Denver Zoo says goodbye to last hippo — and slashes water use by more than 25 percent

Because my favorite animal is a hippo, learning the Denver Zoo no longer has one was sad at first…but finding out why they parted ways makes a ton of sense, and savings!

Mahali the Nile hippopotamus was a fan-favorite at the Denver Zoo for more than two decades. Visitors watched him lurk in his pool with just his eyes, ears and snout above the surface, play with his toys and drink from a firehose.

But Mahali had a not-so-little secret: his habitat guzzled nearly 21 million gallons of water a year — more than a quarter of the entire zoo’s annual water budget — because his pool had to be drained and refilled with fresh water every single day.

So, when the Association of Zoos and Aquariums flagged the aging Old Pachyderms building for “significant updates” and said it was “no longer considered suitable for the species,” zoo leaders saw an opening. They announced in July 2025 that the Denver-born hippo would be transferred to a three-acre habitat at a wildlife preserve in Texas, where a potential mate was waiting.

Mahali, though, had other ideas. He “made it known to his care team that he was not quite ready for this move,” and the transfer was pushed to spring 2026 so he could finish crate training. When the day finally came, keepers drained the pool one last time, and the zoo vaulted past its goal of cutting water use in half from 2018 levels.

To put Mahali’s thirst in perspective: his 21 million gallons a year would have been enough to supply roughly 190 average Colorado households — or about one city block in a Denver suburb.

Mahali was born at the zoo in 2002 to parents Samantha and Bert. He is the zoo’s last hippo, and officials say there are no plans to bring the species back.

It cost nearly $200,000 a year to maintain the hippo habitat, officials said.