WHITE RIVER HESCO FLOOD BARRIER PLACEMENT The plan is to deploy HESCO flood barriers along existing revetments on the left and right banks of the White River to increase the flow containment capacity of the river channel. On both sides of the river the parcels are owned by the City of Auburn. On the right bank (parcel # 6655000025) King County has an easement for its existing flood control facility, which would also allow installation of the HESCO barriers. On the left bank (parcel # 6655000024) King County is currently working with City of Auburn staff to procure an easement for the proposed HESCO placement. HESCOs are a rapidly deployed, temporary flood barrier comprised of geotextile-lined wire baskets that are filled with a gravel-sand mixture. Approximately 1,081 linear feet of HESCO barriers are planned to be placed on top of the A-Street Trailer Court Revetment on the right bank and 335 linear feet of the barriers are planned for placement immediately landward of the top of the Oravetz School Revetment on the left bank. Site maps showing the location of the planned HESCO barriers are included in this application. The plan plan shows the FEMA regulatory 100-year floodplain elevation boundary, as derived from a 2021 LiDAR survey prepared by a licensed surveyor (report submitted with this application). As the site plan shows, our propsed HESCO barriers are outside of the 100-year floodplain. Therefore, we are requesting an exemption from the requirement to obtain a floodplain development permit for this action.
WHITE RIVER EMERGENCY HESCOS AND SEEPAGE BLANKET Three emergency flood fighting actions along the White River. First, approximately 540' of seepage blanket was placed along the landward side of the Oravetz School revetment to reduce potential for levee failure. Second, additional HESCOs were placed within Roegner Park (385' of double stack, 180' of single stack) and along the White River Trail (450' of single stack), to replace portions of the existing HESCOs in Roegner Park and prevent overbank flooding. Third, an additional 200' of single stack HESCOs is being placed at the upstream end of the existing HESCO alignment on the right bank along the A Street Trailer Court revetment to reduce risk of flanking, and 100' of double stack HESCOs is being replaced at the downstream end.
WHITE RIVER EMERGENCY HESCOS AND SEEPAGE BLANKET Three emergency flood fighting actions along the White River. First, approximately 540' of seepage blanket was placed along the landward side of the Oravetz School revetment to reduce potential for levee failure. Second, additional HESCOs were placed within Roegner Park (385' of double stack, 180' of single stack) and along the White River Trail (450' of single stack), to replace portions of the existing HESCOs in Roegner Park and prevent overbank flooding. Third, an additional 200' of single stack HESCOs is being placed at the upstream end of the existing HESCO alignment on the right bank along the A Street Trailer Court revetment to reduce risk of flanking, and 100' of double stack HESCOs is being replaced at the downstream end.