According to the United States Census Bureau, the township has a total area of 7.7 square miles (20 km2), of which 7.3 square miles (19 km2) is land and 0.5 square miles (1.3 km2), or 5.95%, is water.
As of the census[13] of 2000, there were 10,934 people, 4,796 households, and 3,126 families residing in the township. The population density was 1,503.6 inhabitants per square mile (580.5/km2). There were 5,246 housing units at an average density of 721.4 per square mile (278.5/km2). The racial makeup of the township was 94.81% White, 3.69% Black or African American, 0.05% Native American, 0.41% Asian, 0.11% from other races, and 0.91% from two or more races. Hispanic or Latino of any race were 0.55% of the population.
There were 4,796 households, out of which 25.9% had children under the age of 18 living with them, 48.4% were married couples living together, 13.2% had a female householder with no husband present, and 34.8% were non-families. 31.7% of all households were made up of individuals, and 16.9% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.83.
In the township, the population was spread out, with 21.0% under the age of 18, 6.7% from 18 to 24, 26.6% from 25 to 44, 23.7% from 45 to 64, and 22.1% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 86.0 males. For every 100 females age 18 and over, there were 81.5 males.
The median income for a household in the township was $33,482, and the median income for a family was $42,309. Males had a median income of $36,743 versus $22,111 for females. The per capita income for the township was $18,011. About 9.6% of families and 11.4% of the population were below the poverty line, including 20.3% of those under age 18 and 8.1% of those age 65 or over.
The Community Library of Allegheny Valley, Harrison Branch serves the township.[14]
The Burtner House located in Harrison Township. This is a historical landmarks. They hold the Strawberry Festival every summer.
Education
Current buildings
Harrison Township is within the Highlands School District. Highlands High School (9–12), Highlands Middle School (6–8), the district's Buildings and Grounds Complex (maintenance), and Highlands School District administrative offices are in the township. Highlands Golden Rams Stadium (track and football), tennis courts, a soccer field, and the Highlands Community Center are adjacent to the middle school; and several baseball fields are next to the high school.
Former buildings
Historical schools, which are now closed, include: Natrona High School, later used for the Wood Street Elementary School (K–6), then sold and converted into apartments; Riverview Elementary School, used for the administrative offices since the early 1980s, slated to be sold after January 2012; and Birdville Elementary School, which was converted into the Citizens Hose Volunteer Fire Department. Heights Elementary School (K–5) was reassigned as the Heights Early Childhood Center (Kindergarten, the Pre-K Counts Program, Head Start, and the YMCA Before/After Childcare Program) in late June 2011; it closed in June 2012.
Parks and recreation
Several parks are located throughout the township: Harrison Hills Park is a county park located in the northeast area of the township; the Natrona neighborhood has a community playground and riverfront park.