In 2004 the US Army Corps of Engineers began work on this section of the San Lorenzo River Levee Project. In order to work on the bank to the left in this photo the river had to be diverted. Graniterock Construction Co. built this framework in the bed of the river to hold a very large waterproof tarp.
Each of the frames had to be constructed and adjusted by hand. It was a very tedious job.
A channel was cut on the river side of the tarp to allow the river to flow in the Monterey Bay while pumps transported water from the work area into the main stream.
When the tarp was in place the pumping could begin. Note the white pipes along the barrier. Later I will publish what the project looked like when it was finished.