Last week the most reliable long-range weather models released their seasonal prediction for the coming winter’s precipitation, and it’s a doozy. Thanks to what is now being called the “Super El Niño”, San Francisco and the area around I-80 could get as much as 200 percent of our average rainfall. You may have heard that Northern California won’t be as wet Southern California, and that may end up being true: the projection is for the southern part of the state to recieve as much as 400 percent of average.
In my experience, the general public and policymakers are having a hard time getting over their PTSD from the two droughts we experienced during the last 10 years. But the last drought ended in 2023. Statewide, reservoirs are essentially full for this point in the season. Some are actually higher than usual for this date. Groundwater tables in areas where they are connected to surface precipitation have also recovered to their pre-drought levels. Aside from areas that rely on out-of-state water from the Colorado River, which is severely oversubscribed, California is in GREAT shape from a water perspective. If you’re one of those people who is still worried that we might not have enough water, well, you can rest easy.
In fact, if there’s anything to worry about now, it’s the potential for too much water. Climate change is making droughts worse, but it’s also worsening flooding during storms by increasing the amount of water vapor that the atmosphere can hold. We’ve seen this up close and personal here at Terra Firma several times in the last few years: in October of 2021, we received 9 inches of rain in less than two days in a month we usually get less than an inch. And in September of 2023, areas just a few miles east of us received 4 inches of rain in 24 hours: 8 times our average for that month.
You don’t need to know the technical details about El Niño to understand that is has a dramatic effect on the weather all around the world. The impacts vary from region to region, but few of them are beneficial. And this particular El Nino is quite literally “off the charts”, thanks to the human-caused warming of the Earth. The areas susceptible to flooding will likely see worse flooding. The areas that see drought during Ninos will have worse droughts. And the heatwaves that tend to accompany Niños will also be worse, as will the well-documented damage to the world’s economy.
At Terra Firma, we have 33 years of data to give us an idea of what we are likely to experience. Our two wettest-ever winters have occurred during El Niños: 48 inches of rain versus our average of 24. So if anything, I think the 200 percent projection for this winter is conservative. For our winter crops, that means we’re likely to see significant harvest delay and difficulties as well as increased disease pressure. Planting during the wet season will be challenging if not impossible, as will be controlling weeds.
If the excessively wet weather continues into spring, as expected, we will also see problems with planting tomatoes, potatoes, sweet corn, and everything else we grow. We experienced those problems as recently as 2023, when our first tomato field was underwater for several days and never really recovered. Tree fruit is also heavily impacted by too much rain in the spring, which impedes pollination and brings disease.
But with reservoirs around the state and here locally essentially “full” this year, there’s another potential problem. Dams in California have two purposes, but the second one is sometimes forgottten — flood control. If the reservoirs fill too quickly too early in the winter, the water must be released downstream. Continued wet weather after that happens can lead to flooding. Our local dam is just 5 miles up the road, and once it starts spilling water the flow is uncontrolled. The watershed can reach capacity fairly quickly, and the smaller creeks in the area can back up and begin to flood the surrounding farmland, including our fields.
Almost all of the land Terra Firma farms is susceptible to flooding, but some fields are much more so than others. We also have quite a few fields that are simply inaccessible during very wet weather when the soil here turns into something resembling quicksand. So when I first saw news of the building El Niño, I started to plan for it. First, I cut back on certain crops that do poorly in very wet winters, particularly onions and garlic. I made sure that most of the crops we will be harvesting in mid-winter are in fields with all-weather access. And I avoided fields in low spots or areas with poor drainage with a history of flooding. Our strawberries, which are particularly sensitive to waterlogged soil, got planted in one of our most flood-proof fields.
For anyone who might potentially be impacted by flooding, there is no substitute for advanced preparation. Once the rain starts, it’s too late to do much. So I was glad to see the state come out with an Emergency Declaration about the coming winter. That will get the bureaucratic gears moving so that critical resources are available if and when disasters strike this winter, instead of a week or three later. It will also help change the mindset of the millions of people who still think drought is a bigger concern than excessive rain.
Thanks,