Climate Change Impact on Water Availability in NYC Water Supply

Adao Matonse1, Allan Frei1, Donald Pierson2, Mark Zion2 , Elliot Schneiderman2, Aavudai

Anandhi1, and Hampus Markensten3

1 CUNY Institute for Sustainable Cities, Hunter College2 Bureau of Water Supply, New York City Department of

Environmental Protection3 Upstate Freshwater Institute

New York City Department of Environmental ProtectionBureau of Water Supply

Water Quality

Presentation Outline

• Introduction– What is OASIS ?– The OASIS Model Framework– The NYC Water Supply System– Climate Change Simulations for OASIS

• Selected Results• Summary • Preliminary Conclusions• Next Steps• Discussion

02

• It has a Graphical User Interface (GUI)- Control data entry into database- Helps manage simulation runs- Helps access to output files- Graphical display of the system (schematic)

• Routes water from a system of nodes & arcs

IntroductionWhat is OASIS with OCL?

625

630635

650

655995

657

651

EsopusCk

Shandaken Tunnel

DelBnDiv

Catsk_In

EAsh_Spl

WAsh_Spl

Allaben_

986

AshWaste

WAshokan

EAshokan

Schohari

PepacSpl

Reservoir

Junction

Demand

NODES

ARCS

03

IntroductionWhat is OASIS with OCL?

• Software by HydroLogics, Inc.• Modeling operations of water supply

systems• Generalized program• Data-driven: specify features and rules

without altering source code• Use Operations Control Language (OCL)

to set operating rules• Simulates routing by solving a Linear

Program (LP)

04

The OASIS Modeling FrameworkOverview - Climate Change Simulations

System Descriptors

OASIS

WatershedModel

W QualityModel

SystemDesign

DefaultInput

OtherMeasured

Demand Climate Change

Driving Elements

Rules- Constraints

- Goals

GCMSimulation

Integrated System

How to do it?LP

What to do?OCL

05

IntroductionThe NYC Water Supply System

E. Br. Delaware R.

Delaware R.

Lackawaxen R.

Mongaup R.

Neversink R.

Lehigh R.

Tohickon Cr.

Musconetong R.

Assunpink Cr.

Crosswicks Cr.

N. Br. Rancocas Cr..Schuylkill R.

White Clay Cr.

Red Clay Cr.

Tulpehocken Cr.

Jordan Cr.

Dyberry Cr.

W. Br. Lackawaxen R.

Perkiomen Cr.

Maiden Cr.

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D&R Canal

657

OASIS Model of

Water Supply System and

Delaware River Basin

New York City

JeromePk

Stilesvl

Callicoo

OaklandV

NevrsRiv

Woodbrne

Montague

PortJerv

MongpRiv

Hawley__

Wilsonvl

Wallenpa

Barryvil

TocksIsl

Philadel

Schuylkl

Dem_5BPA

Reading_

BlueMrsh

Pottstwn

Berne___

Landingv

Limerick

Graterfd

ChaddsFd

Wilmingt

Demd_8DE

MemBridg

Newark__

Wooddale

Demd_8PA

Chester_

Dem_7BNJ

Dem_5APA

Dem_7ANJ

TrentInc

Demd_4NJ

PPleasntPipersvl

Demd_6PA

Glendon_

Walnutpt

BeltzRiv

Whitehvn

MerrlTrn

MerrlRes

Belvider

Lehigh R.

