1. Erosion Along Waller Creek JACKELIN LEAL CAROLINA HERNANDEZ LEIF MOORE

2. Representation Process Evaluation Change Impact Decision

3. Location RED RIVER STREET E 3 RD STREET STUDY AREA Waller Creek

4. How should the study area be described?

5. How does the study area operate?

6. Is the current study area working well? Cross Section1709189420862214 W.S. Elev (ft)455.26455.46455.53456.11 Avg. Vel. (ft/s)7.047.619.448.56 Shear (lb/sq ft)0.971.151.811.49

7.  Options to prevent erosion: 1. Increase Cross-sectional area of channel to reduce flow rate and therefore shear force (Alternatives A, B and C). 2. Stabilize the stream using materials that can withstand a higher shear (Alternatives D and E). How can the study area be altered?

8. Alternative A: Dredging 0.5 ft Cross Section1709189420862214 W.S. Elev (ft)455.01455.39455.45455.61 Avg. Vel. (ft/s)6.926.277.477.84 Shear (lb/sq ft)0.940.761.111.26

9. Alternative B: Dredging 2 ft Cross Section1709189420862214 W.S. Elev (ft)454.68454.96454.98455.14 Avg. Vel. (ft/s)6.566.197.68.12 Shear (lb/sq ft)0.830.741.151.36

10. Alternative C: Dredging 15 ft Cross Section1709189420862214 W.S. Elev (ft)455.42455.46455.35455.32 Avg. Vel. (ft/s)4.074.426.328.01 Shear (lb/sq ft)0.30.350.761.32

11.  Armor stream bank with limestone terraces beneath pathway. Alternative D Cross Section1709189420862214 W.S. Elev (ft)455.83456.15456.32456.54 Avg. Vel. (ft/s)7.357.188.388.27 Shear (lb/sq ft)1.071.011.411.38

12.  Limestone retaining wall similar to the one on the opposite side of the channel extending from cross-section 1709 to 1894. Alternative E Cross Section1709189420862214 W.S. Elev (ft)456.18456.82457.06457.15 Avg. Vel. (ft/s)8.066.837.427.88 Shear (lb/sq ft)1.280.911.091.23

13.  Alternatives A, B, and C considered not acceptable due to City of Austin standards as provided by Environmental Criteria Manual  Alternatives D and E considered feasible and meets USACE shear criteria  Decision depends on the need for the path, which is currently being blocked off. How might the study area be altered?

14. What differences might the changes cause? ABCDE AlternativeOriginalDredge 0.5 ftDredge 2 ftDredge 15 ftRebuild PathRetaining Wall Cross Section 1709 Flow Velocity (ft/s) 7.046.926.564.077.358.06 Shear Force (ft-lb/s) 0.970.940.830.31.07 Water Surface Elevation (ft) 455.26455.01454.68455.42455.83456.18 Meets Criteria No Yes Cross Section 1894 Flow Velocity (ft/s) 7.616.276.194.427.186.83 Shear Force (ft-lb/s) 1.150.760.740.351.011.41 Water Surface Elevation (ft) 455.46455.39454.96455.46456.15456.82 Meets Criteria No Yes Cross Section 2086 Flow Velocity (ft/s) 9.447.477.66.328.387.42 Shear Force (ft-lb/s) 1.811.111.150.761.411.38 Water Surface Elevation (ft) 455.53455.45454.98455.35456.32457.06 Meets Criteria No Yes Cross Section 2214 Flow Velocity (ft/s) 8.567.848.128.018.277.88 Shear Force (ft-lb/s) 1.491.261.361.321.381.01 Water Surface Elevation (ft) 456.11455.61455.14455.32456.54457.15 Meets Criteria No Yes

15.  Final decision depends on the necessity for the walking trail, which is currently being blocked off. How should the study area by changed?

16. Questions?