Andy Draper - Montgomery Watson HarzaWalter Bourez - MBK Engineers

February 26, 2004

CALSIM II Sacramento RiverBasin HydrologyEnhancements

Current representationProblems

SolutionsWork completedPossible effects to CALSIM simulationFuture direction

Issues

Poor representation of water use in theSacramento Valley means that Calsim IIcannot be used with a high degree ofconfidence to provide absolute values ofwater supply reliabilityCoarse spatial resolution of the model makesCalsim II of limited value for the analysis oflocal projects

Current Representation– overview– demands– water supplies

ProblemsSolutionsWork completedPossible effects to CALSIM simulationFuture direction

Methods developed in late1950’s early1960’sFocus was on water supply– Mainly South of Delta Water supply

Very large areas aggregatedMethods, spatial resolution, and much of thedata are still the same

Rim DSAs (in gray)– represented indirectly

– preprocessed inflow to CalSim II

Valley floor DSAs (in color)– represented directly by series of

nodes and arcs

– Dynamically simulated

DSA represents spatial resolutionof the model

Surface returnflow

Ag +outdoorurban

Deeppercolation ofapplied water

surfacerunoff

GW GW

Stream-gwinteraction

Boundary inflow+

Recharge fromprecipitation

Streamdiversion

GWpumping

DSA Boundary

Current Representation– overview– demands– water supplies

ProblemsSolutionsWork completedPossible effects to CALSIM simulationFuture direction

Sectors– Irrigated agriculture– Outdoor urban (irrigated landscape)– Indoor urban (residential, commercial, industrial)– Wildlife refuges– Environment (min. instream flow requirements)

Outdoor urban aggregated with agriculture

Indoor urban generally not modeled(exception Greater Sacramento Area)

CUAW from CU modelNon-recoverable losses

10-15% CUAW

Deep percolation% CUAW

Surface return flow% of CUAW

GW pumping

SW

DSA Boundary

Depletion

Demand calculated for each DSA based on cropacreageDSA demand subsequently split into project and non-projectProject Demands– Entitled to releases from project storage– Deliveries constrained to lower of land use based demand or

contract allocation

Non-Project Demands– Diversions constrained to lower of land use based demand or

unimpaired river flow– Not entitled to releases from project storage

Stream diversion/pumpingrequirementProject:Non-project splitNon-recoverable loss factorSurface return flow factorDeep percolation factorMaximum contract entitlement

Surface returnflow

Deeppercolation ofapplied water

surfacerunoff

GW

Stream-gwinteraction

Boundary inflow+

Recharge fromprecipitation

Streamdiversion

GWpumping

DSA Boundary

Ag +Outdoor

urban

GWGW

Crop ETAWNon-RecoverableLoss

Current Representation– overview– demands– water supplies

ProblemsSolutionsWork completedPossible effects to CALSIM simulationFuture direction

Assume static land use, fixed water supply contractsand regulatory requirements for each year ofsimulationUse adjusted historical hydrology to representprobable range of hydrologic conditionsAssume temporal and spatial distribution ofprecipitation same as historicalModify historical stream flows for impacts of land usechange and upstream flow regulation

SR 1

Surface waterreservoir

local water supplies

Rim Flow

1

Hydrologic boundary ofsystem represented by model

Average Annual Regulated Inflow = 16,150 taf/yr

TrinityStony Creek

Yuba River

Bear River

Clear Creek

American

Lake Shasta

Feather

Average Annual Inflow = 16,150 taf/yr

Average Accretion = 6,420 taf/yr

Average Depletion = 626 taf/yr

DSA 58

DSA 10DSA 12

DSA 15

DSA 65

DSA 69

DSA 70

DSA 58 DSA 10

DSA 12

DSA 15

DSA 65DSA 69

DSA 70

Time series of inflows to eachof the seven Valley floor DSAsCalculated as closure term inhydrologic mass balance oneach DSARepresents direct runoff fromprecipitationIncludes all error terms

Historical Water Supply from mass balanceProjected Water Supply= Historical Water Supply +Rainfall-Runoff AdjustmentContain errors in mass balance

DSA

Streaminflow

Streamoutflow

Cropevapotranspiration

Native vegetationevapotranspiration

Evapotranspirationfrom urbanlandscape

Runoff

GW pumping

Recharge

Land-use base demands fully metSupply priorities for meeting demand– Minimum groundwater pumping– Surface water

• up to the contract amount for project demand• and up to its availability for riparian demands.

