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

I Live in a Watershed

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

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

Contra Costa County Creek Conditions

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

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

1800 Historical Coyote Creek Drainage Network

2005 Modern Coyote Creek Drainage Network

Unconfined Groundwater Recharge Basin 2005

Las Trampas Creek

Pinole Creek Flood Control Channel

Pinole Creek Greenway Project – Upper Reach

Pinole Creek Greenway Project – Lower Reach

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

Pacheco Marsh – 120 acre Tidal Wetland Restoration

Marsh Creek Reservoir

Marsh Creek Reservoir – 218 Acre Expansion

Strentzel Creek Meadow Grading Plan

Strenzel Creek Planting

Downtown Knightsen

Canada del Cierbo Mitigation

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

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

Downtown Walnut Creek

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

Grayson Creek Channel

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

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

The Impact of Impervious Surfaces

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

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

The Future At the parcel level  LID  Homeowner education  Landscape contractors

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

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