placement in the landscape to establish hydrogeological equivalence is inherent to wetland sustainability.
The biological dynamics should be evaluated in terms of the populations present in reference models for the region and the ecological requirements of those species.
The science and technology of wetland restoration and creation need to be based on a broader range of studies involving sites that differ in degree of degradation, restoration efforts, and regional variations. Predictability and effectiveness of outcomes should then improve.
Hydrological variability should be incorporated into wetland mitigation design and evaluation. Except for some open-water wetlands, static water levels are not normal. Because of climatic variability, it should be recognized that many wetland types do not satisfy jurisdictional criteria every year. Hydrological functionality should be based on comparisons to reference sites during the same time period.
Riparian wetlands should receive special attention and protection, because their value for stream water quality and overall stream health cannot be duplicated in any other landscape position.
A mitigation site needs to have the ability to become self-sustaining. This means that the hydrological processes that define a wetland in the ecosystem need to be present and expected to persist in perpetuity. To aid regulators and mitigators in designing projects that will become ecologically self-sustaining, the committee offers 10 operational guidelines.
Consider the hydrogeomorphic and ecological landscape and climate.
Adopt a dynamic landscape perspective.
Restore or develop naturally variable hydrological conditions.
Whenever possible, choose wetland restoration over creation.
Avoid over-engineered structures in the wetland's design.
Pay particular attention to appropriate planting elevation, depth, soil type, and seasonal timing.
Provide appropriately heterogeneous topography.
Pay attention to subsurface conditions, including soil and sediment geochemistry and physics, groundwater quantity and quality, and infaunal communities.
Consider complications associated with wetland creation or restoration in seriously degraded or disturbed sites.
Conduct early monitoring as part of adaptive management.