This indicator measures community noise levels in the low-density residential land use areas in the Tahoe Region. Cumulative noise or community noise equivalent level (CNEL) is a noise measurement based on a weighted average of all measured noise over a 24-hour period. Excessive noise in the Tahoe Region can impact wildlife, visitors’ experiences, and residents’ quality of life. Primary drivers of community noise levels in the Region have been attributed to anthropogenic activities such as vehicular travel in transportation corridors and aircraft activity at the South Lake Tahoe Airport. Regional programs such as encouraging the use of low-noise pavement and limiting noise at outdoor concerts aim to reduce community noise levels in the Region.  CNEL is monitored in plan areas across the Region once every four years. 

Status

Noise levels in low density residential areas.

2019 Evaluation
See how thresholds are evaluated
Status
At or Somewhat Better Than Target
Trend
Little or No Change
Confidence
Moderate
Applicable Standard
For the low density residential land use category noise levels shall not exceed a CNEL of 50 dBA.
Key Points
  • Compared to the 2015 Threshold Evaluation Report, there is little to no change in overall noise levels in low density residential areas.
  • Noise levels in each plan area are assessed using the maximum 24-hour noise measurement (i.e., the loudest noise measurement of the day, regardless of duration). Most days most plan areas are within the noise standards, although many plan areas exceed the noise standard on a few days.
  • Average noise levels across all monitored low density residential areas are within the threshold standard.
Evaluation Map
Description

Low Density Residential Area Noise Monitoring Locations

About the Threshold
This indicator measures 24-hour noise levels in the low-density residential land use areas in the Lake Tahoe Region. Due to the rural nature of the communities and the pristine natural areas in the Lake Tahoe Region, excessive noise levels have the potential to negatively impact community ambiance, recreational experiences, and wildlife behavior. In the past, visitors and residents of the Lake Tahoe Region have expressed concerns about the decline in serenity of their community, and their enjoyment of the outdoors due to excessive noise from sources such as on-highway vehicles, off-highway vehicles, over-snow vehicles, watercraft and aircraft. In addition to existing federal, state, and local noise control regulations, TRPA adopted 24-hour noise threshold standards, or community noise equivalent levels (CNEL), for all land use categories and plan areas of the Region.
Anthropogenic noise levels affecting these land use categories and transportation corridor are primarily generated from vehicles, roadway traffic, aircraft and recreational activity. Other secondary anthropogenic noise influences include noise attributed to construction. Natural events such as thunderstorms and wind influence noise levels as environmental drivers.
Delivering and Measuring Success

Monitoring Programs

  • Noise - Plan Areas

    Noise monitors are put out in low density residential plan areas for 1 to 2 weeks during peak noise periods (generally summer). The average 24-hour CNEL measured is used to assess noise levels.

Rationale Details
To measure the current status, the average CNEL for all days measured within low density residential land use areas during the current evaluation period of 2016-2019 was used. The average CNEL during this period is 49.29 dB, which is 98 percent of the maximum allowable levels. Therefore, the current status is at or somewhat better than target.
To determine trend, the average CNEL for all days measured within low density residential land use areas for each reporting period is assessed. There has been little to no trend in overall noise levels.
Confidence Details
High. Standardized protocols were used and a large number of sites were monitored.
Low. Standardized protocols were used and a large number of sites were monitored but there is no clear trend.
Moderate.
Additional Figures and Resources

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