Truckee River Modeling System

RiverWare User Group Meeting

March 1, 2005

Tom Scott, Jeff Rieker and Shane Coors

Derby Dam

STAMPEDE

TRUCKEERIVER

CARSON RIVER

LAKE TAHOE

DONNER

Stillwater NWR

LAHONTANBOCAINDEPENDENCE

PROSSER

Reno/Sparks

NewlandsProject

CarsonCity

Fallon

PYRAMIDLAKE

Tahoe City

TRUCKEECANAL

Pyramid Lake Paiute Indian Reservation

NE

VA

DA

CA

LIF

OR

NIA

MARTIS

Many Conflicting Interests…

Pyramid Lake

Pre-Newlands Project Lake Level

80 Feet

Operations

• Current Operations – 1935 Truckee River Agreement– 1944 Orr Ditch Decree– 1959 Tahoe Prosser Exchange Agreement– 1994 Interim Storage Agreement– 1997 OCAP

• Future Operations – Truckee River Operating Agreement (TROA)

Model Objectives

• Efficient management of an increasingly valuable natural resource – the Truckee River

– Track the physical water daily– Track status of accounts in the system daily– Operate according to governing Policy – Forecast and plan for the coming year and years– Provide regular operational forecasts to stakeholders– Administer TROA

Truckee RiverWare Modeling System

Truckee Modeling System Concept

• Takes historic, current, and forecast hydrologic data and simulates system operation, while continuously tracking the status of accounts within the Truckee/Carson river system.

• Examine the analogous processes of managing a small company’s finances, and modeling the Truckee River Basin with RiverWare

Financial Management

• Accounts provide the structure for managing finances within a company

• All $ entering, passing through, and exiting the company are assigned to an account.

• Accounts represent possible categories of income and expenses (i.e. sales, payroll, taxes, etc.)

RiverWare

• In RW, accounts provide the framework to manage Truckee River water according to basin policy

• All water entering, flowing through, and leaving the basin is assigned to an account

• Accounts include water owners and designated usages (ie. TMWA, Floriston Rate, Endangered Species, etc.)

Accounts Structure“Management Framework”

Truckee Accounts Map

Accounting“Establish Current Status”

RiverWare

• Updates the status of all of the accounts on the system to the current time

• References gage flows, reservoir storage volumes, and water usages within the system

Financial Management

• Detailed, balanced accounting of all income and expenses from the beginning of the year to the current time

• Generate the current status of all accounts in the budget

Accounting ModelStep 1: “Establish Current Status”

Accounting Model Summary

• Input is all current streamgage and reservoir storage data in the basin from DIADvisor

• Computes accounts status after yesterday’s inflows, outflows, exchanges, and transfers

• Output is hydrologic and up-to-date accounting data

Forecasting“Project Inflows and Depletions”

Financial Management

• Income and expenses must be forecast from current time to the end of the year

• Forecast based on previous years’ incomes and expenses as well as current financial conditions

RiverWare

• Inflows to all reservoirs and all sidewater forecasted to the end of the year

• Demands and diversions forecasted to the end of the year

• Forecasts are based on analysis of historic values and current hydrologic conditions within the basin

Forecast ModelStep 2: “Project Inflows and Depletions”

Forecasting Model

NRCS ForecastedApril-July Volume

Truckee River at Farad

Volume:TOTAL sum1000’s Acre-feet

Flow:Daily RATEVolume per time

Forecast Model Summary

• Input is NRCS volume forecasts at Farad and Fort Churchill gages.

• Forecasts all inflows and depletions in the basin by a similar years analysis

• Output is forecasted basin hydrology for the remainder of the year.

