How Could A Storm Surge Affect Black Rock?

As water approaches land during a hurricane, the water “piles up” creating a higher level of water and a more powerful rush of water towards land than normal wave action. This is called a storm surge.  If a storm surge occurs at low tide, it obviously has much less impact than a storm surge that occurs at high tide.  Those of us who can recall living in Black Rock in 1985 when Hurricane Gloria hit, remember that the biggest concern was that the storm would hit at high tide.  A storm surge that hits at high tide is called a storm tide.  Shallow waters produce a greater storm surge than deep waters, which means that the areas close to the Sound (which is relatively shallow compared to the ocean), the Ash Creek tidal estuary, and Black Rock Harbor and Burr Creek would be most affected. 

Low lying areas are the most affected, so knowing the elevation of your property and the roads you plan to use to evacuate is important.  For example, a storm surge could come down Ash Creek and continue past Livingston, Courtland, and Clarkson almost to Fairfield Avenue as that area has a low elevation.  Near Burr Creek, Arthur Street and parts of Hackley and Ferris would be likely affected.  Even areas of Grovers Avenue and Gilman Street could be affected.  If you live on Grovers Hill, you would need to wait out a storm surge as there is a flood zone at the bottom of Balmforth on the Grovers Avenue side and Gilman Street is only 10’ above sea level on the other side.  High tide is expected at 11:10 AM on Sunday morning and Irene is expected to arrive on Sunday morning.  It’s too early to tell if Irene will stay on course or still be considered a hurricane when it affects our area or how fast it will travel, but right now there are no indications that it will lose strength or veer off course.  We all hope it will, of course.  Governor Malloy is recommending a voluntary evacuation of residents who live in low lying areas.  A good number of residents in Black Rock live in low lying areas.  Mayor Finch has not yet required evacuations in Black Rock, but that did happen in 1985 with Hurricane Gloria, so it could happen again.  Be prepared to leave with your pets as the National Guard will not rescue animals.

Just because your home is not in a flood plain does not mean it is safe from a storm surge according to a post on The Commercial Record website   The Commercial Record stated that “an estimated 61,000 residential and commercial properties in the Bridgeport area could potentially be impacted by Hurricane Irene storm surge flooding, depending on where the storm makes landfall.   Of the total properties at risk in the Bridgeport area, almost half, or 45 percent, are not in a designated Federal Emergency Management Agency (FEMA) flood zone.”  The analysis assumes a Category 3 hurricane.  Right now Irene is a Category 2 and may be downgraded shortly to a Category 1.  However, hurricanes gain and lose strength as they move over water (where they gain strength) and inland (where they lose strength), so it is still too early to tell.

Hurricane-driven storm-surge flooding can cause significant property damage when high winds and low pressure causes water to amass inside the storm releasing a powerful rush over land when the hurricane moves on shore. In some cases, properties located outside of designated FEMA hazard flood zones remain exposed to potential storm-surge damage.

A 4-7 foot storm surge is expected.  High tide is normally about 3-4 feet above sea level.  The storm tide could be 7-11 feet and many low lying areas of Black Rock are only 10 feet above sea level.  Given the right combination of wind and high tide, a series of waves could come down Ash Creek and flood areas of Gilman, Livingston, Newton, Courtland Street, Clarkson, Beachview Avenue (including the Pleasant Bay condos).  It could also come down Black Rock Harbor and affect Seabright, Hackley, Ferris, and Arthur Street as well as some of the condos in the Anchorage complex and other areas of Grovers near the Black Rock Yacht Club.  The scenario could be better or worse than this.  It will all depend on how strong the hurricane is when it arrives.

Take a look at the City of Bridgeport’s GIS system and look at the flood plain map.  Click on the link on the left sidebar, on the front page of the City website you will see Online Services on the right, under “Most Requested Topics” select “GIS” and agree to the terms.  Scroll down and click on “Click Here” to visit the site.  You will then see a map.  Click on “Flood Plain” to the left and begin zooming and panning until you get to a level where you can see your street and your lot.  The magenta color is for the 500 year flood plain.  You will also want to take a look at elevation levels, which can also be chosen by clicking on the box at the left and hitting the “Refresh” button.