conditions and recent weather conditions can contribute to 

 surface water being present on a nonwetland site, both 

 should be considered when applying this indicator. 



(2) Visual observation of soil saturation. Examination of 

 this indicator requires digging a soil pit (Appendix D, 

 Section 1) to a depth of 16 inches and observing the level 

 at which water stands in the hole after sufficient time 

 has been allowed for water to drain into the hole. The 

 required time will vary depending on soil texture. In 

 some cases, the upper level at which water is flowing into 

 the pit can be observed by examining the wall of the hole. 

 This level represents the depth to the water table. The 

 depth to saturated soils will always be nearer the surface 

 due to the capillary fringe. For soil saturation to im- 

 pact vegetation, it nust occur within a major portion of 

 the root zone (usually within 12 inches of the surface) of 

 the prevalent vegetation. The major portion of the root 

 zone is that portion of the soil profile in which more 

 than one half of the plant roots occur. CAUTION: In some 

 heavy clay soils , water may not rapidly accumulate in the 

 hole even when the soil is saturated. If water is 

 observed at the bottom of the hole but has not filled to 

 the 12-inch depth, examine the sides of the hole and de- 

 termine the shallowest depth at which water is entering 

 the hole. When applying this indicator, both the season 

 of the year and preceding weather conditions must be 

 considered. 



(3) Watermarks . Watermarks are most common on woody vegeta- 

 tion. They occur as stains on bark (Figure 7) or other 

 fixed objects (e.g. bridge pillars, buildings, fences, 

 etc.). When several watermarks are present, the 

 highest reflects the maximum extent of recent inundation. 



(4) Drift lines. This indicator is most likely to be found 

 adjacent to streams or other sources of water flow in 

 wetlands, but also often occurs in tidal marshes. Evi- 

 dence consists of deposition of debris in a line on the 

 surface (Figure 8) or debris entangled in aboveground 

 vegetation or other fixed objects. Debris usually con- 

 sists of remnants of vegetation (branches, stems, and 

 leaves), sediment, litter, and other waterborne materials 

 deposited parallel to the direction of water flow. Drift 

 lines provide an indication of the minimum portion of the 

 area inundated during a flooding event; the maximum level 

 of Inundation is generally at a higher elevation than that 

 indicated by a drift line. 



(5) Sediment deposits. Plants and other vertical objects 

 often have thin layers, coatings, or depositions of min- 

 eral or organic matter on them after inundation (Fig- 

 ure 9) . This evidence may remain for a considerable 

 period before it is removed by precipitation or subsequent 

 inundation. Sediment deposition on vegetation and other 



38 



