Ecological Importance ofFall and Summer Flows in the

Yolo Bypass

Jared Frantzich, Ted Sommer, and Brian SchreierDepartment of Water Resources

Division of Environmental Services

WinterSpring

Summer Fall

Typical Net Flow

Known Region with Enriched Plankton

Willow Slough Bypass

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

.

Toe Drain +Floodplain

Toe Drain

Fall 2012 Unprecedented Delta Phytoplankton Bloom

No comparable Delta bloom for over 20 years!

Willow Slough Bypass

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

.

0

5

10

15

20

-200

0

200

400

600

800

1000

1-Jul 1-Aug 1-Sep 1-Oct 1-Nov

Chlorophyll (µg/L)

Net

Flo

w (c

fs)

Lisbon Flow (cfs)

Rio Vista SondeChlorophyll

10 µg/L

So what have we been up to since 2012?2013 – 2016 Summer/Fall Flow Special Studies

WQ MonitoringNutrients Phyto/ZoopWillow Slough Bypass

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

.

Key Findings from Fall Flow Special Studies

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

.

WWTP

DWTP

1.) Nutrient Transport

2.) Phytoplankton Transport

3.) Improved Zooplankton Abundance

Positive Downstream Food Web Benefits

Cladocerans Calanoid copepods

69% Diatoms 15% Greens

N + P

Willow Slough Bypass

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

.

Key Findings from Fall Flow Special Studies4.) Discharge Volume + Velocity both important for downstream response

0

200

400

600

800

0

5,000

10,000

15,000

20,000

25,000

30,000

2011 2012 2013 2014 2016

cfs

ac-ft

Total Discharge Volume (ac-ft)Max Daily Ave. Net Flow

Toe Drain @ Lisbon Weir

2016 Summer Managed Flow Pulse

Hungry Smelt

Yolo Bypass

Knights Landing Ridge Cut

Reoperation of KLOG

Wallace Weir Coordination

Knaggs Ranch

Increased Keswick Flows

Delivery of Sac River Flow

Additional Pumping

Additional Pumping

2016 Evidence of Downstream Response

-10

0

10

20

30

40

50

60

-200

-100

0

100

200

300

400

500

600

7/1 7/11 7/21 7/31 8/10 8/20 8/30

Chlorophyll (μg/L)Fl

ow (c

fs)

Lisbon FlowRio Vista - Chl Sonde Data

Aulacoseira sp.

0

2000

4000

6000

8000

10000

12000

Diatom - Cymatopleura sp.Diatom - Cyclotella sp.Diatom - Aulacoseira sp.Other GreensOther DiatomsFlagellatesCyanosCryptophytes

During After BloomBefore

Aulacoseira sp. Cyclotella sp.

Summer Flows Transport PhytoplanktonBi

ovol

ume

(µm

³/mL) 44% of BV 20% of BV

Toe

Drai

n

Pros

pect

Low

er C

ache

Rio

Vist

a

Toe

Drai

n

Pros

pect

Low

er C

ache

Rio

Vist

a

Toe

Drai

n

Pros

pect

Low

er C

ache

Rio

Vist

a

Rio

Vist

a

Early July Late July Mid Aug Aug. 22

During – Late July After – Early SeptZooplankton Community Shift to Calanoids

Calanoid copepodids

Bosmina

Cyclopoid copepodids

P. Forbesi adults

4 Most Dominant Zoop Taxa

Summer and Fall Flow Dynamics*DWR DSM2 Flow Model Support

% o

f Par

ticles

(-) Negative % = Landward Flux(+) Positive % = Downstream Flux

Cache Slough Complex

Rio Vista

Summer and Fall Flow Dynamics*DWR DSM2 Flow Model Support

Cache Slough Complex

Rio Vista

% o

f Par

ticles

(-) Negative % = Landward Flux

(+) Positive % = Downstream Flux

Year Lisbon Max Daily Ave Net Flow (cfs)

Lisbon Total Average Net Volume

(ac-ft)2011 412 22,3562012 723 27,2242013 283 11,4372014 239 2,5032015 383 17,9092016 546 12,752

Willow Slough Bypass

Putah Creek

Sacramento

Rio Vista

50 15105Kilometers

Hwy I-80

Bypass

Feather R

. Flow Discharge Volume + Velocity both important for downstream response

*Summer Flow Pulse

Summer and Fall Flow Dynamics

Summer and Fall Flow Dynamics

2012 Fall Particle Release Fate

PTM Study Area Colored by Regions

Wee

k

8/31 9/7 9/14 9/21

*CBEC MIKE21 Historical Flow Modeling

Upper Cache Slough

Cache Slough

Sac River

Little Holland

Toe Drain &Prospect Sl.

LindseySlough

LibertyIsland

Whipple et al. 2012Rio Vista

Yolo Bypass & Cache Slough Complex

Sac River

Flow Pathways Are Important Too

Historical Delta

Future Plans

Increased Project Funds for FY 2017 and 2018

Planning Efforts for 2017 Summer/Fall Flow Pulse

• SFSU Kimmerer Lab: Zooplankton Growth and Reproduction

• SFSU Dugdale/Wilkerson Lab: Measure Primary Productivity and Nutrient Uptake Rates

• Biological Modeling and Contaminants Analysis - USGS

AcknowledgementsKris Tjernell, Project Coordinator

Carl Wilcox & Yolo Wildlife Area Staff

Cindy Messer, Ted Sommer, James Newcomb, & Manny Bahia

Division of Flood Management, Division of Environmental ServicesStaff, & North Central Region Staff

John Brennan, Mike Hall, Darren Cordova, Mike Lear, GlenColusa District Staff, & Reclamation District 108