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Water Quality Model Updates to Support Truckee River Nutrient WQS and TMDL Reviews. December 14, 2011 Laura Weintraub. Review of Model Update Approach. Goal: develop best possible tools given reasonable time, information, and funding - PowerPoint PPT Presentation
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Water Quality Model Updates to Support Truckee River Nutrient
WQS and TMDL Reviews
December 14, 2011
Laura Weintraub
Review of Model Update Approach• Goal: develop best possible tools given reasonable time,
information, and funding• Due diligence to ensure models work well for recent time period• Model update steps:
– Extend models to run through 12/2008– Document changes to models and databases, results of model confirmation
• Disseminate information to the focus stakeholder group– Original calibration reports (Systech 2007, LimnoTech 2008)– Model update report (LimnoTech November 28, 2011)
2
Model Linkage – Observed Conditions
WatershedModel
WaterQuantity
Water QualityModel
Land Use
ClimateSoil Types
Management Practices
Reservoir Releases
WaterQuality
Pollutant Loads
WWTPs
WARMF TRHSPF
3
WARMF Updates4
Recent WARMF Enhancements (post-calibration)
• Model Version Update (October, 2008)– Received from Systech – Finer spatial resolution, general database update and
recalibration• Temperature improvements (Systech)
– Bedrock heat transfer, river ice formation, warming from river friction
5
WARMF Database Updates through 2008
6
Data Type Data Source Updates Made to:
Climate NCDC, SNOTEL Precipitation, temperature, wind, cloud cover, dew pt., air pressure
Air Quality CASTNET, NADP Wet / dry air deposition
Diversions FWM, TROA Information System, Flows for all active diversions within watershed
Point sources TMWRF, NDEP TMWRF plus 4 minor sources
Reservoir releases USGS Releases from managed reservoirs
Land Use / Land Cover (LULC) NLCD, Washoe County Representative of 2006 LULC for entire watershed
Observed Hydrology USGS, TRIG All USGS gages within watershed
Observed Water Quality TMWRF, TRIGReal-time and grab water quality samples at stations throughout watershed
Limited WARMF Model Changes• Adjusted initial soil moisture reflects start of new
time period• Set breakpoint for updated land use / land cover
– Pre-2002 simulations: old GIS layer circa late 1990’s– Post-2002: updated GIS layer circa 2006
• Adjusted organic carbon and nutrient soil concentrations post-2002– Rapid land use change; model does not completely capture impacts
with just surface loading changes– Consistent with findings of Chalk Creek study (JBR, 2010)
• Directly specified reservoir releases (historical data) rather than modeling reservoir operations
7
Flow at Reno/Sparks
80
2000
4000
6000
8000
10000
12000
14000
Flow
(cfs
)
Date
Flow at Reno/Sparks
Modeled (WARMF) Observed
0
200
400
600
800
1000
1200
2000 2001 2002 2003 2004 2005 2006 2007 2008
Flow
(cfs
)
Water Year
Truckee River at Reno/SparksAverage Flow Rate
Model Observed
Flow at North Truckee Drain
9
02468
101214161820
2000 2001 2002 2003 2004 2005 2006 2007 2008
Flow
(cfs
)
Water Year
North Truckee DrainAverage Flow Rate
Model Observed
0
50
100
150
200
250
300
Flow
(cfs
)
Date
Flow at North Truckee Drain
Modeled (WARMF) Observed
Flow at Steamboat Creek
10
0
500
1000
1500
2000
2500
Flow
(cfs
)
Date
Flow at Steamboat Creek
Modeled (WARMF) Observed
0
10
20
30
40
50
60
70
80
90
2000 2001 2002 2003 2004 2005 2006 2007 2008
Flow
(cfs
)
Water Year
Steamboat CreekAverage Flow Rate
Model Observed
11
Total Nitrogen at Reno/Sparks
00.1
0.2
0.30.4
0.5
0.60.7
0.8
0.9
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
Truckee River at Reno/SparksAverage Total Nitrogen
Model Observed
Error bars represent the 90% confidence interval of the mean.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Conc
entr
ation
(mg/
L)
Date
Total Nitrogen at Reno/Sparks
Modeled (WARMF) Observed
12
Total Nitrogen at North Truckee Drain
00.5
11.5
22.5
33.5
44.5
5
Conc
entr
ation
(mg/
L)
Date
Total Nitrogen at North Truckee Drain
Modeled (WARMF) Observed
0
0.5
1
1.5
2
2.5
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
North Truckee DrainAverage Total Nitrogen
Model Observed
Error bars represent the 90% confidence interval of the mean.
