According to the United States Census Bureau, the township has a total area of 96.3 km² (37.2 mi²). 87.2 km² (33.7 mi²) of it is land and 9.1 km² (3.5 mi²) of it is water. The total area is 9.44% water.
As of the census of 2000, there are 28,219 people, 10,092 households, and 7,821 families residing in the township. The population density is 323.7/km² (838.3/mi²). There are 10,616 housing units at an average density of 121.8/km² (315.4/mi²). The racial makeup of the township is 96.56% White, 0.78% African American, 0.49% Native American, 0.59% Asian, 0.02% Pacific Islander, 0.29% from other races, and 1.28% from two or more races. 1.81% of the population are Hispanic or Latino of any race.
There are 10,092 households out of which 39.0% have children under the age of 18 living with them, 65.0% are married couples living together, 8.7% have a female householder with no husband present, and 22.5% are non-families. 17.6% of all households are made up of individuals and 4.5% have someone living alone who is 65 years of age or older. The average household size is 2.77 and the average family size is 3.15.
In the township the population is spread out with 27.7% under the age of 18, 6.8% from 18 to 24, 32.8% from 25 to 44, 24.9% from 45 to 64, and 7.8% who are 65 years of age or older. The median age is 36 years. For every 100 females there are 100.1 males. For every 100 females age 18 and over, there are 99.1 males.
The median income for a household in the township is $65,894, and the median income for a family is $75,842. Males have a median income of $52,276 versus $31,742 for females. The per capita income for the township is $27,916. 3.1% of the population and 1.9% of families are below the poverty line. Out of the total people living in poverty, 3.0% are under the age of 18 and 3.2% are 65 or older.