Indigenous water protectors at Standing Rock, who have fought construction of the Dakota Access Pipeline, are surrounded by militarized police forces. They face an evacuation order that the state of North Dakota and Army Corps of Engineers plan to enforce in the afternoon on February 22. But the water protectors are on treaty territory, and any raid will violate their treaty rights.

During the past weeks, President Donald Trump has pushed forward with plans to grant Energy Transfer Partners an easement for the construction of the Dakota Access pipeline underneath Lake Oahe. His administration has bucked the process of reviewing the environmental impact of the project on indigenous people in order to expedite government approval of the project, which President Barack Obama brought to a halt in his final months in office.

The move to use force to remove indigenous people from treaty land is the latest chapter in the history of United States colonialism. However, the infringement upon tribal treaty rights of the Standing Rock Sioux Tribes and the Cheyenne River Sioux Tribes has not gone unnoticed by the U.S. government when it comes to the pipeline project.

Prior to the end of the Obama administration, the Army Corps solicited the Interior Department’s opinion on how treaty rights should weigh when making considerations in favor of the pipeline project. A memo [PDF] dated December 4, 2016, shows Hilary C. Tompkins, the solicitor at the Interior Department, believed the Army Corps was on solid legal ground to deny the easement. (Note: This is known as an “M-opinion,” a formal legal analysis issued by the Interior Department’s top lawyer).

“If the Corps ultimately does decide to authorize the easement, additional tribal consultation is necessary to develop conditions for the authorization that will protect the tribes’ rights and interests in and around Lake Oahe,” Tompkins concluded.

The memo was filed in a federal court in Washington, D.C., as part of the Standing Rock Sioux and Cheyenne River tribes’ efforts to halt drilling under Lake Oahe. It was suspended two weeks ago by the Trump administration in an attempt to quash the legal analysis done by the department before Trump was inaugurated.

Earthjustice lawyer Jan Hasselman, who represents the Standing Rock Sioux Tribe, called the memo during an interview for E&E News “hugely significant” and indicated it could determine the outcome of the case the tribes filed in federal court.

In response to the Trump administration’s moves to make the memo disappear, “It’s more of the same we’ve seen from this administration—taking thoughtful and considered work and tossing it in the garbage.”

E&E News reported, “Interior removed the memo from the solicitor’s website last week, along with three other opinions that could affect Dakota Access.”

The memo outlined applicable treaty law. The Fort Laramie Treaties of 1851 and 1868 “established the original boundaries of the Great Sioux Reservation.” These treaties set the “eastern boundary of the reservation” as the “east bank of the Missouri River…thence along low-water mark down said east bank.” A subsequent act of Congress in 1889 removed land from the reservation and divided territory into “smaller reservations for various Sioux bands, including Cheyenne River, Standing Rock and Lower Brule.”

The eastern boundaries of the reservations for the Standing Rock and Cheyenne River reservations were set as the “center of the main channel” of the Missouri River by the 1889 Act.

Unequivocally, the memo authored by Tompkins declared, “The tribes enjoy a right to water to support their reservation homeland.”

“For over a century, the Supreme Court has held that when the United States ‘withdraws its land from the public domain and reserves it for a federal purpose, the Government, by implication, reserves appurtenant water then unappropriated to the extent needed to accomplish the purpose of the reservation.'” These rights are referred to as “Winters rights” after a foundational case, Winters v. United States, in which the Court held that although the treaty creating the Fort Belknap Reservation was silent as to water rights, it had to be read as implicitly maintaining the Tribe’s access to water sufficient to support the purpose of the reservation (in that case, farming). Courts applying the Winters doctrine recognize that absent such implied rights, tribes would lose their water via upstream appropriation or degradation by non-Indians under state law.

Upon review of treaty law, Tompkins indicated a “significant portion of Lake Oahe remains within the outer boundary of the Standing Rock and Cheyenne River Sioux reservations.” The tribes also have “on-reservation hunting and fishing rights in the land used to create Lake Oahe.”

