Wednesday, October 7, 2015

King Tides and your Backyard: A Snapshot of our Future

By Rachel Calabro, Community Organizer and Advocate at Save The Bay

As hurricane Joaquin headed away from the East Coast earlier this week, it felt like we dodged a big one. This doesn’t mean, however, that we shouldn’t view this as another wake-up call for what is happening with coastal flooding. The footage coming out of the flood in South Carolina is shocking, but all too real. The potential for our warmer atmosphere to hold water and dump it all at one time is increasing. And, in addition to the growing intensity of rainfall, sea level rise is forcing many coastal residents deal with flooding on a regular basis.

As residents of coastal New England, we need to watch the skies not only for rain clouds, but also for the moon. Why the moon? The full moon brings with it the highest tides of every month. A few times a year (often close to the autumnal equinox), it brings the highest tides of the year, called King Tides.

This is what we experienced last week when everyone was excited about the lunar eclipse. The tides that week were expected to experience a seven-foot difference between the low tide and high tide in Providence. Most full moon tides in Providence average around five feet, and during a half moon, around four feet. The additional two to three feet of water that come during King Tides are just the beginning of the trouble. Add in winds from the south and ample rainfall, and flooding gets worse. Tides last Wednesday registered above eight feet at the top of the Bay.

Save The Bay, along with our partners at the Coastal Resources Management Council and the Coastal Resources Center at URI, is helping to capture photos of these events to share with town and state officials and the public. The photos are available to view at mycoast.org/ri. Volunteers have been out across the state taking photos and using a new smartphone app that is also available to support the mycoast.org webpage.

Car drives through floods along Mathewson Rd. in Barrington.
It doesn’t take much to go from an extremely high tide to water so deep you can’t drive through it. One important thing to remember is that if you are near the coast, this is salt water. Even if it's raining, these are not just puddles, and you can significantly damage your car by driving through it. Don’t let this be you.

Drinking water is on the left side of this dam, while coastal
salt water is on the right.
Roads are not the only infrastructure in danger from high tides. Drinking water reservoirs, waste water treatment plants, pump stations and power lines are all located in coastal areas that will flood in the future. This photo of Nonquit Pond in Tiverton reveals that there are only few years left for this reservoir to retain its current use as a drinking water supply.

National Grid tries to protect is power lines in India Point
Park in Providence.
Snow fencing and hay bales will not stop the inevitable march of the tides.

These photographs are just a vision of the future. Taking the long view is important and planning to accommodate water in whatever way possible will be the best way forward. For now, invest in a moon calendar, and be aware of your surroundings.

Cars are stuck in their driveway at Spadina Avenue
in Warwick. How many days per year will this happen,
and how do we plan for the future?
Currently, this kind of flooding takes place in Rhode Island just a few times a year, but is forecast to become much more common with a continued rise in sea level. This post from the Union of Concerned Scientists points out that by the year 2030, we could be seeing a few dozen days of flooding in locations that only flood occasionally today.

Download a PDF of the full report on coastal flooding here.

If you are interested in helping to record high tide events, the next King Tide will be on October 27th and 28th. Go to mycoast.org or download the app to get started.