c. Soil surveys. Soil surveys are prepared by the SCS for politl- 

 ~ cal units (county, parish, etc.) in a state. Soil surveys 



contain several types of information: 



(1) General information (e.g. climate, settlement, natural 

 resources, farming, geology, general vegetation types). 



(2) Soil maps for general and detailed planning purposes. 

 These maps are usually generated from fairly recent aerial 

 photography. CAUTION: The smallest mapping unit is 



2 acres, and a given soil series as mapped may contain 

 small inclusions of other series. 



(3) Uses and management of soils. Any wetness characteristics 

 of soils will be mentioned here. 



(4) Soil properties. Soil and water features are provided 

 that may be very helpful for wetland investigations. Fre- 

 quency, duration, and timing of inundation (when present) 

 are described for each soil type. Water table character- 

 istics that provide valuable information about soil satu- 

 ration are also described. Soil permeability coefficients 

 may also be available. 



(5) Soil classification. Soil series and phases are usually 

 provided. Published soil surveys will not always be 

 available for the area. If not, contact the county SCS 

 office and determine whether the soils have been mapped. 



d. Stream and tidal gage data. These documents provide records of 

 ~ tidal and stream flow events. They are available from either 



the USGS or CE District office. 



e. Environmental impact assessments (EIAs) , environmental Impact 

 ~ statements (EISs) , general design memoranda (GDM) , and other 



similar publications. These documents may be available from 

 Federal agencies for an area that includes the project area. 

 They may contain some indication of the location and character- 

 istics of wetlands consistent with the required criteria (vege- 

 tation, soils, and hydrology), and often contain flood fre- 

 quency and duration data. 



f . Documents and maps from State, county, or local governments. 



~ Regional maps that characterize certain areas (e.g., potholes, 

 coastal areas, or basins) may be helpful because they indicate 

 the type and character of wetlands. 



£. Remote sensing. Remote sensing is one of the most useful 



information sources available for wetland identification and 

 delineation. Recent aerial photography, particularly color 

 Infrared, provides a detailed view of an area; thus, recent 

 land use and other features (e.g. general type and areal extent 

 of plant communities and degree of Inundation of the area when 

 the photography was taken) can be determined. The multlagency 

 cooperative National High Altitude Aerial Photography Program 

 (HAP) has l:59,000-scale color infrared photography for approx- 

 imately 85 percent (December 1985) of the coterminous United 

 States from 1980 to 1985. This photography has excellent 



45 



