Ridgewood Reservoir, 1916. The history of the land that today forms the Ridgewood Reservoir and Highland Parks dates back (truly) to its creation by the Wisconsin Ice Sheet tens of thousands of years ago. In the more recent era, Highland Park was created over decades in the 19th and early 20th century as land was added piecemeal to the park. In 1856 the city of Brooklyn first purchased land for the construction of the reservoir. Completed in 1858, it operated as a water supply for Brooklyn between 1858 and 1959. Water supplies from upstate began providing the city with water in the first half of the 20th century and after 1959 the reservoir was relegated to backup supply for Brooklyn and Queens. It was decommissioned in 1990 and has since because a public park area, known for its native plants and wildlife.