Scanning a map, atlas, aerial photo, or satellite image of many urban areas shows a disproportionate amount of development (or later, sprawl) taking place in one direction from the city center. Yes, this often has something to do with geographic and topographic features. For instance, Chicago could not develop to the east into Lake Michigan without a great deal of difficulty, expense, and negative environmental impacts. The same is true with Cleveland to the north or Toronto to the south.

But geographic and topographic constraints are not the sole reason for development patterns. In a fair number of cases, the cause appears to be as simple as “going with the flow.” By saying “going with the flow,” I am referring to two separate factors at play. The first is historical, while the second could be construed as either socio-economic or psychological.

As urban areas in the United States developed, historically the simplest and most cost-effective way to rid the community of its effluent was to just send it downstream by discharging it or treating it and then discharging it into the local waterway(s). Granted, this was environmentally dumb and rather unkind to downstream communities – who would want to live anywhere near the stuff being discharged.

Based on this discharge pattern, it would have been rather stupid to draw the community’s drinking water supply from the same location. Instead, it was obtained upstream where the water was presumably cleaner. Since the water was coming from an upstream direction, it was also less costly to connect to the system there versus extending waterlines in the opposite direction. Unfortunately for those residing downstream, the development pattern often meant also being stuck with other the less-desirable land uses like factories, stockyards, power plants, or landfills.

For my native hometown of Indianapolis, since the White River and Fall Creek both flow generally north to south, this led to the north side of the city expanding at a faster rate than the other compass directions. Morse, Geist, and Eagle Creek Reservoirs were all constructed in the northern portions (upstream) of the metro area.

This development pattern continues today, as edge cities and burgeoning suburbs like Carmel, Fishers, Lawrence, Noblesville, and Westfield mushroom across the cornfields north of the I-465 beltway. Similar examples can be found with Columbus, Ohio (Olentangy and Scioto Rivers) or Atlanta, Georgia (Chattahoochee River), as the northern parts of these urban areas continue to boom.

Some other examples of urban areas that tended to spread upstream versus other compass directions include:

Albany, New York (west) along and near the Mohawk River;

Binghamton, New York (west) along and near the Susquehanna River;

Cedar Rapids, Iowa (north) along and near the Cedar River;

Chattanooga, Tennessee (northeast) along and near the Tennessee River;

Des Moines, Iowa (west/northwest) along and near the Des Moines and Raccoon Rivers;

Jackson, Mississippi (north) along and near the Pearl River;

Jacksonville, Florida (south) along and near the St. John’s River;

Little Rock, Arkansas (west) along and near the Arkansas River;

Peoria, Illinois (north) along and near the Illinois River;

Portland, Oregon (south) along and near the Willamette River;

Richmond, Virginia (northwest) along and near the James River;

Rochester, New York (south) along and near the Genesee River;

Sacramento, California (northeast) along and near the American River;

St. Louis, Missouri (west) along the Missouri and Merrimac Rivers; or

South Bend-Elkhart-Goshen, Indiana (east) along and near the St. Joseph and Elkhart Rivers;

Spokane, Washington (east) along and near the Spokane River;

Toledo, Ohio (south and west) along and near the Maumee and Ottawa Rivers; or

Washington, DC (north and west) along and near the Potomac River

The reach for clean, fresh water was not limited to rivers though, as Detroit has grown disproportionately northward towards its drinking water source, Lake Huron (which just so happens to be upstream of the city).

As these urban areas grew larger and sanitation technology improved, the spatial development patterns often became more equalized. In addition, for cities with more than one directional-flow river, such as Pittsburgh or Milwaukee, the development patterns were and are more equally distributed in the upstream direction of those rivers.

In terms of the socio-economic/psychological factors, my thought is that a sort of “growth-begets-growth scenario” develops over time. Once one side of a city becomes a dominant influence, it is difficult to reverse this lopsided spatial pattern as it starts to feed upon itself. The north side of Indianapolis and Columbus, Ohio are very clear examples of this event, as both urban areas tend to be spatially top-heavy to the north. In a non-riverine example, the south side of Birmingham, Alabama is the spatially dominant side of the urban area.

It is important to note that the spatially dominant side tends (not universally) to be the wealthiest part of the metropolitan region. It is certainly the case with Indianapolis, Columbus, Atlanta, Birmingham, and most of the other cities listed above. Unfortunately, that means the less-fortunate have been often left with a disproportionate share of the negative aspects of the urban environment. As urban planners, one of our most important social justice responsibilities is to always consider the individual and combined impacts of our decisions on all residents of the community, not just those with the most money, the loudest voice, or the most political power.