1987 Army Corps Wetland Delineation Manual Atlantic Supplement

The 1987 Army Corps Wetland Delineation Manual Atlantic Supplement provides specialized guidance for identifying and delineating wetlands in the Atlantic coastal region of the United States. This supplement builds upon the standard 1987 Corps manual with region-specific parameters, vegetation indicators, hydric soil characteristics, and hydrology criteria applicable to Atlantic coastal ecosystems. Below are key sections covering methodology, regional adaptations, field procedures, and regulatory applications.

1. Introduction and Purpose 2. Regional Characteristics 3. Three-Parameter Approach 4. Vegetation Indicators 5. Hydric Soil Identification 6. Hydrology Criteria 7. Field Delineation Procedures 8. Data Collection Methods 9. Documentation Requirements 10. Regulatory Context 11. Troubleshooting Common Issues

Introduction and Purpose

This supplement addresses the unique wetland characteristics found in Atlantic coastal regions from Maine to Florida, providing specialized criteria for accurate wetland delineation in tidal influenced areas, coastal plain ecosystems, and estuarine environments.

Component	Description
Geographic Scope	Atlantic coastal states and territories
Primary Focus	Tidal and non-tidal wetlands in coastal zones
Regulatory Basis	Clean Water Act Section 404
Implementation	Corps of Engineers regulatory program
Supplement Status	Regional adaptation of 1987 manual

Regional Characteristics

Atlantic coastal wetlands exhibit distinct features influenced by tidal action, salinity gradients, and coastal geology.

Hydrology: Tidal influence, seasonal water tables, precipitation patterns
Soils: Hydric soil development in coastal plain sediments
Vegetation: Salt-tolerant and freshwater wetland plant communities
Geomorphology: Barrier islands, estuaries, river deltas, coastal plain

NOTE: Regional variations require careful consideration of local conditions and species distributions.

Three-Parameter Approach

Wetland delineation requires positive indicators from all three parameters: hydrology, soils, and vegetation.

Hydrology Indicators: Surface water, soil saturation, water marks
Hydric Soil Indicators: Redox features, organic accumulation, gleying
Hydrophytic Vegetation: Prevalence index calculations, FAC-neutral test

IMPORTANT: All three parameters must show wetland conditions for positive delineation.

Vegetation Indicators

Dominant Species: Obligate wetland (OBL) and facultative wetland (FACW) species
Prevalence Index: Calculation method for vegetation analysis
Atlantic Specific: Salt marsh vegetation, mangroves (southern range)
Indicator Status: Regional plant list with wetland indicator categories
Sampling Methods: Vegetation transects, dominance measurements

Hydric Soil Identification

Field indicators for hydric soils in Atlantic coastal regions including redox features, organic matter accumulation, and soil color patterns.

Key Indicators: Gleyed matrix, redox concentrations, sulfidic materials, histic epipedon, mucky modified mineral layers.

Soil Description: Texture analysis, horizon identification, redoximorphic features documentation. Field Testing: Chroma determination, Munsell color matching, soil sampling procedures.

Hydrology Criteria

Hydrologic indicators specific to Atlantic coastal wetlands including tidal fluctuations, groundwater influences, and precipitation patterns.

Document observed hydrology indicators during site visit
Record water table measurements and saturation duration
Note tidal influence and saltwater intrusion evidence

Field Evidence: Water stains, sediment deposits, drainage patterns, drift lines.

Field Delineation Procedures

Step-by-step methodology for conducting wetland delineations in Atlantic coastal environments.

Pre-field Preparation: Review maps, aerial photos, previous studies
Field Reconnaissance: Initial site assessment, transect establishment
Data Collection: Soil pits, vegetation plots, hydrology observations
Boundary Determination: Flag wetland-upland transition
Quality Control: Verification measurements, peer review
Mapping: GPS data collection, sketch mapping, aerial photo annotation

WARNING! Proper safety protocols required for coastal field work.

Data Collection Methods

Standardized approaches for collecting and recording wetland delineation data.

Documentation Requirements

Comprehensive reporting standards for regulatory submissions and technical reviews.

REQUIRED: Complete data forms, mapping products, photographs, and technical justification.

Regulatory Context

Application of delineation results within Clean Water Act Section 404 regulatory framework and state coastal zone management programs.

Troubleshooting Common Issues

Issue	Potential Cause	Resolution
Conflicting indicators	Recent disturbance, atypical conditions	Additional sampling, historical data review
Seasonal variations	Dry season assessments	Multiple site visits, indirect indicators
Tidal influence uncertainty	Complex hydrology	Tidal gauge data, vegetation patterns
Boundary determination	Gradual transitions	Multiple parameter analysis, professional judgment
Regulatory questions	Jurisdictional uncertainties	Early agency consultation, preliminary determination

Technical Support: Regional Corps regulatory offices provide technical assistance and review.

Updates: Consult current regional guidance and technical standards.