SECURING WATER FOR TODAY AND TOMORROW…

Planning, Resource, and Technology Committee

October 14, 2021

MWA Water Supply Sustainability Series: Part 2

1

PRESENTATION SERIES

PART 1

Why do we

import

water?

1 2 3 4 5

PART 2

Imported

Water from

the SWP

PART 3

Factors Affecting

Sustainability:

Risks

PART 5

Long-term

Planning for

Sustainability

PART 4

Factors Affecting

Sustainability:

Potential Solutions

2

3

MWA’s purpose and roles

Natural local supplies

The Mojave River Basin Adjudication

Support for current and future local economic health

MWA Water Supply Sustainability: Imported Water

Why do we

import water?

Purpose of MWA

4

§ 97-1.5. Purpose of agency Sec. 1.5. Within the limits of its power and authority set forth in this act, the purpose of the agency shall be to do any and every act necessary to be done so that sufficient water may be available for any present or future beneficial use of the lands and inhabitants of the agency, including, but not limited to, the construction, maintenance, alteration, purchase, and operation of any and all works or improvements within the agency necessary or proper to carry out any object or purpose of this act and the gathering of data for, and the development and implementation of, after consultation and coordination with all public and private water entities who are in any way affected, management and master plans to mitigate the cumulative overdraft of groundwater basins, to monitor the condition of the groundwater basins, to pursue all necessary water

5

Imported water mitigates overdraft

Overdraft Balanced Water Supply

Water Out

Water Out

Water Out

Water In

Water In

Imported Water

Primary source of imported water is State Water Project

6

SWP Background

SWP Hydrology

SWP Storage

SWP Conveyance

MWA Water Supply Sustainability Series: Part 2

Imported Water

from the

State Water Project

(SWP)

State Water Project

• One of two major statewide water projects• Coordinate operations with Central

Valley Project

• 29 State Water Project Contractors: 4.2 MAF• 23 Mostly M&I

• ~27 million people

• 6 Mostly Agricultural• ~750,000 acres

Oroville Reservoir

The Delta

California Aqueduct

San Luis Reservoir

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Metropolitan Water District46%

Kern County Water Agency23%

Upper Feather River1%

North Bay2%

South Bay5%

Central Coast2%

Other San Joaquin Valley4%

Other Southern California15%

Mojave Water Agency2%

Table A Shares (% of 4.2 MAF)

8

SWP Facilities and Profile

• ~700 miles of open canals and pipelines (CA aqueduct ~440 miles)

• 28 Dams

• 20 Pumping Plants

• 5 Hydroelectric Power Plants

• 3 Pump/Generating Plants

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State Water Project Purposes

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Water Supply

Flood Control

Fish and Wildlife Mitigation and Enhancement

Delta Water Quality and Outflow

Power Generation

River Regulation (Navigation)

Recreation

SWP Coordinating Agencies

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Federal Agencies

• U. S. Bureau of Reclamation

• U. S. Fish and Wildlife Service

• National Marine Fisheries Service

• U. S. Army Corps of Engineers

State Agencies

• Department of Water Resources

• Department of Fish and Wildlife

• State Water Resources Control Board

Other Agencies

• Western Area Power Administration

• California ISO

State Water Contractors

Terminology

12

State Water Project: Owned and operated by California Department of Water Resources, funded by SWP contractors

Water Year: October to September due to California precipitation and runoff pattern

Contract Year: January to December due to water supply allocation process

Table A: Share of total contracted SWP water supply

Table A allocation: Annual amount of contracted SWP water supply available for delivery from January to December

Article 56/Contractor Carryover: Contractor water stored in San Luis Reservoir

Delta: Estuary created by the Sacramento/San Joaquin River confluence

State Water Project Operations

Redistribute Water Statewide

• North to South

• Winter to Summer

• Wet Years to Dry Years

Oroville Reservoir

The Delta

California Aqueduct

San Luis Reservoir

~75% of Precipitation

~75% of Demand

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Water Year

Sacramento Valley Water Year Classification

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Water Year

San Joaquin Valley Water Year Classification

Wet Above Normal Below Normal Dry Critical

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Seasonal and Annual Runoff and Demand

0%

2%

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

% A

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ual

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Comparison of Runoff and Demand Patterns

Runoff Demand

California Hydrology: Water Year

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Precipitation Index

Northern Sierra 8-Station Index

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Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

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Runoff: Full Natural Flow

8 River Index

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SWP Water Supply Allocations

• Annual water supply allocations• Each year: DWR determines

annual water supply allocation• How much of 4.2 MAF contracted

water supply can be delivered

• Initial allocation in December

• Updated monthly through May

• Based on conservative forecast

• Variable depending on:• Hydrologic conditions

• Reservoir storage

• Conveyance

100% 100%

80%85%

70%

90% 90% 90%

65%

45%

65%

35%39%

70%

60%

40%

35%

60%

20%

35%

5%

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5%

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1999

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2008

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2010

2011

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2014

2015

2016

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2018

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2020

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1

SWP Allocation by Year TypeWet

Above

Below

Dry

Critical

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Factors Affecting SWP Allocation

• Hydrologic Conditions• How much precipitation is expected?

