The project involves the removal of 1000 feet of metal 36”D corrugated pipe and replace with 36” D Aluminized CMP.  This project was completed with a grant from the California Department of Water Resources.  The grant was for $84,200 and was completed 11/2016.  The contractor for this project was White Bear Construction. The original flume was constructed in 1867 and was made of wood.  In 1945 the wood flue was taken out and replaced with the present metal pipe.  Over the years numerous leaks in the pipe have occurred.  Most are occurring along the bottom of the pipe at joints that are rusting out, some by falling rocks hitting the pipe and a few suspect gun shot holes. The amount of water being lost is estimated to range from 500 to 600 ac ft /season.

• Project Concept:  Replace the existing CMP (Corrugated Metal Pipe) with new pipe having the same capacity.  The original design considered replacing the existing CMP with HDPE plastic pipe.  However, after having representatives from the supplier visit the site, it was determined that the rocky conditions presented some unique problems in using this type of pipe.  Other options to replace or refurbish the existing pipe were considered.  These included other types of plastic pipe, plastic pipe inserts and spray-on liners.  These methods were not selected because of one or more of the following reasons: being more expensive, reducing the capacity of the existing pipe and not practical because of the remote, rocky location.  Aluminized CMP was selected as the most economical and practical replacement for the existing CMP.

• Project Layout:  The installation of the new pipe was on the existing bed that the old pipe is on.  Road base material was placed on fill areas identified in the contractor’s White Bear Construction survey notes.  Inlet and outlet remained the same but partially reconstructed to accommodate the new pipe. Earth material was used at the outlet and concrete at the inlet.