Winters in Plant City, Florida can be a scary time of year. When the temperature drops below freezing, the strawberries in this self-proclaimed “winter strawberry capital of the world” get rowdy. Roads begin to buckle, schools are closed, and homes are swallowed up by the earth. The culprit? Sinkholes. Sinkholes caused by the 8,000 acres of strawberry fields surrounding the city.
Under normal circumstances, fields of strawberries are quite harmless. The problems start when near-freezing temperatures threaten the crop and farmers turn on the sprinklers. As the water freezes on the plants, it releases just enough energy to keep the plants themselves from freezing. That’s the risk of growing strawberries in Florida in winter; if the temperature drops too low you could lose your entire crop. Freezing that many strawberries, however, takes a lot of water — a lot more than you might think.
The Institute of Food and Agricultural Sciences at the University of Florida says that each acre of berries needs 6,800 gallons an hour to coat crops in a protective layer of ice. That means a 20-acre farm can use 3.2 million gallons — the equivalent of five Olympic-size swimming pools — in 24 hours. It’s about the same amount of water used by the 32,000 residents of Plant City in a single day. With 8,000 acres of strawberries to cover in a 110-square mile area around the city, that’s over one billion gallons of water per day. [Source]
This past January the city got 11 straight days of near-freezing temperatures. Farmers ran sprinklers night and day with only occasional breaks. Billions of gallons of water were sucked up from the Floridian aquifer beneath the town. Pumping that much water out of the ground at once destabilizes the already sinkhole-prone Florida landscape. Sinkholes began appearing overnight in seemingly random locations around town.
Cindy Kersey and her husband Evan Chreitzberg lost their Plant City home to a strawberry-related sinkhole this past winter. “Cindy was in her kitchen making pesto. She heard a ‘pop.’ It sounded like ice breaking up. She went outside. No ice. She heard a ‘bang’ and found a crack in her bedroom wall.” The house eventually fell into a giant sinkhole and the couple was forced to move. [Source]
Later that same month (January, 2010) another large sinkhole closed Plant City Elementary School. The school escaped damage but students had to be bussed to other schools for three months until the sinkhole could be filled in with grout. In all, more than 20 large sinkholes appeared threatening homes and closing roads including portions of Interstate 4. [Source]
Cones of Depression
Another side effect of the strawberry freeze is the creation of massive cones of depression formed below farmers’ wellheads and stretching out for miles. We’ll leave the definition of “cones of depression” for another blog, but suffice to say that the more water withdrawn, and the faster it’s withdrawn, the more severely the water level of the aquifer is reduced. During the 11-day freeze this past winter, the Floridian Aquifer dropped by 60 feet! This resulted in 760 private wells near the farms drying up, at least temporarily. Ultimately 35 homeowners needed new wells at a cost of $4,000-$12,000 each. [Source]
Strawberries or Sprawlberries, who’s to blame?
It’s easiest to blame the farmers for this water resource fiasco. After all, they’re the ones doing the pumping, but is that totally fair? The farms provide a huge economic benefit to the communities. The Hillsborough County Agriculture Industry Program estimates the overall economic benefit to the region at more than $600 million. The largest shipper of strawberries in Florida, Wishnatzki Farms, is headquartered in the city. [Source]
It’s not hard to see how essential the strawberry crop has become to the city. Losing a whole season’s crop due to cold weather would hurt not just the farmers but the whole region as well. In addition, the farmers aren’t actually breaking any laws by pumping all that water. The city is looking into establishing more stringent water withdrawal limits but, until and unless that happens, the amount of water the farmers have been pumping is apparently within their current permits.
A quick glance at Google Earth and it’s clear to see that Plant City, like so many cities in the U.S., has a sprawl problem. Prior to the mass suburbanization of the country, strawberry fields were located far away from large residential developments. But as sprawling developments of cul-de-sacs began to encroach on agricultural land, more and more private wells were dug near the fields. The result is that these wells are more prone to going dry due to aquifer drawdown caused by the neighboring farms. Whether or not these homes are more prone to sinkholes is unclear.
If Plant City planners and local government did a better job of preserving farmland and encouraging compact development then a greater number of residents could be served by the City’s municipal water supply (meaning fewer private wells) and draw down caused by farmer-owned wells would effect fewer private wells.
When I first heard of Plant City, the phrase “Winter Strawberry Capital of the World” really stuck out. Personally, I don’t really crave strawberries in winter. I try to be a seasonal eater by consuming only fruits and vegetables that are “in season” (see ripe guide at the bottom of this post). This is America, however, and we want everything as soon as we want it, which has of course given rise to the “winter strawberry.” Now, I have no problem with people who live in Florida and grow strawberries in their backyards in the middle of January; I’m just not sure it was wise to turn it into an industry. The fact is that sometimes it gets cold in Florida and that cold can destroy an entire crop of strawberries and the entire economy of the cities that grow them. Is it worth all the sinkholes and dried up wells (not to mention the long term consequences of aquifer depletion) to prop up an industry that may become unsustainable in this region? At the moment it’s clear that Plant City thinks the answer is “yes”. However, the day may come when Florida has to choose between drinking water and winter strawberries.
Hopefully, renewed scientific attention to this problem will offer some potential solutions. There has already been talk of increased water monitoring at farms. An advanced weather forecasting system has also been proposed to ensure that farmers don’t turn their sprinklers on too soon and that they shut them off as soon as possible.
Apparently, before freezing became the popular solution, farmers used pine needles to keep the plants warm at night. It wasn’t as effective as freezing, but maybe that’s a good thing because; well, it turns out that the winter strawberry market is somewhat over saturated. The largest producer of winter strawberries is California and in Winter 2010 they experienced above average crop yields and flooded the market. By March 2010, the price of winter strawberries had dropped so low that Plant City farmers concluded it wasn’t worth the expense “to harvest the berries they had worked so hard to save. Instead they began letting them rot in the field and eventually plowed them over.” [Source]