Big plans to expand and upgrade an aging Santa Ana Zoo are now underway, thanks to a robust public-private partnership making the $60 million project possible. Aimed at renovating the oldest areas of the 70-year-old zoo, the overall project will include sprucing up the property, improving existing animal habitats, and adding new exhibits and attractions. The first phase of improvements will include a brand new above- and below-water river aquarium playground for endangered giant otters, including a 15-foot waterfall, with river’s edge and subterranean viewing areas for visitors. Normally found in the rainforests of South America, freshwater giant otters are larger than the species of sea otters found off California’s coast. New enclosed, treetop and mesh monkey trails and an overhead habitat will also be built, allowing the zoo’s 40-plus monkeys of varying species to move freely above the otter habitat, giving visitors a unique view into their daily routines …