Conducting the Environmental Impact Analysis and Assessment - Environmental Impact Analysis: Process and Methods - page 218

r Reducing the capacity of a water, wastewater, or power generation
facility to more realistically represent future demands and realistic
conservation measures
r Marginal support for public transportation as part of a traffic man-
agement plan centered on extensive highway expansion
r Public education on recycling and waste reduction as part of a new
or expanded solid waste landfill
r Water conservation education as part of a new or expanded water
supply source
r Limiting takeoff and landing times as part of airport expansion to
mitigate noise impacts
However, the classic approach to impact mitigation had several substantial
limitations. One of the most glaring deficiencies was that the after-the-fact
add-on measures often created unforeseen impacts. Because these measures
were incorporated into the proposed action after any environmental analy-
sis or stakeholder scrutiny, the implications of the actions beyond the nar-
row focus of the impact they were designed to mitigate were not examined.
In hindsight such add-on mitigation measures seem shortsighted and defy
common sense (summarized from Erickson 1994):
r Impact to tortoise migration was predicted to result from construc-
tion of a military installation in the desert and a fence was con-
structed to guide the migration safely through the facility. However
the fencing was unsuitable and tortoises were found entangled in
the mesh with resultant fatal cuts and suffocation.
r In order to mitigate wildlife habitat impacts resulting from the pre-
ferred alignment of a new highway, a section of the highway with a
wide median strip was planted with long-duration flowering shrubs
that produce berries with high food value for local bird species.
Initially the mitigation was quite successful; however during peri-
ods of drought, the berries of the chosen shrub species ferment and
the birds feeding on the berries became intoxicated. So when these
birds fly within the travel portion of the highway, many traffic acci-
dents occured. Thus, the entire median strip had to be stripped of
vegetation.
r The selected alternative for a new highway alignment bisected an
area supporting a productive deer population and prevented migra-
tion between two critical habitat types. A large underpass was con-
structed to facilitate safe deer migration with fencing on either side to
guide deer to the underpass and critical habitat on the other side of the
new highway. Local wildlife enthusiasts confirmed that the underpass
was effective in reducing roadkills but the deer population declined