– Additional groundwater pumping for any unmetdemand

Current Representation– overview– demands– water supplies

ProblemsSolutionsWork completedPossible effects to CALSIM simulationFuture direction

Based on:– GIS land use data– Irrigation District boundaries– Unit crop ETAW

Ratio of crop acreage within ‘project’ irrigation district to totalcrop acreage within DSAAcreage weighted by unit crop ETAWAssumes identical water use efficiencyShort-form CVP contractors wrongly assigned to non-project asthey lie outside of irrigation district– 68,000 ac– 245,000 af contract

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Percentage groundwater use thesame for project and non-projectdemandsAll diversions are from the majorstream system ( SacramentoRiver, Feather River andAmerican River)Non-project demands arepredominantly supplied by minorstreams tributary to theSacramento River. Thesesupplies may be more restricted indry years

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DSA aggregate demand function of CUAWand regional efficienciesEfficiencies not related to on-farm water useNo explicit representation of conveyance loss,operational spills, reuseEfficiency not dependent on sourceBasin efficiency is outdated (early 1970’s)

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Calsim II demands are not related to appliedwater demands at the farm level and districtlevel, although most of the available data isat these scales rather than a regional level.

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Difficult to assess impacts of waterconservation measures due to poorrepresentation of efficiencies and losses.

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Demands, deliveries, return flows are difficult toreconcile between models

DSM 2

CU ModelCVPM/CALAG

LCPSIM

HistoricalCVGSM

CVGSM

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Spatial Resolution– Land use based demands for DSA– Contract allocations for individual contractors

Contractors’ demand assumed to beproportional to maximum contract entitlement

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Level 2 supplies approximately 190,000 af

Estimate Historical Refuge Operation to Avoid DoubleCounting of Refuge Demand

Develop Refuge Ponding Operation to BetterRepresent Return Flow Timing and Volume

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Current rice acreage in the Sacramento Valley ~500,000 ac, ETAW ~ 3 ftIn the 1990’s 140-day variety most commonCalsim II crop water use based on 160-day varietyRice Straw Burning Reduction Act 1991Update water requirements to account for:– Shorter growing season– Current ponding practices– Rice straw decomposition

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Current Representation– overview– demands– water supplies

ProblemsSolutionsPossible effects to CALSIM simulationWork completedFuture direction

DWR recognizes these problems and isworking on solutions

Improvement of Sacramento Valley Hydrology– Work in 2003 funded by the California Bay-Delta

Authority and South-Delta Improvement Program

Data from GIS– Ability to aggregate areas by

• DSA• DAU• Planning Area• County• Water district• Land use type• Demand Type (Identified as part of this project)

Criteria• Water supply source• Use of return flows and drainage• Basin characteristics

Various Demand Types Within Areas AreAddressed SeparatelyWork Performed Using GIS

Replace existing DSA-level demandDifferentiate demands by:– Contractor type– Source of water– Cropping pattern– Irrigation efficiency

Revised Areas Land Use

Revised Method– More detailed information to relate CALSIM to

CALAG– Estimate “on farm” applied water

Diversion Requirement

Return Flow

CUAW

NRL

DP

Diversion Requirement = CUAW / EfficiencyBasin

DSA(Basin)

AW100

CUAW70

Return Flow23

DP+NRL7 Field

AW = CUAW / Efficiency

AW100ETAW

70

Return Flow23

DP+NRL7

Field

AW100ETAW

70

Return Flow23

DP+ NRL7 Field

177

23

AW100

ETAW70

ReturnFlow23

DP+ NRL7 Field

AW100

ETAW70

ReturnFlow23

DP+ NRL7 Field

CL1

Qin

ReturnFlow

•

•

•

CL

Inflow AW = CUAW / EffField

Inflow = Qin – CL= CUAW / EffField * RF

RF = Inflow / ‡ Awi (i = 1, number of fields)

