebrate graduation.
The Coastal Highway was forced to shut down for an extended period of time as residents and tourists waited for the water to recede.
Engineers that assessed the system, which runs east to west, claim that the sewer systems were overworked and couldn’t keep up with the rain. Ocean City is also close to sea level and is known as a barrier island which makes flooding more intense.
The little surface area is a growing problem with the city nearly completely built out leading to less rainfall absorption. The result is rainfall that is forced to run into the city’s current sewer drain systems with little absorption along the way.
The topography of the area requires a gravity system to control stormwater. A gravity system utilizes pipes to create water movement, but the ground elevation and the tide limit the scope of the system. The island’s flatness makes it difficult to create a steep enough slope to control the flow of the water to the bayside.
Engineers claim that they’re limited on what methods they can employ to control large rainfall amounts. The hydrology and topography make it difficult to control the water with greater efficiency without a cost-prohibitive pump system being installed.
Ocean City’s buildings are required to be elevated due to the lack of flooding control in the area.
Lower Delaware and Worcester County suffered severe flooding, too. Infrastructure in the United States is aging with the country’s infrastructure receiving a “D” grade. Ground water infrastructure in the United States, according to a study conducted at Utah State University, is starting to fail. The study found that the majority of the infrastructure was installed in the 1800s and between 1900 and 1945.
Cities are struggling with aging infrastructure that needs to be replaced or repaired.
Pittsburgh’s sewer system is slated to cost the city $2 billion as an overhaul is underway to increase waste water capacity by as much as 25% of current capacity. Complex pumps and tanks are also overwhelmed during heavy rains leading to 16 billion gallons of sewage ending up in rivers annually.
Ocean City’s sewer systems are more complex with topography and elevation leaving engineers with very few options to control flooding in the area.