Ken Weinberg, Director of Water Resources Dave Chamberlain, Principal Engineer

Supply/Demand Analysis and Scenario Planning Evaluation Thresholds and Decision Metrics Baseline System Performance Storage Utilization Analysis New Supply and Conveyance Options (Long-Term) Recommended Near-Term System Improvements Project Costs and Rate Comparisons CEQA Process Selection of Preferred Alternative

2

Demand Uncertainty and Sensitivity Revisit the Role of Storage to Optimize

Management of Supplies Measuring System Performance Facility Options to Improve System

Performance Remaining Work

3

2010 UWMP Implementation and Supply Reliability ◦ No Supply/Demand Gaps for Normal Weather Dependent on member agencies achieving conservation

and local supply targets

◦ Supply/demand gaps occur in dry years Multi-year dry weather with MWD allocation of imported

supplies Compounded with lower levels of local supply

development Continued uncertainty in imported water availability

4

Baseline System Analysis Evaluation Metrics and Thresholds ◦ When, how long are facilities operated at maximum? ◦ Is there a risk of eroding level of

service? ◦ Are there supply reliability shortages? ◦ How much shortage is acceptable risk? ◦ What is expected frequency and

duration?

5

Supply and Demand Scenarios

Scenario Description

Baseline (2010 UWMP)

• Supplies and demands per 2010 UWMP • All member agency local supply development - “verifiable” • Conservation targets per SBX7-7 are achieved • Climate change evaluated as a subset of the Baseline Scenario

No Added Local Supplies

• Current member agency local supplies • Conservation same as 2010 – SBX7-7 not met • Upper boundary for WA supply development

Maximum Local Supplies

• Higher member agency local supply development - “verifiable” and “planned”

• Conservation targets per SBX7-7 are achieved • Lower boundary for WA supply development

50% of Local Supplies

• 50% of verifiable member agency local supply development • Conservation savings reach 50% of planned amounts (allows for

member agency uncertainty to meet established targets) • Intermediate scenario - compare project timing 6

8

600

700

800

900

1,000

2020 2025 2030 2035

Tota

l Dem

and

(TA

F)

Baseline Demand without Price Effect Baseline Demand with Price Effect SBX 7-7 Compliance

542 (actual)

647

675

718

754

786

500

600

700

800

2012

2015

2020

2025

2030

2035

Tota

l Dem

and

(TAF

) Total Water Demands Actual 2012 Demand Compared to 2010 UWMP Normal Year Baseline Demand Forecast (TAF)

2010 UWMP Normal Year

Forecast

9

3.44

3.91

3.33

3.74

2.00

3.00

4.00

2020

2035

Popu

lati

on (m

illio

ns)

Series 12 Series 13

Comparison of SANDAG Adopted Series 12 and Preliminary Series 13 Population Projections

Water Authority Service Area

3% Decrease

4% Decrease

10

21 TAF

32 TAF

-

10

20

30

40

2020

2035

Pota

ble

Dem

and

Dec

reas

e (T

AF)

4% Decrease

Estimated Decrease in Total Potable Demand Due to Population Reduction (Derived based on difference between SANDAG Series 12 and 13 Population Projections applied to Water Authority 2010 UWMP Potable GPCD Target of 167)

3% Decrease

11

542 (actual)

647 675

718

754

786

615 641

682

716

747

500

600

700

800

2012

2015

2020

2025

2030

2035

Tota

l Dem

and

(TAF

) Sensitivity Analysis - Total Water Demand (for comparative purposes)

12

443 (actual)

478 (projected) 538

557

595 629

660

511 529

565 598

627

551 571

612 646

678

571

640

710

772

829

535 524

559 591

622

606

661

709

752

400

450

500

550

600

650

700

750

800

850

2012

2013

2015

2020

2025

2030

2035

Wat

er A

utho

rity

Dem

and

(TA

F)

2010 UWMP Normal Year Demand Forecast (A) 5% Reduction Sensitivity Scenario

2010 UWMP w/ Climate Change (A2) No Added Local (B)

Maximum Local (C) 50% of Local (D)

Sensitivity Analysis – Demand on the Water Authority

No Added Local Supply Development

Maximum Local Supply Development

13

Regional and Local Storage has Various Purposes ◦ Emergency Storage – manage supply interruptions ◦ Carryover Storage – manage short-term supply shortages ◦ Seasonal Storage – manage peak conveyance constraints ◦ Operational Storage – capture local runoff, provide forebays for Water

