1. Planning & Environmental Compliance HYDRAULIC MODELING UPDATE
Yolo Bypass Salmonid Habitat Restoration & Fish Passage
Planning & Environmental Compliance
HYDRAULIC MODELING UPDATE
November 19, 2013
Sacramento, CA

2. Hydraulic Modeling Goals
Identify Inundation Footprint
Inundation Frequency
Last Day of Inundation
Flow Characteristics
Depth
Velocities
WSEL
Analyze a Large Period of Time for Several Alternatives

3. Past Yolo Bypass Habitat Modeling
1-D Steady-State of Habitat Flows at Fremont Weir
2-D Steady-State of Habitat Flows at Fremont Weir
2-D Steady-State of Habitat Flows at Fremont Weir & Yolo Bypass Tributary Flows

4. Past Yolo Bypass Habitat Modeling
1-D Steady-State of Habitat Flows at Fremont Weir
Habitat flows introduced at a node; no connection w/ Sacramento River
No other flows were incorporated into the model
A single flow rate was modeled
Flow was calculated in one direction only; not good for out of bank flows
Fremont Weir
KLRC
(not included)
Flow Introduced at Node

5. Past Yolo Bypass Habitat Modeling
1-D Steady-State of Habitat Flows at Fremont Weir
Habitat flows introduced at a node; no connection w/ Sacramento River
No other flows were incorporated into the model
A single flow rate was modeled
Flow was calculated in one direction only; not good for out of bank flows
Time
Flow
Steady State Flow

6. Past Yolo Bypass Habitat Modeling
Fremont Weir
Flow Introduced at Node
Flow Calculated in 1 Direction only
Example Cross Sections
KLRC
(not included)
1-D Steady-State of Habitat Flows at Fremont Weir
Habitat flows introduced at a node; no connection w/ Sacramento River
No other flows were incorporated into the model
A single flow rate was modeled
Flow was calculated in one direction only; not good for out of bank flows

7. Past Yolo Bypass Habitat Modeling
Fremont Weir
Flow Introduced at Node
Flow Calculated in 2 Directions
KLRC
(not included)
2-D Steady-State of Habitat Flows at Fremont Weir
Habitat flows introduced at a node; no connection w/ Sacramento River
No other flows were incorporated into the model
A single flow rate was modeled
Flow was calculated in two directions

8. Past Yolo Bypass Habitat Modeling
Fremont Weir
Knights Landing Ridge Cut
Cache Creek
Willow Slough
Flow Introduced at Node
KLRC Flow Node
Putah Creek Flow Node
Putah Creek
Flow Calculated in 2 Directions
2-D Steady-State of Habitat Flows at Fremont Weir & Yolo Bypass Tributary Flows
Habitat flows introduced at a node; no connection w/ Sacramento River
Flow was calculated in two directions
KLRC, Cache Creek, Willow Slough, & Putah Creek flow included
Single flow rates were modeled

9. Past Yolo Bypass Habitat Modeling
2-D Steady-State of Habitat Flows at Fremont Weir & Yolo Bypass Tributary Flows
Habitat flows introduced at a node; no connection w/ Sacramento River
Flow was calculated in two directions
KLRC, Cache Creek, Willow Slough, & Putah Creek flow included
Single flow rates were modeled
Time
Flow
Steady State Flow
Habitat Flow
Cache Crk.
KLRC
Putah Crk.
Willow Slough
Average Flows Expected When Habitat Flows were Available Between Dec. 1st & Mar 31st, from

10. Yolo County/NHC Review (2012) of The Last Yolo Bypass Habitat Modeling
Model availability
Topography and bathymetry
Boundary conditions
Computation assumptions
Calibration and validation

11. Yolo County/NHC Review
Model Selection / Availability
Consider use of public domain models
A survey conducted at a HMAT meeting on 2/4/13 showed that modelers were less interested in public domain models
TUFLOW Classic Model Selection
Vetted through HMAT
Growing use within DWR
GIS integration
Numerical stability
Robust wetting and drying
1D/2D linking

12. Yolo County/NHC Review
Topography and Bathymetry
Inaccurate data (e.g., obscured LiDAR) should be corrected
New modeling effort is using CVFED LiDAR data or LiDAR data that was QA/Q’d through their exhaustive review process

13. Yolo County/NHC Review
Topography and Bathymetry
Additional data should be collected (e.g., missing creek detail and drain culverts)
New Data
Sacramento Valley CVFED LiDAR
Steamboat Slough
Lower Putah Creek
Sacramento Slough
Knights Landing Ridge Cut
Miner Slough
Willow Slough
CVFED Creek & Rivers single beam
Tule Pond/Canal & Ag crossings
Yolo Bypass Features
Sac. River
Major ag roads, berms, ag structures, & irrigation ditches
Deep Water Ship Channel
not included: Field rice checks & culverts
Prospect Island
Cache Slough
Sutter Slough

14. Yolo County/NHC Review
Topography and Bathymetry
Inaccurate data (e.g., obscured LiDAR) should be corrected
Quality Control
Data sources
Vendor QC
Meets published accuracy standards
Internal QC before and after integration
Obscured data errors
Ponding, aquatic vegetation, dense riparian
Techniques to reduce errors
Manipulate or screen data
Selective 1D/2D linking
Sensitivity Analysis

