Other than some subtle signage on three streets entering Rivergrove, there is no clear demarkation separating Rivergrove from either adjacent community: one has to know that it exists to even be aware that one is driving through the city.
According to the United States Census Bureau, the city has a total area of 0.2 square miles (0.5 km²).None of the area is covered with water.
There were 117 households out of which 34.2% had children under the age of 18 living with them, 69.2% were married couples living together, 3.4% had a female householder with no husband present, and 24.8% were non-families. 18.8% of all households were made up of individuals and 4.3% had someone living alone who was 65 years of age or older. The average household size was 2.77 and the average family size was 3.18.
In the city the population was spread out with 27.5% under the age of 18, 4.3% from 18 to 24, 28.7% from 25 to 44, 32.4% from 45 to 64, and 7.1% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 94.0 males. For every 100 females age 18 and over, there were 102.6 males.
The median income for a household in the city was $85,000, and the median income for a family was $93,212. Males had a median income of $58,125 versus $40,500 for females. The per capita income for the city was $31,546. About 4.8% of families and 4.7% of the population were below the poverty line, including 8.6% of those under age 18 and none of those age 65 or over.