Streambed Alteration Agreement (R5-2001-0207) to Perform Geotechnical Survey Activities (Borings) with the Arroyo Trabuco

Streambed Alteration Agreement (R5-2001-0207) to Perform Geotechnical Survey Activities (Borings) with the Arroyo Trabuco

The operator proposes to alter the stream to perform geotechnical survey activities within the Arroyo Trabuco floodplain underneath the SR-241 bridge. These surveys will provide information which will aid in the design for a bridge widening project over the stream. A separate Streambed Alteration Agreement will need to be obtained for the ultimate widening project. Geotechnical boring samples will be taken at four locations. Each boring will be 8 inches in diameter by 60-80 feet in depth. At each boring site, a maximum 40-foot circumference work area shall be established to provide for equipment turnaround, temporary parking of vehicles, and temporary stockpiling of drill materials. To gain access to the boring sites, two vehicles will be driven over a previously graded unpaved dirt road, which has since become overgrown with native vegetation. To gain access to one location, a dozer will cut an access ramp through the northern and southern banks of the existing creek, which has a height of approximately 2 to 3 feet, by back hoeing the bank away from the stream. After the project is completed, the ramps will be removed and recontoured to pre-project condiditons. Except where authorized, vegetation shall be driven over or hand cut rather than graded. The operator shall not impact more than 3000 feet squared (900 feet squared for constructing ramps and the remaining 2100 feet squared for driving work vehicles over revegetated access road), all of which are temporary impacts. The operator shall restore all stripped or exposed areas with vegetation native to the area.

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