2019_KittitasCountyHMP_Volume2_For Adoption

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CHAPTER 4. CITY OF ELLENSBURG ANNEX 4 4.6. HAZARD MITIGATION ACTION PLAN AND EVALUATION OF RECOMMENDED INITIATIVES Table 4-7 lists the initiatives that make up the jurisdiction’s hazard mitigation plan. Table 4-8 identifies the priority for each initiative. Table 4-9 summarizes the mitigation initiatives by hazard of concern and the six mitigation types. 4.7. FUTURE NEEDS TO BETTER UNDERSTAND RISK/VULNERABILITY The biggest future need to better understand risk/vulnerability would be a re-mapping of the floodplain by FEMA. Ellensburg annually experiences sheet-flow floods, and the floods are not uniformly in flood locations identified on the 1981 FIRM maps. People suffer property damage but are not within a FIRM floodplain and are not eligible for federal flood insurance. People want to develop their properties that are not identified in the floodplain but that consistently flood, and it becomes a regulatory issue for which there is no solid documented basis to regulate the property for flooding. FEMA is in the process of digitizing the existing 1981 FIRMs, and is currently working with Kittitas County to remap tributaries that run through the City using LiDAR technology. 4.8. ADDITIONAL COMMENTS Due to its climate and topography, Ellensburg is prone to unpredictable flood events when there is significant snow pack in the foothills surrounding the City during early and late winter and a heavy rain event occurs combined with warm temperatures and strong winds (strong winds are the norm for this area). The creek that experiences the flood event varies and is dependent on the temperature and the degree of compactness of the snowpack within the creek watersheds. The result is significant overbank flow in the six creeks that run northeast to southwest through the developed city toward the Yakima River, which becomes sheet-flow flooding over large areas of the community. This regular pattern of flooding does not pose major risks to life, but it does cause significant annual damage to public and private property. Although the City’s risk rating for the flood hazard is 36 the regularity of annual flooding and associated property damage makes this hazard risk much higher. The City of Ellensburg already incorporates green infrastructure into its stormwater development standards, which are approved by the Department of Ecology to minimize flood impacts and improve water quality. In addition, because most of the City’s historic downtown structures are masonry buildings constructed in the late 1880s, they are not likely to perform well in earthquake events. The 2001 Nisqually Earthquake, while causing significant damage to the Puget Sound region, in particular the older historic structures, did not cause significant damage in Ellensburg. However, a more local earthquake event, or a much stronger event in the Puget Sound region would likely cause significant property loss and the potential for significant personal injury in the historic downtown area if the two-story brick buildings were to collapse. Retrofitting those historic structures would be an expensive task that is beyond the City’s ability to address and beyond the individual property owner’s ability to finance. Large earthquake events in the Puget Sound region also will likely result in significant logistical problems for the Ellensburg community. I-90 is the major east/west interstate that connects the more rural eastern Washington to the more populated western Washington. Large-scale earthquake damage in the Puget Sound region will likely cause serious disruption to food service delivery from the regional warehouses located in Puget Sound, as well as damage to telecommunications. And if the event is serious enough there is likely to be an exodus of displaced Puget Sound residents seeking shelter elsewhere and if the interstate is open Ellensburg is the first larger city over the mountain passes from Puget Sound and is likely to be impacted by displaced Puget Sound people seeking a safe place.