Inflow = InflowGroundwater + InflowSurface Water

Return FlowBasin = Inflow– NRLField – CUAW – DP

Return FlowBasin = Qin – CL– NRLField – CUAW – DP

Qin = Basin Diversion Requirement orSupply into Basin

AW = Applied WaterCUAW = Consumptive Use of Applied WaterEffField = on Field Efficiency by Crop TypeRF = Reuse FactorNRL = Non-Recoverable LossDP = Deep PercolationCL = Conveyance Loss (DP + NRL)

Explicitly represent:– (CUAW) Crop consumptive use of applied water– On-farm non-recoverable losses– (ETAW/AW) On-farm application efficiency– District level reuse– Inter-district reuse– Recoverable conveyance losses– Non-recoverable conveyance losses

Use existing schematic to extent possible– Include additional “Layering”– Attempt to maintain DSA layout

Revise Feather River representation

Each contractor type ornon-project diverter hasassociated:– stream diversions– groundwater pumping– consumptive use of

applied water– return flows

GW

Boundary inflow+

Recharge fromprecipitation

Streamdiversion

GWpumping

DSA Boundary

GW

Ag +Outdoor

urban

GW

GIS Information ContainsWater Source Attribute– Surface vs. Ground water

Precipitation Runoff and Additional RunoffKept at DSA Level

Separate Water Supply Within Each DSAUsed to Satisfy Demands in ParticularRedefined Area

Represent Ponding OperationDevelopment of Rice Decomposition Water Demandand Ponding

Estimate Historical Refuge Operation to Avoid DoubleCounting of Refuge DemandDevelop Refuge Ponding Operation to BetterRepresent Return Flow Timing and Volume

Rice Water Operations (Average of 1993-99)Rice Water Operations (Average of 1993-99)

-10

-5

0

5

10

15

20Ja

nuar

y

Febr

uary

Mar

ch

April

May

June July

Augu

st

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

Wat

erR

equi

rem

ent(

inch

es)

Growing Season ETAW Growing Season Drainange Decomp Decomp Drainage Cultural Water

Dra

inag

e(in

ches

)

Sacramento NWR Water Operations (Average 1993-99)Sacramento NWR Water Operations (Average 1993-99)

-6

-4

-2

0

2

4

6

8

10

12

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

1000

Acr

e-Fe

et

Deliveries Outflows

Draw-down ofSeasonal Ponds

July through AugustDraw-down of Summer Ponds

and Watergrass Fields

April through JulyIrrigation of Watergrass for Waterfowl

Food and Maintance of Summer

August through DecemberFlood Up of Seasonal Ponds and Marshes,

Maintance of Permanent Ponds

December through FebruarySystem is Closed to Prevent

Flow-thru

Current Representation– overview– demands– water supplies

ProblemsSolutionsPossible effects to CALSIM simulationWork completedFuture direction

Difficult to determine– plus a couple 100,000 AF here– minus a couple 100,000 AF there

Change in timing of flowsChange in locations controlling operationChange in annual flow volumes

Depiction of physical systemHydrologic factorsGround water pumpingDefinition of project and non-projectdemandsRice operation and demandsRefuge

G

DA 58

DA 10

DA 15DA 12

RED BLUFFDIVERSION DAM

HAMILTON CITYPUMPING PLANT

WILKINS SLOUGH(NCP)

COLUSA BASIN DRAINRETURN TO SACRAMENTO RIVER

Department of Water ResourcesSub-BasinsDWR Sub-BasinsDWR Sub-Basins

DSA Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep58 65 65 65 65 65 65 65 65 65 65 65 6510 70 70 70 70 70 70 70 70 70 70 70 7015 70 70 70 70 70 70 79 65 75 78 65 3512 70 70 70 70 70 70 79 65 75 78 65 3569 40 70 70 70 70 70 70 65 75 80 75 30

Colusa Basin Drain Outflow April - October Total FlowColusa Basin Drain Outflow April - October Total Flow

0

100

200

300

400

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600

700

1922

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1990

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1994

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1998

Flow

(100

0A

F)

Historical CALSIM

CurrentOutflow Range

Current Representation– overview– demands– water supplies

ProblemsSolutionsPossible effects to CALSIM simulationWork completedFuture direction

Redefinition of DSA’sRice Decomposition Water RequirementRefuge OperationCALSIM – CALAG relationshipInitial WRESL code

How to complete projectInterest in projectFunding