Flood Control and Erosion Control in Contra Costa County Streams

1. Flood Control and Erosion Control in Contra Costa County Streams StormCon Workshop May 12, 2006 San Ramon, California Mitch Avalon Contra Costa County Flood Control District

2. I Live in a Watershed

3. Flood Control District Role/Responsibility/Opportunity • Manage 72 miles of stream channel • Manage regional detention basins • Watershed-wide planning • C-3/HMP regional facilities

4. Rodeo Ck Pacheco Ck Pinole Ck Garrity Ck East Antioch Ck Rheem Ck Galindo Ck` San Pablo Ck Grayson & Murderers Cks Wildcat Ck Sand Ck Marsh Ck Upper Pine Ck Deer Ck Dry Ck Kellogg Ck Las Trampas Ck Marsh Ck Reservoir San Ramon Ck Green Valley Ck San Ramon Ck Sycamore Ck Alamo Ck West The Flood Protection System

5. Contra Costa County Creek Conditions

6. Flood Control District Role/Responsibility/Opportunity • Manage 72 miles of stream channel • Manage regional detention basins • Watershed-wide planning • C-3/HMP regional facilities

7. Changing Strategies • Stormwater connectivity or stormwater retention • Armored channels or natural systems • Floodplain function • Land use changes and re-engineered creeks • Maintenance activities

8. 1800 Historical Coyote Creek Drainage Network

9. 2005 Modern Coyote Creek Drainage Network

10. 2005 Unconfined Groundwater Recharge Basin

11. Las Trampas Creek - 1966

13. Pinole Creek Flood Control Channel

14. Pinole Creek Greenway Project – Upper Reach

15. Pinole Creek Greenway Project – Lower Reach

16. Recent and Planned Restoration Projects • Pacheco Marsh Restoration • Marsh Creek Reservoir Expansion • Strentzel Creek Meadow Restoration • Knightsen Biofilter • Canada del Cierbo Restoration • San Ramon Creek Bioengineering Repair

17. Pacheco Marsh – 120 acre Tidal Wetland Restoration

18. Marsh Creek Reservoir

19. Marsh Creek Reservoir – 218 Acre Expansion

20. Strentzel Creek Meadow Grading Plan

21. Strenzel Creek Planting

22. Downtown Knightsen

23. Canada del Cierbo Mitigation

24. Canada del Cierbo Mitigation

25. Collaboration – Collaboration - Collaboration • Watershed Councils/Creek Groups • Cities/Municipal Advisory Councils • Neighborhood groups/property owners • Contra Costa Watershed Forum • Watershed Atlas

27. Stormwater Program Role • Coordinated development of HMP • Stormwater C-3 Guidebook • Case Studies/Research • Education/Adaptive Training • Stream and Wetlands System Protection Policy

28. Downtown Walnut Creek - 1958

29. A New Approach • Historic Design Concept - Protect structures and convey stormwater off as fast as possible • New Design Concept - Protect structures and retain stormwater as long as possible

30. Grayson Creek Channel - 1957

31. A New Approach • Historic Design Concept - Protect structures and convey stormwater off as fast as possible • New Design Concept - Protect structures and retain stormwater as long as possible

32. Hydrograph Modification Management • Increase retention time • Increase stream stability • Healthy sustainable watershed • Cumulative improvement

33. The Impact of Impervious Surfaces

34. Stream Stability Approach • Historical System • Present System • Compare Past and Present • Understand Changes • Recommendations and Restoration Templates

35. Sustainable Watershed Creek Stability/Function (Geomorphology) Community Water Quality/Quantity (Hydrology) Habitat (Ecology)

36. The Future • At the parcel level • LID • Homeowner education • Landscape contractors

37. The Future • At the Watershed level • 2nd generation facilities • System preservation/ replacement • Clean Water Regional Treatment • Regional retention facilities • The 50 year plan Marsh Creek Reservoir

38. Remember you live in a Watershed too……….. G:grpdata/admin/mitch/pp presentation/FC-Erosion Control