D&R-King

WBrLackw

Prompton

Honesdal

661

706

621

702 703707

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699

766

761

FEWalter

BeltzRes Aquashic

Palmertn

Schnecks

Allentwn

Hacketts

Bloomsby

Nockamix

AssunCrk

ExtonvilLanghorn

Pembertn

Torresdl

PierII_N

PottsvilCressona

Tamaqua_

Drehersv

Virginsv

BlueMRes

ChestrCk

Jadwin__

Dyberry_

767

768

769 771

671716

676

721711

726

736746

751756

998

BoydsSplEBrBgSpl

Spill Nodes

CrDivSplM_BraSpl

W_BraSplCroFlSpl

TitcsSplAmwlkSpl

CrRvrSplMusctSpl

651

EBCrotJn

WJWW_dem

Kn48_dem

Kens_Spl

WBra_dem

Shaft_11

Shaft_10

CrotJnc1

CrAq_dem

KH_DelAq KH_CatAq

KnCt_demKnDl_dem

CrotJnc2

NCro_Rel

NCro_Spl

CatJunc1

CatJ_dem

RoWB_dem

NwCr_dem

Amaw_dem

Musc_dem

MBra_dem

Shaft_9_

MuscootJW. Br. Delaware R.

EsopusCk

Wallenpaupack Cr.

MongpRes

Demd_1NY

Demd_1NJ

Demd_1PA

HaleEddy

Downsvil

Harvard_

FishEddy

DelBnDiv

Bethlehm

Demd_3PA

Riegelsv

Demd_2PA

Demd_2NJ

Trenton_

Demd_4PA

TT_UpDel

TT_LoDel

BelowDiv

Shaft_13

term_599

Shaft_17

Scho_Spl

CrossRvr

Titicus_

M_Branch

CrotFall

Muscoot_

Amawalk_

Catsk_In

EAsh_Spl

WAsh_Spl

Allaben_

986

AshWaste

Rond_Spl

983

Rond_Rel

EBrBogBr

Crot_Div

Rondout_

New_Crot

993

Scho_LLO

WAshokan

EAshokan

Schohari

616RondLoss

NYorkCty

BQ_Aquif

Hillview

Shaft_6_Shaft_5A

Chelsea_

898

CannoSpl

897 PepacSpl

899

NevrsSpl

Pepacton

NevrsRes

W_Branch

Kensico_

BoydsCor

Cannonsv

East Of HudsonWest Of Hudson

Delaware[1012 sq. mi.]-Cannonsville-Pepacton-Neversink-Rondout

Catskill[571 sq. mi.]-Schoharie-East Ashokan-West Ashokan

Croton[375 sq. mi.]

• Present focus on WOH but,• OASIS has feedback to what is happening in

- Croton and - lower Delaware

• Croton and Lower Delaware are run with present climate

06

Areas in green

IntroductionClimate Change Simulations for OASIS

• GCM Simulations– GCMs: ECHAM, GISS, NCAR– Emission Scenarios: A1B, A2, B1– Time Slices:

• Baseline: 1980 – 2000• Future: 2046 – 2065; 2080 – 2100

• Monthly delta-change GCM air temperature and precipitation as input in:– GWLF Watershed Model

• Generate inflow data for OASIS

07

Selected Results

• Identify Relevant System Descriptors• West Of Hudson Subsystems

– Inflow from GWLF simulations– Drought Conditions– Probability of Subsystem Refill– Storage levels – Inflow – Spills

• Focus on Delaware Results. Catskill results have similar patterns

• Results are preliminary

08

Future_8099

Future_4665

NcarB1-8099

GissB1-8099

EchamB1-8099

NcarA2-8099

GissA2-8099

EchamA2-8099

NcarA1B-8099

GissA1B-8099

EchamA1B-8099

NcarB1-4665

GissB1-4665

EchamB1-4665

NcarA2-4665

GissA2-4665

NcarA1B-4665

GissA1B-4665

Baseline

4000

3500

3000

2500

2000

1500

1000

500Annual I

nflow

(M

GD

)

1164

Delaware Subsystem

ResultsAnnual Inflow

Baseline Median

09

DecNovOctSepAugJulJunMayAprMarFebJan

6000

5000

4000

3000

2000

1000

0

Infl

ow

(M

GD

)

Delaware Subsystem

ResultsMonthly Inflow

Baseline Future-4665 Future-8099

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ResultsAverage Number of Days per Year in Drought

