The highest tides of the year, known as king tides, are back to flood roads, parks and the occasional home or business.
This year, in addition to the army of flood pumps coastal cities are deploying to keep streets dry, the City of Miami hopes its residents will watch for flooding and report what they see. It’s part of a new partnership designed to fill the gaps that computer models can’t fill.
“We always say humans are the best sensors,” said Claudia Sebastiani, Miami community manager at ISeeChange, a New Orleans-based company that collates changes reported by residents in their neighborhood — like points Flood Protection – to help cities decide where to invest in flood protection.
Royal tides began in September, and some of the first posts on the app show the now familiar sight of deep pools of water around storm drains and parking lots. This batch of high tides runs from October 14 to 21, according to NOAA calculations. The tides climbed higher and higher before peaking at Friday morning’s high tide and slowly receding.
“Tides are currently 0.6ft above NOAA predicted peaks which (if consistent) should result in a maximum royal tide of approximately 1.7 FT NAVD,” wrote Alan Dodd, Director of Miami Resilience, in an email.
These annual tides are naturally high thanks to the influence of the moon and the Gulf Stream, but rising sea levels have made them the most visible symptom of climate change. High tides increase as the oceans warm. A recently released report showed that the 2020 high tides in Miami-Dade could be the equivalent of the daily high tide by 2040.
High tides give cities a chance to see how their drainage systems will perform under the high tides of the future and to test out the expensive new improvements they have made.
Miami has already installed 103 one-way tidal gates, which allow water to flow out of drainpipes but prevent it from seeping in, in addition to several pumping stations. For this royal tide, Dodd said the city has placed temporary pumps in five locations: the Shorecrest neighborhood, Morningside Park, Brickell Bay Drive, Fairview Street and North Bayhomes Drive.
Miami Beach, which has spent hundreds of millions raising roads, installing flood pumps and raising levees across the city, is deploying eight temporary pumps. They will be placed at Commerce Street and Alton Road, 8th Street and West Avenue, 19th Street and Jefferson Avenue, Muse Park, 56th Street and North Bay Road, 59th Street and North Bay Road, Rue Notre Dame and Marseille Drive and 29th Street and Indian Creek.
Miami Beach residents who live on regularly flooded streets can request free parking elsewhere in the city during high tides and hurricanes. The city is also “strongly encouraging” residents in these areas to put up flood signs or use sandbags to protect their property, according to a newsletter the city sends out ahead of the king tide events.
In Miami Beach, residents can report flooding by emailing [email protected] In Miami, residents can post photos to the ISeeChange app, which is undergoing a 2-year pilot partnership funded by the Knight Foundation.
“We’re really trying to center residents in this experience, rather than centering the tides all the time,” said Jared Genova, strategist and director of business development for ISeeChange. “If we don’t understand how those three feet really affect people, then we don’t know how to plan for it.”
In New Orleans’ lower Gentilly neighborhood, ISeeChange users documented 28 flood events over four years, leading the city to change its flood protection plans to stockpile even more water under a neighborhood football and baseball field.
Genova said the company hopes to replicate that success in Miami, which is developing an all-new stormwater master plan designed to deal with flooding in the city.
This means that when the models shaping the plan spit out a potential problem, Sebastiani will check it out. She talks to residents to see if there really is flooding and if it is overwhelming their homes and businesses.
Last week, locals showed him how a bus stop in Little Havana submerged in the slightest storm, with floodwater reaching half the adjacent parking lot.
So far, there are only about 50 posts on the site’s Miami page, many by Sebastiani herself. She attributes the low user base to the digital divide in older, more inland neighborhoods. The app is adding Spanish translations, and Sebastiani said she would like to see Haitian Creole added in the future.
The oldest citizen science program focused on the royal tide, Florida International University’s Sea Level Solutions Day, is hosting its fourth annual event on Saturday. Participants check water depth as well as water quality, which can be contaminated by fertilizer washed off lawns, dripping oil from cars or the thousands of leaking septic tanks throughout the county.
The last bout of royal tides this year will be November 13-18, although NOAA does not expect it to be as high as the October tides.
This story was originally published October 15, 2020 2:29 p.m.