Evans: Weathering failing infrastructure

Bill Evans is a meterologist for WABC and author of the science fiction novel "Dry Ice."

Civil engineers, who design our roads, bridges and sewer systems, may soon want to take a course on meteorology. There appears to be an emerging character among some storms: overachiever. South Shore motorists and homeowners discovered what that means this past weekend, as roads and basements were inundated by heavy rain that came and stayed.

The past several seasons, weather computer models have accurately predicted blizzards and nor'easters arriving over our area. But once the storms got here, some of them intensified even more than had been projected. Take this past Sunday's accurately forecast wash out -- on Long Island, it turned into "Where did I park my ark?"

We have been experiencing storms that are more complex and more damaging, making all the previous calculations on how best to hold back the water irrelevant. As civil engineers work inside the exacting science of moving so many cubic feet of water per minute through culverts and sewer pipes, they need to appreciate that the world of concrete and steel is facing unprecedented weather systems that will threaten road safety and transportation.

The algorithms that go into computer weather models will be tweaked to compensate for this anomaly, so forecasts will become more detailed. But the bigger question is, "Should we also tweak our infrastructure in order to compensate?"

At a recent conference with engineers from AECOM, a company that helps manage infrastructure projects throughout the United States and around the world, I learned that many major roads and bridges are designed to 100-year-storm specifications. That is, designs are meant to deal with the kinds of severe weather you would encounter just once in 100 years -- the kinds of storms that are capable of causing catastrophic damage. It's becoming obvious with our changing weather that these cycles are in need of recalculating.

What we build and how reflects the constantly shifting answer to the question, "How much infrastructure do you want to buy?" Want to build to a 200-year-storm cycle? The more robust a design, the more expensive the structure, roadway or bridge will be to construct.

Probably since the first arch bridge was built, infrastructure has been subject to budget pressures. Designs represent a series of compromises dictated by finances. Yet as suggested by last weekend's storm, which dropped 10 inches of rain in several hours across New York, our infrastructure has a specific break point. The flooding of highways, homes and storm drains represents the intersection of severe weather and aging infrastructure, too often ignored.

As the General Contractors Association of New York recently noted, it isn't just about putting money into new infrastructure, it's about maintaining it. While GCA was speaking in defense of the Port Authority's request for toll increases in part to cover bridge and tunnel costs, the far broader implications for maintaining infrastructure can be found when 100-year designs fail because dollars weren't appropriated to care for these investments.

Few expect residential streets and highway arteries to be immune from hurricane flooding; wind velocity, tidal action, storm surge and rainfall trump any mathematical projections for infrastructure design. Yet the summer storm that came to stay for an entire Sunday is neither unusual nor extraordinary. The storms of July 8 and Aug. 1, while not even the caliber of a tropical depression, wrought significant strain and eventually some destruction on infrastructure from New York City, to the Bronx, to Greenwich, Conn., to Long Island.

Hundreds of municipalities across the region are facing the same dilemma: changing weather. It's a reflection of emerging patterns that will return time and again, forcing us to answer a slightly different question: "Do you want to invest in infrastructure to meet these new types of storms, or do you want to relocate to higher ground?"