1

Initial Water Demand EstimatesFor Three 2030 Scenarios

David GrovesRAND

2

1st Cut at QuantifyingNarrative Scenarios

Steps Build model Identify parameter values unique to

scenarios Compute results

3

No single method for choosing numerical values for parameters

There is no “correct” scenarioOther modeling studies can inform quantification Ex: DOF demographic projects – good choice

for Current Trends

Important to quantify drivers independently of scenario results (water demand)Check intermediate results for plausibility

4

Demand Driver Results

Please consult “Quantified Narrative Scenarios” hand-outNew rows…

5

Total Population

Population

30

35

40

45

50

55

2000 2005 2010 2015 2020 2025 2030

Year

Pe

rso

ns

(m

illio

ns

)

Current Trends

ResourceSustainability

Resource Intensive

Current Trends: DOF

Resource Sustain: DOF

Resource Intensive: Old DOF

6

Population Distribution

Po

pu

lati

on

(20

30-2

000)

- 2

Zo

nes

2 ZonesInland & Southern Coastal & Northern

0

2M

4M

6M

8M

10M

12M

14M

16M

Key ScenarioCurrent TrendsResource Sustaina…Resource Intensive

Population Change 2030-2000

Current Trends: DOF

Resource Sustain: DOF

Resource Intensive: DOF + 25% / 16%

7

Housing (Population Density)

SF Homes

7

8

9

10

11

12

13

2000 2005 2010 2015 2020 2025 2030

Year

Ho

me

s (

mill

ion

s)

Current Trends

Resource Sustainability

Resource Intensive

MF Homes

4

5

6

7

8

2000 2005 2010 2015 2020 2025 2030

Year

Ho

me

s (

mill

ion

s)

Current Trends

Resource Sustainability

Resource Intensive

Current Trends: 36% MF housing (2000)

Resource Sustain: 46% MF (+10%)

Resource Intensive: 31% MF (-5%)

8

Employees

Commercial Employees

3.0

3.5

4.0

4.5

5.0

2000 2005 2010 2015 2020 2025 2030

Year

Em

plo

ye

es

(m

illio

ns

)

Current Trends

Resource Sustainability

Resource Intensive

Current Trends: Driven by population*

Resource Sustain: Driven by population*

Resource Intensive: Driven by population*

*Replace with 2030 DOF projections when data available

Industrial Employees

2.5

3.0

3.5

4.0

4.5

2000 2005 2010 2015 2020 2025 2030

Year

Em

plo

ye

es

(m

illio

ns

)

Current Trends

Resource Sustainability

Resource Intensive

9

Changes in Water Use Coefficients

Changes in WUC captures Response to prices, income, natural

conservation and efficiency

Current Trends 10% decrease in WUC from 2000-2030

Resource Sustainability 20% decrease in WUC from 2000-2030

Resource Intensive 5% decrease in WUC from 2000-2030

10

Summary of Urban Drivers

Urban Water Demand Factors for 2000 and 2030.

Year 2030 Model Result Year 2000 Current Trends Resource Sustain. Resource Intensive

Population (millions) 34.1 48.1 48.1 52.3 Inland/Southern Pop. (mil) 25.8 37.3 37.3 41.1 Coastal/Northern Pop. (mil) 8.3 10.8 10.8 11.2 SF Homes (millions) 7.4 10.6 9.2 12.2 MF Homes (millions) 4.1 5.7 7.5 5.2 Commercial Employees (mil) 3.1 4.3 4.3 4.6 Industrial Employees (mil) 2.9 4.1 4.1 4.4

11

Irrigated AreaIrrigated Crop Area - Current Trends

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

2000 2005 2010 2015 2020 2025 2030

Year

Ac

res

(th

ou

sa

nd

s)

Multi-cropped

Irrigated Land Area

Irrigated Crop Area

Irrigated Crop Area - Resource Intensive

0.0

2.0

4.0

6.0

8.0

10.0

12.0

2000 2005 2010 2015 2020 2025 2030

Year

Ac

res

(th

ou

sa

nd

s)

Multi-cropped

Irrigated Land Area

Irrigated Crop Area

Irrigated Crop Area - Resource Sustainability

0.0

2.0

4.0

6.0

8.0

10.0

12.0

2000 2005 2010 2015 2020 2025 2030

Year

Ac

res

(th

ou

sa

nd

s)

Multi-cropped

Irrigated Land Area

Irrigated Crop Area

Current Trends: ICA – Current Trends, MA/ILA – 6%->10%

Resource Sustain: ICA – Constant, MA/ILA – 6%->14%

Resource Intensive: ICA – Constant, MA/ILA – 6%->23%

12

Irrigation Applied Water

Reflects all factors affecting water use per crop typeAlso reflects changes in cropping patterns Can disaggregate in future

Current Trends 5% decrease in AW from 2000-2030

Resource Sustainability 10% decrease in AW from 2000-2030

Resource Intensive Constant AW

13

Summary of Irrigation Demand Factors

Agricultural Water Demand Factors for 2000 and 2030.

