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inundation is less extensive, the shoreline could be considered seaward of the road (e.g., where there are seawalls or natural coastal vegetation). The advantage of excluding gravity flow as a solution is that it is technically sound since gravity flow is not related to runup (or wave runup or the “upper reach of the wash of the waves”). This was rightfully recognized by several technical organizations. It is also politically acceptable solution since it utilizes a definition proposed by various administrative, technical, environmental and business groups. For example, the State Surveyors office was part of the review team that recommended the exclusion for gravity flow – presumably for technical and practical reasons. Finally it provides some discretion to the implementing agency to account for situations as seen in Figure 3-9. The disadvantage is that the transition is not always easy to identify. Also excluding gravity flow will increase development pressure in areas already being flooded and possibly getting worse. Finally, it is up to the State surveyor to make the final decision on gravity flow issues, and given the current scrutiny of the shoreline definition on a State wide basis, they may require a change in the State statute or regulations or both. Under the current regulatory environment, this would be difficult to do, although this report indicates it may be within the State’s discretion to exclude gravity flow without a change in the rules or statutes. 3.4.3 Relying on an Increased Use of the Vegetation Line In determining the “upper reach of the wash of the waves,” the evidence can still be by traditional markers such as the vegetation line or debris line. Where no debris exists, naturally occurring vegetation can be used as a marker, or evidence. At Kapoho, it is difficult to identify debris lines and this is apparently because the major inundation observed for shoreline determinations has been by rising tides rather than wave action. With the paucity of information provided by debris lines, key evidence would come from observation of inundation from high tide events, or the presence of certain types of vegetation. However, using vegetation alone can be tricky since certain types survive seawater inundation and thus are not good indicators of the shoreline. Sea grasses found along the makai side of Waiopae Road would be a poor indicator of the shoreline because they are salt tolerant and survive monthly or even daily inundation. Conversely, naupaka to a lesser extent, and especially milo trees are a good indicator as their tolerance for salt water is less or non-existent. There are some milo trees seaward of Waiopae Road at the east end near Kaheka St. These trees are a good indication that the elevation at that location is sufficiently high so that inundation is currently not a problem and that the shoreline should be seaward of their presence. 35