Alternative Forecast InputMMS ESP Tool

Temperatures

-10.0

0.0

10.0

20.0

30.0

40.0

50.0

2/17/05 2/19/05 2/21/05 2/23/05 2/25/05 2/27/05 3/1/05 3/3/05

Deg

rees

F

30

40

50

70

90

110

NOW

Additional Forecast InputShort-term Realtime Forecast

Mineral2

Current Time

Current Time

0

200

400

600

800

1000

1200

6/17/97 6/19/97 6/21/97 6/23/97 6/25/97 6/27/97 6/29/97

Flo

w (

cfs)

outflow

MNSCAV

Current Time

Operations “Simulate Remainder of Year”

Financial Management

• Take current status of accounts, forecasted income, expenses and operational constraints and simulate flow of $ to end of year

• Generate periodic (daily/monthly) status of accounts – Profit and Loss Statement

RiverWare

• Given current status of accounts, forecasted inflows, and depletions, simulate operations of the system from current time to end of year.

• Generates the status of all accounts and physical quantities (flows, storages, etc.) each day throughout the simulation period

Operations ModelStep 3: “Simulate Remainder of Year”

• The heart of the Operations Model…..

The RulesetDefines basin policy and physical constraints in order to simulate operations to the end of the year

Operations Model“A flavor of Ops”

Operations Model“A flavor of Ops”

Example Rules:

Operations Model“A flavor of Ops”

Operational Criteria on Lake Tahoe• Water Surface elevation must not exceed 6229.1 ft• Operational Maximum release of 300 cfs• Absolute Maximum release of 2600 cfs• Minimum release of 50 cfs in the winter• Minimum release of 70 cfs in the summer• Outflow approaches zero when elevation nears rim according to a rating curve• Must release in conjunction with Boca Reservoir to satisfy the Floriston Rate

• During April – October if Tahoe elevation is above 6225.5, minimize Tahoe releases

• During April – October if Tahoe elevation is below 6225.5, maximize Tahoe releases

• During the Spring when reservoir is near capacity, releases must be made such that reservoir fills to 6229.1 ft but no higher.• If Tahoe is releasing minimum and the flows are not needed to maintain the floriston rate, then an equivalent amount of water is stored in Prosser Reservoir as “Tahoe-Prosser Exchange”

Lake Tahoe

0

10

20

30

40

50

60Ja

n-05

Feb

-05

Mar

-05

Apr

-05

May

-05

Jun-

05

Jul-0

5

Aug

-05

Sep

-05

Oct

-05

Nov

-05

Dec

-05

Month

Re

lea

se

(kA

F)

6,220.00

6,221.00

6,222.00

6,223.00

6,224.00

6,225.00

6,226.00

Re

se

rvo

ir E

lev

ati

on

(k

AF

)

50% Outflow30% Outflow70% Outflow50% Elevation30% Elevation70% Elevation

Combined Forecast

2/9/2005Lahontan Reservoir StorageBoca Reservoir StorageFarad Gauge Flow

Operations ModelSample Output

Data Flow

DIADvisor

DIADvisor host computer

Data Flow Between Models

Reno Carson City

Automation

• Data transferred to database at 2:30 PM each day

• Accounting model run at 3:30 each day

• Data retrieved from Reno in evening, forecast and ops model run when data arrives

• New forecast available first thing in the morning

Water Quality Modeling

• Utilize existing basin-specific water quality models

• Eventually provide real-time decisions

• Operate interactively with RiverWare– Data output from RW to external model– Model returns info to RW– Provides mechanism to link other models

(groundwater, sediment, etc.)

WQ Modeling

• Proliferation of accounts: 7 20

• Each Reservoir goes from single purpose to multi-purpose. Any kind of water in any reservoir

• Extensive exchanges and transfers throughout basin

• “Operation by Committee” – Model must facilitate interaction by stakeholders.

Other Credit WaterWater Quality Water/Fernley M&I Water

California M&I Water

Fish Credit Non-Firm M&I Credit

Fish Water

Firm M&I Credit

M&I Emergency Drought Supply

Acquireddiversion

rights

Single purposepower

component ofFloriston Rates

StorableLittle

TruckeeRiver

PrivateWater &

Former AgriculturalWater Rights

Exchangedfrom

Lake Tahoe

TROAWhat is Next?

The End

Pyramid Lake