James WalterSRP Surface Water Resources

WESTCAS Annual ConferenceJune 20th, 2018

Planning for a Future Climate on theSalt and Verde River

• SRP and the Reservoir System

• Hydro-climatology of the Watershed

• Recent Climate Change Projections

• Uncertainties

Outline

Salt River Project

• Established 1903

• A Federal reclamation project

• A private corporation

• Delivers almost 1 million acre-feet per year

• Established 1937 as a political subdivision of the state of Arizona

• 1,000,000 customers in and around the Phoenix metro area

Salt River Valley Water

Users Association

SRP Agricultural Improvement and

Power District

Flagstaff

PrescottPayson

13,000 Sq. MileProject

Watershed

Tucson

RiverPhoenix

Peoria

Tempe

Mesa

Gilbert

Chandler

Scottsdale

Glendale

Phoenix

Tolleson

Avondale

SRP’s Water Service Area

Salt and Verde Watersheds

VERDE CONSERVATIONSTORAGE:302,403 AF

SALT CONSERVATION STORAGE:2,004,287 AF

2026’

1798’

1529’

1914’

HorseshoeDam

StewartMountain

Dam

RooseveltDam

BartlettDam

Mormon FlatDam

Horse Mesa Dam

Total Conservation Storage: 2,306,690 AF

Horseshoe109,217 AF

Bartlett178,186 AF

Saguaro Lake69,765 AF

Canyon Lake57,852 AF

Apache Lake245,138 AF

Roosevelt Lake

1,631,532 AF

1660.5’

2218’ Top of Safety of Dams

2151’ Top of Conservation

C.C. CraginDam

6720’

C.C. Cragin15,000 AF

East Clear Creek Storage:15,000 AF

Verde River Storage:

287,403 AF

2100’ -

6720’ -

- 2000’

1506’ -

1610.5’ -

- 1748’

1891’ -

SRP’s Reservoirs

SRP’s Delivery System

Salt and Verde Normals (1981-2010)

Rain/SnowMonsoon

Rain

Climate Variability

Salt-Tonto-Verde SWE above 7,000’

16

12

8

4

0

Inch

es

Climate Variability

Climate Variability

Luong et al. 2017

Climate Change - Summer

Climate Change - Summer

Pascale et al. 2017

Seager and Vecchi 2010

Climate Change - Winter

Climate Change - Winter

Woodhouse et al. 2016

Climate Change – Winter (AR’s)

Lu et al 2018

Climate Change – Winter (AR’s)

Singh et al. (in review)

Vano et al. 2014

Climate Change – Uncertainties

Climate Change – Uncertainties

Mearns et al. 2009

Climate Change – Uncertainties

Climate Change – Uncertainties

Verde River Mean Accumulating Daily Inflow

Climate Change – Uncertainties

Climate Change – Uncertainties

Questions

System Health

Streamflow Projection

RPM

• Inflow• Local (ungauged inflow)

• Reservoir Operations

• Deliveries

• Groundwater

• Reservoir/River Losses

Running the RPM

• Monthly time-step

• Can run through GUI

• Batch run• SRP Python script used to

batch inflows into dss

• Hydrologics executable for batch run

• 64 runs takes less than 10 minutes

RPM Output

• Detailed output for storage, demands, deliveries, exchanges, losses, spills, etc.

• Variety of standard reports and graphs

• Ad hoc reports and graphs

• Calculates various statistics about output data

Examples of RPM Output

Purpose of the RPM• Current and future shortages

• Average surface water supply

• Future groundwater supply

• Effect of physical changes to reservoirs (i.e. increased conservation storage)

• Effects of operational changes to reservoirs

• Changes in demands

• Changes in exchanges and transfers

• Sedimentation effects

Benefits from high resolution dynamically downscaling