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Water Trust Board Grant Agreement Scope and Objectives: Removal of islands below the Isleta Diversion Dam Restore this reach of the Rio Grande to the Traditional view of the Pueblo Restore the connection between the shallow ground water aquifer and the river Create habitat for the RGSM 2 backwater features constructed Being done upstream of the Isleta Diversion Dam 2

Design Objectives Maintain year-round wet channel along west bank Integrate with restoration work at cultural site on west bank Assess geomorphology Model three flow events Low flows to maintain flow against west bank Mid-level flow to determine sediment transport High-level flows to determine hydraulic design parameters Endangered species habitat features Remove invasive vegetation 3

2002 4

2005 5

2008 6

2012 7

Design Plan View Cross-sectional View 8

Modeling Tools 1D vs 2D modeling SRH-2D v. 30 Public domain, hydraulics and sediment transport modeling available through USBR Solves depth-averaged, 2D St. Venant equations Calculates sediment transport capacity at each cell for each timestep using Engelund-Hansen equation, compares to supply SMS v Create hybrid mesh Visualize & post-process model output 9

Fixed-bed, Mobile-bed Modeling: Fixed-bed Model Mobile-bed Model Comparison of existing and design hydraulic parameters Results used to: Size rip rap Calculate scour Comparison of existing and design bed elevation change, sediment concentration Results used to evaluate sustainability 10

Inundation Mapping: 100 cfs 1,200 cfs3,000 cfs 11

100 cfs1,200 cfs 12

Bed Elevation Change 13

Project Uncertainties Project is within a sediment laden and dynamic river system Project life span subject to many elements beyond the control of either party long term spring runoff events short term thunderstorm events in upstream tributary arroyos operations of the Isleta Diversion Dam 14

Construction Performed by AJAC Enterprises, Inc. Removed ~70,000 cubic yards of material NTP to substantial completion: 84 calendar days 15

Completed Project 16

Post-Construction Maintenance: Removal of woody vegetation on benches on an annual basis Removal of deposited sediment in channel on an as- needed basis depending on flows Destabilize any emergent islands 17

Thank You 18