Mitigation may include the following alternatives:

  • Restoration
  • Creation
  • Enhancement
  • Contribution to a mitigation bank

To effectively determine the appropriate mitigation alternatives for the Site-specific impacts, Roux Associates evaluates the Site’s current land use and availability; current structures; topography; surface water quantity; soil quality, classification and profiles; climate/weather; and biological communities for applicability of establishing/restoring wetlands at the Site.  Selection of potential mitigation sites is based upon soil type and water availability; existing resource value, size, location and cost; adjacent land uses; potential for human intrusion; and long-term site protection.

Wetland monitoring is required following wetland mitigation activities to ensure successful planting and design.  Mitigated wetlands are monitored to inspect the health and establishment of the newly planted vegetation.  Field surveys are performed to evaluate and document the survival rate of each planted species.  Surveys include an analysis of representative observation plots established in the mitigated wetlands.  Reference plots are similarly established to document background conditions.

Vegetation in the observation plots are compared with the vegetation in the reference plots to determine whether an observed loss of vegetation is a restoration failure or is caused by a natural event that has similarly affected vegetation in other wetlands in the area.  The need for soil amendments and replacement planting are determined based upon comparisons to the reference plots.

Wetland monitoring can also be implemented in conjunction with the installation and operation of Site remediation activities (e.g., groundwater remediation systems).  In these circumstances, the principal objective of wetland monitoring is to determine what affects, if any, operation of Site activities have on adjacent wetlands.  Key investigative elements of wetland monitoring include:

  • Establishment of  vegetation monitoring plots;
  • Establishment of hydrologic monitoring network (i.e., piezometers and stream gauges);
  • Establishment of representative background monitoring stations;
  • Completion of a baseline assessment ; and
  • Quarterly hydrologic and vegetation monitoring.

Wetland monitoring is generally conducted quarterly for a minimum period of two years to evaluate potential hydrologic effects during crucial seasonal cycles and provide a technically credible basis for evaluation.  Additional time may be required to address climatologic extremes that may occur over the base evaluation period.