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surveys and delineation should be conducted (Cowardin et al. 1979; Environmental
Laboratory 1987) and the results submitted for review before impacts to wetland habitat
can be evaluated. A determination on significant impacts of the project in the absence of
this information would be inappropriate and illegal.
A detailed hydrologic study should be conducted using the best available scientific
information to determine the relationship between wetlands of the Crescent City Marsh
Wildlife Area and those of the Martin's Ranch which are proposed for development. The
best scientific information should be used to determine the existing subsurface
connections and relationships between the various wetlands in the watershed, and how
changes would potentially affect water levels at the Crescent City Marsh. Information on
how the Martin's Ranch wetlands are currently contributing to the recharge and/or
storage of subsurface water flowing to the Crescent City Marsh is crucial information
necessary to evaluate potential direct and cumulative impacts to the western lily and other
sensitive species and habitats. The ACOE should request this information and appropriate
hydrologic studies be conducted prior to evaluating this proposal.
VI. Inadequate Mitigation
The proposed project states that 9.46 acres of wetland will be filled, and that these
impacts will be mitigated by creation of replacement wetlands, 3 acres of which are
onsite, 4 acres of which are offsite, and protection of 17 acres of wetlands offsite. These
proposed mitigations are inadequate for several reasons:
Creating replacement wetlands is inappropriate since artificial wetlands cannot replace
the biologically unique ecosystem that is lost when intact wetlands are destroyed.
Creating onsite replacement wetlands will not necessarily mitigate significant negative
impacts to the western lily and other rare, threatened, and endangered plant species in the
Crescent City Marsh Wildlife Area. A detailed hydrologic study should be conducted
using the best available scientific information to determine impacts related to wetland fill,
summer irrigation and pesticide use associated with the proposed golf course, increased
runoff associated with the proposed roads, and changes in water table levels and
underground input associated with the proposed replacement wetland.
Creating offsite replacement wetlands will not mitigate impacts to the biological
resources within the watershed, including the adjacent Crescent City Marsh Wildlife
Area. Offsite mitigation is entirely inappropriate as mitigation to such a unique site and
should not be considered to mitigate the impacts of the proposed project in any way.
The 17-acre offsite wetland proposed for protection as mitigation is already protected
under federal and state law, and no significant conservation benefit would result from
claiming that protection as mitigation for the proposed fill.