Water Supply and Drought Management Update

Water Planning Committee November 20, 2014

Presentation by: Alexi Schnell Water Resources Specialist

Lake Oroville, September 5, 2014

Photo:

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Precipitation Outlook November 2014 – January 2015

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Precipitation Outlook December 2014 – February 2015

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El Niño Watch

El Niño still predicted to develop by December 58% Probability Consensus forecast favors a weak event

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Temperature Outlook December 2014 – February 2015

California Drought Intensifies in 2014

November January Governor declares

“Drought Emergency”

February Water Authority notification of

“Drought Watch”

July Water Authority notification of

“Drought Alert”

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State Water Project Reservoir Storage Conditions

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Storage as of Nov. 13 910,446 AF 26% total capacity 43% historical average

Storage one month ago (Oct. 15) 1,033,129.6 AF 29% total capacity 48% historical average

- Lake Oroville

Lake Oroville Near Record Low Levels

0

1000

2000

3000

4000

Current Level 910,446 AF 26% capacity (Nov. 13, 2014)

Total Reservoir Capacity: 3.5 MAF

Record Low Level

882,000 AF 25% capacity (Sep. 7, 1977)

Rese

rvoi

r Lev

el (T

AF)

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Lake Oroville

100% capacity – July 2011

36% capacity – Jan. 2014

State Water Project Reservoir Storage Conditions

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Storage as of Nov. 13 409,230 AF 20% total capacity 36% historical average

Storage one month ago (Oct. 15) 427,089 AF 21% total capacity 42% historical average

- San Luis Reservoir

Northern Sierra 8-Station Water Year Precipitation Index

Water Year 2015 through November 17, 2014: 4.3 inches, 64% of average

WY 2014

WY 1977 (2nd driest)

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WY 2015

Colorado River Hydrologic Conditions

Water year 2015 precipitation through November 17, 2014 was 73% of average (3.1 inches)

Combined storage in Lake Mead and Lake Powell October 31, 2014: 22.5 MAF, 45% Capacity October 31, 2013: 22.9 MAF, 45% Capacity

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Local Service Area Conditions

Local reservoir storage on November 17, 2014 was approximately 233,356 AF, or 40% of capacity

Water Year 2015 Precipitation

Through November 19, 2014

Station Actual in. % Normal

Lindbergh Field 0.33 59%

Ramona Airport 0.54 69%

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SWRCB Emergency Regulations Monthly Reporting

Water Production by Urban Water Suppliers

SWRCB staff reported statewide production down 10.3% in September

South Coast region down 7.5% in September Approximately 8.5 billion gallons saved

New reporting requirement Residential gallons per-capita per day (R-GPCD) South Coast region reported 119 R-GPCD

Anticipate October statewide production numbers and R-GPCD data released at Dec. 2nd SWRCB meeting

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Fiscal Year Potable Water Use in Water Authority Service Area

20,000

40,000

60,000

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

Acre-Feet

Water Use FY14 (AF) Water Use FY15 (AF)

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Average Daily Maximum Temperature at Lindbergh Field – Departure from Normal (oF)

-2.0

0.0

2.0

4.0

6.0

8.0Fiscal Year 2014 Fiscal Year 2015

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

Hotter

Cooler

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• October 2014 was 5.8o F warmer than normal • Temperatures were 14o F above average the first week of October

Potable Water Use in Water Authority Service Area

% Increase Oct. 2013 to Oct. 2014

Potable Water Use

5.9%

M&I Potable Use (excluding TSAWR)

3.8%

Urban Water Use Reporting

Water Authority agricultural water use (TSAWR) is classified under urban water supplies

Water Authority has largest agricultural component in MWD service area

Intent of SWRCB emergency regulations to reduce outdoor irrigation and other wasteful water practices effort not directed at agricultural irrigation

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Other Factors Affecting October Water Use

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Agricultural

Untreated/Treated Water Shutdown Agriculture customers irrigated in advance

Excessive heat required additional irrigation to protect agricultural investments

M&I

Excessive heat increased water use

Current Drought Activities

Monitor water use and drought conditions

Assist member agencies in compliance with SWRCB Emergency Regulations

Participate in MWD member agency review of Water Supply Allocation Plan

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Initiate review of Water Authority’s Supply Allocation Methodology in early December 2014