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Chapter 2 : Project Area Characteristics
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The Swatara Creek watershed is situated in the south-central section of Pennsylvania. The watershed extends from the southern anthracite coalfields of Schuylkill County through the Karst limestone formations of Lebanon and Dauphin Counties before emptying into the Susquehanna River at Royalton and Middletown, Pennsylvania. The Swatara Creek watershed encompasses parts of Schuylkill, Berks, Lebanon, and Dauphin Counties. Swatara Creek originates near the village of Branchdale and flows in a southerly and southwesterly direction for approximately 69 miles to its confluence with the Susquehanna River. The Swatara Creek watershed is referenced by US Geologic Service’s (USGS) Hydrologic Code (1974) 02050305 in the Mid-Atlantic Region (US Department of the Interior, 1974), it is also designated as sub-basin 7 of the Susquehanna River Basin by the Susquehanna River Basin Commission (SRBC) and the Pennsylvania Department of Environmental Protection (PADEP). The majority of references list the Swatara Creek Watershed as draining approximately 576 square miles of the Susquehanna River basin (McCarren, Wark, and George, 1964). However, GIS calculations and the Pennsylvania Gazetteer of Streams (PADEP, 1989) measures the watershed as draining 571 square miles. For this document, 571 square miles will be utilized as the watershed drainage area for both presentation and calculation purposes. This River Conservation Plan covers this entire watershed, including six (6) major tributaries (Upper Little Swatara, Lower Little Swatara, Little Swatara, Quittapahilla, Manada, and Beaver Creeks) as well as other named and unnamed tributaries. The watershed includes four counties and contains all or part of 46 municipalities (Appendix A). Table 2-1 lists the municipalities located within the watershed. The Swatara Creek watershed encompasses all or parts of 17 different school districts. These school districts are presented in Figure 2-1.
The Swatara Creek watershed is located within two different physiographic provinces, the Ridge and Valley, and the Piedmont. The watershed contains both the Appalachian Mountain and Great Valley Sections of the Ridge and Valley Province, and the Gettysburg-Newark Lowlands Section of the Piedmont Province. The varied physiographic settings of the watershed translate into a variety of landforms found within it. Located in the northern end of the watershed (Schuylkill, northern Lebanon, and the northwestern edge of Berks Counties), the Appalachian Mountain Section of the watershed is characterized by long narrow ridges interspersed by narrow to broad valleys. The southern edge of the southern anthracite coalfields comprises the headwaters of the Swatara Creek. The ridges are primarily composed of resistant sandstones and the valleys of softer shales and siltstone. The vertical relief in this area is moderate to very steep. The elevation of Swatara Creek at its headwaters is approximately 1,510 feet above sea level. When it exits the Appalachian Mountains Section in Lebanon County, the elevation is approximately 425 feet above sea level. Over the approximately 25.6 mile length of this section, this would equate to a 0.8 percent slope. The central section of the watershed (Lebanon, Berks and central Dauphin Counties) is located in the Great Valley Section of the Ridge and Valley Province. This area, as its name suggests, is a broad lowland area south of Blue Mountain. As Swatara Creek flows from the Appalachian Mountain Section into the Great Valley Section, the valley is primarily composed of shales and siltstone. Further south in the watershed and the physiographic section, Quittapahilla Creek, a major tributary enters Swatara Creek. The Quittapahilla flows over the limestones, dolomites, and calciferous sandstones that make up the southern portion of the physiographic province. The vertical relief in this area is mild to moderately steep. The elevation of Swatara Creek entering the Great Valley Section is approximately 425 feet above sea level, and it exits the physiographic province atapproximately 295 feet. Over the approximate 39-mile length of this section, this would equate to a 0.06% slope. The final section of the watershed (southern Dauphin and Lebanon Counties) is located within the Gettysburg-Newark Lowland Section of the Piedmont Physiographic Province. This area is characterized by rolling hills and valleys. Within the watershed, this physiographic section is primarily composed of shales with intrusions of Triassic diabase (a hard volcanic rock). The vertical relief in this section is mild to moderately steep. The elevation of Swatara Creek entering this physiographic section is approximately 295 feet above sea level, and the elevation as it empties into the Susquehanna River is approximately 279 feet above sea level. Over the approximately 4-mile length of this section, this would equate to a 0.1% slope.Land use information was collected through a combination of map review and field verification. The field investigation took place in October, 1999. A total of six (6) land use categories were identified. These land uses include Forested, Agricultural, Developed, Wetland, Water, and Barren. Figure 2-2 at the end of the chapter illustrates the land uses found in the watershed. Land use throughout the Swatara Creek Watershed is diverse and ranges from vast areas of deciduous forests to regional commercial centers. Figure 2-1, Land Use/Land Cover displays the relationship between these various land uses and the natural features found within the watershed. The Anderson Land Use and Land Cover Classification System was used to determine land use types for the watershed. The land use and land cover system presented in this report includes the more generalized first and second levels. A description of the land use/land cover types found within the watershed is presented in Appendix B. Table 2-2, Existing Land Use presents the Level 1 classifications and their subcategories as a percent of the total land within the watershed. Within the watershed agricultural land was the most prevalent land use totaling over 206,658 acres (56.5 percent) of the entire watershed. Nearly all of the agricultural land was cropland/ pasture. It is the primary land use south of Blue Mountain, which traverses from east to west in the northern section of the watershed. Other land uses do occur in the southern section of the watershed, however, minimal in acreage when compared to agricultural land. Most of the municipalities in this area are large townships with small village centers and boroughs, which provide small commercial centers sufficient to provide for the day-to-day needs of the residents. Forestland also comprised a high percentage of land, approximately 118,623 acres (32.5 percent), within the watershed. With the exception of a few scattered areas in the southern region, forestland is located along the mountains in the northern section of the watershed. Mountains of this area include Blue Mountain, Second Mountain, Peters Mountain, and Little Mountain. The highest percentage of Forestland in the watershed was deciduous, although stands of Mixed Forest and Evergreen Forest existed throughout the northern mountainous areas. Most of the Urban/Built Up land was identified along the PA Rt. 422 corridor. Large commercial/ service districts were visible in Lebanon, Cleona, Annville, Palmyra, Hershey, Hummelstown, and Middletown. The largest single area of commercial/service land is located at the Fort Indiantown Gap; however, the majority of this area is utilized for military training exercises and is not in commercial development. Much of the residential land in the watershed surrounds these commer cial centers or other small commercial areas south of Blue Mountain.
