EKI TECHNICAL PRESENTATION #1COSUMNES SUBBASIN GSP DEVELOPMENT

17 OCTOBER 2018

COSUMNES SUBBASIN WORKING GROUP / TAC MEETING

TAC AGENDA ITEM #2

TSS GRANTS AND DATA SURVEY

TSS GRANT

TSS Fact Sheet

SGMA Monitoring well Fact Sheet

GSA commitment to pursue monitoring well project

Responses to date:

OHWD

DATA REQUEST FORMS

Basin Stakeholders

Introductory letter

Stakeholder Survey

Data Request Form

Basin Public Water Suppliers

Introductory letter

GSA Input

Confidentiality clause

GSA contact info

BASIN STAKEHOLDER DATA REQUESTS (PART 1: STAKEHOLDER SURVEY)

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Requests general information from Basin landowners and

stakeholders

➢ Contact info and general location

➢ Stakeholder characteristics (Agricultural, domestic, municipal, tribal,

environmental, etc.)

➢ Familiarity with SGMA and groundwater management issues

➢ Opinions on land and water resources management

➢ Presence of wells on property and willingness to share data

➢ Recommendations to GSA

To be distributed via GSA website, Board meetings, workshops

Alternate distribution could include water bill inserts, local

community organizations

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Requests specific quantitative data from Basin

landowners / stakeholders

➢ Well construction details

➢ Pumping rates and cropping (as applicable)

➢ Water levels and water quality sampling (as available)

Available at: http://cosumnes.waterforum.org

Allows understanding of the historical and current

status of groundwater in the Basin

Actual data from the Basin are required, otherwise

it’s just a guess!

BASIN STAKEHOLDER DATA REQUESTS (PART 2: DATA REQUEST FORMS)

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Requests specific quantitative data from well

operators or potable water suppliers within the

Basin

➢ Exact well locations

➢ Well construction details

➢ Well construction logs, geologic logs or geophysical

logs

➢ Pumping rates and cropping (as applicable)

➢ Water levels and water quality sampling (as available)

➢ Aquifer pumping test data and analyses/reports

Requests will be sent from appropriate GSAs

BASIN PUBLIC WATER

SUPPLIERS DATA REQUESTS

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Customized data requests will be sent to each GSA after the initial data

compilation

Since each GSA is an unique entity the data request will be focused on

their specific areas, water supply, management plans, studies, land use,

etc.

GSA DATA REQUESTS

TAC AGENDA ITEM #3

GSP DEVELOPMENT SCHEDULE REVIEW

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GSP DEVELOPMENT SCHEDULE

Phase 1

GSP Foundation

Phase 1• Data Management System (DMS)

• Gather and Compile Data

• Evaluate Numerical Groundwater Model Options

• Stakeholder Communication and Engagement Plan (SCEP)

Today

2019

Phase 2

Basin Characterization

and Analysis

Phase 3

Sustainability

Planning

Phase 4

GSP Preparation

& Submittal

2020 2021 20222018

PM Phase Project Management

Oct 2018 Apr 2019 Apr 2020 Apr 2021 Jan 2022

PHASE PM – PROJECT MANAGEMENT & ADMINISTRATION

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(October 2018 – February 2022)

Task 1: Proposition 1 Grant

Management, Administration, and

Reporting

Task 2: Project Management

Task 3: Quality Assurance/Quality

Control

EKI - Provide a supporting role to

Sacramento County to satisfy Prop 1

grant administration and reporting

requirements

GSAs - provide any required,

GSA-specific materials to the

County for Prop 1 reporting

purposes

EKI - Conduct project management

efforts: Project budgets, project

schedules, records management,

contract compliance

EKI – prepare a QA/QC Plan

PHASE 1 – GSP FOUNDATION

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(October 2018 – April 2019)

Task 6: Compile Information on

the Plan Area and Basin

Management Activities

Task 4: Select or Design Data

Management System (DMS)

Task 5: Gather Available Data and

Compile into DMS

EKI - Develop options for DMS selection

and/or development and prepare

associated work products (TM #1- Data

Management System Evaluation and

Selection)

Working Group – Review and

provide feedback on TM #1;

Select a DMS

EKI - Provide technical support

required to populate and manage the

Basin DMS

GSAs – Compile and provide local

and Basin-specific data to be included

in the Basin DMS

EKI - Provide technical support

required to compile information on the

Plan Area and Basin Management

Activities

GSAs - Respond to data requests

regarding information required in the

Plan Area

PHASE 1 – GSP FOUNDATION

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Task 9: Refine Stakeholder Communication and Engagement

Plan

Task 7: Conduct Data Gaps Assessment

Task 8: Evaluate Numerical Groundwater Model Options

EKI - Conduct Basin-wide data gaps

assessment and prepare associated

work products (Draft TM #2 – Data

Compilation and Data Gaps Assessment)

GSAs – Identify local data gaps and collect appropriate information for Technical Support Services Grant application

Working Group – Review and provide feedback on TM #2

EKI - Conduct the evaluation of

numerical groundwater model options

and prepare associated work products

(Draft TM #3 – Numerical Groundwater

Model Evaluations and

Recommendations)

Working Group – Review and provide

feedback on TM #3; Select modeling

approach

EKI - Provide limited technical support

to review and provide feedback on the

SCEP and other associated work

products developed by the Water Forum

and Consensus Building Institute (CBI).

