Letter from STPUD: Not all potholes are the same

Potholes in our streets are a popular discussion item in Tahoe. Some potholes are simply holes in the asphalt paving, while others are actually low spots located over a utility pipeline. This summer, several articles have addressed potholes at various lengths. The South Tahoe Public Utility District (District) would like to provide some information concerning the “utility” potholes. There are multiple types of “utility” potholes:

1. Manhole structure on sanitary sewers (stamped STPUD)
2. Manhole structure on storm drain sewers (usually slotted)

3. Slotted drains on storm sewers (usually on side of road)
4. Valve box covers on water pipelines (smaller lids than manholes)
5. Manhole or steel plates on electrical vaults (stamped electrical)

The District is responsible for manholes on sanitary sewers and valve box covers on water lines. Storm drains are the responsibility of either the City of South Lake Tahoe (CSLT), El Dorado County Department of Transportation (EDCDOT), or California Department of Transportation (Caltrans).

Due to freeze/thaw cycles in Tahoe, road surfaces move up and down with changes in temperature. This movement can leave the utility cover higher than the surrounding road surface in winter even if it was flush with the surface in summer. These elevated covers can then be hit during snow plowing operations, causing severe damage, or complete removal, of the utility cover, and significant damage to the snow plow and possible injury to the operator.

To reduce the risk of damage and injury, the top of the cover is typically installed ½ inch below the road surface. The EDCDOT project on Black Bart this year is a good example of this work. On typical EDCDOT or CSLT paving projects, the District will reimburse the agency the costs of having their contractor adjust the elevation of the lids to the ½ inch depth below the new asphalt surface.

On new waterline or sewer line projects, in addition to repaving the lane where the pipe is installed, the District requires that our contractor install all of the covers. Typically, during the active pipeline installation, the top of the backfilled trench will be covered temporarily with a pliable, cold mix of asphalt. This surface can be bumpy, similar to temporary asphalt used on the trenches this summer on Highway 50, where SW Gas installed a new pipeline. Speed should be reduced when driving over these areas. At the end of the project, the contractor returns and replaces the temporary asphalt with a permanent, hot, compacted, smooth rolled asphalt product. The extent can vary, on Highway 50 and in CSLT streets; the District is typically required to pave the entire travel lane, or half the street, respectively. On EDC streets, just the pipeline trench is usually repaved to match the surrounding asphalt.

While we would all prefer a smooth ride, these “utility” potholes are a necessary evil. As members of the public, you can assist in increasing public safety by notifying the proper agency of an issue with a “utility” pothole. Please report lids that are excessively deep (greater than 2-1/2 inches), missing lids, or lids projecting above the surrounding asphalt surface. To notify the District of an issue with a sanitary sewer or water valve lines, please call 530-544-6474.