1. El Charro Specific Plan Hydrology & Hydraulics Daniel J. Schaaf, PE Mary Eliza McNulty, PE

2. Hydrology –Existing and Future Flows –Project Impacts –Interesting Observations Hydraulics –Proposed Features –Floodplain Changes –Sediment and Scour

6. Diverse Channel 12,000 cfs1,500 cfs

7. 100yr Zone 7 Hydrology Q 100ex = 22,074cfs Q 100ult = 24,895cfs At Bernal

8. Impacts to 100yr Hydrology At Bernal Q 100ex = 22,074cfs Q north fill = 22,153cfs Q design = 21,983cfs

9. HMP Impacts 100yr At El Charro Rd

10. HMP Impacts 2yr At Bernal

11. Channel Characteristics Crosswinds

12. Channel Characteristics Proposed Bridge Site

13. Channel Characteristics Golf Course

14. Channel Characteristics Airway Blvd

15. Impacts of Sediment Removal to 100-Year Peak Flow Removing Sediment can decrease downstream peaks HMP can increase downstream peak TIMING!

16. Bridge Scour HEC-18 Offers Limited Equations Contraction, Abutment, Pier, etc. Does not account for flow Re-Entering the Channel Which Ultimate Condition do you Plan for?

17. Scour Protection Alternatives –Locate Bridge in ‘stable’ site –Commit to Establishing Post Project Vegetation –Increase Scour Protection (cost implications) –Avoid Piers –Adopt an Adaptive Approach

18. Questions?