potential impacts of climate change on water quality in the new york city water supply system
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Water Quality. New York City Department of Environmental Protection. Bureau of Water Supply. Potential Impacts of Climate Change on Water Quality in the New York City Water Supply System. Mark S. Zion, Elliot M. Schneiderman and Donald C. Pierson - PowerPoint PPT PresentationTRANSCRIPT
Potential Impacts of Climate Change on Water Quality in the New York City Water
Supply System
Watershed Science and Technical ConferenceWest Point, New York
September 14-15, 2009
Mark S. Zion, Elliot M. Schneiderman and Donald C. PiersonBureau of Water Supply, New York City Department of Environmental Protection
Hampus Markensten, Emmet Owens, Rakesh Gelda, Steve EfflerUpstate Freshwater Institute
Adao H. Matonse, Aavudai Anandhi and Allan FreiInstitute for Sustainable Cities, City University of New York
New York City Department of Environmental ProtectionBureau of Water Supply
Water Quality
NYC DEP Climate Change Integrated Modeling ProjectWater Quality – Phase I
Purpose: To evaluate the potential effects of future climate change on the water quality of New York City Water Supply• Turbidity in Schoharie Reservoir• Eutrophication in Cannonsville Reservoir
Integrated Modeling Strategy• Use of an integrated suite of already developed models• Preliminary development of tools and measures future water
quality
Phase I result highlights• Preliminary model applications to obtain initial estimates of
climate effects
Climate ChangePhase I Study Areas
Location Map
NYState
NY City
• Turbidity – Focus on Schoharie Reservoir
• Eutrophication – Focus on Cannonsville Reservoir
Schoharie ReservoirTurbidity
GCM - Emission Scenario
Current Conditions Scenario
65 Year into Future
Scenario
100 Year into Future
ScenarioECHAM-A1B 1981-2000 2046-2065 2081-2100
ECHAM-A2 “ “ “
ECHAM-B1 “ “ “
GISS-A1B 1981-2000 2046-2065 2081-2100
GISS-A2 “ “ “
GISS-B1 “ “ “
NCAR-A2 “ “ “
•GCM/Emission Scenario data obtained from IPCC AR4 (2007)
•For each GCM/Emission Scenario, precipitation and air temperature are compared in control vs. future periods to derive monthly delta change factors.
Climate Change ScenariosPhase I – Schoharie Turbidity
Delta Change Method Applied for 7 GCM/Emission Scenarios
Phase I - Schoharie Turbidity Modeling System Delta Change, GWLF, OASIS and W2 Models
Historical Meteorology
PrecipAir Temp
StreamFlow
InflowsTurbidity Loads
Stream TempTunnel Ops
Reservoir Water Quality
Pre-Processor
Calculate turbidity inputs using sediment rating curve
Estimate inflow water temperature
Reformat data for W2 model
CEQUAL-W2 Reservoir
Model
Simulate reservoir volume, temperature and constituents in 2 dimensions (vertical,
longitudinal)
Air Temp
GWLF Watershed
Model
Simulate streamflow and evaporation
Tunnel FlowsOASIS
System ModelSimulate tunnel
operations
Delta ChangeCalculate future
climate scenarios
PETStreamflows
Results - SchoharieInput Flow Input Turbidity
In-Lake Turbidity (Segment 7)
Res
ervo
ir In
flo
w (
cms)
Inp
ut
Tu
rbid
ity
(NT
U)
Seg
men
t 7
Tu
rbid
ity
(NT
U)
Average Monthly ValuesCurrent Climate2080-2100 Scenarios
Results - Schoharie
Input TurbidityFraction of Time over 100 NTU
0.00
0.02
0.04
0.06
0.08
0.10
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg
Baseline Scenario2046-2065 Scenarios
2081-2100 Scenarios
Results - Schoharie
Segment 7 In-Lake TurbidityFraction of Time over 100 NTU
Baseline Scenario2046-2065 Scenarios
2081-2100 Scenarios
0.00
0.02
0.04
0.06
0.08
0.10
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg
Results - Schoharie
Segment 7 In-Lake TurbidityFraction of Time over 15 NTU
Baseline Scenario2046-2065 Scenarios
2081-2100 Scenarios
0.00
0.20
0.40
0.60
0.80
1.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg
Cannonsville ReservoirEutrophication
•GCM/Emission Scenario data obtained from IPCC AR4 (2007)
•For each GCM/Emission Scenario, precipitation and air temperature are compared in control vs. future periods to derive monthly delta change factors.
