.
Board Meeting
AUGUST 13, 2020
SANTAROSAPLAINGROUNDWATER.ORG 1
Virtual Meeting
Protocol
1. Please note that the meeting
is being recorded
2. Mute your phone
3. For each agenda item, after
the staff report the Chair will
ask for comments from the
Board and then the public
4. If you have a question before
the staff report is complete,
please use the “chat” or
“raise your hand”
Roll Call
SANTAROSAPLAINGROUNDWATER.ORG 2
Member Agency Directors Alternates
City of Cotati Susan Harvey Mark Landman
City of Rohnert Park Pam Stafford Susan Adams
City of Santa Rosa Tom Schwedhelm Vice-Chair Dick Dowd
City of Sebastopol Michael Carnacchi Neysa Hinton
County of Sonoma Shirlee Zane Susan Gorin
Gold Ridge Resource Conservation District Joe Dutton Mel Sanchietti
Independent Water Systems Evan Jacobs Michael Spielman
Sonoma County Water Agency Lynda Hopkins Chair Susan Gorin
Sonoma Resource Conservation District John Nagle Walt Ryan
Town of Windsor Debora Fudge Dominic Foppoli
8/13/2020
Agenda
1. Call to Order and Roll Call
2. Public comment on matters not listed on the agenda but
within the subject matter jurisdiction of the board
3. Consent Calendar
a. Approve Minutes of June 11, 2020 Board Meeting
b. Approve Year-to-Date Financial Report
4. Directors/Subcommittee Report
5. Advisory Committee Report
6. Information Items
a. Groundwater Sustainability Plan and Sustainable
Management Criteria updates
b. Groundwater User Registration Program
SANTAROSAPLAINGROUNDWATER.ORG 38/13/2020
Agenda (continued)
7. Action Items
a. Fiscal Year 2020-2021 Budget Adjustments
b. Rural Community Engagement Outreach Contract:
Authorize the Administrator to negotiate a contract
with SCI Consulting to provide outreach services
8. Administrator, Plan Manager and Legal Counsel Report
9. Adjournment
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Public comment on
matters not listed
on the agenda but
within the subject
matter jurisdiction
of the board
SANTAROSAPLAINGROUNDWATER.ORG 58/13/2020
Consent
Calendar
a. Approve Minutes of June 11,2020 Board Meeting
b. Approve Year-to-Date Financial Report
SANTAROSAPLAINGROUNDWATER.ORG 68/13/2020
Directors/
Subcommittee
Report
SANTAROSAPLAINGROUNDWATER.ORG 78/13/2020
Advisory
Committee
Report
SANTAROSAPLAINGROUNDWATER.ORG 88/13/2020
Information
Items
a. Groundwater Sustainability Plan and
Sustainable Management Criteria update
b. Groundwater User Registration Program
9SANTAROSAPLAINGROUNDWATER.ORG8/13/2020
a. Groundwater Sustainability Plan (GSP) and Sustainable
Management Criteria (SMC) update
8/13/2020 SANTAROSAPLAINGROUNDWATER.ORG 10
8/13/2020
Status of Groundwater Sustainability Plan Activities
Santa Rosa Plain Subbasin
Groundwater Flow Model & Water Budgets
Development of Monitoring Networks
Sustainable Management Criteria
• Chronic Decline of Groundwater Levels (In progress – pending outcome of 50 year
forecast)
• Land Subsidence (In progress)
• Water Quality (In progress)
• Depletion of Interconnected Surface Water (Initial planning)
• Reduction of Groundwater Storage (Initial Planning – additional work pending
completion of water budgets)
8/13/2020
Santa Rosa Plain Hydrologic Model and Water
Budgets
8/13/2020 SANTAROSAPLAINGROUNDWATER.ORG 12
Presentation Overview
• General Water Budget Components and SGMA Requirements
• Overview of Santa Rosa Plain Hydrologic Model (SRPHM)
o Summary of model revisions
o Application of SRPHM for GSP development
• Overview of results of historical and current water budgets
• Next steps for projected water budgets
Water Budget and Model updates presented in six AC Meetings and one Board
presentation. Model reflects input received at meetings where possible and applicable.