Land Use Acres by County Barren Land primarily consisted of strip mine/ quarry land located in the extreme north section of the watershed in Reilly, Frailey, Porter, and Tremont Townships of Schuykill County. Other areas of strip mine/ quarry land existed in Annville, North Annville, North Lebanon East Hanover and North Londonderry Townships in Lebanon County. These were primarily limestone and shale quarries. Limestone quarries in Derry, South Hanover, and Lower Swatara Townships in Dauphin County were also identified. A summary of the major land uses of the counties in the watershed are presented in the following paragraphs: Berks County A small (northwestern) corner of Berks County is located within the Swatara Creek watershed. Only 10.5% (Approx. 38,315 ac) of the entire watershed is located in Berks County. The majority of the watershed in Berks County is composed of farmland, much of this area is intensively farmed, especially the area in close proximity to Little Swatara Creek. The northern end of the watershed in Berks County adjacent to Schuylkill County is forested. Four small communities (Bethel, Frystown, Mount Aetna, and Rehersburg) are the only major residential development located within the Berks County portion of the watershed. Dauphin County Dauphin County makes up 22.3% (Approx. 81,544 ac) of the Swatara Creek watershed. The majority of the watershed in Dauphin County is composed of agricultural lands and recently developed residential areas. The exception to this statement is lands adjacent to Swatara Creek and its tributaries, which are primarily forested. The Boroughs of Hummelstown, Middletown, and Royalton are the largest incorporated communities in the Dauphin County portion of the watershed. Additional urbanized population centers include unincorporated communities of Linglestown, Paxtonia, and Colonial Park in Lower Paxton Township; Rutherford Heights in Swatara Township; Skyline View in West Hanover Township; and Hershey in Derry Township. These communities also contain the largest area of commercial and industrial land use in this portion of the watershed. Lebanon County The majority of the Swatara Creek watershed, 42.7% (Approx. 156,025 ac), is located in Lebanon County. The majority of this portion of the watershed is agricultural land use. However, the section of watershed north of State Route 443 is primarily forested. Lebanon County also contains a portion of Swatara State Park. The City of Lebanon and Boroughs of Palmyra, Cleona, and Jonestown, and the Township of Annville are the largest population centers in the Lebanon County. These communities also contain the majority of the commercial and industrial land use in the Lebanon County portion of the watershed. Additional residential development is located in the communities of Fredericksburg and Cornwall. Ft. Indiantown Gap, a National Guard training facility, is also located within the watershed in Lebanon County. The facility is used as a training ground for military personnel and subsequently has a variety of land types on site. The mountainous areas on the northern portion of the site are forested. The remainder of the property is primarily a mixture of scrub shrub and field areas. Finally, the southern end of Swatara State Park is located in the watershed near the Lebanon/Schuylkill County line. Schuylkill County Schuylkill County comprises 24.5% (Approx. 89,640 ac) of the Swatara Creek watershed. This area is located in the northern and northwestern ends of the watershed and the majority of it is forested. In addition, the southern anthracite coalfields also extend into this portion of the watershed. This results in significant acreage in barren or mining land use. A substantial portion of the watershed in Schuylkill County is in farmland. These farmed areas are located primarily in the southeastern end of the county. The major population centers within the Schuylkill County portion of the watershed are the Boroughs of Pine Grove and Tremont. These communities also contain the largest commercial and industrial land use acreages. The communities of Donaldson and Newtown also contain some residential and commercial lands. Finally, a large portion of Swatara State Park, which also includes parts of Lebanon County, is located in the watershed between Interstate 81 and PA Route 443 along the southern boundary of the county. The Swatara Creek study area contains all, or part of 46 municipalities in four counties. With the exception of two municipalities in Schuylkill County, the remaining 44 municipalities have enacted zoning ordinances. 43 of these municipal ordinances have been obtained for use on the project. The municipalities donated many of the ordinances; others were purchased by SCWA. Mackin Engineering Company analyzed the zoning ordinance and map for each of these municipalities. All of the existing zoning districts for the municipalities were placed into one of the following categories: residential, commercial, industrial, agricultural, institutional, or conservation. A composite map of the project area was developed utilizing these categories. The composite map (see Figure 2-3) provides an overview of the uses allowed in the watershed; however, this map should not be used for planning purposes since it is not an accurate reflection of specific existing zoning. Agriculture is the primary zoning found in the watershed. Potential conflicts could exist between agricultural land uses located directly next to the streams and conservation efforts. A majority of the farms in these locations allow their livestock direct access to the streams. This presents the potential for stream contamination. Additional conflicts could arise from the increased residential development occurring in the watershed. New housing developments not only encroach on the streams of the watershed, but landscaping, the planting of new grass, and the associated large scale use of chemical herbicides and pesticides could create contamination problems within the watershed. Pockets of commercial zoning are concentrated in the more developed urban areas, while agricultural zoning districts are found in the less developed rural areas. Land included in the 100-year floodplain is designated as conservation areas in many of the municipalities. In these conservation zones, development is usually restricted to uses that will not damage or cause pollution during flooding events. 