Sediment Deposition on North Intake Bay March 26

Current Opened Gate: Automatic operation #1~8, and 20.

Gates #1~8 and #20 were opened and 3.5 ft water depth was measured on PLC screen.

High sediment has deposited at the north intake bay as shown as figures 1 and 2. The intake gate has been opened for 3 weeks so far and approximately 4 ft of sediment pack was piled up at the intake bay entry. Some of sediments were flushed out by sediment pump in this morning effectively. However, the sediment pump was out of order temporary in this afternoon. On the couth intake channel, 4 inches of sediment was deposited couple weeks ago.

Figure 1 Figure 2

Tim Wawrzyniec, UNM research scientist, took 3-dimensional LiDAR image for the erosion at west side bank (figure 3). This image has 1 cm resolution and will be used for evaluation of eroded volume.

Figure3

Sand bar removed at last November has been appeared again. Figure 4 shows the sand bar (in green circle) placed in middle channel. Recent high sediment deposition on the diversion dam upstream is probably caused from both large sediment load incoming and gate operation test. The sand bar relocation will be tested with center gates opening.

Figure 4