SANTAROSAPLAINGROUNDWATER.ORG 138/13/2020
Water budget requirements and
definitions
In accordance with the GSP Regulations §354.18, the water
budget provides an accounting and assessment of:
• the total annual volume of surface water and groundwater
entering and leaving the basin
• change in the volume of groundwater in storage
Water budget must include:
◦ Inventory of all inflows (supply) and outflows (demand)
◦ Summary of both surface water and groundwater budgets
◦ Evaluation of changes of groundwater in storage
◦ Estimation of groundwater overdraft (if applicable)
◦ Estimation of sustainable yield
Three water budgets for GSP:
1. Historical conditions
2. Current conditions
3. Projected conditions over the 50-year planning and
implementation horizon
SANTAROSAPLAINGROUNDWATER.ORG 14
From: Water Budget BMP, California Department of Water Resources, 2016
8/13/2020
Water Budgets – Time Periods
SANTAROSAPLAINGROUNDWATER.ORG 15
Time
Period
Proposed Date Range Water Year Types
Represented in Time
Period
Historical water years 1976 to 2018 Very dry: 1
Dry: 7
Normal: 20
Wet: 13
Very wet: 2
Current water years 2012 to 2018 Very dry: 0
Dry: 2
Normal: 4
Wet: 1
Very wet: 0
8/13/2020
Groundwater Modeling Overview
• Physically-based representation of groundwater and surface-water.
• Include important processes such as groundwater pumping,
precipitation and recharge, aquifer properties, and groundwater-
surface water interaction.
• Primary tool to understand and quantify the movement of water
through the subsurface, and how, for example, groundwater pumping
impacts the storage of groundwater in an aquifer.
Santa Rosa Plain Hydrologic Model (SRPHM) Updates
•Model developed by USGS: SRPHM V1.0
•Model being updated here: SRPHM V1.0+
SANTAROSAPLAINGROUNDWATER.ORG 168/13/2020
SANTAROSAPLAINGROUNDWATER.ORG 17
Now Finished Up Next Future Work
Update Model
1. Incorporate new Ag Package
to estimate agricultural
groundwater pumping
2. Refine rural residential
demands
3. Update model through 2018
A. Climate
B. Land Use Changes
C. Pumping
4. Check overall model
calibration, recalibrate if
needed
Calculate Water Budget from
Model Output
1. Summarize historical and
current water budgets
Prepare future model
1. Develop climate change
inputs
2. Develop estimates of
projected land-use change,
including rural domestic and
agricultural growth
3. Develop projected model
Run Future Scenarios to
Iteratively Evaluate:
1. Sustainable Management
Criteria
2. Projects and Actions
1. Finalize Future Scenarios for
Sustainable Management
Criteria and Projects and
Actions
2. Start implementing SRPHM
2.0 for GSP 5-yr update (this
will likely start following
completion of GSP, likely
early 2022)
2019/2020 2020/2021 2021/2022
8/13/2020
Model updates
Di
ffe
re
nt
u
se
rs
Update Municipal and Industrial Pumping
*entire model area
Imperviousness
Update Climate inputs
Crop Coverage
Rural domestic parcels with
groundwater pumping
SRPHM Integrated Simulated Processes Provide
Detailed Water Budget Estimates
SANTAROSAPLAINGROUNDWATER.ORG 198/13/2020
SRPHM
Simulation
Boundary
Model footprint covers the Santa Rosa
Plain Subbasin and the surrounding
Laguna de Santa Rosa watershed
SANTAROSAPLAINGROUNDWATER.ORG 208/13/2020
SANTAROSAPLAINGROUNDWATER.ORG 21
SRPHM Calibration Assessment –
Simulated Groundwater Hydrographs
8/13/2020
Surface Water
Budget
Inflows, outflows, and net
streambed exchange
During the historic period,
from Water Year 1976 to
2018, on average the
groundwater system
discharges 300 acre-
feet/year to streams.
During the current period,
from Water Year 2012 to
2018, streams are losing
1,300 acre-feet/year to the
groundwater system.
SANTAROSAPLAINGROUNDWATER.ORG 22
outflow from
streambed to
groundwater
8/13/2020
Groundwater Budget - Inflows
SANTAROSAPLAINGROUNDWATER.ORG 23
Current (WY 2012 to 2018)
Groundwater Inflows Budget
Summary (acre-feet/year)
Deep
Percolation
of
Precipitation
and Applied
Water
Streambed
Recharge to
Groundwater
Septic
Return
Flows
Subsurface
Inflow from
Surrounding
Watershed
Subsurface
Inflow from
Neighboring
Basins
Mean 25,200 14,900 1,200 2,000 7,400
8/13/2020
SANTAROSAPLAINGROUNDWATER.ORG 24
Groundwater Budget - Outflows
Agricultural
Pumping
Groundwate
r ET
Subsurface
Outflow to
Adjacent
Basins
Discharge to
Streams
Surface
Leakage
M&I + Rural
Domestic
Mean 10,400 9,500 4,700 13,700 5,200 9,500
Current (WY 2012 to 2018)
Groundwater Outflows Budget
Summary (acre-feet/year)
8/13/2020
