Laserfiche WebLink
2025 Hazard Mitigation Plan <br />Kittitas County, Washington <br />FIRM maps.152 The 500-year floodplains show areas with a 0.2% chance of flooding each year. The <br />Kittitas County FIRMs initially became effective on May 5, 1981, and the current FIRMs became effective <br />on September 24,2021. Figure 4-15 illustrates the Kittitas County SFHA, including each Flood Zone, <br />and the 500-year floodplain <br />Figure 4-15. Kittitas County Special Flood Hazard Area <br />4.6.5.3. HazardExtenUlntensity <br />Flood depth and velocity are the primary factors affecting flood extent/intensity. The deeper and faster <br />floods flow the more damage they can cause. However, shallow flooding with high velocities can cause <br />as much damage as deep flooding with slow velocity. This is especially true when a channel migrates <br />over a broad floodplain, redirecting high velocity flows and transporting debris and sediment. Flood <br />extent/intensity is often evaluated by examining peak discharges. Table 4-64 lists the peak flows utilized <br />by FEMA to map Kittitas County's floodplains.l53 <br />152 lbid. <br />153 Kittitas County. (1996). Comprehensive Flood Hazard Management Plan. Retrieved from <br />httos :/iwww.co. kittitas.wa. us/u n lo ads/docr rments/orrblic- <br />wo rks/f loo d/d oc u m e n ts/ 1 I I 6 % 2 0 K itt i ta s % 2 0 C o u nlv %20 Com orehensive%20 Flo odo/o2oHazardo/o2)ManaoementTo <br />Riv€r Flood zono <br />AE <br />AO <br />.2% Annual Ch6nce Flood Haard <br />W.Mu^icip€llies <br />f- ra*es <br />! Kittitas county <br />County wA: <br />Flood Hazard Area <br />- - - MajorRoad <br />- Local R@d <br />- -- Minor RMd <br />Olher Road <br />R€mp <br />---- FsnY <br />Pedestrian <br />R@tyn !,rr_, <br />t <br />I <br />t <br />oi. <br />i- Roslyn <br />,if+i .^{-8,' .P,tir'-v <br />t <br />I <br />I <br />lftiitas <br />* <br />2814 <br />NOAANGDC. and olher catributorg <br />3.5 7 <br />Soures-Esrl <br />Esri, <br />20Plan.pdf <br />Chapter 4: Hazard ldentification and Risk Assessment 126