Suisun Marsh Salinity Control Gate: Purpose, Operation, and Hydrodynamics/Salinity Transport Effect

Suisun Marsh Salinity Control Gate: Purpose, Operation, and Hydrodynamics/Salinity Transport Effect CWEMF February 28, 2008 Chris Enright DWR

Summary SMSCG purpose, components, operation Suisun Marsh/Bay hydrodynamics SMSCG effect on Marsh/Bay salinity & X2 Frequency of SMSCG operation

Suisun Marsh and Bay Suisun Marsh Salinity Control Gate (SMSCG) Wetlands and Water Resources- S. Siegel

SMSCG Purpose Guiding Conceptual Model: Reduced outflow increases salinity. Increased salinity reduces waterfowl food plant abundance and diversity. SMSCG Purpose: Reduce salinity in Suisun Marsh to help mitigate the impacts of the water projects Wetlands and Water Resources- S. Siegel

SMCSG: Tidal pump induces a net downstream flow (~2,800 cfs). Opens on ebb tide Closes on flood tide Wetlands and Water Resources- S. Siegel

SMSCG Components Downstream Roaring River Roaring River fish screen 3 Radial Gates (108 ) 36 Stop logs (120 ) Boat lock (20 )

Salinity Standard Compliance Locations Both regulatory and contractual

Looking Upstream (southeast) Gates Open Stop Logs Out

Looking ~Upstream (east) Gates Open Stop Logs Installed

Acoustic Velocity Meter Used to trigger gate closure at -0.1 fps velocity AVM Piles

SMSCG Boat Lock (looking downstream - flood tide)

SMSCG Boat Lock (looking upstream - flood tide)

Suisun Marsh Salinity Control Gate Configurations June September SMSCG Not Operating Lock Open October May (when needed to meet standards) SMSCG Operating

Downstream SMSCG Side View Gates Open In operation: Closes on flood tide when current > -0.1 fps Open on ebb tide when upstream water level is 0.3 ft > downstream water level

Downstream SMSCG Side View Ebb Gates Closing

Downstream SMSCG Side View Gates Closing

Downstream SMSCG Side View Slack Tide Gates Closing

Downstream SMSCG Side View 0.1 fps Slack Tide Gates Closing

Downstream SMSCG Side View Flood Gates Closed

Downstream SMSCG Side View End of Flood Gates Opening

Downstream SMSCG Side View Gates Opening

Downstream SMSCG Side View Gates Open

Downstream SMSCG Side View

Tidal Time Scale Flows 400,000 cfs 200,000 cfs

Tidal Time Scale Flows Suisun Slough +/-10,500 cfs Montezuma Slough +/-63,000 cfs Montezuma Slough +-5,500 cfs 400,000 cfs 200,000 cfs

Tidal Time Scale Flows Hill Slough +-1700 cfs Sheldrake Sl. +-400 cfs First Mallard Branch +-400 cfs Suisun Slough +/-10,500 cfs Montezuma Slough +/-63,000 cfs Nurse Slough +-12,000 cfs Montezuma Slough +-5,500 cfs 400,000 cfs 200,000 cfs

Tidal Time Scale Excursion 1 mile Release Drifter (slack after flood) End (slack after ebb) Ebb Tide Drifter Tracks (one ~6 hour ebb tide) 400,000 cfs 200,000 cfs

200 6 Ebb Tidal Time Scale Flows Tidal Flow Net Flow TCFS 100 3 0-100 -3-200 -6 Flood SMSCG operating 1998.72 1998.74 1998.76 1998.78 1998.80 Measured here (Oltmann 1998)

Sub-tidal Time Scale ( Net( Net ) ) Flows Typical Fall conditions (low outflow) ~2-8,000 cfs Delta Outflow Index

Sub-tidal Time Scale ( Net( Net ) ) Flows Typical Fall conditions (low outflow) Suisun Marsh sloughs have small net flow Suisun Slough ~ 0 cfs Montezuma Slough ~ 0 cfs Montezuma Slough ~ 0 cfs (SMSCG open) ~2-8,000 cfs Delta Outflow Index

Sub-tidal Time Scale ( Net( Net ) ) Flows Typical Fall conditions (low outflow) Suisun Marsh sloughs have small net flow SMSCG induces net downstream flow of ~ 2,800 cfs Suisun Slough ~ 0 cfs Montezuma Slough ~ 0 cfs Montezuma Slough +2,800 cfs (SMSCG operating) ~2-8,000 cfs Delta Outflow Index

Sub-tidal Time Scale ( Net( Net ) ) Flows Typical Fall conditions (low outflow) Suisun Marsh sloughs have small net flow SMSCG induces net downstream flow of ~ 2,800 cfs SMSCG affects Marsh and Bay salinity field Suisun Slough ~ 0 cfs Montezuma Slough ~ 0 cfs Montezuma Slough +2,800 cfs (SMSCG operating) ~2-8,000 cfs Delta Outflow Index

Salinity Response to SMSCG Operation 20 15 10 5 20 S64 15 SMSCG SC (mmhos/cm) SC (mmhos/cm) 10 5 20 15 10 5 20 15 10 5 20 15 10 5 Gates Open Gates Operating S49 Beldons Landing Gates Open S42 S21 S35 2002.72 2002.74 2002.76 2002.78 2002.80

19 17 A96 SMSCG effect on Montezuma Slough Average salinity gradient one day before SMSCG operation S54 S49 Beldons Landing N SC mmhos/cm 15 13 11 9 7 5 8000 7000 6000 5000 4000 3000 2000 1000 0 S54 Outflow Index Before Op After Op 1993 1994 1999 2000 2002 2003 2005 7-yr S49 Average salinity gradient 10 days after SMSCG Operation Salinity transect depicted in plot Suisun Marsh S71 SMSCG C2 0 5 10 15 20 25 30 35 Kilometers upstream from A96 (western Suisun Bay) A96 S64 S71 S64 C2

30 Martinez SMSCG effect on Suisun Bay N 25 Average salinity gradient one 10 days after SMSCG operation Suisun Marsh Suisun Marsh 20 SC mmhos/cm 15 10 5 8000 7000 6000 5000 4000 3000 2000 1000 0 Outflow Index Before Op After Op Port Chicago Martinez Chipps Is Average salinity gradient 1 day before SMSCG Operation Pt Chicago SMSCG Salinity transect depicted in plot Collinsville Chipps Is Collinsville Antioch 1993 1994 1999 2000 2002 2003 2005 7-yr 0 0 5 10 15 20 25 30 35 Kilometers upstream from Martinez Antioch Shift in X2

SMSCG Open SMSCG Operating (Spring) SMSCG Operating (Fall-Winter) Courtesy Wim Kimmerer

SMSCG Operation Frequency Versus Outflow Number of Gate Operation Days 120 100 80 60 40 20 1991 1993 1990 1992 2000 1989 2004 2001 1995 2005 1998 2008 1994 2003 2002 Drought Years Salmon Passage Study Years Post NOAA Fisheries Agreement 2006 1999 1997 0 2007 1996 0 5000 10000 15000 20000 25000 30000 35000 Average OCT-NOV-DEC Outflow

Number of Gate Operation Days 160 140 120 100 80 60 40 20 0 SMSCG Operation Frequency Versus Outflow 1990 1992 1991 2001 1994 1989 2007 2002 2000 Drought Years Post NOAA Fisheries Agreement 1993 2005 1995 2003 2004 1999 1996 1997 1998 2006 0 20000 40000 60000 80000 100000 120000 140000 Average Jan through May Outflow

Thank You Paul Massera Jim Sung Kate Le Brad Tom