Data Dump: Oak Flat land swap finalized
Plus: The Monster March Melt is upon us
⛏️ Mining Monitor ⛏️
The U.S. Forest Service late last week completed the transfer of 2,422 acres of emory oak-studded and boulder strewn public land in central Arizona to Resolution Copper, a subsidiary of global mining corporations BHP Billiton and Rio Tinto. The newly privatized land includes Chíchʼil Bił Dagoteel, or Oak Flat, a 760-acre parcel that President Dwight D. Eisenhower withdrew from mineral entry in 1955. The land transfer removes one of the biggest regulatory obstacles blocking the company’s bid to mine a massive copper deposit that lies about one mile below the surface of Oak Flat.
Some conservation groups initially withheld opposition to the land swap because of the ecological value of the land Resolution was giving up, some of which lies along the San Pedro River, an important corridor for migratory birds. In 2015 Congress passed a bill, with bipartisan support, allowing the swap to proceed. But the company and its politician enablers failed to recognize the significance of Oak Flat to the San Carlos Apache and other tribes in the region—and underestimated the fierceness of their resistance.
Over the ensuing decade, completion of the land exchange has been held up by legal challenges and widespread opposition from Indigenous and environmental groups. Apache Stronghold, a non-profit devoted to protecting sacred sites, took its case up the legal ladder, calling on federal courts to halt the land exchange on the grounds that privatizing and destroying Oak Flat with mining and resulting subsidence would violate the Religious Freedom Restoration Act. Ultimately the Supreme Court refused to take up the case, and other legal challenges also were shot down by the courts.
The fight is not over, however. Shortly after the transfer was announced, a group of Apache women appealed to Supreme Court Justice Elena Kagan to intervene and block the exchange. Even if that fails, Resolution will still need to obtain numerous permits before it can proceed. The land exchange removes most of the project from USFS jurisdiction, leaving it in the hands of state regulators.
Because of the depth of the deposit, the mine would be underground rather than open pit, and would use the cave panel method. This may make it less visible initially, but the magnitude of the endeavor will ultimately have significant impacts on a large swath of public and private lands. As material is removed from underground, the surface will sink, or subside, creating a huge crater and destroying Chíchʼil Bił Dagoteel. Dewatering the mine workings will affect the region’s hydrology, diminishing or drying up springs and “groundwater dependent ecosystems.” And the tailings pile is expected to cover thousands of acres in Dripping Springs Wash, basically filling a desert waterway with a mountain of acid-generating, metal-laden waste.
Mining, ore processing, and slurrying operations would require large amounts of additional water. The company plans to acquire at least some of that from the Central Arizona Project, which is currently facing potentially significant cutbacks due to Colorado River water shortages.
Here are some data from the Environmental Impact Statement for Alternative 6, which was chosen in the record of decision:
1.8 billion metric tons: Estimated size of the copper ore deposit under Oak Flat, one of the world’s largest.
The subsidence crater at Oak Flat will eventually be about 1.8 miles across and between 800 and 1,115 feet deep.
1.37 billion tons: Estimated volume of tailings produced over the life of the mine
20 miles: Length of slurry pipeline that would carry tailings from the ore processing facility to the Dripping Springs Wash tailings depository.
4,002 acres; 490 feet: Area and height of the proposed tailings depository.
9,900 to 17,000: acres of soil and vegetation expected to be disturbed. The analysis notes: “… impacts to soil health and productivity may last centuries to millennia … ”
377: Number of National Register of Historic Places-eligible sites directly affected by the project.
The project would result in the reduction of 13,781 acres of livestock grazing leases and 2,797 animal unit months over 9 allotments, and 14 grazing-related facilities (water sources) would be lost along with infrastructure at the Slash S headquarters.
87,000 acre-feet: Estimated volume of water that would be pumped from the mine (dewatering) over the project’s life. (Some hydrologists have questioned this estimate, saying it is too low).
Dewatering would affect 18 to 20 groundwater dependent ecosystems, i.e. springs.
540,000 acre-feet: Estimated amount of water that would be pumped from the Desert Wellfield in the East Salt River valley for mining and processing operations over the life of the project.
1,400; $149 million: Estimated number of full-time workers at the peak of the project and total annual employee compensation.
On a related note, I’m looking into water use at existing Arizona mines for a future Land Desk dispatch. Stay tuned. And in the meantime, if y’all have any good, reliable sources for this sort of information, I’d appreciate you sending it along to me.
🥵 Aridification Watch 🐫
Typically I wouldn’t depress you all with any snowpack/water news until early April, when mountain snowpacks typically peak, and when we should have a fairly clear picture of what we’re facing as far as spring runoff. But the Bureau of Reclamation released their projections for Lake Powell on Friday, and the heat wave that’s bearing down on the Southwest is threatening to melt whatever snow is still remaining. Without some cooler weather combined with big snows, a lot of areas may have already seen their peak snowpack, which would mean spring runoff is beginning now.
Yikes!
First, the Lake Powell projections. Notice that the probable minimum inflow (the red line) reaches 3,500 feet in July. Dam engineers really don’t want it going below that level (3,510 feet would be safer). And even the green line, or the most probable inflow, would drop to that point in September. Keep in mind that these projections are often over-estimates, meaning we could hit that critical level even earlier — especially given this friggin’ heat wave. And yet, the general public still has no idea how the Bureau of Reclamation might handle the situation.
One thing you can probably bet on: The Bureau will try to buoy Lake Powell’s levels by drawing down the Upper Basin reservoirs that are in the Colorado River Storage Project. That would be Flaming Gorge on the Green River, Navajo Reservoir on the San Juan, and the Wayne Aspinall Unit (Blue Mesa, Crystal, and Morrow Point) on the Gunnison. This will, of course, affect recreation on those reservoirs as well as downstream irrigators.
And on to the heat wave. Here are some forecasts for the next few days.
The earliest 100°F day on record in Phoenix was on March 26. That record will fall this week, along with many others, I’m sure. I mean, extreme heat warnings in March? Come on!
Then there’s the far-less blistering, but equally concerning temperatures in the mountains. Silverton, at 9,318 feet in elevation and near the headwaters of both Colorado River and Rio Grande tributaries, is looking to have a full-on March thaw — even at night. Look at those lows for Wednesday through Friday: All above freezing. No bueno.
Of course, this is coming on the heels of the warmest meteorological winter (Dec-Feb) on record for many places. Here’s a sampling from the National Weather Service’s Grand Junction, Colorado, office.
And don’t worry, I’ll bring you the cruelest snowpack/runoff report in the cruelest month of April, even if there’s no snow left to report on.