Groundwater Sustainability Plan Development Update –

North American Subbasin

February 13, 2020

The Sustainable Groundwater Management Act

• Passed in 2014, effective January 1, 2015

• Required creation of a Groundwater Sustainability Agency (GSA) by July 1, 2017

• Development of a Groundwater Sustainability Plan (GSP) by January 1, 2022

• Achieve Sustainable Management by 2042

• Failure results in state intervention

What Do We Have to Do?

• Partner with other GSAs in the basin

• Engage with basin stakeholders (nasbgroundwater.org)

• Fill some data gaps• New monitoring wells • Collect water quality information• Collect surface water data

• Develop some tools• Regional database system• Regional groundwater model (water

budget, sustainable yield, pumping estimates)

• Prepare a GSP (and then implement it)

Total Budget

GSA Percent of Area

Contribution

SGA 36.2 $262,682

West Placer 33.4 $242,980

South Sutter WD 19.4 $141,021

RD 1001 w/ PG-VMWC

5.2 $37,525

Sutter County w/NCMWC

5.8 $42,194

Total 100 $726,402

Funding Source Amount

State Grant $994,276

Local In-Kind Contribution/Past Expenses

$325,985

Direct Funding Contributions $726,402

Total $2,046,663

Local Funding Share

• They will include:• Description of the GSAs and a funding plan for future

implementation of GSP

• Description of Past and Current Conditions

• Projected future (50 years) – Based upon planned development, agricultural projections, and future climate conditions

• Sustainable Management Criteria (SMC)

• Description of monitoring network used to evaluate SMC

• Projects and Management Actions

What is in a GSP?

What are the SMC Indicators?

Sustainable Management Criteria Overview• SMC are determined locally

• SMC Include:

• Sustainability Goal (Basin-wide)

• Undesirable Results (Basin-wide)

• Minimum Thresholds (Site-Specific)

• Measurable Objectives (20 yrs, Site-Specific)

• Interim Milestones (5 yrs, Site-Specific)

• DWR expects these to be specific and quantifiable

Source: DWR

An example of an existing SMC approach at SGA

-20

-15

-10

-5

0

5

10

15

20

25

30

Jan-10 Jan-11 Jan-12 Dec-12 Jan-14 Jan-15 Jan-16

MW - 6, Thresholds

Upper Threshold

Lower Threshold

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

1/1/2014 1/1/2015 1/1/2016 12/31/2016 1/1/2018 1/1/2019 1/1/2020

Roseview Park, Thresholds

Seawater Intrusion

Sources: USGS/DWR

Subsidence due to Groundwater Withdrawal

-30

-25

-20

-15

-10

-5

0

5

10

1/1/2012 12/31/2012 12/31/2013 12/31/2014 12/31/2015 12/30/2016 12/30/2017 12/30/2018 12/30/2019 12/29/2020

MW 315 MW 465

Roseview Park

-40

-35

-30

-25

-20

-15

-10

-5

0

1/1/2012 12/31/2012 12/31/2013 12/31/2014 12/31/2015 12/30/2016 12/30/2017 12/30/2018 12/30/2019 12/29/2020

MW 170 MW 530

Churchill

Historic Local Subsidence Information

Recent Subsidence Information

Sutter Extensometer

Considerations when establishing land subsidence thresholds:

• Is aquifer material susceptible to subsidence?

• Current, projected and historical low groundwater levels

• Historic rate and extent of subsidence

• Susceptible infrastructure and land uses

• Adjacent basin thresholdsSource: DWR SMC BMP

Key Points for Engagement

Start development of SMCs – late summer 2020

Draft of SMCs – winter of

2021

Public Draft of GSP – summer

of 2021