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La Cueva Channel Debris Removal Structure INTRODUCTIONThe purpose of this
study was to determine a way to remove the debris from the La Cueva Arroyo before
it discharges into the North Diversion Channel. Due to space limitations, a
full size sedimentation pond cannot be used; so alternative BMP’s (Best
Management Practices) will be analyzed. Structural BMP’s that are
hydraulically driven, easy to maintain, and contain little or no grating will
be preferable.
Figure 1: La Cueva
Site Layout (Balloon Fiesta Park is to the North)
OPTION 1: REVERSE FLOW DEBRIS FILTER
Full modeling report in
[pdf]
SUMMARYThe Reverse Flow
Debris Filter (RFDF) creates dead zones by reversing the flows so that water
flowing through the structure can only leave by a certain path. Floating and
neutrally buoyant material would be removed because the upper portion of
water cannot pass through the structure, though any dense material would be
swept out. The maximum flow rate that the structure would treat is around 150
cfs. With the 1:12 scale model, testing was completed using a number of
different scenarios. RECOMMENDATIONSThe addition of a horizontal plate at the end of the ramp created the desired results. The filter removed most of the floatable and neutrally buoyant material, and two linked in series could potentially remove an even higher percentage of the material. Another option is the addition of a grate at the discharge point, which would be possible because most debris will not be carried to the screen, and as the filter drains after use, the water will flow back into the structure and self clean. OPTION 2: FLOATING DEBRIS BOOM
SUMMARY
The floating debris boom (previously modeled in Year 15) was placed on-site at the North Pino Arroyo
for testing. There is currently a debris intake structure located in the
channel that diverts debris into a baffle weir debris removal structure. The
debris boom was built out of rope and ‘noodles’ (a pool toy shaped like a
noodle made out of foam). A number of different configurations were tested,
including long and short booms, as well as between 5 and 12 noodles per boom
section. Figure 2: On-site testing of floating boom.
RECOMMENDATIONS
The testing of the floating booms on-site was not
completed. The absence of suitable storm flows during the testing period led
to a lack of data regarding the suitability of booms. One observation made
during testing was that the booms would roll as water flowed underneath,
which would allow trapped debris to pass down the channel. Most channels in
the Albuquerque area are super-critical, but the floating boom seems to work
best in a sub-critical channel. The high velocities can damage the structure
and reduce the debris removing effectiveness. [Back] [Top of the Page]
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