2023-04-24-minutes-public-works-study-session

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Kittitas County Members of the Board April 24, 2023 manner, under unsafe operating conditions, allowed to dynamically overload the bridge, and was over legal limit when crossing. 2) The McElroy Bridge is an existing bridge that was constructed around 1960 and approved in 1963 by Kittitas County Road Engineer D.E. Akins, the then Board of Commissioners, signed by Chairman Howard P Sorensen, and filed for record at the request of the Kittitas County Board of Commissioners. There are clear unimpeded sightlines across the 100 -foot long bridge and the access has safely and efficiently operated as a private one -lane usage without safety incident. The one -lane bridge functions effectively as it serves only the closed community of Elk Meadows functioning as a cul-de-sac without through access. Traffic utilization across the bridge is estimated at a typically about 20 -vehicle trips per day in winter and probably not more than 250 - vehicle trips per day peak in summer. Traffic safety is assured by the very low traffic volumes, low traffic speeds of the private community, adequate sight distance, and fully stopped conditions at each end. The required girder repair did not change the conditions of the original 1963 County Engineer approval, nor impact the demonstrated historic safe performance. Public Works staff statements that the bridge must meet a two-lane minimum with of 22 -feet applicable to County through roads, high speed roads, and higher volume roadways, is mistaken. 3) The McElroy Bridge Access crosses the Yakima River downstream of the Lake Easton dam, for which flow is regulated by the Bureau of Reclamation. In addition, there are five bridges upstream of this access including Rail Road Street Bridge with piers in the water, two WA State 1-90 bridges with piers at the edge of water, the East Sparks Road Bridge, and the private Sun Island Drive Bridge. Each upstream crossing can have some impact and may reduce the potential for logs and debris that the McElroy Bridge access must clear. Furthermore, McElroy's repaired girders from January 2022 were constructed of a stiffer and shallower steel that created a raised flood clearance over the main Yakima River channel of at least 0.5 -feet as well as an improved floodway opening by more than 5%. FEMA figures provided from Kittitas County before the repair showed the calculated 100 -year flood elevation as only 0.5 -feet different than the bottom of old bridge, which was recently corrected. These installed repairs benefitted local flood performance at the bridge and it is also a simple matter to lift the bridge up more to further improve flood performance during required abutment maintenance. Also, historic observation at the bridge showed that in the more than 60 -years of valuable use, the flood elevation had not reached the bottom of the bridge. In January 2009 large logs and debris did accumulate at the central pier's upstream independent protective lead pile, for which it was installed. This debris caused the river to locally divert around the west approach resulting in erosion of the west approach roadway gravel that was repaired along with removal of the log debris. The bridge was not impacted, other river debris passed below the structure, and maintenance repairs were completed very quickly in less than two days. The flood risk to the bridge has been reduced by the recent girder repairs and can easily be improved further with allowed maintenance. The County's application of criteria used throughout the state at other very different, non-regulated flow conditions, should not be applied at this bridge where upstream structures are changing the debris load and flow is regulated. The bridge was already improved in January 2022 and had a more than a 60 -year history of successfully clearing flooding and passing debris that can be easily increased, if verified as necessary. Finally the Staff Report stated that permits were issued with clear communication to the Elk Meadows Homeowners Association that the bridge, previously approved by Kittitas County in 1963 and safely operated for more that 60 -years was, temporarily permitted. This is not true. The repair to the existing structure took place without new environment impact to the river, no new shoreline impact and was exempt maintenance of existing facilities per WAC 197-800(3). Also, the County Engineer's letter of February 8, 2023 paragraph three stated, "This letter formalizes those calculations did not meet HL -93 load rating resulting in the bridge authorized as a temporary structure." Stamped calculations were provided February 10,• 2023 showing that the bridge repair satisfied HL -93 (a highway load condition, which would not occur here, of a three axle 72,0001b truck combined simultaneously with heavy traffic on the bridge of 640lbs per linear foot). Therefore the bridge resulted in a permanent structure as was previously assured in 1963. ISE, PLLC Page 2 of 3