ABSTRACT

Introduction ................................................................................................................................. 246 Wetland Components ................................................................................................................. 246

Hydrology ............................................................................................................................... 246 Vegetation ................................................................................................................................ 247 Hydric Soils ............................................................................................................................. 247

Preliminary Off-Site Investigations .......................................................................................... 248 Published Soil Surveys .......................................................................................................... 248 Hydric Soil Lists ..................................................................................................................... 248 National Wetland Inventory Maps ...................................................................................... 252 Topographic Maps.................................................................................................................. 252 Federal Emergency Management Agency Maps ............................................................... 252

Detailed Examination and Delineation Procedures ...............................................................253 Landform Recognition ...........................................................................................................253 Field Indicators of Hydric Soils ............................................................................................254 Combining Field Indicators of Hydric Soils .......................................................................258 Field Indicators of Hydric Soils for Delineation and Identification ................................ 259

Regional Field Indicators of Hydric Soils ................................................................................ 262 Why Regional Field Indicators? ........................................................................................... 262 System for Regionalizing Field Indicators .......................................................................... 263 Hydric Soil Determination and Delineation ...................................................................... 265 Vertical and Horizontal Soil Variability .............................................................................. 266

Discharge Recharge and Flowthrough Hydric Soils .............................................................. 266 Problem Hydric Soil Delineations ............................................................................................ 267

High Shrink/Swell Potential Soils ....................................................................................... 267 Playas ....................................................................................................................................... 268 Saline Playas ............................................................................................................................ 268 High Plains Playas (Depressions) ........................................................................................ 268 Soils with Red Parent Material ............................................................................................. 269 Disturbed Soils ........................................................................................................................ 269

Summary ...................................................................................................................................... 271 References .................................................................................................................................... 271

For centuries wetlands were regarded as little more than habitat for mosquitoes, snakes, and other pests. Today, in addition to recognizing wetlands as habitats for a variety of wildlife species (including mosquitoes and snakes), we are aware that wetlands are the nursery grounds for our fisheries, filter pollutants, reduce flooding, protect against erosion, provide timber products, recharge groundwater reserves, and furnish society with educational, scientific, recreational, and aesthetic benefits. Local, state, and federal governments have enacted laws that regulate the use of wetlands to preserve these public benefits.