Water Supply Board Briefing

Water Operations Department

March 8, 2016

Water Supply Briefing

• California Water Supply

• Current Water Supply

• Water Supply Projections

• Water Supply Schedule

2

California Water

Supply

4

California Water Supply

Snow Surveys

4

March 2015 March 2016

Michael Macor. SF Chronicle Rich Pedroncelli, AP

DWR allocations are 30% for CY16

5

California Water Supply

Automated Survey - Snow Water Equivalents

5

Automated Snow Measurements – Snow Water Equivalents

Year % of Normal

on March 7

2015 18%

2016 82%

• Snow station surveys conducted around March 1, 2016

• Manual readings confirm

preliminary automated measurements

California Water Supply

Reservoir Storage – March 7

March 7, 2016 Storage

Average Storage on March 7

Storage on Feb 21

6

7

California Water Supply

Folsom Lake Flood Releases

7

Current Water

Supply

8

Current Water Supply

Mokelumne Precipitation

0.45” 0.08”

0.06”

2.56”

Rainfall Year 2016

Average

9

5.83”

11.45”

10.9”

2.06”

5.00”

Current Water Supply

East Bay Precipitation

0.04” 0.03” 0.03” 0.01”

1.94”

Rainfall Year 2016

Average

10

5.02”

7.51”

0.92” 4.21”

Current Water Supply

Precipitation & Snow

As of 3/7/2016 Cumulative

Precipitation % of

Average

East Bay

East Bay Watershed 19.71” 95%

Mokelumne Basin

4-Station Average 38.39” 108%

Caples Lake Snow Depth 78” 105%

Caples Lake Snow Water Content 28.8” 106%

11

Add current photos

12

Current Water Supply

Caples Lake Snow Depth

0

10

20

30

40

50

60

70

80

90

O N D J F M A M J

Sn

ow

D

ep

th

(in

)

Date

2015-16

2014-15

Historical Average

Current Water Supply

Gross Water Production

100

150

200

250

300

1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun

gro

ss

wa

ter

pro

du

cti

on

(m

gd

)

3-Year Avg of FY 2005-2007

FY 2016

FY 2013 (184 MGD)

FY 2016 Operational Estimate (149 MGD)

Current Water Supply

Water Savings

14

Savings Rate (2013 Baseline)

March 8, 2015 –

March 7, 2016 23%

June 1, 2015 –

Feb 29, 2016 24%

Current Water Supply

Reservoir Storage

As of

3/7/16

Current

Storage

Percent of

Average

Percent of

Capacity

Pardee 181,480 AF 102% 92%

Camanche 125,100 AF 45% 30%

East Bay 127,160 AF 93% 84%

Total System 433,740 AF 73% 57%

15

Water Supply

Projections

Water Supply Projections

(Runoff Projections as of March 8, 2016)

Forecast Annual Runoff

Total System Storage

(on Sept 30, 2016)

No Rain To-Come 490 TAF 420 AF

95% Exceedance (9.5 of 10 years are wetter)

610 TAF 515 TAF

90% Exceedance (9 of 10 years are wetter)

640 TAF 535 TAF

50% Exceedance (5 of 10 years are wetter)

740 TAF 630 TAF

10% Exceedance (1 of 10 years is wetter)

980 TAF 630 TAF

Average Year 745 TAF 630 TAF 17

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Proposed DMP Guidelines

Demand Management Program Guidelines

• Include four stages of drought

• Allow for rationing >15% in extreme situations

Stage Projected

TSS (TAF)

Quantity of CVP

and

Supplemental

Supply Needed

(Acre-Feet)

District-Wide Water

Use Reduction Goal

0 Normal 500 or more 0 Wise water use

1 Moderate 500 - 450 0 Voluntary up to 15%

2 Significant 450 - 390 0-35,000 Voluntary up to 15%

3 Severe 390 - 325 35,000-65,000 Mandatory up to 15%

4 Critical <325 >65,000 Mandatory ≥ 15%

Water Supply Projections

Mokelumne Precipitation Rainfall Year 2016

Wettest of Record

87.3” (RY83)

Driest of Record

23.0” (RY77)

RY 2016 To-Date

38.39”

Average 48.3”

10% Exceedance

90% Exceedance

Median

19

0

5

10

15

20

25

30

35

40

45

50

2012 2013 2014 2015 2016

Precipitation (in) - Recent Years

Water Supply Projections

Precipitation Comparison

20

DRY – 45”

MEDIAN – 49” Historical Avg – 48.3”

22.5”

Through Mar 7

38.4”

Through Mar 7

15.7”

20.3” 27.4”

Remainder

15.4”

6.6”

7.0”

6.7”

34.0”

31.1”

27.3”

29.2”

Water Supply

End of September Storage

21

30 TAF Encroachment

25 TAF SS

DRY – 535 TAF

MEDIAN – 630 TAF

45 TAF Conservation

40 TAF SS

15 TAF Conservation

Water Supply Projections

Weather Forecast

22

Water Supply Projections

10-Day NOAA Precipitation Probability Estimate

23

~70% Chance of

Above-Normal

Precipitation

In the Mokelumne

Watershed

Water Supply Projections

14-Day NOAA Precipitation Probability Estimate

24

Likely Normal

Precipitation

In the Mokelumne

Watershed

Water Supply Projections

NOAA Precipitation Probability Estimate through May

25

33 to 40% Increased

Chance of Above-

Normal Precipitation

In the Mokelumne

Watershed

26

Water Year 2016

As of March 6, 2016

• Mokelumne River basin runoff is 202 TAF

• Projected end of water year storage is

535– 630 TAF (90% - 10% exceedance)

• Mokelumne River watershed season to

date precipitation is 108% of average

• East Bay watershed season to date

precipitation is 95% of average

• Precipitation accumulation season – 74%

complete (26% remaining)

Water Year 2016

Water Supply Schedule

Date Activity

Feb 2 • DWR February Snow Survey

Feb 23 • Drought Financial Impacts

Early

March

• DWR March Snow Survey

Mar 20 • USBR Initial Allocation

March to

April

• Water Supply Updates

• Continue public outreach

April 1 • DWR April Snow Survey

April 26

• Water Supply Availability and

Deficiency Report

• Consider change in Drought Stage 27

St. Patrick’s Day 2016 Luck?

Total System Storage