13
Total Nitrogen at Steamboat Creek
00.5
11.5
22.5
33.5
44.5
5
Conc
entr
ation
(mg/
L)
Date
Total Nitrogen at Steamboat Creek
Modeled (WARMF) Observed
0
0.5
1
1.5
2
2.5
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
Steamboat CreekAverage Total Nitrogen
Model Observed
Error bars represent the 90% confidence interval of the mean.
Total Phosphorus at Reno/Sparks
140
0.05
0.1
0.15
0.2
0.25
Conc
entr
ation
(mg/
L)
Date
Total Phosphorus at Reno/Sparks
Modeled (WARMF) Observed
0
0.01
0.02
0.03
0.04
0.05
0.06
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
Truckee River at Reno/SparksAverage Total Phosphorus
Model
Observed averages are not shown because 76% of values are less than the practical quantification limit of 0.04 mg/L.
PQL = 0.04 mg/L
Total Phosphorus at North Truckee Drain
15
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
North Truckee DrainAverage Total Phosphorus
Model Observed
Error bars represent the 90% confidence interval of the mean.
00.10.20.30.40.50.60.70.80.9
1
Conc
entr
ation
(mg/
L)
Date
Total Phosphorus at North Truckee Drain
Modeled (WARMF) Observed
Total Phosphorus at Steamboat Creek
16
0
0.2
0.4
0.6
0.8
1
1.2
Conc
entr
ation
(mg/
L)
Date
Total Phosphorus at Steamboat Creek
Modeled (WARMF) Observed
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
2000 2001 2002 2003 2004 2005 2006 2007 2008
Conc
entr
ation
(mg/
L)
Water Year
Steamboat CreekAverage Total Phosphorus
Model Observed
Error bars represent the 90% confidence interval of the mean.
Summary of WARMF Results• Flow
– Strong model performance at Truckee River at Sparks (upstream boundary for TRHPSF): r2 = 0.87
– Moderate performance at North Truckee Drain and Steamboat Creek• Day to day variability is small compared to Truckee River• Although variability not captured well, model accurately describes
average flows
• Nutrients– Model predictions fall within range of uncertainty of
observed data for large majority of years– Results consistent with previous calibration
17
Known Limitations in WARMF Performance
• Snow melt peaks under-predicted during wettest years– Does not impact critical low flow periods
• Summer residential irrigation not captured (potable / reuse water)– Little impact to summer flows in Truckee River downstream of
confluence with Steamboat Creek and NTD• Remaining underprediction of spring streamflow
temperatures– Sensitivity analysis showed only minor changes to DO with higher
temperatures during this non-critical late winter / early spring period
18
Above limitations do not preclude the use of the model for intended need
TRHSPF Updates19
Recent TRHSPF Enhancements (post-calibration)
• Organic labile nutrient representation– New state variables for org. labile nitrogen and organic labile
phosphorus– No longer derived indirectly from BOD and phytoplankton
stoichiometry– Directly accounts for settling and decay
• TRHSPF linkage with WARMF– Upstream and tributary boundary conditions from WARMF– Provides capability to evaluate Truckee River response to changes in
watershed activity
• Implemented discrete segment for Gilpin Spill bypass– Model accounts for potentially “depleted” segment between Derby
Dam and Gilpin Spill return20
TRHSPF Database Updates through 2008
21
Data Type Data Source Updates Made to:
Climate (Hourly) NCDC, WRCCAir Temperature, Dew Point, Wind, Cloud Cover, Solar Radiation (by reach)
Diversions FWM, TROA Information System Flow for 10 diversions
Point Sources TMWRF WQ input updated for 16 parameters
Observed Streamflow USGS Flow for 6 locations
Observed Water Quality TMWRF (YSI & Grab)
WQ (YSI) updated for 3 parameters at 9 locations.
WQ (Grab) for 18 parameters at 9 locations.