Climate Change ScenariosPhase I – Cannonsville Eutrophication
Delta Change Method Applied for 9 GCM/Emission Scenarios
GCM - Emission Scenario
Current Conditions Scenario
65 Year into Future
Scenario
100 Year into Future
ScenarioECHAM-A1B 1981-2000 2046-2065 2081-2100
ECHAM-A2 “ “ “
ECHAM-B1 “ “ “
GISS-A1B 1981-2000 2046-2065 2081-2100
GISS-A2 “ “ “
GISS-B1 “ “ “
CGCM3-A1B 1980-1999 2046-2065 2081-2100
CGCM3-A2 “ “ “
CGCM3-A2 “ “ “
Phase I - Schoharie Turbidity Modeling System Delta Change, GWLF, UFI-1D/PROTECH Models
Historical Meteorology
PrecipAir Temp
InflowsMeteorology
Nutrient LoadsStream TempReservoir Ops
Reservoir Water Quality
Pre-Processor
Adjust reservoir water balance based on future inputs
Estimate inflow water temperature
Estimate dew point temperature
Reformat data for W2 model
UFI-1D /PROTECH Reservoir
ModelSimulate reservoir
volume, temperature, nutrients and
phytoplankton functional groups in vertical dimension
Air TempWind SpeedPAR
GWLF Watershed
Model
Simulate streamflow, evaporation, nutrient and sediment loads
PETStreamflowsNutrient Loads
Delta ChangeCalculate future
climate scenarios
Historical Operations
Example: Strategy to Evaluate Watershed Management
0
5000
10000
15000
20000
25000
30000
35000
1966 1971 1976 1981 1986 1991 1996
)
0
1
2
3
4
5
1966 1971 1976 1981 1986 1991 1996
)
0
2000
4000
6000
8000
10000
1966 1971 1976 1981 1986 1991 1996
)
Streamflow
Dissolved P
Particulate P
Baseline Loads
Reservoir Reservoir Model Model
(calibrated)(calibrated)
0
5000
10000
15000
20000
25000
30000
35000
1966 1971 1976 1981 1986 1991 1996
)
0
1
2
3
4
5
1966 1971 1976 1981 1986 1991 1996
)
0
2000
4000
6000
8000
10000
1966 1971 1976 1981 1986 1991 1996
)
Streamflow
Dissolved P
Particulate P
Scenario Loads
Baseline Reservoir
Chl a
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
96
0
15
30
year
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
96
0
15
30
year
Baseline Chl a Frequency Distribution
?
