The Trouble with Rivers

To roughly quote Douglas Adams, “The story so far: In the beginning the United States was created and its accompanying Constitution did not provide any kind of framework for local governments. This has made a lot of people very angry and been widely regarded as a bad move.” I said roughly.

The intentional ambiguity included in the Constitution led to a general idea that states were, at least to some extent, self-governing. However, the stresses associated with any self-governing body can become fairly great, especially within the framework of a fledgling United States which had yet to land on stable ground in the wake of its first major war. These pressures led to states subdividing their area into counties, thus delegating many bureaucratic issues to the smaller local governments and easing the administrative workload on the state government. Although the English had split up some of the Mid-Atlantic colonies in this way in the late 1600 and early 1700s, the practice of creating a county network didn’t really arise until after independence.

Creating the boundaries for county lines was harder than it initially seemed, as accurate surveying and mapping technology were many decades away at the point of independence. The lack of precise surveying led to a dependence on natural landmarks to mark where county boundaries were. Many times rivers, rock formations, or even large trees were used to represent county lines. Of course, today we have much more exact technologies for surveying and mapping, and don’t have to rely on the environment to let us know where we are spatially. County lines aren’t changed much anymore, so the remnants of using natural landmarks as county line indicators is present when looking at maps of certain states. For a good point of comparison, look at the county maps of the two states below. The state on the left is Virginia, one of the first states to start using a county system, and on the right is Wyoming, a state which joined the Union relatively late and is far less densely populated than Virginia.


Aside from the obvious difference in quantity, the counties within Virginia have a more sinuous and wavy outline, while the counties in Wyoming have a more regular shape, and seem to be uniformly geometric. Just by looking at the outlines it is clear that Virginia based its county boundaries off of natural landmarks, most likely rivers, and that Wyoming (for the most part) did not. It is worthwhile to consider that Virginia had its counties aligned much earlier than Wyoming’s, and that advances in survey and mapping could have made it possible to depend less on natural landmarks by the time Wyoming was a state.

The problem that arises from defining county parameters from natural landmarks is the all-powerful fact that the Earth is not a static entity. It is rare that the natural marker that distinguished a county line 200 years ago will be unchanged today. Trees die, mountains crumble, and rivers meander, and although we have attempted to wrangle natural forces in to better suit our lifestyles, time and time again it has proven that nature is stronger than our collective geographic sensibilities.

Controlling nature can be, complicated.

Controlling nature can be, complicated.

What prompted my investigation into naturally-marked county lines was an incident in Washington state in the late 1950s, and while it didn’t make national, or even regional news, it highlights the main issue associated with our dependence on naturally-highlighted boundaries. 

Cowlitz and Clark are two neighboring counties in south-west Washington state, both sidled up against the state’s border with Oregon. The Lewis River, a tributary of the Columbia, has marked the boundary between the two counties since the state was subdivided. Before we continue on to why the Lewis River is significant to this story, it is important that we know just a smidgen about river morphology. A river of any size or volume can, over time, establish a sinuous, meandering path. This path is formed by a process in which the river alternately erodes sediment from the outside of its bend and deposits said sediment on the interior of its bend.

Image courtesy Zina Deretsky, National Science Foundation.

Image courtesy Zina Deretsky, National Science Foundation.

Because rivers are dynamic, and sometimes stochastic, meanders change frequently. After a long period of time the meanders become exceptionally curved, causing the neck of the meander to become so narrow that the river cuts through this bottleneck during an event like a flood. When this happens, the meander is isolated from the river, and forms an odd, horseshoe-shaped lake known as an oxbow is formed.

An oxbow lake with its parent river in the Kanuti National Wildlife Refuge in Alaska.

An oxbow lake with its parent river in the Kanuti National Wildlife Refuge in Alaska.

The majority of the time, oxbows are formed naturally by flooding, but in rare occasions oxbows can also be formed through human intervention. This brings us back to the Lewis River, which, like any river, has fairly large meander bends. During the mid-1950s, a new state highway was being built in Washington state. US State Highway 99 (now Interstate 5), was built to better accommodate travel along the western coast of the US, and ended up crossing right though one of the meander bends along the Lewis River. Rather than build a bridge over the bend, the contractors decided instead to divert the river, and have the road cut straight through the meander. This diversion created a man-made oxbow lake, and permanently separated the two bodies of water.

And never the two shall meet.

And never the two shall meet.

Normally, the creation of an unnatural oxbow wouldn’t be cause for concern, but it is important to remember that the boundary between Clark and Cowlitz county was based on the Lewis River, and the Lewis river was forever altered by the presence of Interstate 5. Although the river is now completely separate from the oxbow, the county line still follows the old course of the Lewis River, the one that includes the meander. Notice that in the photo above, there are structures located within the oxbow. It was these structures in conjunction with the new course of the Lewis River that caused county commissioners within Cowlitz county to petition for the county line to be moved so as to follow this new course. This would mean that those people who lived within the oxbow, formerly residents of Clark county, would become residents of Cowlitz county solely because the natural landmark had shifted.

The commissioners from Cowlitz county argued that, “said property is now properly within the boundaries of Cowlitz County and should be on Cowlitz County’s assessment rolls.” It is in this incident, and the ensuing court case, that the major problem of using natural landmarks as boundaries was highlighted. Although Washington law states that:

. . . when grants of land border on running water, and the course of the stream is changed by that process known as accretion‑-that is to say, the gradual washing away on the one side and the gradual building up on the other‑-the owner’s boundary changes with the changing course of the stream. . .  

The Attorney General decided that the county line could not be moved from its original placement, and that the structures within the oxbow would remain under Clark county jurisdiction. His reasoning was as follows:

…when a stream which is a boundary, from any cause, suddenly abandons its old channel and creates a new one, or suddenly washes from one of its banks a considerable body of land and deposits it on the opposite bank, the boundary does not change with changed course of the stream, but remains as it was before.  This sudden and rapid change is termed in law an avulsion, and differs from an accretion in that the one is violent and visible, while the other is gradual, and perceptible only after a lapse of time.

Essentially, if the oxbow is formed gradually, the county line can change, but if it is sudden (and man-made, in this case), then the law doesn’t apply.

The hubris of man, demonstrated here.

Hubris, demonstrated here.

Similar issues have happened all over the country (see this map from the Arkansas-Mississippi border), and it all begs the question: why are we still using natural landmarks as boundary markers? Before accurate surveying and mapping technology was readily available, the answer was that it was easy and the only viable option. Now though there are many different options, and the only way to avoid issues like what happened in Cowlitz county is to implement them. Our national grid is malleable, let’s try to bend it a little.

– Ben Kessler

The official opinion on the Cowlitz county case can be found here.


2 responses to “The Trouble with Rivers

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