Working Group - Review and provide

input to Basin-wide SCEP to align with

local outreach goals and objectives

(October 2018 – April 2019)

PHASE 1 – GSP FOUNDATION

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Task 10: Conduct Stakeholder Engagement Related to the GSP

Foundation Phase

Task 11: Participate in Intrabasin& Interbasin Coordination Efforts

EKI – Provide limited support to the Water

Forum and CBI to conduct preliminary

stakeholder engagement-related activities,

including: Preparation of one stakeholder

workshop presentation, attendance at one

stakeholder workshop

Working Group/GSAs – Begin to

implement the SCEP within local

jurisdictions (meetings, stakeholder

survey, public notices, etc.)

EKI – Provide technical support for Phase 1

intrabasin and interbasin coordination efforts

through attendance at regular Working

Group/TAC meetings and preparation of

associated materials, attendance at regular

SGMA meetings in neighboring subbasins (up

to one per month), and through as needed as

GSA-specific outreach

Working Group - Attend regularly

scheduled Working Group/TAC

meetings to provide input on

matters associated with GSP

development

(October 2018 – April 2019)

REMAINING PHASES

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Phase 2: Basin Characterization

and Analysis

• Focuses on technical analysis of Basin conditions.

• Hydrogeologic conceptual model

• Groundwater conditions

• Water Budget

Phase 3: Sustainability

Planning

• Focuses on planning for the sustainable management of the basin

• Sustainability Criteria

• Monitoring

• Projects & Management Actions

Phase 4: GSP Preparation and

Submittal

• Preparation of the GSP and associated deliverables for use by Basin GSAs in adopting the GSP, with subsequent submittal to DWR

(April 2019 – April 2020) (April 2020 – April 2021) (April 2021 – February 2022)

TAC AGENDA ITEM #4

GROUNDWATER MODELING

OBJECTIFIES FOR MODEL SELECTION

Support GSP development

Support adaptive management through GSP implementation

Coordinate with other regional planning efforts, current and future

GSP development on ESJ Subbasin

GSP development in other Sac County basins

Regional planning efforts by SAFCA and others

MODEL CONSIDERATIONS - COSUMNES GSP

1. Support water budget calculations (past, current, and future).

i. Proportional contribution of Cosumnes River recharge to South American and Cosumnes

subbasins

ii. Proportional contribution of Dry Creek and Mokelumne River recharge to Cosumnes and

ESJ subbasins

iii. Subsurface flows across subbasin boundaries

2. Project future hydrologic conditions:

i. Groundwater levels

ii. Streamflow depletions

iii. Land subsidence potential

MODEL CONSIDERATIONS - COSUMNES GSP

3. Calculate the groundwater storage response to potential management actions,

projects, and climate change

4. Assist with development of Sustainable Management Criteria

5. Prioritize data gaps and refine monitoring network over time

PRACTICAL CHARACTERISTICS FOR NUMERICAL MODEL

1. Model mesh and simulation period (appropriate spatial and temporal

resolution)

2. Reliable and physically based boundaries

3. Physical processes accurately represented

4. Ease of use: modifications, refinement, and transparency of input and

output dynamics

5. Cost (as-is, adaptation, new)

6. Effectiveness for its purpose: water budget calculations and sustainability

planning

AVAILABLE MODELING OPTIONS

Model

Existing“AS-IS”

Updated( )

New

ESJ

SacIWRM

SVSim

C2Vsim-FG

CVHM

AVAILABLE EXISTING MODELS

SacIWRMC2VSim-FGSVSim

CVHM

QUESTIONS FROM SEPTEMBER 19, 2018 MEETINGWhat is the best quality of representation for the Cosumnes Subbasin?

1. It would be useful to have a better understanding of the role of mesh in the model.

2. How do the outputs from [either of these two] models:

• help understand movement of water between basins?

• interface with other basins’ models?

3. How do you add new conductivity data to the model?

4. Is there an unsaturated zone layer?

5. How do these models fit with the Cosumnes’ deadlines?

6. What is the cost difference between these? What is the opportunity cost (i.e. how would remaining funds be allocated)?

7. What difference is there among models with regard to autonomy and their independent use?

1. MESH CALCULATES APPROXIMATE SOLUTION TO

GROUNDWATER-FLOW EQUATIONS.

