Reservoir Operations and Water Supply Planning at Salt River Project Roosevelt Dam and Lake, AZ Reservoir Operations and Water Supply Planning at Salt River Project Jon Skindlov meteorologist /climatologist Water Resource Operations Salt River Project, Phoenix, AZ DOI project workshop 28 March 2014 University of Arizona, Tucson, AZ
VARIABILITY – VULNERABILITY – UNCERTAINTY
Salt River Project SRP Agricultural Improvement and Power District Salt River Valley Water Users Association Established 1937 as a political subdivision of the state of Arizona 32,452 million kWh sold in FY13 969,000 customers in and around the Phoenix metro area Established 1903 A Federal reclamation project A private corporation Delivers almost 1 million acre-feet per year
WATER --Reliable Supply --Drought --Flood Roosevelt Dam and Lake Phoenix Superstition Mtns. WATER Salt River --Reliable Supply --Drought --Flood Roosevelt Dam and Lake Looking west, late winter 2008
Colorado River Storage Capacity Lake Powell 24.4 maf Total System (Upper and Lower Colorado) 59.2 maf Lake Mead 26.3 maf SRP lakes 2.3 maf 5
Salt/Verde watershed area (13,000 sq mi) Las Vegas Salt/Verde watershed area (13,000 sq mi) SRP… Manages 4 reservoirs on the Salt River, 2 on the Verde River and 1 on East Clear Creek; Operates approximately 260 groundwater wells; Delivers nearly 1 million acre-feet of water per year to the 250,000 acre SRVWUA service area. Mogollon Rim Salt River CAP
Salt/Verde watershed area (13,000 sq mi) CAP CAP canal “metro area” SRVWUA area (375 sq mi: 250,000 acres) 40 miles
Salt River Project Reservoir System Roosevelt Dam C.C. Cragin Dam 2218’ Top of Safety of Dams East Clear Creek Storage: 15,000 AF 2151’ Top of Conservation 6720’ 6720’ - Horseshoe Dam C.C. Cragin 15,000 AF 2100’ - Roosevelt Lake 1,653,043 AF Horse Mesa Dam 2026’ Horseshoe 109,217 AF - 2000’ 1914’ Bartlett Dam 1891’ - Apache Lake 245,138 AF 1798’ Mormon Flat Dam Bartlett 178,186 AF - 1748’ Stewart Mountain Dam 1660.5’ 1610.5’ - Verde River Storage: 287,403 AF 1529’ Canyon Lake 57,852 AF 1506’ - VERDE CONSERVATION STORAGE: 302,403 AF Saguaro Lake 69,765 AF SALT CONSERVATION STORAGE: 2,025,798 AF Total Conservation Storage: 2,328,201 AF 01/09/07 REF/SVRSCIAF-8
WINTER (build supply): 1971-2000 WINTER (build supply): Precip. (Dec-Mar): 6.3 in Runoff (Dec-May): 665 Kaf SUMMER (meet demand): Precip. (Jul-Sep): 6.8 in Runoff (Jul-Sep): 120 Kaf 9
Longer Period Of Sustained Drought Salt River Project Historic Drought Periods (Average Runoff 1913–2010 = 1,198,536 AF) 10 20 30 40 50 60 70 80 90 100 Longer Period Of Sustained Drought 7 Years 1942 - 1948 62% 4 Years 1974 - 1977 52% 19+ Years 1995 – 2014? ??% 5 Years 1953 - 1957 47% % Average 7 Years 1898 - 1904 35% 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Year
DRY WET DRY WET DRY 1892-1904: 2 wet, 11 dry 1905-45: 28 wet, 13 dry 1946-64: 5 wet, 14 dry 1965-95: 19 wet, 12 dry 1996-2013: 4 wet, 14 dry
What is Normal? 15 years above 1,000,000 acre-feet 11 years below 500,000 acre-feet
Creating Dependability from Variability From 2001-2010 total demand: 785 to 910 kaf Demand and constraints on operations due to regulations, urbanization, diminished GW pumping Impacts dependability we have on supply. Mention that wet years in the midst of a drought are not uncommon
Water Resources Planning Will Change
Change in Agricultural Water Use 1955 1975 PHX PHX Pop. 0.5 M Pop. 1.3 M 1990 2008 PHX PHX Pop. 2.1 M Pop. 4.0 M Salt River Water Users Association area
Urbanization of Member Lands SRP expects to be “fully urbanized” by 2017
http://phoenix.gov/waterservices/wrc/yourwater/wrplan.html
P G S PHX T M G C
Primary water sources for Valley cities: SRP (surface and ground) [demand: 300 – 340 kaf] Primary water sources for Valley cities: SRP (surface and ground) CAP (surface) City wells (ground) http://phoenix.gov/waterservices/wrc/yourwater/wrplan.html
KNOWNS and UNKNOWNS
Longer Period Of Sustained Drought Salt River Project Historic Drought Periods (Average Runoff 1913–2010 = 1,198,536 AF) 10 20 30 40 50 60 70 80 90 100 Longer Period Of Sustained Drought “Drought of Record” 7 Years 1942 - 1948 62% 4 Years 1974 - 1977 52% 19+ Years 1995 – 2014? ??% 5 Years 1953 - 1957 47% % Average 7 Years 1898 - 1904 35% 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Year
Storage Planning Diagram
Storage Planning Diagram
www.srpnet.com Jon.Skindlov@srpnet.com Questions?
http://phoenix.gov/waterservices/wrc/yourwater/wrplan.html
Journal of Hydrology 509 (2014) 454–473
http://phoenix.gov/waterservices/wrc/yourwater/wrplan.html http://phoenix.gov/webcms/groups/internet/@inter/@dept/@wsd/documents/web_content/wsdfaqsupply030714.pdf
Upper Colorado River Basin Salt-Verde-Tonto River Basin
Demand Demand is the water that is called for at a predetermined time to be delivered to shareholder or contract customer land, water treatment plants, or power plants. Today, demand is difficult to predict: Water use efficiency Increasing densification Extended drought Agriculture to urban Economic downturn From 2001-2010 total demand ranged from 785 KAF to 910 KAF.
Demand Demand is difficult to predict: Water use efficiency Increasing densification Extended drought Agriculture to urban Economic downturn