Treatment Plants ◦ Other – includes recreation, flood protection needs

Master Plan Evaluation Included ◦ Modeling reservoir operations

based on Member Agency input ◦ Optimizing regional storage for

seasonal and carryover operations ◦ Evaluating benefits/impacts of

additional regional storage on new infrastructure

15

Total Available Capacity: 740,000 AF

Reservoirs Not Connected to Aqueduct System: 210,000 AF

Balance Available for Regional Use: 530,000 AF ◦ Includes forebay storage

16

17

In-Region Storage Capacity Total Connected Storage Capacity 530,000 AF Unavailable Dead Pool 17,000 AF Emergency Storage Pools:

• Member Agency 175,000 AF • Water Authority 90,000 AF

Carryover Storage 100,000 AF Balance for Local Operations, Other Use 148,000 AF

Local Operations Pool (Local Runoff) ◦ First priority supply use, when available

Emergency Pool ◦ Not available for operations

Carryover Pool ◦ Available in allocation years ◦ Short-term supply for 3 years

Seasonal Storage Volumes ◦ Water Authority: 40 – 50,000 AF as

needed ◦ Member Agency: contribution is part of

normal operations Modeled 90,000 AF increase in

regional storage for carryover and seasonal use

0

100000

200000

300000

400000

500000

600000

700000

800000

Regi

onal

Sto

rage

Cap

acit

y

18

Dead Pool

Emergency Pool

Carryover Pool

Local Operations Pool

Not Connected to Aqueducts

19

Local Operations Essential to capture local surface runoff for local supply, manage flow to local treatment plants

Seasonal Storage Ability to manage short-term supply imbalances and conveyance limitations

Carryover Storage Reduces severity of supply shortages

Increased Regional Storage

• Greater operational flexibility and extends drought protection

• Management of short-term (1 or 2 years) supply imbalances

• Constrained by conveyance limitations on reservoir puts/takes

• Potential supply availability constraints

Determining the Need to Add Capacity What are the Warning Signs?

Metric Threshold Basis

Conveyance Utilization

• Exceed 95% of pipeline capacity for 45 days each year and 15 sequential days during peak season

• Two consecutive years

Conveyance utilization below 95% provides operational flexibility to manage daily MA flow requests

Risk of exceeding Conveyance Utilization threshold: • May not meet daily delivery requests • May draw down emergency or carryover storage pools • May not be able to refill storage pools • No system redundancy

21

Separate evaluations of treated and untreated water conveyance systems ◦ Increase demand for untreated supplies to meet

region’s expanded treatment plant capacity

Treated system has sufficient capacity through 2035 planning horizon

Untreated system has existing and future potential system constraints ◦ Evaluate expected magnitude and frequency

22

Miramar

Otay

Perdue

Levy

Alvarado

Twin Oaks Valley 100 MGD

Escondido/Vista ID

Poway Badger

Olivenhain

Weese

Untreated Water Delivery System Conveyance Constraints

23

Future System Capacity Constraint - Pipelines 3 and 5 (beyond 2020)

Existing / Future System Capacity Constraint – Serving South County WTPs

Crossover Pipeline to serve WTP (beyond 2025)

SV Pump Station (to optimize storage use)

Total Number of Days During Peak Season

Year in which 5% or More of Traces Indicate Exceeding Threshold

UWMP Demands

Maximum Local

50% of Local

45 2017 2019 2015 60 2018 2022 2016 90 2020 2024 2017

120 2024 2027 2021

24

• Untreated conveyance use is less sensitive to selection of thresholds or demand scenario – Pipelines need to operate at near capacity to meet summer peak demands

• Use of greater frequency (e.g. 25% of traces rather than 5%) moves time of need out by 2-3 years

25

5%

25% 10%

Lines represent % of traces (frequency)

Urban Water Management Plan Scenario (Expected)

45 days

60 days

90 days

120 days

50% 75%

26

5%

25% 10%

Lines represent % of traces (frequency)

Maximum Local Scenario (IPR and Other Local Projects)

45 days

60 days

90 days

120 days

50%

75%

27

5%

25%

10%

Lines represent % of traces (frequency)

Urban Water Management Plan Scenario (Expected)

45 days

60 days

90 days

120 days

50%

Conveyance Risks (untreated water) ◦ Conveyance risks increase around 2020 ◦ Suggested time frame for new infrastructure

development is 2020 to 2023 ◦ Coordination with member agencies can reduce near

–term conveyance risk ◦ Existing system bottlenecks should be addressed to

improve operational reliability

Conveyance Constraint 28

Max Fill

Addressing Supply Availability through Facility Implementation

Metric Threshold Basis

Delivery Reliability

• Annual supply shortage exceeds 20 TAF

• Two consecutive years

Annual shortages below 20 TAF may be mitigated by operational or management actions. Would not provide basis for new infrastructure or supply development.

