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Floodwaters need not be deep or fast to affecl the integrity of an anchoring system, Soil satura, tion occurring during periods of prolonged flooding can reduce the holding capacity of ground anchors causing them to pull out as shown in Figure 1,25, Figure 1.25 Failed Ground Anchor Deep flooding accentuates the forces acting upon the foundation and anchoring systems of a manufactured home, In addition, increased flood depths affect a non-elevated manufactured home by directly transferring forces to the walls and floor, The initial imbalance of water levels between the exterior and interior of the manufactured home will likely result in buoyancy. This uplift force can com- pletely dislodge an inadequately anchored manufactured home from its foundation, This typically occurs in fast rising waters or when the rate-of-rise' of floodwaters is very fast. In situations where the rate-of-rise of floodwaters is slow, allowing the manufactured home to fill with water and therefore counteracting the buoyancy forces, or where adequate anchoring is employed to resist dislodging the manufactured home from its foundation, deep flooding can substantially damage a non-elevated manufactured home by direct inundation, Although the manufactured home may remain in place, as shown in Figure 1,26, it will likely be a total loss due to the damage caused by water inundation, Figure 1.26 Deep Flooding Damage In addition to having high erosion and scour potential, deep velocity flooding also emphasizes the need to consider debris impact potential. Coastal Flooding-Coastal flooding is generally due to ocean-based storm systems, Hurricanes, tropical storms, and extratropical storms, such as "northeasters," are the principal causes, with flooding occurring when storm tides are much higher than the normal tide, This is a "storm surge" and exhibits high water velocity and wave action, The maximum intensity of a storm tide oc- curs at high tide, so storms that persist through several tide cycles, such as "northeasters," are the most severe, The velocity and range of coastal floods vary in part with the severity of the storm of which they are a part, The damaging effects of coastal flooding are caused by a combination of the storm surge, rain, wind, waves, erosion, and battering by debris, The extent and nature of coastal flooding is also related to physiographic features of the terrain and the characteristics of the adjoining body of water. Pacific coastal areas are principally vulnerable to earthquakes, tsunamis (seismically induced tidal waves) and other natural forces that can trigger excessive erosion, mud slides, and flash flooding, Great Lakes coastal areas are subject to erosion and severe winter storms. The Atlantic and Gulf Coasts are consistently exposed to the forces of hurricanes, lesser tropical storms, and northeasters, 10