B.  BACKGROUND:  NATURAL HISTORY OF THE CHARLESTOWN AREA

1. Location on the Fall Line – Charlestown’s 110 acres is located on the Fall Line of the eastern seaboard at 76 degrees, 42 minutes, 6 seconds West Longitude and 39 degrees, 16 minutes, 18 seconds North Latitude. The Fall Line is an important geographic feature lying between the Coastal Plain and the Piedmost uplands. The lower part of the Fall Line begins where rivers become no longer navigable for small This highly significant fact led to the establishment of early towns and roads all along the Fall Line, since the westward movement of goods had to shift from boats and ships to land transportation or canals at that point. The towns also developed due to the construction of mills along the Fall Line, which used the flowing water for power to turn their wheels, blades, and grindstones. Many of these towns grew into major eastern cities, such as Philadelphia, Baltimore, Washington DC, Richmond, and others. The earliest north-south road connecting these early towns grew into U.S. Route 1, the primary eastern highway before the advent I-95 of the interstate highway system.

2. Geology and Soils – The geology and soils of the Fall Line change from hard, crystalline rock in the upper western areas (like the granite found near Ellicott City) to softer sedimentary soils of the Coastal Plain to the east. The elevation of Charlestown ranges from 130′ in the eastern portion of the property to 315′ in the southwest part of the property near the Most of the soil in the upper Charlestown area appears to be stony clay, derived from breakdown of the Piedmont’s rocks. The soil in the lower part of the Charlestown property is a rich sedimentary loam accumulated in the flood plain of Herbert Run, the stream following the Fall Line as it crosses the property.

3.  Watershed – Charlestown lies within the watershed of the Patapsco River, the primary feeder to Baltimore Harbor, and subsequently the Chesapeake Bay. Rainfall and stormwater drainage from the Charlestown property flow into the East Branch of Herbert Run, which joins the West Branch due south of the campus near the MARC station and subsequently flows into the Patapsco.

4. Area Land Use Patterns –

Historically, Native Americans lived in the Baltimore and Patapsco River valley areas since at least 12,000 years ago. “Patapsco” is derived from an Algonquian word meaning “backwater”, which probably referred to the slow moving portion of the river nearest to the Chesapeake Bay. The Native American’s relative lack of impact on their environment was changed during colonial times, which brought deforestation and agriculture, both of which resulted in sedimentation of the Patapsco, rendering it no longer navigable west of Elkridge Landing, which was a major port in early colonial times. The hunting of beaver and other animals gradually depleted the natural fauna of the area. These patterns, as well as urbanization and road building, increased as the human population continued to grow.

Contemporary land use patterns In the Charlestown area now range from urban in Baltimore to the northeast, to surrounding suburban areas which include neighborhood housing, shopping centers, large grassy areas associated with local schools, hospitals and cemeteries, and major nearby rail and highway transportation systems. Charlestown is in Baltimore County, and a small northeast portion of the property lies within the Baltimore City limits. The Inner Harbor lies only five miles east of Charlestown, and Thurgood Marshall Baltimore-Washington International Airport lies six miles south of the campus. With the Interstate 695 Beltway a half mile southwest of Charlestown and Interstate 95 a mile to the southeast, access to downtown Baltimore, the airport, and other locations is quick and easy.

5. Climate and Weather – The Charlestown climate is pleasant, with four distinct seasons. Maryland is in the Mid-Atlantic region, between warm and cool temperate climatic zones, and warmed by the Gulf Stream. The climate of this area is moderated by the Atlantic Ocean and the Chesapeake Bay to the east, and is milder than that of the mountainous parts of the state to the west. Rainfall averages 3-4 inches per month and is evenly distributed throughout the year when averages are taken over a 30-year Similarly, the average annual rainfall is 42 inches, and the average annual snowfall is 22 inches. Charlestown lies within USDA Plant Hardiness Zone 7b, with an average 200-day growing season which is gradually increasing due to global warming.

6. Wind, Air, and Noise – The prevailing winds in this region are westerlies due to our latitude, with minor gradual shifting from the northwest in winter to southwest in summer. Although Charlestown is located near major interstate highways and the large urban area of Baltimore as sources of air pollution, the prevailing westerlies tend to bring in fresh air from the less developed areas to the west. The “good air” was known to early residents of this area, many of whom built summer homes in Catonsville to escape the heat, humidity, and odors of An elevation change of a few hundred feet can make a noticeable difference. These features of the local climate are also important to Charlestown residents, many of whom are elderly and may not well tolerate pollution and temperature extremes.Interestingly, wind direction can also play a minor role in area noise levels. The westerlies slightly suppress the noise from I-95 to the southeast of the campus, but they do not suppress the low rumble from the closer I-695 to the southwest. Similarly, prevailing winds determine the way that an airport’s major runways are laid out, thus determining preferred take-off and landing directions for flights out of BWI airport, since taking off and landing into the wind are the norms. Thankfully for Charlestown, the prevailing westerlies have most flights taking off to the west, so their run-up and take- off noise is directed more to the east, away from our campus. Occasionally, though, we can hear the jet engine noise at Charlestown (especially if the wind is from the south), even though the airport is six miles away. Our more likely sources of local noise are simply routine traffic, construction, and diesel trucks and buses, although Charlestown for the most part is a quiet place.

7. Eastern Deciduous Forest Biome – Charlestown is in this botanical region, with native climax tree vegetation including several species of oaks, American Beech, various hickories, Tulip Poplar, and various maples. Many of the animals associated with this biome are still found in this area, although large predators are rare. Approximately 40% of the Charlestown campus is covered with trees, with the great majority being mature native forest, even though most of the region was deforested at least twice in the Charlestown’s Three Ecosystems –

 The three Charlestown Ecosystems: 

1. The first ecosystem is fully urban, i.e., the main campus, which is composed of two dozen major buildings with connecting roadways, walkways, and Construction and landscaping have greatly modified the original habitat and topography. Ornamental trees, bushes, flowers, and grasses have been planted and are maintained in this area.
2. The second ecosystem is the Lake Charles area, a multi-purpose stormwater retention location which is a typical lentic (still water) ecosystem. The original vegetation of this area was removed for the most part, and the land was contoured to form the lake bed and dam. Ornamental trees were planted on the east side of the lake between the water and an encircling service road/path. Native and invasive trees grow on the west and south sides of the lake, and invasive trees (mostly black locust) are routinely removed from the earthen dam, which forms the northeast side of the lake. Low vegetation is mowed around most of the lake’s perimeter. The lake is annually stocked with largemouth bass for the resident fishermens’ catch-and-release program. Sunfish are also in the lake, and top-feeding minnows are present, which help to ensure there is no mosquito problem in the vicinity.
3. The third Charlestown ecosytem is native deciduous forest, which makes up more than a third of the campus The major portion of this forest surrounds the East Branch of Herbert Run on the north side of the campus. Being on the Fall Line, the western portion of the stream flows downhill beside the Charlestown Nature Trail through a narrow wooded valley. The eastern portion of the stream flows more slowly, through its own flood plain in the woods. These lotic (flowing water) habitats are unique on the campus.