Napa Valley vineyard

The Hidden and Not-So-Hidden Effects of Wildfires on Wineries

By Dan Turpin | Published May 22, 2023

Wildfires have become increasingly more destructive in recent years, burning more than double the average area than in the past. In 2021, wildfires caused between $70 billion and $90 billion in damage and economic loss, with more than half of those damages occurring in the state of California alone.1 For states like California, which is the largest producer of wine in the United States, the economic impact of wildfires looms especially large.2

When a wildfire impacts a vineyard, wineries are impacted in many ways, making an estimator’s job all-encompassing. They must consider the entire property — both what’s outside (e.g., the vineyards, irrigation and septic systems, etc.) as well as the physical buildings on the property. Each asset has different requirements estimators must be aware of, making the task particularly complex.

Here are the main considerations estimators should be aware of when assessing the impact of wildfires on wineries.

Perimeter Considerations

1. The effect of heat on future yields.

A vineyard doesn’t have to be scorched to incur severe damage. Plants might seem only mildly affected at first glance, but heat can wreak just as much havoc as the fire itself. Even a small amount of heat can damage vines to the point where the production of fruit is slowed or stopped completely — impacting future yields.

2. Damage to the drip irrigation system.

Like heat damage on plants, impairment of the drip irrigation system on the property due to extreme heat might not be easy to spot at first. Drip systems include a number of components, including various pumps and filters, chemical injectors, main and submain lines, drip hoses and emitters. Heat can cause emitters and rubber drip hoses to become brittle, and metal wires found in some of the system’s parts can melt and weaken, as well. Because a lot of this damage is underneath the surface, estimators will need to conduct thorough testing of the system and be prepared to discover more damage than what can be seen with the naked eye.

3. Erosion of the natural landscape.

One big effect wildfires can have on the environment is soil erosion. Wildfires burn what’s known as the litter layer — the leaves, bark and twigs that naturally fall to the ground — as well as grasses, shrubs and trees on the land. Once burned, the area becomes vulnerable to erosion caused by rain and other extreme weather.3 To stop erosion and prevent further issues, restorers often have to implement tactics such as putting in swales, which manage runoff, as well as other control measures, which should be factored into the claim estimate.

Building Considerations

1. Erosion around structures.

In addition to the potential of erosion affecting the surrounding land on which the winery sits — whether that’s a rolling hill, hillside or flat field — erosion can also occur around a burned-down building on the property. Once a building has burned, it’s important to protect the top soil from eroding or falling away so that the building can eventually be restored without having to replace the soil.

2. Tricky code requirements.

Wineries are often built on hillsides, which means the structures need proper underpinning to hold them safely in place. The process of underpinning, also called piering, involves installing anchors underneath a building to support the weight by the more stable soil deep below the surface.4 If, during the restoration of a winery, it’s found that the footings and foundation of the structures are not up to code, restorers must remove and replace the foundation entirely, which can add 25% to 30% to the project’s cost.

3. The need for generators.

Wildfires can and often do knock out the area’s electricity grid. And while most areas have backup generators, those generators are also vulnerable to fire if they aren’t properly secured by surrounding concrete. Generators must be operational because wineries need electricity to chill their product, which is accomplished by running water through ridges on the sides of the large stainless steel tanks that hold the wine. If the electricity goes out and there isn’t a backup generator, tens of thousands of gallons of wine can be lost. Also beware that the cost of running a generator can cost thousands of dollars per day, depending on the size.

4. Leaking wine tanks.

If a wildfire happens to overtake one of the stainless steel tanks holding the wine, it can rupture and melt, causing wine to leak out. This is a problem not just because of lost wine but also because if there happens to be a nearby body of water, the wine can contaminate the water, killing fish and other wildlife. It is imperative to contain tanks if impacted by a wildfire, or wineries could face actions by the Environmental Protection Agency.

With the wildfire season continuing to lengthen every year,5 more destruction is due to follow, making the task of estimating the impact of heat and fire on wineries increasingly important.

For help estimating damage from a wildfire, contact RMC Group.

This information is intended for informational purposes only. Each restoration project has unique properties and must be evaluated individually by knowledgeable consultants. RMC Group is not liable for any loss or damage arising out of or in connection with the use of this information.

1 AccuWeather “2021 wildfire season: AccuWeather estimates $70 billion to $90 billion in damages,” October 1, 2021. 
2 Wine America “United States Wine and Grape Industry FAQS,” 2019. 
3 Colorado State University “Soil Erosion after Wildfire,” January 2012. 
4 Waterproof Magazine “An Introduction to Piering,” 2012. 
5 U.S. Environmental Protection Agency, “Climate Change Indicators: Wildfires,” 2022