Water and the Limits of Human Knowledge

The advancement of science has transformed the way we think, share, and regulate water. A long time ago, in what the Florida Supreme Court calls “ancient law,” no human appreciated the distinction between groundwater and surface water. We did not know that gravity pulls water downward, below the surface, below beyond the water table. We did not know that the water table fluctuates based on rainfall, tides, and other surface water influences. We did not know that the below the water table, there are aquicludes that separate water tables just beneath the surface from artesian aquifiers like the Florida Aquifier. We did not know these distinctive sources of water, let alone understand how they interact.

So from England, we inherited the ill-informed idea that “to whomsoever the soil belongs, he owns also to the sky and to the depths.” But we cannot blame the English Rule on the English. The real culprit is ignorance. Ignorance was indeed the motivation for American courts to continue the English Rule in middle of the 19th century. The Connecticut Supreme Court, for example, declined to regulate groundwater because it moved “by influences beyond our apprehension.” The court continued, “These influences are so secret and uncontrollable, we cannot subject them to the regulations of law, nor build upon them a system of rules, as has been done, with streams upon the surface.” The Pennsylvania Supreme Court reached a similar conclusion: “One can hardly have rights upon another’s land which are imperceptible, of which neither himself or that other can have any knowledge.”

Eventually, scientists learned about the interdependence of water systems, and our judicial systems replaced the English Rule with the American Rule. As the Florida Supreme Court put it, “use your own property so as not to injure that of another.” The American Rule recognizes intricate hydrological realities of how we share groundwater. But Hawaii courts have gone further, recognizing the “precautionary principle” to water use. This is the idea that when we confront scientific uncertainty, we should proceed with caution. The precautionary principle promotes effective environmental measures, even when we are not certain of their necessity. Under the precautionary rule, ignorance is not an excuse. The precautionary principle demands certainty that no other person will suffer.

Florida does not appear to have fully embraced this approach. One Florida court has allowed relatively relaxed water management practices because the statutory “time for construction, testing, and research” did not yet pass. This policy means that water users can shoot first, then ask questions later. This attitude is unfortunate. We are still learning about the impact of water quality on our food system. But we have learned enough to better appreciate the limits of our knowledge, and the harm that may result when we do not exercise caution in the face of ignorance. One farm’s water practices could harm other farms and everybody’s food supply. In their article “Arsenic in Groundwater” published in Environment International, hydrogeologists Hugh Brammer and Peter Ravenscroft have shown us that phosphorus and other nutrients influence the amount of arsenic available for plant uptake, and that arsenic accumulates in irrigation water. Arsenic-whether from water or some other source, has led crop diseases known as “straighthead” and “parrot beak.” In some crops, yields have been reduced by as much as 90%. Through the centuries, we have appreciated the limits of human understanding of our food and water systems. When we approach the limits of human knowledge, we should act with humility and precaution.

The precautionary principle should be applied to water uses. We should be certain that our withdrawal, distribution, and handling of water is safe, rather than wait for evidence to mount to show that water uses are unsafe. We need legislation that specifically requires water permit applicants to prove safety before getting their permits. By putting safety first, we protect our water, and ensure that our food systems will not be compromised by suboptimal water management practices.

This article has previously been published by the Florida Food Policy Council.