The site has become a higher priority for the County of El Dorado to address localized flooding across Sawmill Road, approximately 0.4 mile west of U.S. Highway 50/State Route 89. At this location, there is a relative low spot on the north side of Sawmill Road which fills with storm water runoff without any conveyance, causing a safety issue for vehicles during the freeze/thaw cycles. During winter operations when flows that overtop the roadway freeze, road maintenance operations has spread abrasives to increase traction. The use of traction abrasives has the potential to affect water quality while the overtopping of the roadway can create hazardous driving conditions. Recent roadside ditching operations aid in the storage of storm water runoff but lacks the capacity during significant precipitation events, e.g., rain-on-snow events.
The work will be completed by Transportation maintenance staff and includes the installation of a culvert crossings with an inlet structure on either ends of the culvert under Sawmill Road, then another pipe crossing under the pave path with a steel flared end section with a rock energy dissipator at the pipe outlet. The finish grades of the inlet structures will allow for flows to cross under Sawmill Road, reducing flooding impacts and lessen the need for traction abrasives at this location during the winter. All improvements are to be constructed within the County maintained rights of way and within an existing easement for the paved pathway.