water banking-greg thomas

8/14/2019 Water Banking-Greg Thomas

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System-Wide Investigation of

Central Valley Conjunctive Water

Management Opportunities


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In Intensively Developed

Water Systems

Old Paradigm:

Water for flow restoration vs. water forhuman uses = ZERO SUM GAME

New Paradigm:

No new water development without astrong environmental restoration component

Environmental flow restorationembedded within water augmentation


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Mandates

CVPIAdevelop and implement a least-cost program to supplement andreplace the CVP water dedicated to fish and wildlife restoration throughimprovements in reservoir operations, water banking, andconjunctive use. [3406(b)(3) and 3408(j)]

CALFED Bay-Deltaimprove water supply reliability for all sectors

Environmental Water Account

Other Critical Unmet Needs Restore anadromous fishery of the San Joaquin River CVP contract deliveries AFRP program Dilution water to improve water quality


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Components Reservoir operators would agree to re-operate the

reservoir to generate source water* for banking for afee

Local interests controlling a groundwater basin wouldagree to temporarily rent unused aquifer storagespace for a fee or share of the water

Potential beneficiaries of the groundwater bankingprogram would purchase a specified amount of the

banked groundwater

* Water will be regarded as new water if it would otherwise have beenreleased for flood control purposes and flowed out to sea


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The Delta

Shasta

Oroville

New Bullards Bar

Folsom

Camanche

New Hogan

New Melones

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The Delta

Camanche

New Hogan

New Melones

New Don Pedro

New Exchequer

Millerton lake

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Reservoirs, Ownership, and Capacity


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Modes of Groundwater Banking

0

500000

1000000

1500000

2000000

2500000

10/1/93

4/1/94

10/1/94

4/1/95

10/1/95

month/day/year

surface

storage

(ac-ft)

0

20000

40000

60000

80000

100000

120000

140000

aquiferstorage

(ac-ft)

Measured New Don PedroAdjusted New Don PedroGroundwater Bank

Pre-DeliveryReservoir Recovery

NHI Approach

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Average Annual Yield Estimates for Eleven

Regulated Tributaries of the Central Valley


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Factors Taken Into Account inCalculating Re-operation Yield

Pre-existing rights &entitlements

AFRP flows Temperature regulation


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Next StepsReiterate reservoir yield analysis using

CALSIM II

Shasta (ongoing)Other 10 reservoirs (prospective)


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Potential Groundwater Banking Sites

Sacramento Valley

San Joaquin Valley

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Hydrogeologic Suitability of Central

Valley Sites for Groundwater Banking


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Hydrogeologic

SuitabilitySub-index

Sacramento Valley

San Joaquin Valley

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Evaluation Criteria

Relative contribution of surface water &groundwater

Proximity of groundwater-irrigated landsto surface water distribution networks

Available aquifer storage space


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Promising

Central ValleyDAUs

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What is an Environmental Flow: moving from

minimum flow to variable flow

This is the same volume!

Its not just a matter of water volume


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Making Rivers Function Like Rivers Again:

Impact of River Development on Floodplains


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Problem: Flow characteristics should be linked

to biological benefits

Solution: Progressively develop applied

biohydrology

Link to CALFED Science ProgramConduct adaptive management of flow

experiments

Fluvial Restoration Concept


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Problem: Shaving hydrologic peaks reduces natural

variability

Solution: Convert from uncontrolled to controlledfloods


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Problem: Capturing pulse flows is an engineering

challenge

Solution: Coordinate & rotate reservoir operation

for fluvial benefit



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Floodplain / fluvial process investigation

Determine the available water for environmental flows Define environmental flow requirements (magnitude,

frequency, duration) Identify the floodplain constraints that limit the

magnitude parameter

Assess the sediment needs and availability forgeomorphic restoration

Next Steps


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Regionalized and System-Wide Configurations

What we know How much water we have to play with Locations of 2 storage sites Ranking of tributaries by restoration potential

What we need to learn Feasibility of linking particular reservoirs to particular

2 storage sites through particular natural channels and

artificial conveyance and reintegrating the supply into theexisting CV delivery system

How to figure this out System-wide gaming and whole-system modeling with

CALSIM II

Next Steps


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The Local Control Imperative

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Risk Factors Analyzed

Hydrogeologic Leaky aquifers Adverse effects on other groundwater pumpers Reduced natural infiltration Groundwater invasion of crop root zones / wetlands

regulations

Water Quality Degrading aquifer water Leaching soil contaminants

Financial Delta pumping restrictions to delivery of banked water


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Risk Factors Analyzed Legal

Injury to other groundwater users

Limiting the rights of current / future groundwater users Legal action against other groundwater users

Political Adverse community reactions


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Factors for Success

Overall Project Design Banked water imported Facilities sited in existing water district service area or

AB-3030 planning area Operations performed by overlying water district /

groundwater management authority

Local benefits obligated in enforceable contracts For unincorporated areas, create local water management

authority

Issues, alternatives, mitigations routinely analyzed inNEPA / CEQA with public participation


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Constraints & Design Specificationsfor System-Wide Maximal ScaleConjunctive Use

Groundwater banking projects will operate on thebasis of voluntary, compensated contractualarrangements among reservoir owners, localgroundwater management authorities, conveyanceoperators and end use beneficiaries.

No changes in existing laws will be assumed,although the final report may identify legal reforms ormeasures to clarify existing laws that would facilitatethe program.


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Constraints & Design Specificationsfor System-Wide Maximal Scale

Conjunctive Use

Projects will cause no uncompensated adverseimpacts on other groundwater or surface water rightsholders.

Projects will provide net environmental benefits.


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Constraints & Design Specifications

for System-Wide Maximal Scale

Conjunctive Use

Projects will be operated in an economically optimalfashion (i.e., the volumes of water and scale ofoperations will be limited by the marginal cost ofsubstitute supplies).

No new public subsidies will be assumed. That is tosay, the project will be designed to be self-financing.


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www.conjunctiveuse.org37


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Prospective Workplan Reassess new water yield potential of 11 reservoirs Analyze and rank tributary restoration potential

Define environmental flow prescriptions (with CALFEDScience Program)

Identify floodplain constraints Assess sediment needs and availability

Implement system-wide modeling Identify optimal regional configurations

Analyze groundwater banking land use compatibility Formulate and implement pilot demonstration projects Conduct economic optimization analysis Prepare final report Conduct executive briefings

water banking-greg thomas

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