Lake Oahe "a memorandum and an executive order asking USACE to expedite its consideration of the company’s application for an easement to start construction." The USACE subsequently "withdrew its call for the environmental study." On 7 February 2017, the USACE approved an easement through Lake Oahe. On 9 February 2017, the Cheyenne River Sioux filed the first legal challenge to the easement, citing an 1851 treaty and interference with the religious practices of the tribe. Lake Oahe Lake Oahe (oh-WAH'-hee) is a large reservoir behind Oahe Dam on the Missouri River; it begins in central South Dakota and continues north into North
Perunchani Dam of the reservoir. The dam is located about from Nagercoil, the administrative headquarters-town of Kanyakumari District, and about from the town of Kulasekharam. The average annual rainfall in the catchment is , and the average annual yield at the dam site is . The dam was constructed between 1948–1953 by the then State of Travancore-Cochin. The height of the straight gravity masonry dam above the deepest foundation is , with Full Reservoir Level (FRL) at , which is also the Maximum Water Level (MWL). The dam is long. The gross storage capacity of the reservoir is at the FRL, which