Roosevelt Lake and Dam, AZ Benefits of Improved Long Range Weather Outlooks to the Project Improving Sub-Seasonal and Seasonal Precipitation Forecasting for Drought Preparedness San Diego, CA May 27-29, 2015

Charlie Ester Manager, Water Resource Operations Hohokam Civilization, c.1000 A.D.

Bridge over Grand Canal, 1909 Early Canals: Pre-1880s

@10,000 @ 700 0 0 President Theodore Roosevelt Board of Survey Map, 1914

Reclamation Act and the Association: 1902/03

@90,000 20,457 0 0 Roosevelt Dam construction, stiff legged derrick, 1910

Theodore Roosevelt Dam: 1906−1911

131,364 34,488 1,284,205 4 Las Vegas

SRP manages six reservoirs on the Salt (4) and Verde (2) rivers and one on East Clear Creek in , and operates approximately 267 groundwater wells, which provide a renewable water supply to the 250,000 acre service area.

Salt River CAP SRP Watershed

Williams KEY MAP Flagstaff

E. Clear Creek Watershed

Verde River Sedona Watershed SRVWUA Salt River EAST CLEAR CREEK Watershed WATERSHED SALT RIVER Prescott Camp WATERSHED Verde VERDE RIVER Show Low WATERSHED Payson

Alpine

Agua Fria Agua SRV Phoenix Globe WUA Roosevelt Dam

Construction from 1903-1911 Modified from 1989-1996 Lower Salt Reservoirs

Horse Mesa Dam

Construction from Construction from 1924-1927 1923-1926

Construction from 1928-1930 Verde Reservoirs

Bartlett Dam Horseshoe Dam

Construction from 1936-1939 Construction from 1944-1946 Reservoir System

Roosevelt Dam C.C. Cragin East Clear Creek Storage: 2218’ Top of Safety of Dams Dam 15,000 AF 2151’ Top of Conservation 6720’ 6720’ -

Horseshoe C.C. Cragin 2100’ - 15,000 AF Roosevelt Lake Dam Horse Mesa 1,631,532 AF 2026’ Dam Horseshoe - 2000’ 1914’ 109,217 AF Bartlett 1891’ - Apache Lake Dam 245,138 AF 1798’ Mormon Flat Dam Bartlett - 1748’ Stewart 178,186 AF Mountain 1660.5’ Dam 1610.5’ - Verde River Storage: 1529’ 287,403 AF 1506’ - 57,852 AF

VERDE CONSERVATION Saguaro Lake SALT CONSERVATION 69,765 AF STORAGE: STORAGE: 302,403 AF 2,004,287 AF Total Conservation Storage: 2,306,690 AF

01/09/07 REF/SVRSCIAF-10 SRP Water Service Area

13,000 Sq. Mile Project Watershed

Flagstaff

Payson Prescott

Phoenix River

Peoria Glendale Tolleson Scottsdale Phoenix Mesa Avondale Tucson Tempe Gilbert Chandler Water Wells & Recharge Facilities

~267 Active Wells Age Range 1909-2013 GRUSP NAUSP

30 miles or 50 kilometers Salt River, and Verde River Streamflow (Average Runoff 1913–2014 = 1,169,526 AF) Salt River Project Historic Drought Periods (Average Runoff 1996–2014 = 783,262 AF)

100 Longer Period Of 90 Sustained Drought

80 7 Years 1942 - 1948 70 62% 4 Years 1974 - 1977 + Years 20 60 5 Years 52% 1995 – 2015? 1953 - 1957 ??% 47% 50 7 Years 1898 - 1904

% % Average 40 35%

30

20

10

0 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Year Winter Outlook 14-15

Dec 2013 - Mar 2014

Cold

Warm & Dry Weather Forecast “Tools”

Winter Outlook 2014-2015 NATURE – Wet Winter - Lots of acorns - Pine cones gathered on the top of the tree - Frequent rings around the sun - Large spider webs - Woolly worms with thin brown stripe - Bees become secluded - Woodpeckers sharing trees - Raccoons with thick tails - Mice overeating - Wildlife putting on early and thick winter coats - Squirrels gathering nuts - Spleen of big game animals

WINTER OUTLOOK – (Early and Thick Winter Coat) Water Demand Reservoir Storage Synoptic Scale Patterns Total SRP Storage Current Storage = 2,096,000 AF = 181% of Plan and 151% of Median 2,500

2,250

2,000

1,750

1,500

1,250

1,000

750

500 Actual Volume vs. Plan = + 924 kaf Volume (AF x 1000) 250

0

Jul Jul May Jun Aug Sep Oct Nov Feb Mar Apr May Jun Aug Sep Oct Nov Dec'04 Jan'05 Dec'05 Jan'06 Month May'04 Plan Actual Median Teleconnections Groundwater Project Reservoir Operation Plan

Drought Monitor Other Sources

Allocation Drought Outlook

HistoricalSalt River Project Annual Runoff Inflow, Storage, & Pumping NWS Outlook

4800000 4500000 4200000 3900000 3600000 3300000 3000000 2700000 2400000 2100000 Water Mix

(Acre-Feet) 1800000 1500000 1200000 900000 600000 300000 0

1889 1891 1893 1895 1897 1899 1901 1903 1905 1907 1909 1911 1913 1915 1917 1919 1921 1923 1925 1927 1929 1931 1933 1935 1937 1939 1941 1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

Pumping Inflow Project Reservoir Operation Plan (Seasonal)

Objective: Provide an adequate and reliable water supply to our shareholders.

