Last week Governor Newsom issued a directive that would allow water managers to intentionally divert surplus water from rivers in the wet season into farm fields to recharge groundwater. Just a day or two later, the Pajaro River broke through a levee and flooded the small town of Pajaro as well as thousands of acres of prime, vegetable-growing farmland near Watsonville.
It’s very important to distinguish between these two phenomena. Carefully-planned, intentional flooding of farmland is a well-established practice that can have numerous benefits with few downsides. Unplanned, accidental flooding of farmland can be destructive and disastrous.
Most people in Northern California have driven from the Bay Area to Sacramento over the Yolo Bypass — a large area of flooded farm fields between Davis and the Sacramento River. That area was intentionally created to protect the City of Sacramento from flooding. There is a human-engineered passive system that redirects water from the American and Sacramento Rivers when the water level gets too high.
Farmers who manage land in the Yolo Bypass fallow their fields every winter, and are well aware that those fields might not be available for planting in a wet year. They wouldn’t leave tractors, for example, parked in the area. And the infrastructure — roads, pumps and powerlines — is all designed to accommodate flooding. Meanwhile, the water is controlled and diverted in such a way that strong currents don’t wash the soil away.
In contrast, when the levee on the Pajaro broke, many fields had already been planted for the season: those crops are lost now. Like humans, most living plants cannot survive being completely submerged for very long. Infrastructure like farm buildings are likely damaged. Pumps are ruined, and wells filled with surface water that is contaminated with bacteria, mud and possibly hazardous chemicals. Tractors and trucks stored next to fields are now inoperable.
Uncontrolled flooding also damages the farm fields themselves by moving large amounts of soil and possibly depositing objects like trees or other debris and possibly burying them so that they will damage farm equipment.
Floodwaters don’t just contaminate wells — they can actually contaminate the soil in a field. This is especially true if the flooded area is downstream of an urban area or sewage treatment plant. Food safety rules now prohibit farmers from planting or harvesting fresh vegetables or fruit from fields that have been flooded for at least three months after the flooding takes place. (Farm fields in the Yolo Bypass and other intentionally flooded areas are never planted with vegetables).
In other words, the farmers in the Pajaro area are looking at a huge financial loss this year with a one/two punch of damage to their farms and loss of income from this year’s crops. All told, there are many thousands of acres of vegetable fields in the Salinas Valley that will be out of commission this year entirely.
Here at Terra Firma we have experienced some localized flash flooding here this winter when rainfall exceeded the capacity of the soil to absorb it. But our fields are not located near any waterways considered “flood risks”.
So lots of mud, but no floods.