Risk of exceeding Delivery Reliability threshold: • Regional supply shortage (economic impacts) • May draw down emergency storage pools • Member Agencies will bear risk of shortages

29

Supply Shortage Year in which 5% or More of Traces Indicate Exceeding Threshold

UWMP Demands

50% of Local

No Added Local

20,000 AF/Year 2033 2027 2021

30,000 AF/Year >2035 2028 2021

40,000 AF/Year >2035 2029 2021

50,000 AF/Year >2035 2030 2022

30

• Supply shortages are sensitive to demand scenario (no substantial shortages for UWMP demands or lower)

• Magnitude of shortage is generally driven by supply uncertainty; when supply is unavailable the uncertainty is larger than the 20 TAF threshold

• Use of greater frequency (e.g. 10% or 25% of traces rather than 5%) reduces shortage magnitude

31

5%

25% 10%

Lines represent % of traces (frequency)

Urban Water Management Plan Scenario (expected) 112 years of Hydrology

20,000 AF

30,000 AF

40,000 AF

50,000 AF

32

5%

25%

10%

Lines represent % of traces (frequency)

50%

50% of Future Local Supplies Scenario 112 years of Hydrology

20,000 AF

30,000 AF

40,000 AF

50,000 AF

Supply Shortage Risks (untreated water) ◦ Shortage risk is low through 2025, regardless of demand

scenario ◦ Beyond 2025, shortage risk strongly depends on demand

growth, member agency achievement of established targets for conservation, and local supply development

◦ Some shortages will be caused by conveyance limitations, but these will likely be short duration and relatively small in magnitude

◦ City of San Diego IPR resolves most long-term supply-demand imbalances

33

Miramar

Otay

Perdue

Levy

Alvarado

Twin Oaks Valley 100 MGD

Escondido/Vista ID

Poway Badger

Olivenhain

Weese

Untreated Water Delivery System Conveyance Constraints

35

Capacity Constraint - Pipeline 3-4 Conversion, North County ESP Pump Station, Regulatory Storage

Existing System Capacity Constraint – Pipeline 3 and 4 Intertie

Crossover Pipeline (low probability; beyond 2025)

SV Pump Station (to optimize storage use) Third Pump to increase flow

Future System Capacity Constraint – Mission Trails Suite of Projects

Project Purpose Estimated Cost

New 30 Inch South County Inter-tie

Alleviate conveyance bottleneck south of Alvarado

$6,000,000

Pipeline 3/4 Conversion Address untreated water conveyance constraint at MWD delivery point

$220,000,000

North County ESP Pump Station

Meet ESP delivery needs $21,563,000

Construct as Defined

Project Purpose Estimated Cost

Mission Trails Suite of projects

Increase untreated water conveyance to serve South County WTPs

$63,917,000

Regulatory Storage Provide operational storage for increased deliveries

$55,650,000

Third VFD San Vicente PS Meet ESP, Carryover Storage needs $8,044,000

Revise Scope, Size and Timing

Project Purpose Estimated Cost

Pipeline 6 Address untreated water delivery constraint at MWD delivery point

$480,000,000

Second Crossover Pipeline

Address untreated water delivery constraint s/o Twin Oaks

$371,041,000

Delay Beyond 2030

Continue to meet with Member Agency TAC ◦ Review cost and technical data ◦ Comments and input on selecting a preferred alternative

Comprehensive evaluation of proposed projects and modifications to current CIP ◦ Integrating long-term supply options into analysis ◦ Project cost estimates and comparison to future imported water costs ◦ Status of “Deferred Projects” ◦ Analysis of reliability improvements

Decision matrix on project timing ◦ Dependency on Member Agency actions ◦ No regrets actions ◦ Timing of future Water Authority Board decisions

39

Date Description

May 23, 2013 Water Planning Committee Meeting - Report on May 16th Workshop action items

June 2013 Member Agency Technical Advisory Committee Meeting

June 27, 2013 Water Planning Committee Meeting - Discuss comprehensive evaluation of all alternatives

July 2013 Member Agency Technical Advisory Committee Meeting

July 2013 Special Meeting of the Water Planning Committee – Review draft Master Plan document, project costs, and rate impacts

July 25, 2013 Water Planning Committee – Board input for final preparation of the draft Master Plan, CAP, and PEIR for public review

August 2013 Water Planning Committee – Obtain Committee approval of “Staff Recommended Alternative.”

September 2013 Public Release of the Draft Program EIR, CAP and Draft Master Plan for the 45-day review period.

February 2014 Regular Board Meeting - Certification of Final PEIR and approval of Final Master Plan and CAP. 40