Groundwater Repeat of time series based on Nowlin (1987) / Brock (1992) / Pohll (2001)
WQ input updated for 13 parameters
Limited TRSHPF Model Changes• Flow balance corrections
– Truckee Canal and Gilpin Spill flow based on USGS gages– Known limitations in gage accuracy– Truckee Canal flows adjusted to prevent negative Truckee River flows
for periods of obvious mismatch – “error” sent down the canal
• Addressed occasional model instability when model segment flow dropped to “zero”– Applied minimal “floor” segment volume (100 ft3)– Holds back minimal flow in segment during unstable timestep– Result: adjustment to flow out of segment < 0.05 cfs
22
TRHSPF Flow Results
23
0
200
400
600
800
1,000
1,200
1,400
2000 2001 2002 2003 2004 2005 2006 2007 2008
Stre
amflo
w (c
fs)
Calendar Year
Average Annual StreamflowVista
Model Data
0
200
400
600
800
1,000
1,200
1,400
2000 2001 2002 2003 2004 2005 2006 2007 2008
Stre
amflo
w (c
fs)
Calendar Year
Average Annual Streamflow"Near" Tracy
Model Data
0
200
400
600
800
1,000
1,200
1,400
2000 2001 2002 2003 2004 2005 2006 2007 2008
Stre
amflo
w (c
fs)
Calendar Year
Average Annual StreamflowBelow Derby Dam
Model Data
0
200
400
600
800
1,000
1,200
1,400
2000 2001 2002 2003 2004 2005 2006 2007 2008
Stre
amflo
w (c
fs)
Calendar Year
Average Annual Streamflow"Near" Nixon
Model Data
TRHSPF Flow Results
24
0
2,000
4,000
6,000
8,000
10,000
12,000Fl
ow (c
fs)
Flow at VistaModeled (TRHSPF) Observed (USGS)
0
2,000
4,000
6,000
8,000
10,000
12,000
Flow
(cfs
)
Flow below Derby DamModeled (TRHSPF) Observed (USGS)
0
2,000
4,000
6,000
8,000
10,000
12,000
Flow
(cfs
)
Flow near NixonModeled (TRHSPF) Observed (USGS)
TRHSPF Total Nitrogen Results
25
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Nitr
ogen
(mg/
L)
Calendar Year
Average Annual Total NitrogenLockwood
Model Data
Error bars represent the 90% confidence interval of the mean.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Nitr
ogen
(mg/
L)
Calendar Year
Average Annual Total NitrogenTracy/Clark
Model Data
Error bars represent the 90% confidence interval of the mean.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Nitr
ogen
(mg/
L)
Calendar Year
Average Annual Total NitrogenPainted Rock
Model Data
Error bars represent the 90% confidence interval of the mean.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Nitr
ogen
(mg/
L)
Calendar Year
Average Annual Total NitrogenWadsworth
Model Data
Error bars represent the 90% confidence interval of the mean.
TRHSPF Total Nitrogen Results
26
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Tota
l Nitr
ogen
(mg/
L)
Total Nitrogen at LockwoodModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Tota
l Nitr
ogen
(mg/
L)
Total Nitrogen at Tracy/ClarkModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Tota
l Nitr
ogen
(mg/
L)
Total Nitrogen at Painted RockModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
TRHSPF Total Phosphorus Results
27
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Pho
spho
rus (
mg/
L)
Calendar Year
Average Annual Total PhosphorusLockwood
Model Data
Error bars represent the 90% confidence interval of the mean.
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Pho
spho
rus (
mg/
L)
Calendar Year
Average Annual Total PhosphorusTracy/Clark
Model Data
Error bars represent the 90% confidence interval of the mean.
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Pho
spho
rus (
mg/
L)
Calendar Year
Average Annual Total PhosphorusPainted Rock
Model Data
Error bars represent the 90% confidence interval of the mean.
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Pho
spho
rus (
mg/
L)
Calendar Year
Average Annual Total PhosphorusWadsworth
Model Data
Error bars represent the 90% confidence interval of the mean.