Condition - Delaware Subsystem

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0

5

10

15

20

25

30

35

40

45

Bas

eli

ne

Ech

am

A1B

-466

5

Ech

am

A1B

-810

0

Ech

am

A2-4

66

5

Ech

am

B1-4

66

5

Ech

am

B1-8

10

0

Gis

sA

1B

-466

5

Gis

sA

1B

-810

0

Gis

sA

2-4

66

5

Gis

sA

2-8

10

0

Gis

sB

1-4

66

5

Gis

sB

1-8

10

0

Nca

rA1

B-4

665

Nca

rA1

B-8

099

Nca

rA2

-46

65

Nca

rA2

-80

99

Fu

ture

Scen

ari

os

Da

ys

pe

r Y

ear

Watch Warning Emergency

ResultsAverage Number of Days per Year in

Drought Condition

12

0

2

4

6

8

10

12

14

16

18

Days

per Y

ear

Watch Warning Emergency Watch Warning Emergency

Baseline Average CC Scenarios

Delaware Reservoirs

0

2

4

6

8

10

12

14

16

18

Days

per Y

ear

Watch Warning Emergency Watch Warning Emergency

Baseline Average CC Scenarios

Catskill Reservoirs

Day

s pe

r Y

ear

Day

s pe

r Y

ear

Baseline BaselineFuture Scenarios

Future Scenarios

Delaware Subsystem Catskill Subsystem

Results Probability of Refill by June 1st

13

Function of:- Current day’s storage levels- Expected system diversions- Inflow Forecast between today and Jun 1st

Fraction of Months below 90 percent chance to refill - Delaware Subsystem

0

0.05

0.1

0.15

0.2

0.25

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

BaselineFuture Scenarios

ResultsInflow – Storage – Spill

Baseline Future

14

DecNovOctSepAugJulJ unMayAprMarFebJan

350

300

250

200

150

100

50

Sto

rage (BG)

Delaware Storage

DecNovOctSepAugJulJ unMayAprMarFebJan

7000

6000

5000

4000

3000

2000

1000

0

Inflow

(M

GD)

Delaware Inflow

DecNovOctSepAugJulJ unMayAprMarFebJan

2500

2000

1500

1000

500

0

Spill (M

GD)

Delaware Spill- Future Inflow more uniform and high in winter months

- Future storage and Spill increase during Fall and winter

- Future and current storage similar in summer but with less variability for future

Summary• Climate projections from 3 GCMs, 3 emission

scenarios, 1 baseline and 2 future time slices applied in this study

• Monthly delta-change method for climate projections

• Projected air temperature and precipitation used in GWLF to generate inflows used in OASIS

• Simulations for future on WOH watersheds• Croton and Lower Delaware run on present

climate• Rules and Demands were assumed stationary

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Preliminary ConclusionsInflow

• Most GCMs project increased Winter and reduced early Spring inflows due to earlier snow melt

• Inflow patterns for all scenarios are similar but GISS and NCAR are of a greater magnitude

• Inflows for 2046-2064 and 2080-2100 time slices appear similar on annual basis

• Seasonal changes more pronounced in the 2080 - 2100 simulations

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Preliminary ConclusionsSystem Indicators

• Reduction in number of days per year system is under Drought Watch, Warning and Emergency with high variability between GCM predictions

• Increase in Subsystem Probability of Refill by Jun 1st for future scenarios

• Increased spills during winter

• Increased future storage levels during winter months while similar storage levels with less variability in late Spring and Summer

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Next Steps• Improve Quality of Input data• Apply Climate Change Data to EOH and

Lower Delaware• Project Future Demands Under Climate

Change• Optimize OASIS Rules• For Each of Above:

– Generate Indicators– Evaluate System Performance and Sensitivity– Integrate New Selected Indicators Into OASIS

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Questions?