Waller Creek Outlet CFD Modeling Results Connection #2 with 3’ High Spillway Flip Bucket 500-Year Flood (11,270 cfs) Lady Bird Lake Inflow (3.5 ft/s) at El. 428 ft 10/21/20081ALDEN RESEARCH LABORATORY, INC.

General View of the CFD Model 10/21/20082 General View

Plan View of the CFD Model 10/21/20083

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Velocity Contours at Water Surface 10/21/20085

Flow Patterns From the Tunnel Shaft to the Spillway 10/21/20086ALDEN RESEARCH LABORATORY, INC.

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Flow Impacts Caused by Stacked Rock at the Ends of the Spillway Crest 10/21/200818ALDEN RESEARCH LABORATORY, INC.

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Velocity Profiles Along the Ogee Spillway Section 10/21/200821ALDEN RESEARCH LABORATORY, INC.

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Hydraulic Jump at the Toe of the Spillway Velocity and Froude Number 10/21/200825ALDEN RESEARCH LABORATORY, INC.

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Scour Potential In the Exit Channel, both Concrete Apron and Riprap Section 10/21/200828ALDEN RESEARCH LABORATORY, INC.

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Water Surface Elevations At Spillway Crest and Upstream 10/21/200839ALDEN RESEARCH LABORATORY, INC.

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Pressure Forces On the Pipe Riser and Water Intake Screen 10/21/200841ALDEN RESEARCH LABORATORY, INC.

Pressure Force on Pipe Riser and Water Intake Time (second)X-Force (lbf)Y-Force (lbf)Z-Force (lbf)Total (lbf) Average /21/200842