Municipalities along the east coast of the United States of America are the frontrunners in need of stormwater infrastructure retrofits, mainly due to the age of their crumbling infrastructure and increase in population. A common example of this issue are cities near the coast lines – more specifically a city in North Carolina near Pasquotank River.

The city experiences frequent flooding due to 2 separate issues coined as “Dry and Wet Days”.  The Dry Day flooding referrers to roadway flooding caused by the local River that drains the city’s streets and roads. The Wet Day flooding referrers to roadway flooding caused by precipitation.

The impact of a Dry Day flooding is best explained as increase in the Pasquotank River’s water surface elevation (WSE) consequently bypassing the land barrier block and trespassing into the local streets via the stormwater infrastructure network.

The impact of a Wet Day flooding is a more commonly known flooding due to precipitation and lack of adequate stormwater infrastructure to convey the surface runoff.

As precipitation flooding is a frequent event along the east coast, it is important to note the Dry Day’s impact on the available outfall WSE – the combined effect of the Dry and Wet Days yields a significant issue with a lack of simple solutions. Addressing the impact of both ‘Days’, the way forward requires an in-depth analysis  via a stormwater model conducted in PCSWMM.