Of all the words one can use to describe West Windsor’s geology, the best is “flat.” That does not mean that the township all lies in one plain, but it does mean that there are very few high points that you might call “hills.” Much of the land is in the range of 60 to 80 feet above sea level. For a place that is about 40 miles from the nearest “sea level,” that amounts to an average slope of at most two feet per mile. There’s a kind of high spot in the Penns Neck area where the elevation gets up to 100 feet above sea level, and another at that height farther east along Route 1 in Plainsboro.

But for an area like West Windsor that covers about 25 square miles, that is flat. And when you realize that the “steepest” slope in one area of the township is confined to the southern boundary of the Delaware and Raritan Canal just east of Lake Carnegie, you can understand that most of the rest of the township has very few sloped areas. By comparison, the high point in Princeton is on Nassau Street at Palmer Square where the elevation bench mark says 215 feet above sea level.

One important result of the flatness is that the water in the natural waterways such as Big and Little Bear Brooks and the Millstone River flows very slowly. And when we have sustained rainfall that causes local flooding, it means that the flooded areas are slow to return to normal. No amount of clever engineering can change that. As the saying goes, “you play with the hand you were dealt.”

Yes, it is possible to let water accumulate in localized man-made detention or retention basins to control how the flooding is relieved, but that does not and never will prevent flooding again in the future. (Detention basins are supposed to “detain” the water temporarily to keep it from flooding roadways until the rain stops. Retention basins are designed to “retain” the water more or less permanently.)

Over the centuries when farming was what you did in West Windsor, the flatness was a mixed blessing. In terms of planting, growing, and harvesting crops it was a benefit. But in times of heavy sustained rainfall, the problems were much the same as they are now, except the effect was more on the crops than it was on the transportation.

When we first came to West Windsor in 1957, one of the first things I did was to buy a set of maps of the central New Jersey area published by the United States Geological Survey. They were considered to be the most accurate available and were free of advertising. The set I received covered the area of most of Mercer and Middlesex counties. The map scale is 1:24,000. That is 1 inch on the map is equal to 24,000 inches at full scale or about 0.38 miles. Although all the maps contained the latest measured topography, they varied in representing the latest in development, both residential and commercial. So if you want to see where the houses were in West Windsor by ground survey in 1942, look at my map. Later, I bought newer maps of part of the area that showed developments as updated by aerial survey in 1970.

One area of West Windsor that emphasizes its flatness lies along Bear Brook Road and between the railroad main line and Route 1. It is called “Upper Bear Swamp.” It all lies within a contour at 60 feet above sea level and is “fed” by Little Bear Brook — or, depending on the rainfall rate, it may “feed” Little Bear Brook.

That’s right — as I have pointed out before — Little Bear Brook may flow either eastward or westward depending on the rainfall rate. That just shows that a brook in a swamp is a hard thing to pin down. And to complicate things further, the western end of the swamp either feeds or is fed by Duck Pond Run, also depending on the rainfall rate.

Because of the flatness in the area of the swamp, that area along Bear Brook road was always hard to farm because of the poor drainage. In fact, for a number of years instead of farming it, the owner had the West Windsor Lions Club operate a boys’ day camp on the property just south of the road.

Finally, the developer Toll Brothers came along and, after building up the elevation with huge amounts of fill, built the Estates at Princeton Junction. The development required the realignment of the western portion of Bear Brook Road and the provision of a special drainage method along the curbs. The original road alignment is still visible in the woods nearby.

Now that we know that West Windsor is home to Upper Bear Swamp, you may ask, “Is there a Lower Bear Swamp and where is it?” If you search under that name, you won’t find one. But there are several swamps listed just under the name “Bear Swamp” or “Bear Swamp Wildlife Management Area.” They’re scattered about, north and south. In any case, there’s plenty of evidence that there were once lots of bears in New Jersey and that some of them liked living in or near swamps.

But our own Upper Bear Swamp enters West Windsor’s history in a different way. It is the same swamp that was once known as Tatamy’s Swamp. It was named for Moses Tunda Tatamy, an important member of the Lenape people who were the original inhabitants of the portion of the eastern seaboard that included what became the state of New Jersey. Tatamy lived in the early 18th century and was an important figure in the relationships between the native people of the area and the French and English settlers.

One of the important points that is usually made about the early history of Princeton during walking tours conducted by the Historical Society of Princeton is that the Lenape people used a trail along what became Nassau Street as their means of reaching the Delaware River, which was an important fishing source. This and many other aspects of the history of the Princeton-West Windsor area are discussed in great detail in a fascinating history compiled and written by Richard S. Walling of Edison, New Jersey.

A number of the familiar old family names in West Windsor are mentioned, and it is a revelation to anyone who has lived here for a while to recognize some of the names that have been part of the community for 200 years or more. Names like Schenck, Penn, Lyell, Bergen, Mount, and Dey have been around here for a long time.

A copy of the history “Locating a Lenape Landscape, Tatamy’s Swamp” by Richard S. Walling is available at the West Windsor Senior Center. I will talk more about it in a future column.