Draft Environmental Impact Statement for Roca Honda Mine

Vegetation
Topic Alternative 1 – No Action
• Would have essentially no
impacts on vegetation at the
RHR permit site.
• No disturbance of the site’s
vegetation communities and
sensitive plants from clearing,
grubbing, grading, and other
project-related activities, either
at the mine site or along the
proposed treated water pipeline
route.
• Natural and unnatural
disturbances may occur in the
area, as they have in the past, but
overall, the three communities
now present – juniper savanna,
piñon-juniper woodland, and
grassland and/or shrubland –
would be expected to remain for
some decades into the future.
• Over the coming decades,
climate change’s effects may
begin to alter the vegetation
composition and structure of the
RHR permit area, with some
species and commun-ities
increasing in abundance while
others decrease.
Alternative 2 – Proposed Action
(Two-shaft alternative)
• A total of 218 acres of vegetation would be
severely disturbed or essentially eliminated
for the duration of the mine—183 acres
within the three main sections (12 acres in
Section 9; 71 acres in Section 10; and 100
acres in Section 16) plus 35 additional acres.
• Most of the impacted acreage in Section 9
would be piñon-juniper woodland; in
Section 10 desert grassland/shrubland; and
in Section 16 juniper savanna and desert
grassland/shrubland.
• Unlikely to affect special status plant
species.
• Negligible to minor linear impacts to
existing vegetation communities on
approximately 84 acres of right-of-way
along the proposed treated water pipeline
route.
• Overall impacts to vegetation would be
both short term and long term (but not
permanent). Short-term impacts would be
adverse, localized, moderate in magnitude,
probable, and of slight to moderate
precedence/uniqueness.
• Long-term impacts would be fewer because
of proposed reclamation and mitigation.
They would be adverse, localized,
negligible to minor in magnitude, probable,
and of slight uniqueness.
• In sum, impacts on vegetation within the
RHR permit area would be less than
significant.
• Cumulative impacts to vegetation are
minor.
Chapter 2. Alternatives, Including the Proposed Action
Alternative 3 – One-shaft
Alternative
• Overall impacts on vegetation would be of
a similar nature to but on a smaller scale
(155 acres of disturbance) than those from
alternative 2 (218 acres).
• For duration of the mine, 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 by
alternative 2.
• Alternative 3 reduces the area of impacts
to vegetation from the mine itself overall
by about 29% and the area of vegetation
impacts on National Forest System lands
by about three-quarters (76%).
• 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.
• Not likely to affect special status plant
species.
• In sum, impacts on vegetation would be
less than significant.
• Cumulative impacts to vegetation are
minor.
DEIS for Roca Honda Mine, Cibola National Forest 67