Tahoe Resource Conservation District

Elks Club

151102_UT

Site Photo

Elks Club Catchment Map

Catchment Map

 

Catchment Size:

14.4 acres

Dominant Land Use:

This catchment is comprised of medium density development including single family residential and secondary roads.

Percentage of Impervious Surface:

29% of the catchment is impervious

Jurisdiction:

El Dorado County

Description:

The Elk’s Club monitoring site is located in the Upper Truckee River watershed on the northern side of Elk’s Club Drive in El Dorado County, CA. Runoff originates primarily from the road surface of Elk’s Club Drive and discharges to a vegetated swale on the northern side of the road.  This site is not directly connected to Lake Tahoe and is therefore not monitored as an urban catchment outfall.  Instead, it is monitored for its potential to provide more data to verify that repaving roads reduces fine sediment particle (FSP) loads in stormwater.

A preliminary study conducted by El Dorado County in water years 2013 and 2014 showed that up to 30% of FSP in runoff from a degraded road originates from the road surface itself.  In other words, a road in poor condition can contribute almost of a third of the total FSP load in stormwater in the form of tiny particles of asphalt and asphalt binder.  A road in poor condition crumbles more easily when subjected to vehicular traffic, especially large and heavy snow plows wearing snow chains. It cracks more easily from the freeze/thaw cycle and breaks apart more easily when metal edged blow blades skim its surface.  Badly cracked roads are also very hard to sweep, so recovering road abrasives is more difficult on degraded roads.  A newly paved road does not degrade as easily from regular traffic and snow removal activities, provides a smooth surface for abrasive recovery, and provides an exceptional driving experience. Monitoring stormwater runoff at this site should provide additional data to support the hypothesis that repaving roads reduces FSP loads. If successful, this study could help get repaving roads recognized as a water quality Best Management Practice (BMP), a win-win for water quality and transportation.