1. Implementation of Lower San Joaquin River Flow Objectives
Yongxuan Gao
Timothy Nelson
William Anderson
CWEMF Annual Meeting 2019
Folsom, California

2. Purpose of this Presentation
Describe quantitative methods for adaptive implementation of flow objectives in the Lower San Joaquin River (LSJR) watershed
Provide hypothetical examples to demonstrate adaptive implementation methods on the Stanislaus River, a tributary to the Lower San Joaquin River

3. Presentation Outline
Background of the Lower San Joaquin River (LSJR) flow objectives
Methods for Adaptive implementation
Hypothetical examples of adaptive implementation

4. Background
The State Water Board adopted the Amendments to the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan) on December 12, 2018
The flow amendments are not self-implementing and will require a future water right or water quality proceeding to assign responsibility for implementation
Stakeholders are currently discussing Voluntary Agreements that include flow and non-flow measures like habitat restoration as an alternative form of meeting the fish and wildlife objectives
This presentation does not presuppose how the objectives will ultimately be met but only illustrates how adaptive implementation can be modeled

5. Flow Objectives on the LSJR (Feb – Jun)
Narrative flow objective: maintain inflow conditions to support natural production of viable native San Joaquin River Watershed fish populations
Numeric flow objective: maintain 40% of unimpaired flow (UIF), with an allowed adaptive range between 30% - 50%, inclusive, from each of the Stanislaus, Tuolumne, and Merced Rivers from February through June

6. Adaptive Implementation
A feature of the LSJR program of implementation that allows for adjustment of the required percentage of unimpaired flow in specified ways to improve the functions of those flows and better achieve the water quality objective

7. Adaptive Implementation Methods
The required percentage of unimpaired flow for February through June
may be adjusted to any value between 30% and 50%, inclusive
may be managed as a total volume of water and released on an adaptive schedule during Feb through Jun: total volume of water must be at least equal to the volume of water that would be released
may be delayed until after June to prevent adverse effects to fisheries: only allowed when the unimpaired flow requirement is greater than 30%, and only a certain percentage of the flow can be shifted
Vernalis base flow for Feb through Jun may be adjusted to any value between 800 and 1,200 cfs, inclusive

8. Example 1- Variable Quantity Adjusted from 40% to a Different %
Adaptive Method a)

15. Example 2- Simple Flow Shaping
Adaptive Method b)

16. Water Year
2002
Year Type
Dry
TAF Shaped 25
Feb (% of UIF) 30 40
Mar (% of UIF)
Apr (% of UIF) 46
May (% of UIF)
Jun (% of UIF)

17. Water Year
2002
Year Type
Dry
TAF Shaped 25
Feb (% of UIF) 30 40
Mar (% of UIF)
Apr (% of UIF) 46
May (% of UIF)
Jun (% of UIF)

18. Example 3- Flow Shaping and Shifting
Adaptive Method c)

19. Floodplain Activation
Water Year
1999
Year Type AN
TAF Shaped 29
TAF Shifted 35
Feb (% of UIF) 30 40
Mar (% of UIF)
Apr (% of UIF) 45
May (% of UIF)
Jun (% of UIF) 25
Floodplain Activation

20. Water Year
1999
Year Type AN
TAF Shaped 29
TAF Shifted 35
Feb (% of UIF) 30 40
Mar (% of UIF)
Apr (% of UIF) 45
May (% of UIF)
Jun (% of UIF) 25

21. Thank you
Questions?