Tompkins conducted an analysis of treaty law as it might relate to “off-reservation portions of Lake Oahe.” Pipeline drilling on that “may infringe upon Sioux treaty rights if the activities negatively impact on-reservation hunting and fishing.”

“The Standing Rock Sioux tribe has provided the Corps with a detailed technical review of the risks and potentially significant consequences of a DAPL leak,” Tompkins acknowledged. There is a “possibility of impacts on tribal treaty rights that warrant additional review. In this regard, the Corps has a valid rationale to expand its [National Environmental Policy Act] review and authorize independent experts to opine on the potential for a catastrophic spill at the proposed location.”

Remarkably, the memo gave critical attention to the fact that the Army Corps rejected routing the pipeline “ten miles of north of Bismarck, North Dakota,” but approved the route that is about a half mile from the border of the Standing Rock Sioux reservation.

“The Corps’ reasons for rejecting the Bismarck route also largely apply to concerns regarding tribal treaty rights associated with the Lake Oahe route. As such, if the Bismarck route is impermissible, the Lake Oahe route should be equally impermissible,” Tompkins stated.

An environmental assessment (EA) was put together by the Army Corps, and Tompkins scrutinized the assessment quite thoroughly.

In the EA, the Corps ultimately rejected the Bismarck route due in large part to its proximity to a central municipality and to “multiple conservation easements, habitat management areas, National Wildlife Refuges, state trust lands, waterfowl production areas, and private tribal lands.” The Corps also noted that the Bismarck route crossed or was in close proximity to “several wellhead source water protection areas,” and thus determined that the agency should avoid that route so as ”to protect areas that contribute water to municipal water supply wells.” The Corps further sought to “minimize[] impacts on sensitive resources ( e.g., piping plover critical habitat, eagle nests, etc.),”as well as to completely avoid “high risk features” such as national parks. But while the Corps determined that these concerns rendered the Bismarck alternative non-viable, and thus chose not to analyze their decision in detail in the EA, the EA minimizes identical considerations with respect to the Lake Oahe route’s threat to on-reservation tribal hunting, fishing, and water rights.

The Corps developed a rationale for putting the pipeline at Lake Oahe with “no input from the tribes.” It inaccurately minimized the risk a pipeline spill would pose to tribal drinking water supplies.

Tompkins was understandably baffled. “A pipeline spill would thus pose the same risk to tribal water (which, unlike Bismarck water, carries associated treaty and Winters rights) that the Corps found to be impermissible for Bismarck water, and yet the threat to tribal water was considered mitigated by the same pipeline technology that the Corps found would not protect Bismarck residents.”

“The EA does not explain why, if existing safeguards are inadequate to mitigate spill risk from a pipeline running ten miles from a city, they nevertheless protect federally reserved tribal waters less than one mile from an Indian reservation,” Tompkins added.

There may be no clearer articulation of how illegal and abusive the federal government’s actions are as they disrespect the Standing Rock Sioux and Cheyenne River’s sovereignty.

According to indigenous women at the Oceti Sakowin Camp, which will soon be raided, there is a risk of arrest, police brutality, federal prosecution, and prison time. They call on people to stand with them to protect the water and treaty rights of indigenous people.

“In the history of colonization,” one water protector declared, “they’re always giving us two options. Give up our land or go to jail. Give up our rights or go to jail. And now, give up our water or go to jail.”

Chase Iron Eyes of the Standing Rock Sioux described the militarized law enforcement amassing to force the removal of indigenous people as a function of its role as a “violent enforcer of the will of capital. The corporate state is here: an oil war in the heartland.”

As Ruth Hopkins, a Dakota/Lakota Sioux writer for Indian Country Today, put it, “Forced removal isn’t just in the history books. It’s happening tomorrow on treaty lands at Standing Rock.”

Interior Dept. Solicitor Memo On Dakota Access Pipeline by Shadowproof on Scribd