klamath basin water distribution model workshop

Klamath Basin Water Distribution Model Workshop

OUTLINE

Brief Description of Water Distribution Models

Model SetupsExamples of networks and inputs

Demand Estimates and Checks

Two Simple Modeling Examples

The Klamath Basin

Question and Answers

•What is a water distribution model?

A water accounting system. Routes water within a distribution network (stream, canal, etc.)to demands based on priority and supply.

Brief Description of Water Distribution Models

River

Demand 1,1967 priority

Basin Boundary

Demand 2,1905 priority

Basin Outlet

Demand 3, 1865 priority

Demands #1 and #2 normallywould not compete for water because they are on different tributaries. However, due to theexistence of a downstream demand(#3) with a senior priority date, there is an interaction betweendemands #1 and #2.

Model Setups

• Network Examples and Data Requirements

• Network Examples

•General Network Description

•The Ideal Network

•The Workable Network

•The Common Network

General Network Description

•Links represent tributaries or streams

•Source (inflow) nodes represent flows at tributary confluence

•Physical length of links are unimportant. Monthly time step eliminates need to calculate travel times.

•Relative placement of source nodes, demands and tributary confluence are important.

• Unknown Parameters

Physical

River

Demand 1

Basin Boundary

Schematic

River

Source 1

Source 3

Source 2

Demand 1

Demand 2

Source 1 Source 2 Source 3 Net Demand 1 Net Demand 2 Basin Outflow

Demand 2

Basin Outlet

Basin Outflow

• 3 Types Sources (Inflows) Net Demands Outflows

In aggregatedterms, if any twoparameters areknown the thirdcan be determine.

General Network Description

Tributary 1

Tributary 2

Tributary 3

The Ideal Network

•All demands, inflows and outflows within the basin are measured.

•No estimates required.

River

Flow AccountingPhysical

River Gage

Demand 1

Demand 2

Basin Boundary

Schematic

Source 1

Source 3

Source 2

Demand 1

Demand 2

Source 1+ Source 2+ Source 3- Demand 1- Demand 2 Gage Record

Because of return flows, Sources -Demands Gage Flows

Return flows can be directlycalculated.

Sources - Gage Record= Net Demands

Demands-Net Demands= Return Flows

The Ideal Network

The Workable Network.

•Two out of three parameters are known.

inflows and outflows, orinflows and demands, or

outflows and demands.

• Other parameter can be calculated directly.

Physical

River Gage

Demand 1

Demand 2

Basin Boundary

Schematic

River

Source 1

Source 3

Source 2

Demand 1

Demand 2

Source 1+ Source 2+ Source 3- Net Demand 1 - Net Demand 2 = Gage Record

Calculated Net Demandsdirectly (in aggregate terms)

Flow Accounting

Source Flows- Outflows= Net Demands

The Workable Network

Project Areas 1 and 2are similar to the “workable network”. Net demands are calculated from gage recordsof inflows and outflows from the project.

The Common Network.

• Only one out of three parameters are known. (Usually sub-basin outflow).

• Requires estimation of one of the unknown parameters.

Physical

River Gage

Demand 1

Demand 2

Basin Boundary

Schematic

River

Source 1

Source 3

Source 2

Demand 1

Demand 2

Source 1+ Source 2+ Source 3- Net Demand 1- Net Demand 2 = Gage Record

Flow Accounting

Gage Record+ Net Demands= Source Flows(Zero Demand Flow)

The Common Network

Need to estimate eithersource flows or net demands.Due to data limitations andtime constraints, net demandswere estimated in most areas above Klamath lakeinstead of source flows. Sourceflows can then be calculatedaccording to the formula below.

Physical

River Gage

Demand 1

Demand 2

Basin Boundary

Schematic

River

Source Flow

Net Demands

Flow Accounting

Gage Record+ Net Demands = Source Flow

OR

Zero Demand Flow

The Common Network Aggregated

This estimation of net demandsand consequent calculationof source flows does not allowthe modeling of the individualtributaries and demands.The demands and tributariesare aggregated.

Network Example Summary

•The Ideal Network - No estimates required Gage data used directly to determine demands and flows.

•The Workable Network - Net Demands are directly calculated. Demands may be Aggregated. •The Common Network - Estimates of either source flows or net demands are required. Demands and source flows are aggregated.

Demands

•Estimates: How are net demands estimated?•Checks

Net Demand = (Evapotranspiration - Precipitation - Soil Moisture) x Acreage •Evapotranspiration estimated from Temperature Records using Hargreaves Equation.

•Precipitation taken from Rain Gage Data

•Soil Moisture estimated using Soil Conservation Service Surveys, and Antecedent Precipitation

•Crop Acreage

Example:

Monthly Net Demand = (Evapotranspiration - Precipitation - Soil Moisture) x Acreage

Monthly Net Demand = (7 inches - 0.5 inches - 0.5 inches) * 1000 acres

= 500 ac-ft or 8.1 cfs

Demand Estimates Checks•Diversions

Simulated versus Measured• Canal Data• Depleted Flow Data

• Annual Net Demand EstimatesSimulated versus Measured

•Average•Yearly Trends

•Annual Crop ETSimulated versus “Agrimet” Data

Diversions

•Simulated versus Measured Canal Data

Modoc Diversion Canal:Comparison of simulated monthly average versus miscellaneous daily measurements.