1. Population The Swatara Creek Watershed encompasses approximately 571 square miles and covers sections of Dauphin, Lebanon, Berks and Schuylkill Counties (PADEP, 1989). There were an estimated 290,869 persons living within the watershed boundaries in 1998, which is approximately 2.4 percent of Pennsylvania’s 1998 population (Pennsylvania State Data Center, 1999). Estimates revealed that the population within the watershed increased by 4.3 percent between 1990 and 1998. In contrast, the growth rate for the state of Pennsylvania has been 1.0 percent for the same time period. Lebanon County experienced an overall growth rate of 3.2 percent between 1990 and 1998, while its municipalities within the watershed experienced a slightly smaller population growth rate of 2.7 percent. The countywide population for Dauphin County grew at a 3.3 percent rate during this time and Dauphin County watershed municipalities grew at a 6.6 percent rate. Berks County has experienced the largest population growth within the past decade with a 5.8 percent increase in countywide population and a 6.9 percent increase for watershed municipalities. During the past decade, Schuylkill County was the only county within the study area to experience a decrease in countywide population (-2.8 percent); however, the population within the municipalities of the watershed decreased at a slightly slower rate of 2.1 percent. Table 2-3 compares the change in population from 1990 - 1998 for the counties within the watershed. When identifying population characteristics of the study area, it is important to consider the distribution of population by age group. Each age group has specialized needs that impose different demands upon various municipal and county services. For instance, the "wage-earner" group (ages 18-64) is that portion of the population which is of working age and able to provide for a family. Ideally, this sector of the population should have the largest amount of persons in order to support those persons not able to work or contribute to the tax base. Age groups such as 65 and over normally include retired persons who eventually require additional medical services and specialized housing needs. Similarly, those under the age of 18 also require specialized services, such as, infants and toddlers who require specialized child care services or children aged 5-18 that utilize the public education system. It is important that government leaders know the characteristics of their population to properly plan for future population demands such as additional schools or assisted living facilities.
As shown in Table 2-4, the population distribution for the four counties within the watershed is similar to the state’s; except for Schuylkill County, whose percent of population for the Age 64+ category is 5 percentage points higher than the Pennsylvania average of 15%.
It is important to compare the specific municipal data to the county average in order to determine the characteristics of the Swatara Creek Watershed study area. For instance, watershed municipalities in Berks County have two categories that vary from the county average; the "age 18 and under" group which was 6 percentage points higher than the county average and the percent of the population"64+" was 6 percentage points lower than the county average. Similarly, comparing the Schuylkill County municipalities reveals that the "64+" population was lower by 5 percentage points than the county average. The remaining two age groups, the "18-64" age group and the "under 18" age group were comparable to the county averages. Table 2-4, provides an age comparison of the region as a whole compared to Pennsylvania, the specific municipalities within the study area, and their respective counties. Population trends become apparent when comparing the increase or decrease of persons within a location over a period of time. The 30-year period between 1960 and 1990 was used to identify trends within the Swatara Creek Watershed. Berks, Dauphin and Lebanon Counties all experienced an increase in population over this thirty-year period. However, the growth varied from Lebanon’s 25.2 percent to a smaller increase of 22.2 percent in Berks County and an 8 percent increase in Dauphin County. The only county to experience a decrease in population was Schuylkill County, which lost of 11.8 percent of its population from 1960 to1990 (Table 2-5). During this 30-year time period, Berks County had the largest average population increase for municipalities located withintheWatershed(77.6 percent)(seeTable2-5). Dauphin County, which had the smallest population growth rate of the study area, had a 58.8 percent growth in its watershed population. Lebanon County municipalities in the watershed experienced a population increase of 26.0 percent, which was comparable to the overall county growth rate. Schuylkill was the only county within the watershed to experience a decrease in countywide population; however, the municipalities located within the study area experienced an average population increase of 18.6 percent.
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