Flood Control and Erosion Control in Contra Costa

Flood Control and Erosion Control in Contra Costa County Streams Storm. Con 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 n Manage regional detention basins n Watershed-wide planning n C-3/HMP regional facilities n

The Flood Protection System An tio Sa n ine r. P pe d e k y. C Dr llo Ke on Marsh Ck Reservoir Ck k y. C lle en Va e Gr Sycamore Ck es t on W m Ck Ck Ra o n am Sa Al pas Ck am n. R Sa Las Tram gg Ck Ck De Ck k r. C Ck k Ck Ga lind Ck o ` ar sh o. C k cat C Wild ch Up Grayson & Murderers Cks Pab l Ck San Ck st M Ck Pa ch Ck eco o de Ro Ea le no Pi eem ity rr Ga Ck Rh

Contra Costa County Creek Conditions

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

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

1800 Historical Coyote Creek Drainage Network

2005 Modern Coyote Creek Drainage Network

2005 Unconfined Groundwater Recharge Basin

Las Trampas Creek - 1966

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 n Marsh Creek Reservoir Expansion n Strentzel Creek Meadow Restoration n Knightsen Biofilter n Canada del Cierbo Restoration n San Ramon Creek Bioengineering Repair n

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

Canada del Cierbo Mitigation

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

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

Downtown Walnut Creek - 1958

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

Grayson Creek Channel - 1957

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

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

The Impact of Impervious Surfaces

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

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

The Future n At the parcel level ¨ LID ¨ Homeowner education ¨ Landscape contractors

The Future n 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

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