TRHSPF Total Phosphorus Results
28
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Tota
l Pho
spho
rus
(mg/
L)
Total Phosphorus at LockwoodModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Tota
l Pho
spho
rus
(mg/
L)
Total Phosphorus at Tracy/ClarkModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Tota
l Pho
spho
rus
(mg/
L)
Total Phosphorus at Painted RockModeled (TRHSPF) Observed (TMWRF) Observed (CMP)
29
0
2
4
6
8
10
12
14
16
18
20
1/1/2000 5/1/2000 8/30/2000 12/29/2000 4/29/2001 8/28/2001 12/27/2001 4/27/2002 8/26/2002 12/25/2002
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Lockwood(2000-2002)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2003 5/2/2003 8/31/2003 12/30/2003 4/29/2004 8/28/2004 12/27/2004 4/27/2005 8/26/2005 12/25/2005
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Lockwood(2003-2005)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2006 5/2/2006 8/31/2006 12/30/2006 4/30/2007 8/29/2007 12/28/2007 4/27/2008 8/26/2008 12/25/2008
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Lockwood(2006-2008)
Observed (YSI) Modeled Range (TRHSPF)
30
0
2
4
6
8
10
12
14
16
18
20
1/1/2000 5/1/2000 8/30/2000 12/29/2000 4/29/2001 8/28/2001 12/27/2001 4/27/2002 8/26/2002 12/25/2002
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Tracy/Clark(2000-2002)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2003 5/2/2003 8/31/2003 12/30/2003 4/29/2004 8/28/2004 12/27/2004 4/27/2005 8/26/2005 12/25/2005
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Tracy/Clark(2003-2005)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2006 5/2/2006 8/31/2006 12/30/2006 4/30/2007 8/29/2007 12/28/2007 4/27/2008 8/26/2008 12/25/2008
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Tracy/Clark(2006-2008)
Observed (YSI) Modeled Range (TRHSPF)
31
0
2
4
6
8
10
12
14
16
18
20
1/1/2000 5/1/2000 8/30/2000 12/29/2000 4/29/2001 8/28/2001 12/27/2001 4/27/2002 8/26/2002 12/25/2002
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Painted Rock(2000-2002)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2003 5/2/2003 8/31/2003 12/30/2003 4/29/2004 8/28/2004 12/27/2004 4/27/2005 8/26/2005 12/25/2005
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Painted Rock(2003-2005)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2006 5/2/2006 8/31/2006 12/30/2006 4/30/2007 8/29/2007 12/28/2007 4/27/2008 8/26/2008 12/25/2008
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Painted Rock(2006-2008)
Observed (YSI) Modeled Range (TRHSPF)
32
0
2
4
6
8
10
12
14
16
18
20
1/1/2000 5/1/2000 8/30/2000 12/29/2000 4/29/2001 8/28/2001 12/27/2001 4/27/2002 8/26/2002 12/25/2002
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Wadsworth(2000-2002)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2003 5/2/2003 8/31/2003 12/30/2003 4/29/2004 8/28/2004 12/27/2004 4/27/2005 8/26/2005 12/25/2005
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Wadsworth(2003-2005)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2006 5/2/2006 8/31/2006 12/30/2006 4/30/2007 8/29/2007 12/28/2007 4/27/2008 8/26/2008 12/25/2008
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Wadsworth(2006-2008)
Observed (YSI) Modeled Range (TRHSPF)
33
0
2
4
6
8
10
12
14
16
18
20
1/1/2000 5/1/2000 8/30/2000 12/29/2000 4/29/2001 8/28/2001 12/27/2001 4/27/2002 8/26/2002 12/25/2002
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Marble Bluff Dam(2000-2002)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2003 5/2/2003 8/31/2003 12/30/2003 4/29/2004 8/28/2004 12/27/2004 4/27/2005 8/26/2005 12/25/2005
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Marble Bluff Dam(2003-2005)
Observed (YSI) Modeled Range (TRHSPF)
0
2
4
6
8
10
12
14
16
18
20
1/1/2006 5/2/2006 8/31/2006 12/30/2006 4/30/2007 8/29/2007 12/28/2007 4/27/2008 8/26/2008 12/25/2008
Diss
olve
d Ox
ygen
(mg/
L)
Dissolved Oxygen at Marble Bluff Dam(2006-2008)
Observed (YSI) Modeled Range (TRHSPF)
Prediction of Annual Nutrient Loads
• Noted limitations in WARMF-predicted snow melt peaks
• Important to adequately predict total annual loads from Truckee River to downstream water bodies
• Compared with load estimations from data– Results within range of
uncertainty of LOADEST results for majority of years 34
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1,800,000
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Nitr
ogen
(lb/yr
)
Calendar Year
Total NitrogenAnnual Load Above Derby Dam
Model (TRHSPF) Data (LOADEST)
Error bars represent the 95% confidence interval of the mean.
