Localized Flooding Most Likely Consequence of Florence

Increased Rains Add to Threat in Already Wet Year

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The Canal Basin has already been flooded due to hydrologic pressure from the groundwater due to increased rains and tidal surge, closing the Yards Park water features. The Capitol Riverfront BID has been preparing for the additional impacts of fallout from Hurricane Florence. Photo: Bill Matuszeski

As Hurricane Florence moves towards a landfall somewhere near the border of the Carolinas, it is decreasing in intensity but increasing in size. The District may experience some fallout from the hurricane over the weekend.

While high winds are often thought of as the most threatening aspects in hurricane-related weather, felling trees and downing power lines, increased rainfall in the wake of Florence is likely to have the greatest effect on the District generally and Ward 6 in particular.

Parts of DC lie in a historic floodplain, an area prone to flooding due to heavy rainfall, coastal storms, or both. DC sits on a 100-year floodplain, an area that has a 1 percent chance of flooding in any year. Residents can check if homes or offices are in the floodplain by going online and inputting addresses into the Flood Risk Map.

The Capitol Weather Gang reports that since the storm is predicted to track south of the District, they do not expect increased rain or strong winds over the weekend. However, the storm is expected to turn north early next week, bringing with it the potential for increased rain between Monday and Wednesday.

Preparations

According to the Gang, this is the District’s fourth-wettest year on record. By August 22 DC had reached the average yearly total rainfall of 39.74 inches; that total has now risen to nearly 46 inches as of September 12. So, it won’t take much more rain to cause flooding.

The communities near the river front are preparing for increased water levels. President of the Capitol Riverfront BID Michael Stevens said that most of the BID is outside of the floodplain. Still, the area has already experienced consequences of increased rainfall.

Water has flooded into the Yards Park water feature because of hydrologic pressure from the groundwater due to increased rains and tidal surge.

“We have drained the canal basin and will leave it empty until the rains have ended next week and groundwater is not coming into the basin,” said Michaels. “We will deep clean and refill the canal basin when the weather stabilizes, in hopes of having the water features open until the end of October.”

Stevens said the flood walls installed at stretches of Yards Park have worked well, and that the BID monitors the high tide time every day and National Weather Service reports about the high tide crest.

He added that retail at Yards Park overlook have suffered from the same water rise that closed the water park, and have sandbagged their storefronts and are temporarily closed. “We are fortunate that most of our office buildings, residential buildings and retail and restaurant establishments are on higher ground,” said Stevens.

The Wharf DC is also along the shores of the river, with construction proceeding on Phase II of the development.

Director of Security and Public Safety for The Wharf Association Diane Groomes said that “the Wharf Community Association is closely monitoring weather forecasts and current conditions, and is communicating and coordinating with local agencies in preparation for a potential weekend weather event.”

Localized Flooding

Even communities located further from the river can experience the consequences of increased rainfall. One of the greater threats to Hill residents is localized flooding due to blocked or overwhelmed catch basins, the 25,000 drainage openings on city streets, said DC Water spokesperson Vince Morris. A team of 500 emergency personnel stands ready to be deployed to assist in clearing blockages throughout the city.

“But constant rainfall could overwhelm the system,” causing local flooding, Morris cautioned.

Flooding can also threaten the cleanliness of the river, carrying items and pollutants along with it as water flows to the Anacostia. Residents can take steps ahead of the storm to help prevent flooding and its consequences:

  • CHECK all gutters and storm drains and remove debris and blockages.
  • COVER and SECURE garbage and recycling bins, propane tanks, and other outdoor containers so they do not collect water, spill, or get knocked over.
  • REPORT clogged storm drains to DC Water:
  • PUT OFF digging and applying pesticides, herbicides, and other chemicals 24 hours before it is expected to rain, when it is raining, or when the soil is saturated; the rain will just wash off the dirt and chemicals into District waterways.

The path and impact of Hurricane Florence may change and is being constantly monitored as it moves closer to landfall. Residents are encouraged to stay informed via the District’s Emergency Alert system.

Mayor Muriel Bowser announced Monday morning that she had signed an Executive Order declaring a State of Emergency in the District, effective immediately. Mayor Bowser and Director of DC Homeland Security and Emergency Management Agency (HSEMA) Chris Rodriguez encourage residents to:

  • Sign up for emergency text alerts at alerts.dc.gov
  • Reach out to friends, family and neighbors to help them sign up for alerts
  • Go to the grocery store
  • Check emergency first aid kit
  • Fill prescriptions to the end of next week
  • Determine what medical devices, prescriptions require power or refrigeration and develop a plan
  • Charge all mobile devices and back-up power sources
  • Acquire flashlights, batteries
  • Review your family’s emergency plan

For tips on coping with emergencies, visit the HSEMA website at https://hsema.dc.gov.