This indicator measures community noise levels in the Commercial land use areas. 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 Basin. CNEL is monitored in plan areas across the Region annually.

Status

Average of CNEL noise levels in commerical areas.

Data collected by the Tahoe Regional Planning Agency. Access detailed datasets, including Noise Data Summaries, on Tahoe Open Data.

Evaluation Map

Commerical Area Noise Monitoring Locations

2023 Evaluation

Status
At or Somewhat Better Than Target
Trend
Little or No Change
Confidence
Moderate
View Evaluation

Applicable Standard

N19: Background noise levels shall not exceed the following levels: 60 dBA CNEL (Average Noise Level)) in the Commercial Areas Land Use Category.

Key Points

  • There is little to no change in overall noise levels in commercial 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.
  • The average noise level across all monitored commercial areas is well within the threshold standard.

About the Threshold

This indicator measures 24-hour noise levels in commercial land use categories in the Lake Tahoe Basin. Due to the rural nature of the communities and the pristine natural areas in the Lake Tahoe Basin, excessive noise levels may negatively impact community ambiance, one’s recreational experience, and wildlife behavior. In the past, visitors and residents of the Lake Tahoe Basin have expressed concerns about declining serenity in 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 standards, or community noise equivalent levels (CNEL), for all land use categories, plan areas, and transportation corridors of the basin. TRPA and local jurisdictions review proposed public and private projects to determine if the project would result in increases in existing CNEL that would exceed applicable standards (TRPA Code of Ordinances). Projects that would exceed applicable CNEL standards are required to mitigate project-related noise.

Anthropogenic noise levels affecting these land use categories 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 - Shorezone

    TRPA monitors noise from motorized watercraft in the shorezone of Lake Tahoe to ensure noise levels are not being exceeded to maintain the serenity of Lake Tahoe and to protect sensitive wildlife.

Rationale Details

At or Somewhat Better Than Target. To measure the current status, the average CNEL for all days measured within Commercial land use areas during the current evaluation period of 2020-2023 was used. The average CNEL during this period is 53 dB, which is 88% of the maximum allowable levels. Therefore, the current status is at or somewhat better than target.
Little or No Change. To determine trend, the average CNEL for all days measured within Commercial land use areas for each reporting period is assessed. The percent change is -0.25, therefore, little or no change has occurred.

Confidence Details

High. Noise monitoring follows monitoring protocol and has consistent data for several monitoring periods with spatial variation.
Moderate. Confidence of trend is determined by the duration of trustworthy data and both the coefficient of determination and t-test significance. There is a long term trustworthy dataset for noise. R²= 0.537, p-value= 0.06. therefore, the confidence of trend is moderate.
Moderate. If one confidence rating is high and the other is moderate, the overall confidence rating is the lower confidence rating.

Additional Figures and Resources

No photos available.


No documents available.