Picture titled by DWR: "DWR utility craftworkers Gary Hage and Chris Williams prepare a section of Lake Oroville flood control spillway for survey marking. Photo taken March 31, 2017"
They are likely going to paint jig outline horizontal stripes at the large sidewall drain outlets. These precise width & spacing "survey" lines will help facilitate water flow assessment & analysis of the drain outflow during spillway operation. Knowing the total drain waterflow from each outlet drain is useful as this may be compared to the 3D subslab voiding data along with the calculated seam & crack penetration estimations.
Monitoring all of the drain outlets will require keeping someone busy with camera work (drone?) + pre-setup ladders. Camera work imaging may be more challenging on the east hillside as there doesn't seem to be a good footpath along the side wall backside or up on the hill. I'd look for camera mounted tripod setups if they want simultaneous data collection. Either that or someone is going to be very busy flying a drone around.
DWR utility craftworkers Gary Hage and Chris Williams prepare a section of Lake Oroville flood control spillway for survey marking. Photo taken March 31, 2017. Note the size of the drain outlet.
DWR utility craftworkers Gary Hage and Chris Williams prepare a section of Lake Oroville flood control spillway for survey marking. Photo taken March 31, 2017.
