nothin City Readies New Tools For Superstorms | New Haven Independent

City Readies New Tools For Superstorms

CHRIS HEITMANN PHOTO

West Rock Ave., 2012 flash flood.

Hurricane Jose didn’t end up hammering New Haven. But the city was ready with new 4,000-pound bulk bags” just in case.

Chances are, the bags will be put into use soon when a different superstorm decides to sweep through the city and cause streets to flood.

In an interview, City Engineer Giovanni Zinn described new measures, like purchasing the bags, the city has taken this year now that climate change has made severe storms more common. And the city has been hustling to prepare. There have been six floods in the last five years, including one conventional flood and two flash floods in May and June of 2014. Superstorm Sandy in 2012 cost the city well over $3 million to clean up.

As initial reports suggested that Hurricane Jose might veer closer to New Haven (than it ended up doing), top city officials huddled with the mayor this past Friday morning to chart storm prep — if not for Jose, for others in this season of tropical storms and then into the winter snowstorm season. Officials anticipate that we’ll be seeing higher sea levels, harsher hurricanes, and more frequent floods.

Paul Bass Photo

Giovanni Zinn in the WNHH FM studio.

There’s no question that certainly in the design of infrastructure and how we manage our infrastructure, climate change is a huge deal,” Zinn said during an appearance on WNHH radio. We’re a low-lying coastal city. Our city drains by gravity — all the pipes are pitched in a way to get down to the water. As that water rises, the capacity of those pipes goes down.

You get six, seven, eight inches of rain and a storm surge that doesn’t allow you to drain the city, that’s a problem. That water has to go somewhere.”

Long Wharf, Union Avenue near Union Station, Morris Cove, and Westville center are among the areas that are particularly vulnerable.

A $500,000 federal disaster relief grant since Sandy enabled the city create a mathematical model of the stormwater system. A second $4 million disaster relief grant is enabling New Haven to put roadside rain gardens (aka bioswales”) throughout downtown’s 600-acre storm sewer shed; and to work with the state Department of Transportation to route piping across the railyard (“a nightmare in its own right”) near Union Station, Zinn said.

Officials have also embarked on an outreach campaign to inform residents in flood-prone neighborhoods about how best to protect themselves against the threat of rising water. (Read about that here.)

City of New Haven

Meanwhile, according to Zinn, the city has several new tools this year, including new inundation maps.”

Alfredo Herrera, a new city government GIS [geographic information systems] guru,” has created a tool to craft those custom maps to predict which parts of the city will flood given the combination of rainfall and storm surges. Until now, the city relied on static FEMA maps given to every city, predicting what would happen in, say, a Category 1 Hurricane or a Category 2 Hurricane. But not all hurricanes have the same storm surge,” Zinn noted.

A four-foot storm surge, for instance, will produce different flooding than a six and half-foot surge. The quantity of damage that you get is not linear as the storm surge rises,” Zinn said. Herrera’s maps (above is an example) pinpoint the expected parts of town to be affected by the combination of rain and storm surge.

REBECCA TURCIO PHOTO

Drivers await rescue at Lombard and James during a flood.

Herrera was able to develop the tool using new data from the state, which used an airplane to shoot a laser down every few inches and hit every point of ground” to develop detailed very accurate” topographic data.

If a superstorm hits, the city’s also prepared to erect temporary storm barriers at strategic spots in an effort to prevent flooding. For instance, officials plan to block the two I‑95 underpasses along Long Wharf Drive if necessary, to prevent water from overwhelming Sargent Drive and the Union Station area. Similarly, they’d block a low-lying area of Cart Road near the Morris Street tide gates on the East Shore, where the water can sneak around the sides,” Zinn said.

Melissa Bailey Photo

Waves lap over the sidewalk at Elm and State in a2012 flash flood.

And then there are those bulk bags. The city bought 130 of them, each a cubic yard, to fill with sand. The plan is to deposit them to create temporary barriers at spots like the Blake Avenue bridge in Westville/West Hills to prevent floodwaters from getting through and to keep water flowing along the West River. The plan is to use a forklift to put them in place when a particularly threatening storm is on the way. Each one’s worth about 50 sandbags,” Zinn said of the bulk bags. They’re a lot faster to deploy.”

Click on or download the above audio file (or on the Facebook Live video below) to hear the full episode of WNHH radio’s Mayor Monday” with guests Zinn and city transit chief Doug Hausladen. Discussion of storm preparation begins at the 17:35 mark. The episode also covered updates on the west side cycletrack, the September Car Free Challenge, Walktober,” the Grand Prix, the W House and Armory projects, and the Brewery Street seawall.

This episode of Mayor Monday” was made possible with the support of Gateway Community College and Berchem Moses P.C.

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