Wawona Geotechnical Investigation for Utility River Crossing

A geotechnical investigation and analysis is required on the alluvial soils for the under-river utility crossing on the South Fork Merced River at Wawona. A 10' x 10' exploratory soil pit will be excavated to an approximate depth of 14' to: determine the geology for a 9' deep open-cut trench, determine alluvial sands size through a sieve analysis for proper sizing of dewatering screens, determine the depth of bury on the two existing water mains to complete an analysis on the rate the river is scouring the bed, and determine if the proposed bury depth of 8' for the under-river utility corridor is adequate based on past river scour and bank erosion. This exploratory soil pit will be excavated next to the existing 10" water mains on the north side (firehouse side) of the river bed. The north side was chosen due to ease of access and exposure of the river bed. The soil pit will be filled in and the area restored after the completion of the test. The surface area of the project does not include any vegetation.

All equipment and materials brought into the park will be inspected and free of non-native, invasive plants and animals, and noxious weeds.