Draft Environmental Impact Report - California Off Highway Vehicle ...

General Plan Impact Analysis
IMPACT
3.3-1
Increased Off-Site Noise Levels Related to OHV Use
3.3 Noise
While conducting the community noise survey for this DEIR during the peak activity season, OHV
activity was audible at off‐site sensitive receptors (i.e., residences). Therefore, OHV use currently
contributes to ambient sound levels at nearby residences during the peak season. Additionally,
when surrounding traffic noise is low, such as on weekends, OHV activities at Clay Pit SVRA would
be more audible to people using the outside areas at these residences.
OHV use within the SVRA is estimated to increase by 50% following buildout of the facilities
envisioned in the General Plan. This increase in OHV activity would result in an approximately 1.5‐
dBA increase (Caltrans 2009:7‐5) in noise levels during periods of peak use over current noise
levels near the closest noise‐sensitive receptor, which is a residence on Larkin Road (66.8 dBA Leq,
Table 3.3‐1). Special events are anticipated to attract approximately the same numbers of visitors
and OHVs as a typical peak use day. Therefore, noise levels for special events are also anticipated
to produce an approximately 1.5‐dBA noise level increase. This estimated 1.5‐dBA noise level
increase would not exceed the established threshold of a 5‐dBA increase in ambient noise levels,
which is considered “readily perceptible” (Caltrans 2009:7‐5).
Because off‐site noise levels related to OHV use would increase less than 5 dBA, noise from
increased recreational activities following implementation of the General Plan, including
construction and operation of the headquarters facilities, would be a less­than­significant impact.
Mitigation Measures: No mitigation is required.
IMPACT
3.3-2
Increased Off-Site Noise Levels Related to Traffic
Traffic noise modeling was conducted using the FHWA Highway Traffic Noise Prediction Model
and traffic data provided by the project traffic engineer (KD Anderson & Associates 2011). Traffic
noise modeling was conducted for both the existing conditions and for future conditions with and
without implementation of the Clay Pit SVRA General Plan.
Traffic noise predictions are based on 24‐hour roadway counts and peak‐hour intersection counts.
Traffic volumes were taken from the project traffic report (KD Anderson & Associates 2011). For
modeling purposes, future (Year 2030) roadway geometries, traffic mix, and speed conditions are
assumed to remain the same as existing conditions. Table 3.3‐4 summarizes the modeling and
predicted noise level increases expected following implementation of the General Plan.
Clay Pit State Vehicular Recreation Area
Draft EIR 3.3-17 February 2012