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Iron Horse Trail West Las Positas at 95 80 18 Dorman West Las Positas at 155 167 19 Willow: West Las Positas at 272 271 45 Santa Rita Santa Rita at Valley: 117 232 61 West Las Positas Reconstruction Project West Las Positas Boulevard has a history of soil settlement and differential movement that has created an uneven roadway surface and some localized roadway failures. The City has implemented several maintenance repairs projects and geotechnical investigations over the years to remediate uneven roadway experiencing pavement distress and/or settlement. The various repairs have provided a short-term fix, but these repairs have not lasted as long as anticipated. To address the settlement, a more comprehensive reconstruction of the worst affected segments of the road is necessary. In October 2021, the City Council awarded a contract to BSK Associates (BSK) to conduct an extensive geotechnical study to identify the causes of road failures and develop recommended repair strategies. The study included the collection of soil samples from 19 locations (borings) with the collections occurring at varying depths from seven to 40 feet deep, as well as review of similar soil investigations from adjacent properties. The borings identified that the area consisted of expansive clay soils 35 to 40 feet deep that have consolidated and are highly susceptible to shrinkage and contraction when dried out. The study determined the primary cause of settlement is attributed to the loss in soil moisture along the roadway edges and medians within the top five feet of soil, causing the surficial soils that are highly susceptible to shrinkage and swelling to contract when dried out. With the settlement issue worsening in recent years, staff has accelerated efforts to advance the Reconstruction Project. In May 2022, the City issued a Request for Qualifications for professional services to develop project plans, specifications and estimates for the reconstruction of West Las Positas Boulevard between Foothill Drive and Owens Drive. Staff intends to recommend a contract for design service for approval by the City Council at an upcoming meeting. Originally, the West Las Positas Reconstruction Project and the Bicycle and Pedestrian Corridor Plan had been conceived somewhat separately, since the Reconstruction Project was thought to be on a longer implementation timeframe due to its likely significant cost. However, as the need to undertake the Reconstruction Project has become more urgent, there is an opportunity to integrate the two efforts more closely and potentially achieve some cost efficiencies for later phases of the Bicycle and Pedestrian Corridor Plan. The City Council's 2021 Work Plan combined the West Las Positas Reconstruction and the West Las Positas Bicycle and Pedestrian Corridor Page 5 of 14