Kevin L. Hoover Waters Edge Hydrology, Inc. khoover@wehydro.com – Wetland Conservation Approaches

Kevin L. HooverWater’s Edge Hydrology, Inc.

khoover@wehydro.com – http://wehydro.com

Wetland ConservationWetland ConservationApproachesApproaches

“Wetland Triangle”

HydricSoils

WetlandHydrology

HydrophyticVegetation

Water M akes Soils Hydric

Water and SoilsSupport Plants

Soils Retain Water

Wetland ConservationCategories

• Creation – conversion of existing uplands to wetlands.

• Restoration – recovery of historic wetlands from current disturbed or upland conditions.

• Enhancement – improving the functions and values of wetlands.

• Preservation – protection of wetlands from existing or potential future impacts.

Implementation Approaches

• Earthwork Methods

• Hydrologic Improvements

• Soil Amendments

• Vegetative Management

• Habitat Improvements

Earthwork Methods

• Excavate or fill upland areas to expand existing wetlands or create new wetlands.

• Remove historic fills to re-expose buried wetlands.

• Make the area flat overall, but leave the ruts.• Apply fluvial geomorphology to create flood bank

wetlands and sloughs.• Install subsurface barriers on sloped sites.

Hydrologic Improvements

• Disrupt artificial drainage where present.• Eliminate historic upstream diversions.• Create impounding structures to increase the

spread of hydrology.• Decrease depths of open water areas (6” or less is

optimal for emergent vegetation).

Soil Amendments

• Organic content is essential to good plant growth and water retention.

• Disturbed wetlands may have lost their organic surface soil horizons, exposing low-organic mineral soil.

• New topsoil may be added to improve conditions.• Alternately, organic matter may be tilled into the

mineral soil.• Composted organic matter, such as manure or leaf

litter, makes the best amendment.

Organic Content of Natural Vs. Created Wetlands

0%

5%

10%

15%

20%

25%

Natural Wetlands Created Wetlands

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Vegetative Management

• Fence off livestock and exclude vehicular traffic along riparian corridors to allow recovery of vegetation and soil disturbances.

• Remove invasive species and seed or plant with native species.

• Plant woody species along riparian corridors.• Plant adjacent uplands for fringe habitat.• Consider forage, nesting, and escape cover when

selecting species.

Habitat Improvement

• Bird boxes, nesting platforms, “loafing” rafts, etc.• Brush piles and snag trees.• Migration-friendly culverts.• Create connections between existing wetlands as

migration corridors.

North Corner Site

• Restoration of historic wetlands by blocking off agricultural drainage ditches.

• Enhancement of marginal wetland areas by improved hydrology.

• Creation of new wetlands by excavation and impoundment.

• Preservation of existing wetlands and upland habitat.

Antwerp Site

• Enhancement of existing wetlands by improved hydrology.

• Creation of new wetlands by excavation and impoundment.

• Protection of wetlands by access restrictions and earthwork buffers.

• Planting of adjacent upland areas for habitat improvement.