Rectangles approximating a curve:

Narrower

rectangles

More accurate

approximation

1. FINER MESH (SMALLER CELLS) REDUCES ERROR

Cells approximating an area:

Smaller cell

area

More accurate

approximation

COSUMNES SUBBASIN REPRESENTED IN C2VSIM-FG MESH

COSUMNES SUBBASIN REPRESENTED IN CVHM GRID

GUIDELINES FOR SELECTING MESH/GRID DESIGN

Expected shape of the water table/potentiometric surface (e.g., mounding or

drawdown).

Variability in water transmitting and storage properties.

Variability in recharge, pumping, and surface-water groundwater interactions.

Size of the model area.

- Minimize nodes for computer storage and model operation time.

- Compromise between accuracy and practicality.

- Represent system accurately.

- Need to select/utilize meaningful boundaries.

2. MODEL INTERFACE WITH GROUNDWATER LEVELS,

FLOWS, OR BOTH.

“BASIN”

“GSA”

INTERFACING WITH NESTED MODELS.

IWMF

• Element nodes

• Parametric grid

MODFLOW

• Cell by cell

3. HOW DO YOU ADD WATER STORAGE AND

TRANSMITTING PROPERTIES?

IWFM

C2VSim-FG = YES

SVSim = YES

SacIWRM (UPDATED) = ?

MODFLOW

CVHM = NO

4. IS THERE AN UNSATURATED LAYER?

Note: simplified, one-dimensional

vertical flow only.

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5. MODELING TIME LINE AND COSUMNES DEADLINES

Phase 1

GSP Foundation

2019

Phase 2

Basin Characterization

and Analysis

Phase 3

Sustainability Planning

Phase 4

GSP Preparation

& Submittal

2020 2021 20222018

PM Phase Project Management

Oct 2018 Apr 2019 Apr 2020 Apr 2021 Jan 2022

Task 8 Task 14 & 15 Phase 3 Phase 4

Evaluate Numerical

Groundwater Model

Options

•Develop/Repurpose Numerical Groundwater Model

•Develop Basin-Wide Water Budget

Use Model Results to

Develop Sustainable

Management Criteria

Finalize Model Results

Visualizations to be

included in the

Complete Draft GSP

SVSim

CVHM

Cosumnes

SacIWRM (updated)C2VSim-FG

Reported Release Dates

6. ESTIMATED MODEL DEVELOPMENT COSTS IN

PREPARATION TO SUPPORT GSP

Characterize uncertainty of existing model and use a-is (~ $50,000-$100,000)

Update/Refurbish existing model (~ $100,000-$200,000)

Construct new “stand alone” or “nested” model (~ $250,000)

Prop 1 Budget: $247,000

7. OPTIONS, AUTONOMY AND INDEPENDENT USE

Supporting

AgencyDWR USGS Work Group

Source Code

(Engine) IWFM MODFLOWIWFM/MODFLO

W

Application SVSimSacIWRM

(updated)C2VSim-FG CVHM Cosumnes Basin

Average Element

Area in Cosumnes

Basin (acre)205** 106 393 640 ?

Layers 9 3 4 10 ?

Autonomy (1-3)* 2 1 2 2 3

* 1= Multiple Entities; 2 = State/Federal only; 3 = Local only

** Entire model area

NEXT STEPS

Complete model evaluations (February 2019)

- Detailed review of CVHM (current version)

- Detailed review of CV2Sim-FG (when released)

- Others if/when available

Prepare model to support GSP (April 2019)

Employ model to develop GSP (April 2020)

WG AGENDA ITEM #2

UPDATE FOR ESJ SUBBASIN

ESJ GWA 10/11 MEETING SUMMARY

Each GSA was requested to provide a preliminary list of potential projects and/or

management actions to include in the GSP

Requested project details: Project Name, Submitting GSA, Other Participating Agencies, Basic Project

Description, Project Size (i.e. volume of added supply or demand reduction), Project Costs (capital,

O&M), Planning Horizon (timeline)

22 potential projects were submitted by GSAs as of October 10

Direct/In-Lieu Recharge (5),

Surface Water Supply Augmentation (6),

Recycling/Transfers (5),

Conservation (4),

Stormwater (2)

ESJ GWA 10/11 MEETING SUMMARY

The TAC identified and ranked assessment criteria for which to evaluate potential projects for inclusion into the GSP, in the following order:

1. “Implementability” (i.e., feasibility & time constraints)

2. Unit Cost (i.e., cost per unit supply augmentation or demand reduction)

3. Environmental Benefits/Impacts

4. Location (i.e., relative to known and/or anticipated impacts)

5. DAC Presence & Benefits

6. Water Quality Benefits/Impacts

List of potential projects will be further evaluated and narrowed down based on evaluation criteria at next month’s meeting

Final project list should, at a minimum, cover the long-term groundwater deficit calculated from the projected water budget (~30,000 AFY)