Mānā Plains Forest Reserve is located on western side of Kauaʻi. Mānā Plain Forest Reserve once contained expansive wetland habitats for native species. Prior to its drainage and conversion to agricultural lands during the early 1900s, approximately 1,700 acres of permanent, semi-permanent, and seasonal wetlands were present on the Mānā Plain, which was one of the largest seasonal wetlands in the Hawaiian Islands. Approximately 200 acres of aquatic habitats exist on the Mānā Plain currently. These habitats include manmade drainage ditches, reservoirs, and artificial open water and wetland habitats. Most of these aquatic habitats only provide marginal resources for endemic Hawaiian waterbirds due to the presence of invasive vegetation, mammals, and invasive fish species.