1981 Modoc Diversions

0

10

20

30

40

50

60

70

80

Mar Apr May Jun Jul Aug Sep Oct

(cfs

)

Predicted (Monthly) Actual (Single Measurement)


0

10

20

30

40

50

60

70

80


(cfs

)

Predicted (Monthly) Actual (Single Measurement)


01020304050607080


(cfs

)

Predicted Monthly Actual Single Measurement


01020304050607080


(cfs

)



01020304050607080


(cfs

)



01020304050607080


(cfs

)



01020304050607080


(cfs

)


Average for Available Records

0

10

20

30

40

50

60


Div

ersi

on (

cfs)

Modoc Simulated

Diversions

•Simulated versus Measured Depleted Flows

Wood River 91-93:Inflows from tributaries calculated

from miscellaneous records.

Demands estimated using previously described method.

Outflows taken from BOR gage data.

Physical

RiverGage

Demand 1

Demand 2

Basin Boundary

Schematic

Source 1

Source 3

Source 2

Demand 1

Demand 2

Source 1+ Source 2+ Source 3- Net Demand 1- Net Demand 2 = Outflows

Flow Accounting

Compare SimulatedOutflow to Gage datato check estimates

Wood River

0100200300400500600700

cfs

Simulated Flow Zero Demand Flow

Measured Flow

Wood River

0100200300400500600700

cfs

Simulated Flow Zero Demand Flow Measured Flow

Wood River

0

100

200

300

400

500

600

700

10 19

93

11 19

93

12 19

93

1 199

3

2 199

3

3 199

3

4 199

3

5 199

3

6 199

3

7 199

3

8 199

3

9 199

3

10 19

94

cfs

Simulated Flow Zero Demand Flow Measured Flow

Average Measured vs. Simulated Flows of Wood R (4/1991-12/1993)

0

50

100

150

200

250

300

350

400

450

10 11 12 1 2 3 4 5 6 7 8 9

Month

cfs

Simulated Flows Measured Flows

Diversion Check

Simulated diversions appear to be reasonable when compared to measured canal and

depletedflow data.

Annual Net Demand Estimates

Simulated average annual demand above Klamath Lakeversus measured average annual demand in the Project.

• Climate is similar.• Same basin. • Demand is normalized by acreage (ac-ft/ac).

Annual Average Consumptive Demand (ac-ft/ac)

1.52

1.84

0

0.5

1

1.5

2

2.5

3

(ac-

ft/a

c)

Estimated Above Klamath Lake Historical Net Demand In Project

Annual Consumptive Demand (ac-ft/ac)

0

1

2

319

74

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

(ac-

ft/a

c)

Estimated Net Demand above Klamath Lake Historical Project Demand

Annual Net Demand Estimates Check

• Estimated annual demands above Klamath Lake appear reasonable when compared to measured data available elsewhere in the basin.

• Yearly simulated variations in annual demands generally follow measured data.

Annual Crop ET

• Simulated annual crop ET versus “Agrimet” data in Lakeview.

Simulated Net ET above Klamath Lake vs ET from LakeView Agrimet Station

0.0

5.0

10.0

15.0

20.0

25.0

30.0

1993 1994 1995 1996 1997

Net

ET

(in

)

Simulated LakeView

Model Examples

Integrating Instream Demands

• Single Tributary System• Two Tributary System

Actual

River

Demand 1

Demand 2

Basin Boundary

Schematic

River

Zero DemandFlows

Demand A

Flow Accounting

ZDF-Instream Demands= Flows Available for Irrigation Demands

InstreamDemand

InstreamDemands

Demand A,1864

InstreamDemand C

ZDF Tributary A

ZDF Tributary B

InstreamDemand D

Demand B,1905

Instream demand D has a call on upstream demands. However, the shortages appear in Demand A instead of Demand B even through Demand A has a senior priority date. The reason is that instream demand C is effectively causing the shortages to Demand A, which consequently increases flows to instream demand D. Thus demand B is not called to reduce its use.

Counterintuitive DemandInteraction.

Klamath Basin Setup

Spencer Creek

Lake Ewauna

Project Area A2

Other Tributaries Seeps and Springs

Wood River and Tributaries

Accretions Middle Sprague

ZDF Sycan

Accretions Middle Williamson

ZDF Lower Williamson

Klamath Straits Drain

ZDF Upper Williamson

LEGEND

Channels Source Nodes Consumptive Uses Junctions Marshes/Lakes

GAUGE OVERLAP PERIOD (73-97)

Project Area A1

ZDFSprague

LRDC

Ewauna Accretions

klamath basin water distribution model workshop

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