5 6 7 8 9 10 11 12 13 14 15 16 17 18
Chl a (µg/L)
Number of years
0
1
2
3
4
5
6
7
8
5 6 7 8 9 10 11 12 13 14 15 16 17 18
Chl a (µg/L)
Number of years
0
1
2
3
4
5
6
7
8
5 6 7 8 9 10 11 12 13 14 15 16 17 18
Chl a (µg/L)
Number of years
0
1
2
3
4
5
6
7
8
5 6 7 8 9 10 11 12 13 14 15 16 17 18
Chl a (µg/L)
Number of years
0
1
2
3
4
5
6
7
8
Reservoir Reservoir Model Model
(calibrated)(calibrated)
Scenario Reservoir
Chl a
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
960
15
30
year
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
960
15
30
year
Scenario Chl a Frequency Distribution
freq
freq
mg/m3
mg/m3
Example: Changes in Mean Annual Chlorophyll
ConcentrationEpilimnion Cannonsville Reservoir Due to MOA
Programs Fre
qu
ency
Fre
qu
ency
Pre - MOA
Current ClimatePost - MOA
0
3000
6000
9000
1966 1970 1974 1978 1982 1986 1990 1994 1998 2002
Input DP Load
5 10 15 20 25 30
5 10 15 20 25 30
0.00
0.25
0.00
0.25
Chlorophyll (mg m-3)
Chlorophyll (mg m-3)
Pre - MOA
Post - MOA
Results - Cannonsville
Input DP Load Input PP Load
2081-2100 Climate Scenarios
DP
Lo
ad (
kg/d
ay)
PP
Lo
ad (
kg/d
ay)
Reservoir Inflow
Res
ervo
ir In
flo
w (
cms)
Average Monthly ValuesCurrent Climate2080-2100 Scenarios
Results - Cannonsville
EpilimnionChl-a Concentration
EpilimnionWater Temperature
Water Temperature (C)
Fre
qu
ency
10 20 3000.00
0.25
Fre
qu
ency
Chl-a Concentration (mg/m3)
10 20 30 400
0.00
0.50
Current Climate
2080-2100 Scenarios
Daily Histograms
Ch
l-a
Co
nc.
(m
g/m
3 )
2
4
68
10
1214
Month
Wat
er T
emp
erat
ure
(C
)
5
10
15
20
25
Month
Average Monthly ValuesCurrent Climate2080-2100 Scenarios
Results - Cannonsville
Thermal StratificationDensity Difference
(Epilimnion – Hypolimnion)
Den
sity
Dif
fere
nce
(kg
/m3)
Current Climate
2046-2065
2081-2100
0
Growing Season AveragesChl-a Total P
Fre
qu
en
cy
Chl a (mg/m3) Total P (mg/m3)
50.00
15 20 25 30 20 40 60 80 30
Pre-MOA
Current Climate - Post-MOA
Future Climate: 2046-2065
Future Climate: 2081-2100
5
0.25
0.00
0.25
0.00
0.25
0.00
0.25
0.00
0.30
0.00
0.30
0.00
0.30
0.00
0.30
Fre
qu
en
cy
Results - CannonsvilleEpilimnion Chl-a ConcentrationFraction of Time over 15 mg/m3
Future Climate: 2080-2100
Pre-MOA
Post-MOA / Current ClimateBoxes/whiskers show range of 2081-2100 climate scenarios
Summary of ResultsSchoharie Reservoir Turbidity:
• Increased fall and early winter flows lead to increase turbidity loading during these time periods. Reduced spring flows lead to reduction in loading during these periods
• Turbidity levels in the reservoir at the Shandaken Tunnel gate are increased in fall and early winter, reduced in late winter and unchanged in summer.
Cannonsville Reservoir Eutrophication
• Slightly longer period of thermal stratification.
• Enhanced phytoplankton blooms due to slightly increased DP
loads and thermal stratification changes
• Increased phytoplankton much less than magnitude of
reductions in algal growth due to watershed management
program implementation
Future Work – Phase II
Extend turbidity analysis to Ashokan Reservoir
Implement fully connected OASIS/W2 model
Incorporation of improved watershed turbidity loading models
Extend eutrophication analysis to other Delaware System reservoirs
Implement feedback between OASIS and UFI-1D/PROTECH model results
Improved simulation of watershed biogeochemistry to better reflect climate change effects on nutrient loads
Potential Impacts of Climate Change on Water Quality in the New York City Water
Supply System
Watershed Science and Technical ConferenceWest Point, New York
September 14-15, 2009
Mark S. Zion, Elliot M. Schneiderman and Donald C. PiersonBureau of Water Supply, New York City Department of Environmental Protection
Hampus Markensten, Emmet Owens, Rakesh Gelda, Steve EfflerUpstate Freshwater Institute
Adao H. Matonse, Aavudai Anandhi and Allan FreiInstitute for Sustainable Cities, City University of New York
New York City Department of Environmental ProtectionBureau of Water Supply
Water Quality
