Some environmentalists and Ojibwe tribes are angered at the state's decision to allow Enbridge to move 5 billion gallons of water as it builds a replacement for its Line 3 pipeline — up from 510 million in the company's original permit.

The water involved is in shallow aquifers, and it is temporarily being moved so that it doesn't drain into the pipeline's trench during construction.It's pumped from wells 10 to 15 feet deep and moved nearby to seep back into the soil to restore groundwater balance.

Earlier this month, the Department of Natural Resources (DNR) approved Enbridge's request to move 10 times as much water as originally planned, amending a permit it originally granted in November. The company started construction late last year, and the 340-mile oil pipeline is now more than 60% built.

White Earth and Red Lake — the state's two largest Ojibwe bands — say they weren't adequately consulted about the DNR's decision.And critics say the sheer volume of water transferred could endanger the ecosystem near the pipeline, including wild rice beds, and even more so during the current drought.

"The surface water and shallow groundwater is more sensitive to drying out in these conditions," said Christine Dolph, a research scientist at the University of Minnesota's ecology department. "The huge increase in volume is really concerning, and it is unclear why [Enbridge] would have been off by so much. It indicates they don't understand the system they are working in."

Enbridge requested the increase in "construction dewatering" early this year, saying winter conditions were much wetter than expected.Also, the company said at the time that it was switching from sump pumps to move water to "well point" water extraction.

The latter, which state agencies recommended to Enbridge, decreases turbidity — a good thing — but requires the transfer of more water.

In its amended permit issued June 4, the DNR concluded that Enbridge's increase in dewatering was necessary for the safety of workers in the pipeline's trench.

"Our evaluation of nearby wetlands is [also] that the temporary dewatering of trenches is not expected to have any significant impact on nearby wetlands or other surface waters, even in drought conditions," the DNR said in an e-mail to the Star Tribune.

"The current drought conditions may actually reduce the need for dewatering in some areas because less water may be seeping into trenches in drought-affected areas," the agency said.

Enbridge, in a statement to the Star Tribune, said it expects soggy conditions to remain, giving no indication it would reduce dewatering.

"Groundwater activities are temporary, confined to the work area and [the water] is immediately discharged back to the surrounding area," the company said.

The Minnesota Chippewa Tribe, which is composed of six of the state's seven Ojibwe bands, sent a letter to Gov. Tim Walz last week, asking that the DNR rescind the amended water permit, particularly since northern Minnesota is already in a moderate drought.

"Water levels are already dangerously low and displacing this many gallons of water will undoubtedly have a detrimental impact on our wild rice," the letter said.

White Earth Band of Ojibwe Chairman Michael Fairbanks said in an interview that the big increase in dewatering "is kind of like attacking our crop, our way of life." Wild rice is not only an Ojibwe food staple, it also is considered sacred.

The Red Lake Band of Chippewa, which is not part of the Minnesota Chippewa Tribe, has also asked the state to rescind the amended permit. "There's no doubt it is impacting water tables that are already strained," said Sam Strong, the band's tribal secretary.

Strong and Fairbanks said the Walz administration did not engage in meaningful consultation with the tribes on the permit change — even though the governor signed an executive order in 2019 expanding tribal-state relations.

Walz's office said in a statement that "the governor is committed to maintaining strong government-to-government relationships with tribal governments. … However, the governor does not have the authority to direct a state agency to rescind an issued permit amendment."

Enbridge asked the DNR for the water increase in January. The DNR said in its e-mailed statement that on May 14 it sent e-mails to 18 tribal organizations about the proposed permit change, soliciting comments. Staff from the White Earth and Mille Lacs Ojibwe bands, and the Minnesota Chippewa Tribe, attended one meeting with the DNR, the agency said.

Strong said the DNR's notification was not sent to tribal leaders.

The "dewatering" issue is the latest controversy over Enbridge's $3 billion-plus new pipeline, a conduit for thick Canadian crude. The new pipeline will replace the Calgary, Alberta,-based company's current Line 3, which Enbridge says is corroding and operates at 51% capacity for safety reasons.

Several environmental groups and some Ojibwe bands, including White Earth and Red Lake, have opposed the new pipeline, which runs partly on a new route. They say the new Line 3 — one of the largest construction projects in Minnesota in recent years — will open regions of lakes, rivers and wild rice beds to degradation from oil spills, as well as exacerbate climate change.

According to the DNR's permit, water near Line 3's construction trench is discharged a few hundred feet away into a "geotextile filter bag in a well-vegetated upland location'' — or, when that's not available, into a "straw or hay bale dewatering structure."

Dewatering occurs at a given location for only a few days, but it is being done in many places along the pipeline's new route.

"The whole region is basically saturated with wetlands," said the U's Dolph, who was a pro-bono expert witness for tribes and environmental groups who opposed the Minnesota Pollution Control Agency's water permits for Line 3.

The MPCA consulted on the DNR's dewatering permit, noting to the DNR in a March 28 letter that it "is concerned with Enbridge's ability to manage this requested, substantially larger, increased volume of water."

Those concerns stemmed from earlier Enbridge "dewatering discharges" that have allegedly "beennon-compliant with MPCA authorizations," the letter said.

The MPCA declined to provide further detail, saying it was still investigating the matter.