15. Yolo County/NHC Review
Boundary Conditions
The reliability of inflows should be verified (e.g., Westside tributaries)
Hydraulic structures should be added (e.g., Los Rios Check Dam)
Hydraulic roughness should be verified
Waterfowl assumptions should be included (i.e., managed ponding)

16. Model Domain and Boundary Conditions
NEW
OLD

17. Model Boundary Conditions
OLD
NEW
Time
Flow
Steady State Flow
Steady State Flow
Daily Flows Modeled, So Flow Varies With Time. Water Years 1997 – 2012 Will Be Modeled.
Flow
Habitat Flow
Cache Crk.
KLRC
Putah Crk.
Willow Slough
Time
Average Flows Expected When Habitat Flows were Available Between Dec. 1st & Mar 31st, from

18. Westside Tributaries Boundary Conditions Source Data type
Ridge Cut Slough inflow
DWR’s Water Data Library (A02930) and this study1
Gauged flow and estimated flow
Cache Creek Settling Basin inflow
This study
Estimated flow from gauge data
Willow Slough Bypass inflow
Yolo Bypass Management Strategy
Estimated flow
Putah Creek inflow

19. Knights Landing Ridge Cut

20. Cache Creek

21. Hydraulic Structures Affecting Shallow Flooding
Wallace Weir
Three agricultural crossing on Tule Canal
Swanston Ranch check dam
Willow Slough access and check dam
Los Rios Check Dam
Lisbon Weir

22. Hydraulic Structures Affecting Large Floods
Fremont Weir
Sacramento Northern railroad
Interstate 5 causeway
Sacramento Weir gate operations
Southern Pacific railroad
Interstate 80 causeway and embankments
Delta Cross Channel operations
Multiple bridges on the Sacramento and American
Various restricted height levees

23. Hydraulic Roughness CV Riparian Mapping Project

24. Yolo County/NHC Review
Computational Assumptions
Model cell size should be refined
TUFLOW
End user can easily change
Balance resolution, accuracy, and runtimes
Currently using 100 to 200 ft cells
Field scale features
GIS integration
3D breaklines (e.g., berms and ditches)
Sensitivity testing

25. Yolo County/NHC Review
Computational Assumptions
Wetting and drying should be validated
TUFLOW Wetting & Drying
Very robust
Start fully dry
Isolated pools
Does not lead to instabilities
Default thresholds
0.007 ft cell ctrs
0.003 ft cell sides

26. Yolo County/NHC Review
Calibration and Validation
Detailed model calibration and validation should be performed
Calibration and Validations
1997 Flood (V)
Yolo Bypass
Corps / gauge flows
HWMs
2006 Flood (C)
Sacramento River
Sutter Bypass
Gauge flows
2010 Low Flow (C)
Tule Canal and Toe Drain capacity
ADCP and HWMs
2011 Recession (C)
Yolo Bypass
Air photo sequence
Gauge flows
Limited HWMs

27. Questions?

28. Time Period Selection

29. Linking 1D and 2D Domains
From TUFLOW Manual

30. Test Model Test Model Created to… Rough Model Determine Feasibility
Estimate Grid Resolution
Rough Idea on Runtimes
Rough Model
Older Lidar
Some modifications made to ensure flowpaths in canals and under bridges

31. Resolution Comparison

32. Courant Criteria Timestep is Courant Limited Almost always < 10
Often around 5 or less
Cutting cell size in half increases runtimes 8 times!
𝐶 𝑟 = ∆𝑡 2𝑔𝐻 ∆𝑥 Where: ∆𝑡=𝑡𝑖𝑚𝑒𝑠𝑡𝑒𝑝, 𝑠 ∆𝑥=𝑐𝑒𝑙𝑙 𝑠𝑖𝑧𝑒, 𝑓𝑡 𝑔=𝑎𝑐𝑐𝑒𝑙𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑑𝑢𝑒 𝑡𝑜 𝑔𝑟𝑎𝑣𝑖𝑡𝑦, 𝑓𝑡 𝑠 2 𝐻=𝑑𝑒𝑝𝑡ℎ 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟, 𝑓𝑡
Cell size
Depth
Timestep
Courant
200 10 60
5.4
100 30 50 12
4.8

33. Estimated CPU time - 6 month Simulation
Test Model Runtimes
Grid Resolution
Estimated CPU time - 6 month Simulation
hours
400 ft
0.73
200 ft
5.8
150 ft
17.1
100 ft
62.6
50 ft
524.2 (22 days)
Model Runtimes will vary from above:
Domain will be different
Runtimes will vary depending upon number of wet cells
Easy to switch cell resolution: Initial runs coarse resolution. Final runs fine resolution.
Many simulations will be run at the same time (32+)

34. Ponded Water Model will not drain entirely
Small drainage paths may not be well represented
Puddles really exist (would evaporate/infiltrate)
Puddles in long-term simulations
Make it difficult to determine end of inundation period
Provide decreased storage during next inundation period
Look unrealistic
Increase runtimes (wet cells)
Infiltration options under review