The Milwaukee County Zoo is a 190-acre home to more than 2,200 animals and over 340 species. The zoo’s elephant habitat expansion strongly emphasizes animal health, enrichment, and natural behaviors. To support this vision, County Materials donated two 36-inch reinforced concrete pipe sections that were carefully adapted into interactive feeding stations.
Openings cored into the concrete pipe sections allow elephants to reach inside with their trunks, encouraging them to root and forage for food just as they would in the wild. Zookeepers regularly place food within the structures, providing daily opportunities for exercise, problem-solving, and play.
The pipes were installed in both the indoor and outdoor habitats. Only the top third of each pipe is exposed above ground, ensuring stability and long-term safety.
To transform the concrete pipe sections into a puzzle feeder, County Materials worked closely with zoo staff to determine the best size for the holes to ensure they were large enough for the elephants to reach their trunks inside, but too small for them to get a leg or foot stuck inside, which could lead to an injury or cause distress.
Reinforced concrete pipe has proven to be an ideal material for these enrichment projects because of its enhanced strength, which can withstand the weight of a six-ton elephant and endure outdoor conditions year round. Its mass makes it too heavy for the elephants to dislodge from the ground, keeping both elephants and visitors safe. The zoo can expect the concrete pipe to last for decades with minimal need for maintenance, making it a cost-effective enrichment solution.
While reinforced concrete pipe is traditionally used in storm and sanitary applications, concrete pipe puzzle feeders have become common enrichment features in elephant enclosures at zoos. Enrichment promotes optimal psychological and physical health for animals in human care, prolonging their lives and supporting the survival of endangered species such as the Savanna Elephants at the Milwaukee County Zoo. By promoting the health of these elephants, these enrichment projects enable them to make more contributions to scientific research throughout their lives.
This section of Highway 83 benefitted from a total reconstruction. Slopes were flattened and curves were straightened to make travel much safer for the public. All reinforced concrete pipe and precast concrete box culvert crossings were upsized to improve drainage as well.
The project was completed on October 14, 2019. A major benefit of using precast box culverts included the quick installation, which reduced any chance of delays occurring as can happen with cast-in-place in the wet spring and summer seasons. The use of precast also greatly shortened the time needed for the open window of excavation.
Location: Milwaukee County Zoo Elephant Enclosure
Date Completed: 2025
Project Owner: County Materials Corporation & Milwaukee County Zoo
Contractor: County Materials Corporation
Designer: County Materials Corporation & Milwaukee County Zoo