Into the flood zone

How mandatory flood protection systems are evolving for commercial buildings

As the destructive impact from super storms and daily flooding due to climate change become an inevitable commonality, new technologies must arise and evolve to protect commercial buildings.

A new dormitory at Arizona State University was in a flood zone due to the threat of flash floods in the desert. Savannah Trims designed and manufactured flood doors with flood glass designed to withstand 5-foot water levels on one side of the building and 7-feet on the other. These doors have been installed on ground level to protect lobbies and retail storefronts. In addition, FEMA, the Army Corp of Engineers and the National Flood Insurance Program are continually revising flood zones and requiring mandatory flood protection systems to be installed in new commercial buildings and those undergoing a 50%-plus renovation. South Florida-based Savannah Trims is on the frontlines of the flood battle, developing defensive systems which include flood gates, flood doors, flood barriers, and the latest innovation, flood glass. The latter (Flood Glass) has the advantage of always being on station, requiring no deployment or storage and is becoming the clear go-to solution. We sat down with former US Army Combat Engineer Gene Kennedy, president of Savannah Trims, to get insights on some common questions regarding these products and the mandatory standards now in place.

As storms and flooding become more common, what are cities doing to respond?

There’s no question that rising seas and more frequent flooding are putting cities at risk. In many cases, the installation of flood protection systems have been voluntary. However, in recent years, governmental agencies have implemented mandatory flood protection standards for new and renovated buildings.

How are these new standards determined?

In recent years, the Army Corp of Engineers, FEMA, American Society of Civil Engineers and the National Flood Insurance Program have implemented standards for the construction and renovation of commercial buildings. These organizations regularly update flood maps that reflect expanding flood zones. They must implement flood protections, which include flood doors, barriers,

gates and flood glass. These can shield from damaging flood waters. As the size of flood zones grows, more buildings require these protective systems.

What are some of the most high-profile or unusual enforcements of these new regulations?

SuperStorm Sandy ravaged New York City for more than $19 billion in damages, most of it from flood damage. The damage was widespread as a storm surge hit a 600-mile stretch of the Eastern Seaboard. Lower Manhattan’s Battery Park was hit by 14-foot waves. More than 80% of Atlantic City was underwater. Some of the Boardwalk was swept away. New Orleans was among the first of large cities to be affected when Hurricane Katrina generated a 27.8 storm surge which topped levees, killing almost 2,000 residents and causing $105 billion in damage. Since then miles of levees have been built and repaired along with a large surge barrier. Walls and levees have been raised. These efforts have all been effective. Keep in mind that less catastrophic storms, rainfall, and rising tides, are also influencing the construction and renovation of buildings. Streets in cities such as Miami and Philadelphia regularly flood from heavy rainfalls. Flood zones in these cities are expanding, requiring more flood protection systems.

What are the various technologies used to protect commercial buildings from flooding?

As with many technologies, flood protection is evolving. Examples of these mandatory systems are flood gates, flood doors, flood panels, and stacking flood barriers which all require storage and manual installation as storms approach. Rushed deployment can be problematic as they are somewhat cumbersome, detract visually, and require trained personnel and may have missing components due to theft and loss.

We’ve heard of flood glass. Could you please explain this protective system?

Flood glass is a relatively new technology developed by Savannah Trims. It has emerged as an effective, permanent, and convenient way to meet the evolving standards and protection requirements. The major benefit is that it is permanent and does not require storage or manpower to install. The emergence of flood glass is similar to that of hurricane shutters. Early versions of shutters required significant manpower with the installation of cumbersome plywood and aluminum panels. Today, many buildings have turned to impact glass. Flood glass is similar in that it is permanent and always deployed. Regardless of the systems, the goal is to make buildings “watertight, substantially impermeable to flood waters” and to provide some degree of protection against impact of floating debris.

A new dormitory at Arizona State University was in a flood zone due to the threat of flash floods in the desert. Savannah Trims designed and manufactured flood doors with flood glass designed to withstand 5-foot water levels on one side of the building and 7-feet on the other. These doors have been installed on ground level to protect lobbies and retail storefronts.

There is no question that large storms and climate-change flooding will increase in coming years. Governmental agencies will continue to re-map areas.

St. Denis Catholic School, Manasquan, NJ. Removable Flood Barriers.

Where can we learn more about the standards set by these government organizations?

The following are brief explanations:

> FEMA Sections 102 / 3-93 —

Refers to flood proofing for non-residential structures and reviews a range of flood proofing techniques including natural and man-made barriers.

> ASCE (American Society Of

Civil Engineers) — ASCE /SEI 7-10 considers minimal design loads for buildings and other structures to include the forces of flood water.

> US Army Corp. Of Engineers:

Chapter 7/Section 701.2.2

Type 2 Closures — Requires dry barriers or seals allowing only slight seepage during Hydrostatic pressure conditions of flooding to the RFD (Regulatory Flood Datum).

The commercial flood protection standards call for these technologies to withstand debris impact from a 1,000-pound log floating at 5-8-feet per second.

What are the major challenges in manufacturing these flood protection systems?

The major challenge is that every job— whether it is flood gates, flood doors, flood barriers or flood glass—is custom designed for each building due to the vast array of building types, the multitude of construction methods and materials and the variations of opening configurations. In addition, each building may be in different parts of a flood zone, thereby requiring different levels of protection. In short, there are no “off-the-shelf” solutions.

What are some of the considerations when designing these systems?

Again, each job is different based on FEMA’s projections that include: > Flood warning time > Use of building > Floodwater velocities > Floodwater depths > Debris impact > Flood frequency

This research will dictate the height of flood glass, barriers and gates and strength, how much water pressure they can withstand, and effectiveness in preventing penetration by floating debris. All of these components are designed, engineered, tested and verified in order to secure a Flood Proofing Certificate for Non-Residential Buildings.

Can you give us a few examples?

Here are some interesting projects we’ve worked on. Protecting The World Trade Center: Lower Manhattan is at significant risk. At the center of the Battery in New York is the World Trade Center and its underground infrastructure. A flood glass system was installed on elevators that bring commuters from the subway to street level. These reinforced glass panels are designed to withstand 7-feet of water. It provides a passive system requiring no deployment assembly or storage of materials. From an architectural standpoint this solution provides the least visual impact as there are no visible means of barrier attachments. Flood doors also have been installed here to protect utility equipment. This area, according to flood mapping, must protect flooding up to 17 feet.

The Triboro Bridge — This landmark structure is also subject to flooding. During recent renovations, engineers and architects had to budget for flood doors to protect utility equipment. The mapping called for doors to be able to sustain up to 27-feet of flood waters.

Floods In The Desert — A large dormitory at Arizona State University in Flagstaff found itself in a flood zone in the middle of desert due to threats of flash flooding. The administration rejected removable flood barriers since flash floods come with no warning and could not be installed. The school installed flood doors with flood glass designed to withstand 5-foot water levels on one side of the building and 7-feet on the other. These doors have been installed on ground level to protect lobbies and retail storefronts.Today, many buildings have turned to impact glass. Flood glass is similar in that it is permanent and always deployed.

Gran Paraiso, Miami, FL Removable Flood Barriers What does the future hold in regard to flooding and evolving protection products?

There is no question that large storms and climate-change flooding will increase in coming years. Governmental agencies will continue to re-map areas. This will result in larger flood zones requiring flood protection deployment. As this inevitable situation continues, new products—like flood glass— will come to market. It’s important for engineers, architects, property managers, and building owners to stay abreast of these changes as they design new commercial buildings and renovate existing structures. CCR