Water Demand: The quantity of water needed to satisfy shareholder demand and contract obligations for Agricultural, Municipal, Industrial, Domestic, Recreational, and Wildlife uses.

Management Philosophy: • Ensure carry-over storage to manage the worst drought on record. • Reduce the probability of having to cut the allocation of water to 2.0 AF/AC to less than one percent. Methodology: • The end of every wet runoff season is the start of the next severe sustained drought period. SRP Storage, Pumping & Water Allotment Planning

Ground Water 2200 Production (KAF)

2000 Median Inflow 1800

1600 - 75

1400 - 150 1200 11-year Tree Ring Drought - 200 1000 - 250

800 - 325 3.0 AF/AC

Reservoir Storage Reservoir (KAF) Storage 600 2.0 AF/AC 400

200

0

May-01 Sep-01 Jan-02 May-02 Sep-02 Jan-03 May-03 Sep-03 Jan-04 May-04 Sep-04 Jan-05 May-05 Sep-05 Jan-06 May-06 Sep-06 Jan-07 May-07 Sep-07 Jan-08 May-08 Sep-08 Jan-09 May-09 Sep-09 Jan-10 May-10 Sep-10 Jan-11 May-11 Sep-11

Year Methodology Process

No, Maintain Current Operating Plan Identify Sustainable Storage Target, Demand, and Total Is Risk 1% or Greater? Reservoir Storage Yes, Determine Volume and Source of Supplemental Supply Needed to Achieve Desired Reliability Winter Season Runoff ! Planning Process

• Planning Goals – Minimize Risk of Reducing Allocation – Minimize Risk of Spill

• Planning Horizons – Seasonal (3 months to Years) – Sub-seasonal (2 weeks to 3 Months) – Event Driven (0-15 Days) Possible Beneficial Scenarios

Alter Surface/Ground water mix of Allocation • reliable “wet” forecast could prompt a decrease in groundwater usage that is offset by increased surface water usage • reliable “dry” forecast could prompt an increase in groundwater usage that is offset by decreased surface water usage • Preserve carry-over storage • Use of current delivery capacity • Reduces the use of augmentation sources • Initiate drought management plans

Alter Groundwater Recharge Goals • reliable “wet” forecast could prompt greater recharge efforts

Make Decisions of Least Regrets: Avoid Unrecoverable Actions

Save Money—Everyone’s Favorite

Weather Forecast Tools (Event Driven)

0-15 Days

Dynamic Weather Forecast Models (GFS, NAM, WRF, ECMWF & etc.,)

Model Output Statistics (MOS)

Expert Guidance (CPC 6-10 day/8-14 day & WPC QPFs) Weather Forecast Tools (Seasonal)

0-15 Days 3 Month – Years

Dynamic Weather Forecast Models Expert Guidance (GFS, NAM, WRF, ECMWF & etc.,) (CPC Monthly and Seasonal Outlooks)

Expert Guidance Statistical Tools (CPC 6-10 day/8-14 day & WPC QPFs) Dynamic Models Model Output Statistics (MOS) (CFS) Water Necessary to Recover

Historical Recovery Water Drought (KAF)

Reduction Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 Year 11 Total

1212-1218 20% 132 114 298 544

1576-1586 15% 169 143 285 316 913

1665-1671 20% 29 190 40 256 515

1817-1824 20% 337 140 261 19 112 869

1895-2005 20% 298 180 38 516

1998-2004 20% 19 242 283 544 “The Gap” Weather Forecast Tools (Sub-seasonal)

0-15 Days 3 Months – Years

Dynamic Weather Forecast Models Expert Guidance (GFS, NAM, WRF, ECMWF & etc.,) (CPC Monthly and Seasonal Outlooks)

Expert Guidance Statistical Tools (CPC 6-10 day/8-14 day & WPC QPFs) Dynamic Models Model Output Statistics (MOS) (CFS)

2 Weeks to 3 Months

Dynamic Models? Statistical Tools?

Possibilities to fill “The Gap” QPF/Precipitation Guidance

Categorical Probability Based Extended QPFs

Probability of Threshold Exceedence Ranges Above/Near/Below Median Ranges Multi-Day & Multi-Week 2 or 4 Week Time Frames Time Frames Weekly/Multi-weekly e.g., CPC Seasonal Outlooks Time Frames e.g., WPC QPFs

e.g., NCEP Ensemble PQPF Summary of Gap Filling Needs

Figure provided by the International Research Institute As a water supply (IRI) for Climate and Society (updated 14 April 2015). manager, what should you do? Winter Outlook

Analog Years—Huh?

Winter Precipitation with ENSO Greater than 0.0

20

17.5

15

12.5

10

7.5 Inches of Precipitation Inches 5

2.5

0 1980 1983 1987 1988 1990 1991 1992 1993 1994 1995 1998 2003 2004 2005 2007 2010

Strong El Niño Moderate El Niño Weak El Niño Neutral (greater than 0.0) Precipitation Uncertainties For the Watershed

La Niña Weak Moderate Strong n 21 9 8 4 Max 12.67” 11.41” 12.67” 5.21” Median 4.98” 6.02” 5.22” 4.89” Min 1.49” 2.05” 1.49” 3.53” Filling “The Gap” Weather Forecast Tools (Sub-seasonal)

Mid-season updates with more specifics that:

• Identify trends that narrow the range of forecast possibilities

• Identify thresholds offering greater confidence in a forecast outcome

• Identify and incorporate “season changing” events

• Need more communication and collaboration between the forecaster and the water resource manager.

• ? Questions?