We live on a small bay on the south shore of long island. We have a storm sewer that empties into the bay through our bulkhead. When we have storm surges, or extremely high tides (2-3 times a year) water travels up the storm sewer to the street. From the street it starts coming up the driveway to the house. The lower level is a garage that is converted to mixed use (workshop/gameroom). When the water comes up it gets into the workshop/gameroom.
In 2005 we got hit pretty bad, 10 inches of standing water, we had to gut the whole lower level. Post 2005, we installed a french drain system with a sump pumping the water to the sewer system. The interior walls were constructed 3 1/2 inches from the foundation walls and divert any water to the french drain system. It has worked for the last few years, but as hurricane season approaches, I constantly wonder if I could improve the grading of the property by raising the concrete around the perimeter, I just didnt want to tear up the existing concrete before trying something like this.