By Charles R. Horner
Property owners, managers of public property, and attorneys who counsel them should know the basics of the law of surface water, particularly in our chronically humid, periodically diluvial region. Surface water law, as the name indicates, concerns the flow and drainage of water over land. It is but one component of a vast body of water-related law that governs such other matters as surface and groundwater appropriation, wetlands, streams, riparian zones, stormwater, and flood protection, to name a few. This article discusses the common law of surface water in Washington.
Surface water law focuses on problems that arise from water flows across property boundaries. This law developed to facilitate the profitable use of land while proscribing certain “unacceptable” impacts to other property owners. It is therefore not surprising that some aspects of surface water law conflict with modern environmental policies and regulations that may also have a major bearing on the use of property. Property owners facing these issues should consult an environmental or land use attorney.
Categories of Surface Water
Washington surface water law recognizes two categories of flowing surface water, the somewhat confusingly termed “surface waters” (which sometimes appears in the singular form) and “natural watercourses.” See King County v. Boeing Co., 62 Wn.2d 545 (1963). These categories, which are defined largely by how they differ, are linked to distinct sets of rights, duties, and standards of liability.
Surface waters are often described as “vagrant and diffused [water] produced by rain, melting snow, or springs.” They include flood water that escapes from the “flood channel” of a river or stream. Halverson v. Skagit County, 139 Wn.2d 1 (1999). The essential attribute of surface waters is their diffuse flow over broad areas of land, such as sheet runoff from a parking lot or field, rather than in a “definite course or defined channel.”
A natural watercourse is “defined as a channel, having a bed, banks or sides, and a current in which waters, with some regularity, run in a certain direction.” Natural watercourses are not limited to permanent rivers and streams. They include any “natural drain,” defined as a “course, formed by nature, which waters naturally and normally follow in draining from higher to lower lands,” even if only intermittently.
Surface waters may be transformed into a natural watercourse and vice versa. Surface waters lose their character as such where they form or enter a natural watercourse. On the other hand, water that escapes from a natural watercourse during a flood is deemed surface waters. See Sund v. Keating, 43 Wn.2d 36 (1953).
The law’s distinction between “surface waters” and “natural watercourses” can sometimes appear unduly artificial in light of hydrologic realities. For instance, what should we call a broad sheet of water (think “wetlands”) that, nonetheless, functions similarly to a river? See Miller v. Eastern Ry. & Lumber Co., 84 Wash. 31 (1915) (although a swamp or swale is not ordinarily a watercourse, it may be a watercourse “[w]here there is a spreading of a stream which still moves by natural gravitation in a certain direction to a common or defined channel . . .”).
Rights, Duties, and Liabilities in Relation to Surface Water
Surface waters and natural watercourses are governed by distinct sets of rules. Washington’s law on surface waters has been defined by the “common enemy doctrine,” a shield for the actions of individual property owners whose harshness is largely alleviated by several major exceptions. Natural watercourses, on the other hand, are governed by concepts of riparian rights, the mutual duties running between upstream and downstream property owners.
The common enemy doctrine states that a property owner may repel or dispose of “surface water in any way they see fit, without liability for resulting damage to one’s neighbor.” This quaintly individualistic doctrine, seemingly so accommodating to filling, draining, paving, and other development activities, is limited by exceptions that defeat the rule in many cases. Two of these exceptions have existed for many decades, while a third has only recently been explicitly adopted in Washington.
The first exception is that “surface waters may not be artificially collected and discharged upon adjoining lands in quantities greater than or in a manner different from the natural flow thereof.” Increases in runoff resulting solely from the creation of impervious surfaces will not create liability under this exception (but they could do so under the “due care” exception described next). If, however, a property owner causes surface waters to be discharged in a concentrated manner onto another property, the owner will be liable for resulting damage without regard to negligence, i.e., strictly liable. Burton v. Douglas County, 14 Wn.App. 151 (1975).
The collection and discharge exception is applicable to any constructed feature, including a street surface, that collects a concentrated volume of runoff and discharges it onto adjacent property. See DiBlasi v. City of Seattle, 136 Wn.2d 865 (1998). Furthermore, a property owner who diverts surface waters from their natural flow path or watershed is strictly liable for resulting harm. Buxel v. King County, 60 Wn.2d 404 (1962).
The second longstanding exception to the common enemy doctrine is that “the flow along natural drains may be hastened or incidentally increased by artificial means, so long as the water is not ultimately diverted from its natural flow onto the property of others.” An owner is strictly liable for damage from diverting surface waters to a watercourse they would not naturally reach. See Colella v. King County, 72 Wn.2d 386 (1967). The occurrence of an act of nature, such as a major storm, does not prevent a property owner’s liability under either “strict liability” exception to the common enemy doctrine if the owner contributed to causing the harm.
In 1999, the Washington Supreme Court explicitly adopted a “due care” exception to the common enemy doctrine. Currens v. Sleek, 138 Wn.2d 858. This exception provides that “landowners who alter the flow of surface water on their property must exercise their rights with due care by acting in good faith and by avoiding unnecessary damage to the property of others.” The property of the plaintiff in Currens was flooded after the defendant clearcut her uphill property and did not complete any of the mitigation mentioned in her environmental checklist. The due care exception essentially creates a negligence cause of action for altering the flow of surface waters. Although Currens did not quite do away with the common enemy doctrine, it clearly expanded the scope of potential liability for actions affecting surface waters.
Riparian rights concepts inform the law governing natural watercourses. A property owner who obstructs a natural watercourse is strictly liable for harm to upstream and downstream owners. See Wilber v. Western Properties, 14 Wn.App. 169 (1975). A diversion of water from one watercourse to another should also result in strict liability consistent with the analysis applicable to diversions of surface waters. See Laurelon Terrace, Inc. v. City of Seattle, 40 Wn.2d 883 (1952). On the other hand, the Washington Supreme Court has stated that an owner who diverts a watercourse, such as by breaching a natural barrier so that a stream flows in a new direction, is liable if he or she has acted either “intentionally or negligently.” Sund v. Keating, 43 Wn.2d 36.
An owner may, as an incident to developing his or her property, increase the volume and rate of flow in a watercourse that is the natural receiving water. The owner may, however, be liable for negligence if he or she increases overall volumes beyond the watercourse’s capacity in its “natural condition.” See Patterson v. City of Bellevue, 37 Wn.App. 535 (1984). Reflecting the limits of surface water law, the court in Patterson advised that flow increases falling short of actionable negligence needed to be addressed through “concerted political action rather than in the courts.”
Why Surface Water Law is Important
Flooding, landslides, and severe property damage can be among the dramatic results of improper actions affecting surface water. Such events can saddle property owners with heavy, even strict liability based on actions taken many years earlier, such as building streets that channel water or installing undersized culverts that obstruct streams.
Surface water issues can arise on any property, whether large or small or public or private. Governments need to pay as much attention to surface water law as private owners since they are deemed to act in their proprietary capacity when they alter surface water flows. Given the high stakes, anyone who owns, manages, or provides legal counsel concerning real property should be aware of surface water law.
Charles R. Horner has many years of legal and technical experience in dealing with surface water issues. He has recently established his own practice in Seattle and intends to continue emphasizing surface water, environmental, land use, and real property issues. Mr. Horner can be reached at (206) 412-2154 and by e-mail at crhorner@seanet.com.
