Inyo County, CA
Owens Dry Lake Project
The Owens Dry Lake Project was initiated to flood the surface of a dry lake as dust blowing off the surface of the lake was the source of significant caustic contaminants and presented a health hazard. A network of irrigation pipes was needed to distribute water over the large surface area. SGH evaluated the pipe and provided recommendations.
Given the severe soil conditions, fiberglass pipe was selected for the project. We analyzed several different soil stiffness categories at two compaction levels, as defined in Manual M45 (AWWA, 1996) and also reviewed the contractor’s proposed construction procedures. Our analysis indicated that a 9 psi (62 kPa) stiffness pipe could just meet the requirements of the design method presented in Manual M45. Based on experience with low stiffness pipe in wet and variable conditions like those on this project, we recommended that 18 psi (124 kPa) stiffness pipe was more appropriate for the project. SGH specified a system for monitoring and controlling the installation quality without specifying means and methods of construction. Measurements of deflection and flattening demonstrated that the installation met the performance requirements and the pipe is performing well.