Date: 2021-09-17 02:24:20
Extra high tides will be more common in St. Johns County over the next few days and in the months to come, which could bring flooding in downtown St. Augustine and other areas.
“We’re in that season,” said Jessica Beach, the city’s chief resilience officer.
Beach is among the city officials leading efforts to combat flooding downtown, and the city has projects underway to help alleviate flooding.
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The city of St. Augustine issued a warning to residents about king tides, the phrase the city uses to refer to extra high tides, and when they’re expected. Based on National Oceanic and Atmospheric Administration data, here is when the city expects king tides:
- Friday through Monday.
- Oct. 4-13
- Oct. 19-22
- Nov. 3-10
- Dec. 2-8
“King tides are the highest predicted high tides of the year, and they often cause nuisance flooding in coastal and low-lying areas,” according to the city. “More severe flooding can occur if the king tide coincides with severe weather conditions (heavy rain, strong winds, big waves). However, sea level rise is causing these tides to happen more frequently, last longer and extend further inland.”
The city advised people to avoid driving through standing water and avoid parking and leaving vehicles in flood-prone areas. If people have to drive through standing water, they should drive slowly and with caution and avoid creating a wake.
Beach said residents’ garages have been flooded by vehicles creating a wake.
About king tides
Al Sandrik, warning coordination meteorologist with the National Weather Service, calls them spring tides because they “spring forth” — it doesn’t have to do with the season.
According to the National Oceanic and Atmospheric Administration, “During full or new moons — which occur when the Earth, sun and moon are nearly in alignment — average tidal ranges are slightly larger. This occurs twice each month. The moon appears new (dark) when it is directly between the Earth and the sun. The moon appears full when the Earth is between the moon and the sun.
“In both cases, the gravitational pull of the sun is ‘added’ to the gravitational pull of the moon on Earth, causing the oceans to bulge a bit more than usual. This means that high tides are a little higher and low tides are a little lower than average.”
St. Augustine regularly sees issues with flooding from extra high tides and nor’easters, as well as heavy rains.
Easing flooding in St. Augustine
The city has projects underway to combat flooding.
The city has installed more than 40 backflow prevention valves in its infrastructure to keep high tides from backing up through the stormwater system and causing flooding, Beach said. The city is working on prioritizing the remaining areas that need protection. The city has around 100 valves total.
The area north of the Bridge of Lions to the Castillo de San Marcos National monument has valves installed to prevent backups, but south of the bridge is still vulnerable along the bayfront, Beach said.
The city plans to install backflow prevention valves south of the bridge as part of a major flood-reduction project focused on Lake Maria Sanchez, Beach said. The project is expected to reduce flooding in a swath of downtown and provide greater protection against storms.
The project is in design, and documents are expected to be sent for review by summer of 2022 to the state and then to the Federal Emergency Management Agency, Beach said. If approved, bidding for construction of the multimillion-dollar project could begin in 2023.
Also, the city is working on finishing a project to strengthen 13 of its 94 sewage pumping stations against flooding. Pumping station outages lead to sewage spills.
Lift stations help move the city’s sewage to its wastewater treatment plant. The lift stations were damaged in Hurricanes Matthew and Irma.
The city recently finished strengthening a lift station next to the Plaza de la Constitucion. Among other things, the lift station control panel at the east end of the Plaza can withstand being submerged in water, said Stephen Slaughter, city engineering manager.