Bridgewater is located at . Mormon Trail Lake and Park are located outside of town. According to the United States Census Bureau, the city has a total area of, all land.
As of the census of 2010, there were 182 people, 89 households, and 48 families living in the city. The population density was. There were 100 housing units at an average density of. The racial makeup of the city was 95.1% White, 0.5% Asian, 0.5% from other races, and 3.8% from two or more races. Hispanic or Latino of any race were 0.5% of the population. There were 89 households of which 20.2% had children under the age of 18 living with them, 43.8% were married couplesliving together, 6.7% had a female householder with no husband present, 3.4% had a male householder with no wife present, and 46.1% were non-families. 43.8% of all households were made up of individuals and 28.1% had someone living alone who was 65 years of age or older. The average household size was 2.04 and the average family size was 2.83. The median age in the city was 47.3 years. 21.4% of residents were under the age of 18; 4.8% were between the ages of 18 and 24; 20.3% were from 25 to 44; 24.6% were from 45 to 64; and 28.6% were 65 years of age or older. The gender makeup of the city was 53.3% male and 46.7% female.
2000 census
As of the census of 2000, there were 178 people, 87 households, and 56 families living in the city. The population density was 620.7 people per square mile. There were 105 housing units at an average density of 366.1 per square mile. The racial makeup of the city was 99.44% White. Hispanic or Latino of any race were 0.56% of the population. There were 87 households out of which 17.2% had children under the age of 18 living with them, 52.9% were married couples living together, 4.6% had a female householder with no husband present, and 35.6% were non-families. 32.2% of all households were made up of individuals and 17.2% had someone living alone who was 65 years of age or older. The average household size was 2.05 and the average family size was 2.50. Age spread: 17.4% under the age of 18, 4.5% from 18 to 24, 20.2% from 25 to 44, 24.7% from 45 to 64, and 33.1% who were 65 years of age or older. The median age was 49 years. For every 100 females, there were 93.5 males. For every 100 females age 18 and over, there were 93.4 males. The median income for a household in the city was $30,536, and the median income for a family was $31,625. Males had a median income of $27,188 versus $20,417 for females. The per capita income for the city was $18,780. None of the families and 7.0% of the population were living below the poverty line, including no under eighteens and 6.6% of those over 64.