Year 2030 Factor Year 2000

Current Trends Resource Sustainability Resource Intensive Irrigated Crop Area (1000 Acres)

9,510 8,520 9,520 9,520

Irrigated Land Area 8,980 7,740 8,360 7,740 Multi-cropped Area 540 780 1,160 1,780 Effective Applied Water (AF/Acre)

3.23 3.045 2.875 3.16

14

Environmental Water Demand

Unmet needs based upon memo from Environmental Defense (Dec. 8, 2003)

Current Trends 100% Unmet Needs by 2030

Resource Sustainability 150% Unmet Needs by 2030

Resource Intensive 100% Unmet Needs by 2030

15

Results

16

Urban Water DemandUrban Water Demand

8

9

10

11

12

13

14

2000 2005 2010 2015 2020 2025 2030

Year

Urb

an

Wa

ter

De

ma

nd

(M

AF

)

Current Trends

Resource Sustainability

Resource Intensive

17

UU

20

30

-20

00

Zo

ne

ScenarioCurrent Trends Resource Sustainable Resource Intensive

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

Key ZonesSouth/DryValleyNorth/Coast

Urban Demand Change – by sector and zone

Urb

an

Us

e 2

03

0 -

20

00

(T

AF

)

ScenarioCurrent Trends Resource Sustainable Resource Intensiv e

0

500

1000

1500

2000

2500

3000

Key Urban Use by Sector (TAF)SF UseMF UseCommercial UseIndustrial Use

Public Use--

2030-2000 by Sector

2030-2000 by Zone

South/dry = SC, CR, SL

Valley = SR, SJ, TL

North/coast = NC, SF, CC, NL

18

Results – Agricultural Demand

Agricultural Water Demand

28.0

29.0

30.0

31.0

32.0

33.0

34.0

35.0

2000 2005 2010 2015 2020 2025 2030

Year

Wa

ter

De

ma

nd

(M

AF

)

Current Trends

Resource Sustainability

Resource Intensive

19

Urban, Ag, Envir. Demand By Region

South / Dry Hydrologic Regions

-1

-0.5

0

0.5

1

1.5

2

2.5

Current Trends ResourceSustainability

ResourceIntensive

Dem

and

Ch

ang

e (2

030-

2000

) [M

AF

]

Urban

Agricultural

Environmental

(0.63 MAF) (0.15 MAF) (2.7 MAF)

Valley Hydrologic Regions

-6-5-4-3-2-1

01234

Current Trends ResourceSustainability

ResourceIntensive

Dem

and

Ch

ang

e (2

030-

2000

) [M

AF

]

Urban Agricultural Environmental

(-2.6 MAF)

(-1.5 MAF)

(0.27 MAF)

South/dry = SC, CR, SL

Valley = SR, SJ, TL

North/coast = NC, SF, CC, NL

North / Coast Hydrologic Regions

-0.4-0.3-0.2-0.1

00.1

0.20.30.40.50.6

Current Trends ResourceSustainability

ResourceIntensive

Dem

and

Ch

ang

e (2

030-

2000

) [M

AF

]

UrbanAgriculturalEnvironmental

(0.30 MAF)

(0.50 MAF)

(1.06 MAF)

20

Total Demand

UrbanAgriculturalEnvironmental ObjectivesStop groundwater overdraft 1 - 2 1 - 2 2 - 4Total -0.6 - 0.4 0.2 - 1.2 6.0 - 8.0

1 1.5

4.6-1.6

1

Scenario 2Resource sustainability

Scenario 3Resource intensiveWater Demands

2.8-5.4

Changes in Water Demand from 2000 to 2030

1.5-3.8

Scenario 1Current Trends

South/dry = SC, CR, SL

Valley = SR, SJ, TL

North/coast = NC, SF, CC, NL

Urban+Ag+Env Demand Change by Scenario

-3

-2

-1

0

1

2

3

Current Trends ResourceSustainability

ResourceIntensive

Dem

and

Ch

ang

e (2

030-

2000

) [M

AF

]

South/DryValleyNorth/Coast

(-1.6 MAF)

(0.86 MAF)

(4.0 MAF)