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This indicator measures the number of single noise-event exceedances caused by motorized watercraft in the shorezone of Lake Tahoe. Single noise event threshold standards are based on the numerical value associated with the maximum measured level in acoustical energy during an event. High noise levels can reduce the public's enjoyment of the natural environment, impact the quality of life for residents, and disturb native wildlife. Single noise event violations in the shorezone can be caused by boats navigating too close to shore within the no-wake zone and loud boat engines outside the no-wake zone. Regional programs such as prohibiting noisy boat engines and enforcing the no-wake zone aim to reduce single noise events in the shorezone of Lake Tahoe.
- Status
- Somewhat Worse Than Target
- Trend
- Little or No Change
- Confidence
- Moderate
- The number of noise exceedances on the shoreline has gone up and down with no trends evident since monitoring began.
- The number of noise exceedances is very low compared to the number of boating hours, with most sites recording no noise exceedance(s) during the most recent monitoring in 2019.
- Most noise violations occurred at Rubicon Point and Emerald Point.
- The majority of noise violations appear to come from "go-fast / cigarette" boats, with some violations being caused by boats navigating too close to shore within the no-wake zone.
- In 2019, TRPA increased patrols for the no-wake zone and began sending notices to noisy boats to cease operation on Lake Tahoe.
Shoreline Noise Monitoring Locations
- This indicator measures noise generated from motorized watercraft in the shorezone of Lake Tahoe. Residents and visitors are concerned about the declining serenity of their communities and their enjoyment of the outdoors due to excessive noise from sources such as motorized watercraft. Excessive recreational boat noise can also disturb sensitive wildlife. For this reason, TRPA adopted policies and ordinances to reduce noise levels and maintain serenity in Lake Tahoe’s shoreline area, while continuing to afford recreational opportunities.
- Watercraft-generated single-event noise exceedances are driven by the type of watercraft engine and exhaust system and boater behavior (proximity to shore, operating speed, etc.). Shoreline topography, wave slap, and wind can also influence noise levels.
Local and Regional Plans
Monitoring Programs
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Noise - Shorezone
Noise monitors are put out for two weeks during peak boating season (July 4th to Labor Day). Noise monitors automatically record all single noise events that exceed 75 decibels (dB).
- The current status was determined using the total number of noise exceedances caused by motorized watercraft in the most recent year of monitoring. There was an average of 0.21 exceedances per day at all monitoring sites in 2019. Therefore, the status was determined to be somewhat worse than target.
- Trend was determined by analyzing the average number of noise exceedances per day at all monitoring sites combined in each year of monitoring. Over this time, there was little to no change in the number of noise exceedances.
- High. Standardized protocols were used and a large dataset was used.
- Moderate. Standardized protocols were used throughout the monitoring effort and a large data set exists. However, there is no clear trend and data is highly variable.
- Moderate.
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No documents available.