• Snowpack: acts as natural storage

• Direct runoff to reservoir storage, streams

• How much runoff is expected?• Forecast is conservative: based on a dry condition

• 9 out of 10 years will be wetter than forecast

17

Factors Affecting SWP Allocation

• Reservoir Storage• Amount of storage remaining from last year

• Amount of runoff expected to be stored

• Target amount to save in case next year is dry

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Oroville Reservoir

• Storage Capacity: ~3.5 MAF

• Primary Purposes: • Water supply

• Flood protection

• Secondary Purposes: • In-stream flow and temperatures for fisheries

• Power generation

• Recreation

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San Luis Reservoir

• Capacity : 2.028 MAF SWP share: 1.062 MAF (~52%)

• Largest Off-Stream Storage Reservoir in US

• Joint-Use Facility• CVP and SWP

• Primary Purpose• Water Supply

• Secondary Purpose• Power• Recreation

• Contactors can store Article 56 Carryover here

San Luis Reservoir

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San Luis Reservoir and SWP Carryover Storage

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SWP San Luis Reservoir Total Available Storage = 1062 TAF

SWP Project Water Stored in San Luis Reservoir = 562 TAF

Unused SWP San Luis Reservoir Storage = 500 TAFSWP Contractor Carryover Storage = 300 TAF

Unused SWP San Luis Reservoir Storage = 200 TAF

SWP Contractor Carryover Spill: Carryover can be stored in unused SWP San Luis Reservoir storage

San Luis Reservoir and SWP Carryover Storage

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SWP San Luis Reservoir Total Available Storage = 1062 TAF

SWP Project Water Stored in San Luis Reservoir = 562 TAF

SWP Contractor Carryover Storage = 500 TAF

SWP San Luis Reservoir Total Available Storage = 400 TAF

SWP Project Water Stored in San Luis Reservoir = 662 TAF

Convert 100 TAF from Contractor Carryover to SWP Project Water

SWP Contractor Carryover Spill: Carryover cannot prevent SWP Project Storage

SWP Conveyance: The Delta

• Convergence of many California major rivers

• Approx. 40% of State’s run-off passes through Delta

• Drinking water supply for two-thirds of Californians

• Support California billions of agricultural industry

• Largest estuary on United States’ Pacific Coast

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0

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Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Am

ou

nt

(MA

F)

Average (27.8 MAF) 1977 (6 MAF) 1983 (69 MAF)

Annual/Monthly Variation of Inflow(Sacramento-San Joaquin Delta Variation)

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Delta Inflow, Outflow, and Diversions

Delta Inflows

Sacramento River San Joaquin River

East Side Streams Delta Precipitation

Delta Outflows and Diversions

Consumptive Use Delta Outflow

Contra Costa and North Bay SWP Export

CVP Export

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Key Delta Operating Agreements and Regulations

• SWRCB Permits and Conditions - Water Rights Decision 1641

• Endangered Species Act (ESA) / California ESA Requirements• U.S. Fish and Wildlife Service Biological Opinion (2019)

• N.O.A.A. Fisheries (NMFS) Biological Opinion (2019)

• CDFW Incidental Take Permit (2020)

• Coordinated Operations Agreement – SWP and CVP Sharing Formulas

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• State Board D-1641• Flow standards for fisheries

• Export to inflow ratio

• Outflow (year-round)

• X2 (spring)

• Water quality standards• Municipal (intakes)

• Agriculture (western and interior Delta)

• Fish and wildlife

State Water Resource Control Board

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Water Quality Standards

Federal and State Endangered Species Act

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Chinook salmon(Spring and Winter Run)

Central Valley Steelhead

Green Sturgeon

CESADelta Smelt

Longfin smelt

• ESA and CESA Water Supply Operational Criteria• Manage exports

• Delta Cross Channel

• Old and Middle River flow

• San Joaquin River Inflow to Export Ratio (CESA Only)

• Delta Outflow• Summer habitat actions that

may include flow

ESA/CESA Delta Requirements

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Old RiverMiddle River

Delta Cross

Chanel

San Joaquin

River

Delta Requirements: Risks to Water Supply

493

251

771 817

364

585

47 92

542

751

225

1,545

540

0

200

400

600

800

1000

1200

1400

1600

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Avg

Wat

er

Sup

ply

(TA

F/yr

)Estimated Annual SWP Water Costs

Due to Biological Opinions and Incidental Take Permit

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SWP Delivery Capability

• SWP Delivery Capability• Long-term expected SWP water supply allocation over range of hydrology

• Delivery Capability Report• Provides information about the key factors affecting the operation of the SWP

• Evaluates long-term capability as a source of water for beneficial use

• Meets the requirements of Attachment B to the Monterey Plus Settlement Agreement of May 2003

• Evaluation of SWP delivery capability• Assumes static land use, infrastructure, and regulations

• Evaluates over historical 82-year hydrologic sequence

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SWP Water Supply Risk

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0%

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100%

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SWP

Wat

er S

up

ply

Allo

cati

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Annual SWP Allocation Expected Delivery Capability

Pelagic Organism Decline

Wanger Decision

2008/09 BiOps 2020 BiOps

and ITP

Future Regulations

?

2004 BiOp

Summary

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MWA’s primary purpose is to import water for basin management

The primary source of imported water is State Water Project water

The State Water Project helps match water supply with water demand

• North and south

• Wet and dry

The State Water Project allocates water supply to contractors annually

State Water Project delivery capability is at risk

Other State Water Project Risks

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Financial Risks

• Cost compression

• Contracts currently through 2035; Financing only through 2035

• Power costs

• Environmental regulation costs

Aging Infrastructure

• Oroville Dam Spillway

• Thermalito fire

• Aqueduct damage and subsidence

• Clifton Court Forebay gates

Climate Change

• Efficiency of reservoirs

• Sea level rise and ocean salinity intrusion

SWP Contractors and DWR:SWC Board and Committees

35

Water Operations

Operations, Maintenance,

and EngineeringEnergy

Audit FinanceEnvironmental

ComplianceLegal

PRESENTATION SERIES

PART 1

Why do we

import

water?

1 2 3 4 5

PART 2

Imported

Water from

the SWP

PART 3

Factors Affecting

Sustainability:

Risks

PART 5

Long-term

Planning for

Sustainability

PART 4

Factors Affecting

Sustainability:

Potential Solutions

36

Questions?

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