Draft Environmental Impact Statement for Roca Honda Mine

Chapter 3. Affected Environment and Environmental Consequences
Alternative 2
Under the proposed action, approximately 183 acres of vegetation within the 3 sections (12 acres
in Section 9; 71 acres in Section 10; and 100 acres in Section 16) would be disturbed and/or
essentially eliminated for the duration of the Roca Honda Mine. Within these 3 sections, 83 acres
of vegetation on the Cibola National Forest (Sections 9 and 10) would be adversely affected. An
additional 35 acres would be adversely affected outside the 3 sections. A total of 218 acres of
disturbance is anticipated within Forest Service, private, and State land. A total of 93.5 acres of
Forest Service land would be disturbed, with 8 acres in Section 11 and 2.5 acres along the
pipeline corridor in addition to the 83 acres within Sections 9, 10, and 16. Most of the impacted
acreage in Section 9 would be piñon-juniper woodland; most of the impacted acreage in Section
10 would be desert grassland/shrubland; and most of the impacted acreage in Section 16 would be
juniper savanna and desert grassland/shrubland. Most of the impacted acreage on Section 11 and
the pipeline corridor would be desert grassland/shrubland and piñon-juniper woodland.
As noted above, when the mine closes, final reclamation, including revegetation, would be
undertaken. Since the approved post-mining land use is livestock grazing, revegetation design,
species mix, and methods proposed in the RHR reclamation plan would result in the area
supporting this land use while at the same time furnishing self-sustaining habitat and forage for
indigenous wildlife species.
Alternative 3
For the duration of the mine, alternative 3 (the one shaft alternative) would result in disturbance
or elimination of approximately 120 acres of vegetation, of which 20 acres would be Cibola
National Forest lands in Sections 9 and 10—compared to 83 acres of Cibola National Forest
vegetation adversely affected in these three sections by alternative 2. The acres disturbed on
Cibola National Forest in Section 11 and along the dewatering discharge pipeline would remain
the same as under alternative 2. Therefore, alternative 3 reduces the area of impacts to vegetation
overall by about 29 percent and the area of vegetation impacts on National Forest System lands
by about 67 percent.
These impacts would persist for about 2 decades, for the operational lifetime of the mine. Upon
reclamation and revegetation, the magnitude and extent of these adverse effects would gradually
diminish as restoration took place.
Like alternative 2, alternative 3 is not likely to affect special status plant species (table 32).
In conclusion, impacts of alternative 3 on vegetation would be insignificant. While alternative 3
has a lower potential to adversely affect vegetation than alternative 2, both would be insignificant,
once mitigation measures, reclamation, and restoration are taken into account.
Cumulative Effects
Cumulative vegetation effects were evaluated for the general environs within 1 mile of the mine
and the Mt. Taylor Ranger District generally. Past and present vegetative impacts in the project
area include livestock grazing and stock pond construction, recreation (e.g., hunting), exploratory
drilling, mining, power line construction and operation, and access road construction.
Approximately 180 acres of direct vegetation loss would occur at the mine site to construct mine
facilities, about 83 acres of which would be on the Cibola National Forest. Approximately 35
210 DEIS for Roca Honda Mine, Cibola National Forest