Rapid Repair of Levee Breaches Demonstration 2009

UC Berkeley Floating Sensor Network team successfully completes levee plug test with Department of Homeland Security and US Army Corps of Engineers.

Floating Through the Levee Breach

US Army Corps of Engineers builds the sample levee to be broken.

On November 9, 2009, a subset of our team led by EECS Ph.D. student Andrew Tinka participated to a levee plug test ran by the US Army Corps of Engineers, in partnership with the Department of Homeland Security. EECS Ph.D. student Kevin Weekly, CEE Ph.D. student Saurabh Amin, CEE Systems Engineering M.S. students Jack Reilly and Leah Anderson performed the first operational deployment of the Generation 2 drifters, which are now communication enabled (radio and GSM). The test was set up at the Federal Agriculture Department's Hydrologic Engineering Research Unit, Stillwater, OK, which has a testing facility capable of performing levee breach tests. The UC Berkeley team deployed 10 Generation 2 drifters to demonstrate the tracking capabilities of the drifters, and their ability to navigate safely through heavy currents such as the ones encountered after a levee breach.

The US Army Corps of Engineers built a sample levee (see figure above), downstream from an area which they later filled with water (see figure below). Once the area upstream from the levee was filled with water, they opened a small dent in the levee, through which water could flow, which progressively eroded the whole levee until it broke.

Area to be filled with water before the levee is broken. Note on the right: levee plug system to be deployed later during the experiment.

At the proper time, after the area upstream from the levee was filled with water, the US Army Corps of Engineers started digging a dent in the levee, which led to levee erosion and finally destroyed the whole part of the levee built from dirt. Then the area filled with water started going through the levee at a flow rate of 125 cubic feet per second, quickly emptying the ``lake’’ which had been created behind the levee. EECS Ph.D. student Kevin Weekly then started releasing drifters upstream from the breach to demonstrate the ability of the drifter to survive floating through the breach and turbulence downstream from the breach (in particular the transition from supercritical to subcritical flow). CEE Systems Engineering M.S. student Jack Reilly subsequently caught the drifters downstream from the breach.

Finally, the US Army Corps of Engineers demonstrated the rapid deployment of a levee plug, followed by the deployment of a secondary system deployed upstream from the levee plug, which would later enable engineers to fix the levee while retaining the water upstream from the levee (see picture below)

Levee plug is deployed by the US Army Corps of Engineers to fill the levee (right inflatable device on the picture). Then, a secondary device is deployed (left on the picture), to block the water upstream, which will enable the levee plug to be removed, the area to be dried (while retaining the water upstream) so that engineers can fix the levee.

The goal of the deployment for our lab was to demonstrate the capabilities of our drifters, for the first time in an operational context. The operation is a success. The drifters survived the test, and were later used for a second test to demonstrate the tracking capabilities of our system.

Hybrid GSM – Radio Tracking of GPS Positions of the Drifters.

In the afternoon of the demonstration, the UC Berkeley team demonstrated the ability of tracking the drifters along their trajectories. The supply canal of the hydraulic facility shown earlier, providing water at a discharge rate of 125 cubic feet per second was used as a second deployment. The drifters were released one by one upstream from the water supply canal, and transmitted their GPS recorded positions to our based station, either by radio or GSM, based on the availability of the GSM network in the area (the GSM signal in the deployment area was very weak, so the communication heavily relied on the use of both channels). The positions of the drifters could be tracked through their journey through the canal, to demonstrate their tracking capabilities.

Area upstream from the levee is progressively filled with water to create optimal levee breach scenario.

Generation 2 drifter floating along the water supply canal towards the experiment site

CEE Systems Engineering student Jack Reilly downstream in the canal, after catching six drifters at the end of the experiment.