0
50,000
100,000
150,000
200,000
250,000
2000 2001 2002 2003 2004 2005 2006 2007 2008
Tota
l Pho
spho
rus (
lb/yr
)
Calendar Year
Total PhosphorusAnnual Load Above Derby Dam
Model (TRHSPF) Data (LOADEST)
Error bars represent the 95% confidence interval of the mean.
Summary of TRHSPF Results• Flow
– R2 ranges between 0.85 to 0.88 for all stations– Rating of “very good”
• Nutrients– Model predictions fall within range of uncertainty of
observed data for large majority of years– Observed error statistics consistent with original
calibration• Dissolved Oxygen
– Time series plots and observed error statistics consistent with original calibration
35
Summary of Model Update• Confirmation of WARMF and TRHSPF for 2000-2008
period – Model updated to reflect rapid regional growth through
2006• Both models are ready for use to support the third-
party WQS and TMDL review efforts• Third-parties welcome comments and questions
from Focus Stakeholder group
36
Next Technical Steps in WQS Review Process
• Solicit feedback from stakeholder group on modeling tools – Submit comments by January 4, 2012
• Construct / run a set of scenario runs– Establish representative low flow– Link flow management model with WQ models– Vary N and P concentrations DO response
• Document any recommendations for revised WQS
• Submit report to NDEP for WQS Review 37
Questions?
38
EXTRA SLIDES
39
Model Database Updates: WARMF Land Use / Land Cover
• Old Land Use / Land Cover (LULC) data reflective of late 1990’s
• Rapid growth and development through 2006• New LULC reflective of recent growth• Combination of several datasets
– 2006 National Land Cover Dataset (NLCD) – underlying base layer– 2010 Washoe County / Truckee Meadows Regional Planning Agency –
developed parcel data supersedes NLCD data– Site-specific additions based on “parks” layer /Google Earth: ski
resorts, golf courses, parks, animal feeding operation
40
41
42
Late 1990’s currently in WARMF
43
New 2006/2007 layer for import to WARMF(increased development)
TRHSPF Modifications for Gilpin Spill• Truckee Canal return flow 7.5
miles downstream of Derby Dam• Allows for fine tuning of TCID
diversions and safety control to return water to river quickly
44
Gilpin Spill in TRHPSF• Return flow at Gilpin Spill is ungaged
– Typically 40-50 cfs is returned, capacity of 2700 cfs • 7.5 Mile Reach between Derby Dam and Gilpin Spill
– Historically as low as 3 cfs– Recent USGS flows higher flow conditions
• TRHSPF previously only diverted “Net” Truckee Canal diversion flow (no bypass from Gilpin Spill)– No additional depletion in stretch just below Derby
• Need to accommodate possible depleted conditions in WQS/TMDL analysis
45
Gilpin Spill in TRHSPF “Improved”• Model Gilpin Spill explicitly• Calculate diversion and return based on USGS flows• Add a model segment to represent Gilpin Spill “bypass”• Assume water quality in the return is the same as Derby
Dam
46
301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
-USGS Gage
Notes:
"Total" Truckee Canal = TR near Tracy – TR below Derby Dam "Net" Truckee Canal = Truckee Canal Near Wadsworth Gilpin Spill = “Total” Truckee Canal Flow Diversion – “Net” Truckee Canal Flow DiversionTR at Wadsworth = TR Below Derby Dam + Gilpin Spill – Ag Diversions + Ag Returns
Truckee River
Truckee Canal
Gilpin Spill
Vista(010350000)
Below Derby Dam(010351600)
Wadsworth(010351650)
Truckee Canal Truckee Canal near Wadsworth
Painted Rock
Near Tracy(010350340)
Lockwood
TCIDtot = TR near Tracy – TR below DerbyTCIDnet = Truckee Canal near WadworthGilpin Spill = TCIDtot - TCIDnet
