One Year Later: The Changes Brought by Helene

It’s been over a year since Hurricane Helene caused historic devastation. The storm was the deadliest to hit the US since Hurricane Katrina in 2004. In NC alone, Helene caused 107 deaths along with billions of dollars in damage. Lakes flooded, entire buildings were swept away, and even the paths of streams and rivers changed. This catastrophe will also have a lasting impact on engineering practice and policy as North Carolina moves forward. These changes might only just now be becoming visible, but here are a few examples of changes that we have either noticed or may be involved in.

More Support for Private Bridges

A Two Lane Bridge, Completely washed out

Many smaller, private bridges failed during Hurricane Helene. Even now, when most larger roads have reopened, many homeowners are stranded because their privately owned bridges still require replacements and repairs. To assist families that have lost safe access to their communities and support better maintenance, the NC Department of Public Safety launched the North Carolina Private Road and Bridge Program. This program provides homeowners with bridge replacements and repairs, and reimbursements for homeowners who have started repair projects out of pocket. Owners are even given guidebooks to assist with monitoring wear and tear and scheduling inspections. Regular repairs and maintenance will help extend the lives of these bridges and hopefully prevent such widespread failures.

EAPs

The South Mountain Dam, which we’ve recently completed an EAP for

Another major change is a new focus on EAPs and dam safety. The A&O team has seen a sudden influx of requests for EAPs from state divisions, municipalities, local neighborhoods, and even private owners. While there has always been a requirement that EAPs should be updated yearly, it seems that several dams held off updates if they already had a plan in place or were not aware of the need at all. Since the start of 2025, Dam Safety has been alerting dam owners to the need for inspections and requesting updates. This is likely because Helene’s downpour pushed several dams to their limit. For instance, during the storm, Lake Lure was forced to activate its EAP and elevate it to “Event Level 1, RED URGENT!! DAM FAILURE IMMINENT OR IN PROGRESS” and evacuate any people at risk. While we were fortunate enough that no dam breach occurred, that might not be the case next time, and if the worst occurs, an active EAP can save lives.

Design for Resilience

a damaged culvert

A final major change is a shift in what clients want from bridges. Resiliency is now a key factor of design, especially for communities impacted by Helene. New RFQs from towns and cities in Western NC have started requesting that structures be designed to resist heavier floods. Even the NCDOT is updating their design standards to improve stormwater and infrastructure resilience. The hydraulic component of bridge design is now more important than ever, and new flood studies may one day use a 500+-year-flood as opposed to the current 100-year. It is likely that enduring damaging flood events will be a major focus on structural design for the foreseeable future.

New programs to promote regular maintenance, renewed focus on preventative measures, and design with resilience in mind are only a few of the changes that Hurricane Helene has brought. We are learning from the mistakes and oversights that the storm revealed, including the hard truth that an unprecedented event is always possible. As we provide new EAPs, bridge inspections, and more flood-ready designs, we hope to support our communities as we rebuild for our future.

Sources:

Helene wiped away private roads and bridges. A new state program is stepping in to help

Helene Recovery Projects at a Glance

A Review of Best Practices for Natural Disaster Infrastructure Recovery to Inform Hurricane Helene Recovery Strategy in Western North Carolina

Flood Studies: A Brief Introduction

We’ve had a lot of flooding in central North Carolina over the last year. Hurricanes, tropical storms, and even summer thunderstorms have caused local lakes and rivers, such as Lake Jorden and Crabtree Creek, to rise and flood nearby roadways, bridges, and structures. In July of 2025, UNC published a study showing that flooding is more common and widespread in the state than we had previously thought. In the face of this study and the apparent increase of damage, flood preparedness tools can reduce the risk of the loss of property and life. One of the tools that A&O employs is the flood study.

What is a Flood Study

A ruined bridge in a state park

A flood study is an analysis of a stream, river, or lake to learn what the impact of a flood would be. FEMA and other official studies use the 100-year flood, a flood that has a 1% chance of occurring each year, as a standard. This is mostly for insurance or regulatory purposes, and it’s possible to use a 25-year, 500-year or even a 1,000-year flood in a study as well. Using a flood study, it’s possible to learn how deep a projected flood will be, how far it will go past the banks or shore, and even the velocity of the flood waters.

What are they used for?

A damaged section of Hillsborough’s RiverWalk Trail

The primary goal of flood studies is risk prevention. In this vein, the first step in preventing loss of property or life in a flood is to make sure that the buildings are not constructed within a flood hazard zone. While flood studies are often used for insurance, developers and property owners can also have a flood study done so that structures can be built outside of affected areas.

Are they only for buildings?

The eno river suspension bridge with a tree branch brought from floodwaters still attached

Flood studies are just as important for greenways, roadways and bridges. When constructing a roadway or pedestrian bridge over water, a flood study can estimate the likely location and height of floods. This helps us to design and place bridges to span those areas. Roadways and greenways can use them so that people and cars can travel more safely and minimize the risk of flood damage. Dams that affect people or property also require flood studies as part of the EAPs discussed in our other posts. Flood studies are a necessary part of the safety of multiple types of structures.

As we become more aware of the risk of flooding in North Carolina, the need for risk assessment increases. By constructing buildings outside of potential hazard zones, building bridges that span floodplains, and designing roads to avoid dangerously low areas, losses of life and property can be potentially avoided. Even in the case of sudden emergencies or flooding that exceeds the proposed scope, existing prevention measures, such as EAPs, can help to forewarn people most at risk. While we hope that the future brings a decrease in severe storms and the disasters associated with them, A&O hopes to be at the forefront of helping communities understand potential flood risks and developing practical solutions to support them and prepare them for the future.

If you are interested in learning more about our work in bridge design, flood studies, EAPs and inspection services, please visit our project pages.