Common law and state statute often combine to determine how surface water may be diverted or redirected. Both vary significantly between states and there may be as many variations of these rules as there are states to apply them.

Typically, courts apply any of three well-established doctrines when dealing with water that flows over land without a recognizable channel. The modified common enemy doctrine, the modified civil law rule and the reasonable use doctrine may all come into play depending on the specific situation and the jurisdiction in which the case is heard. The South Carolina court recently concluded that all three have merit.1

The common enemy doctrine may be traced to early rulings in Massachusetts2 and New Jersey.3 These two opinions emphasized the paramount right of anRiver owner to make changes to drainage patterns on his land regardless of the misfortunes that result for those unfortunates below. This uncompromising attitude has been largely superseded in modern common law.

A recent Connecticut decision provides a summary of changes made to the original common enemy doctrine. Keller v. Town of Southbury4 confirms that this principle permits the owner of one tract to allow surface water to flow onto the adjoining parcel. However, this ruling also observes that the common enemy doctrine is modified by the reasonable use doctrine. This modification is considered beneficial because it increases the flexibility of the court when dealing with unique circumstances inherent in each case. Many courts today describe this merging of concepts as the “modified common enemy doctrine.”

Keller v. Town of Southbury concludes that in its modified form, the landowner may take only those reasonable steps that are dictated by the relevant surrounding circumstances. Issues considered can include the motives of the landowner, the cost of damages and whether damages were foreseeable.

A recent Maine decision adds the caveat that under this doctrine, the upper landowners may be held liable if they collect or concentrate surface waters into basins or drainage structures and then discharge the water over neighboring tracts–particularly tracts that would not have been the recipients of the naturally occurring surface flow.5

An early California ruling implies a “natural easement” in the relationship between two adjacent fields. This circumstance occurs when one field is lower than the other, and the two are situated in such a way that water naturally flows from the upper field and crosses the lower. In such a scenario, this court held that:

The prevailing doctrine appears to be that when two fields are adjacent and one is lower than the other, the owner of the upper field has a natural easement to have the water that falls upon his land flow off from the same upon the field below, which is charged with a corresponding servitude.”6

This ruling affirms that while the owner of the lower field has no right to erect barricades to divert the water from the lower field, the owner of the upper field is not allowed to excavate in order to concentrate or redirect water flow in a manner of variance with the natural drainage.

This is by no means a universal rule and Ogburn v. Connor recognizes several jurisdictions that did not follow the principles described above. In addition, this case observes that different concepts often apply depending on the character of the land and the location of the subject parcel. Courts are reluctant to enforce this principle when clear-cutting or extensive development significantly alters the original drainage patterns.

The California case discussed above appears to represent an example of the “modified civil law rule.” Iowa courts have developed a similar premise described as follows:

There has been adopted and developed in this jurisdiction what may best be characterized as a modified civil law rule which recognizes a servitude of natural drainage as between adjoining lands. Under this concept a servient estate must accept surface waters which drain thereon from a dominant estate. On the other hand, no right exists to alter the natural system of drainage from a dominant estate in such manner as to substantially increase the servient estate burden.7

Some local development regulations apply a variation of this idea to mandate that water flow off of a tract may not occur at a greater rate than would occur when the tract was undeveloped.

Florida courts also recognize the civil law and common enemy doctrine as legitimate “property rules,” but this jurisdiction also emphasizes a difference between these two and the reasonable use doctrine.  Although the reasonable use doctrine is often considered to be on an equal footing with the other two, this court considers it a more general principle that may be applied as a “tiebreaker” when neither of the other two principles seem to apply.8

A recent Missouri ruling describes a shift from the modified common enemy doctrine to the reasonable use doctrine. Acknowledging past adherence to the modified common enemy doctrine, the Missouri court notes:

At the time this case was tried, Missouri followed the “modified common enemy doctrine” with respect to surface water … an upper landowner was protected from liability to a lower landowner for obstructing the flow of surface water, provided that: (1) the discharge flows into a “natural drainway channel” located on his property “where the surface water from the drained areas would naturally go ... even though in doing so they [the upper landowner] might increase and accelerate the flow of surface water in its natural channel onto the lands of the plaintiff,”…and (2) the upper owner “acts without negligence and does not exceed the natural capacity of the natural drainway to the damage of the neighbor. In 1993 our Missouri Supreme Court replaced the modified common enemy doctrine with the “rule of reasonable use.”9

This decision appears to have been due to growing inconsistencies in the courts’ application of the many corollaries of the modified common enemy doctrine. Ultimately, the court must balance the rights of individual landowners with the rights of the adjoining owners and of the public.

Kueffer v. Brown then included specific elements for the reasonable use doctrine:

In adopting this doctrine the supreme court held that surface water rights and liabilities were not exclusively property law questions, but were also to be analyzed as a form of nuisance … the elements of the rule of reasonable use are: each possessor is legally privileged to make a reasonable use of his land, even though the flow of surface waters is altered thereby and causes some harm to others, but incurs liability when his harmful interference with the flow of surface waters is unreasonable. Reasonableness is a question of fact, to be determined in each case by weighing the gravity of the harm to the plaintiff against the utility of the defendant’s conduct. Liability arises when the defendant’s conduct is either (1) intentional and unreasonable; or (2) negligent, reckless, or in the course of an abnormally dangerous activity.10