Background on Water Quality Models for the Truckee River

WQS Review Process

November 2, 2011

Laura Weintraub, Dave Dilks

Overview

• Water Quality modeling to support the WQS (water quality standards) review process

• Watershed model: – WARMF development and calibration

• River water quality model: – TRHSPF development and calibration

• Overview of model updates• Intended use of the models

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Need for Water Quality Modeling in WQS Review Process

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Conceptual Watershed/Water Quality Model

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Model Linkage – Observed Conditions

WatershedModel

WaterQuantity

Water QualityModel

Land Use

ClimateSoil Types

Management Practices

Reservoir Releases

WaterQuality

Pollutant Loads

WWTPs

WARMF TRHSPF

Model Calibration Process• Certain model parameters cannot be directly

measured, and must be indirectly estimated by finding which values allow the model to best describe the observed data – Process is called model calibration

• Calibration guidelines– Keep calibration parameters within reasonable range – No single objective measure of model calibration

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Compliance with Dissolved Oxygen (DO) Standard is Key Element for Aquatic Life Beneficial Use

7Truckee River downstream of Lake Tahoe

Dissolved Oxygen

Sunlight

Flow

Algae

AerationNutrients (N&P)

Temperature

Organic Matter

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Use of Models in the WQS/TMDL Process

WatershedModel

Water QualityModel

Land Use

Climate

ManagementPractices

WaterQuality

Nonpoint Loads

WWTPs

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Use of Models in the WQS/TMDL Process

WatershedModel

Water QualityModel

Land Use

Climate

ManagementPractices

WaterQuality

Nonpoint Loads

Meets WQS?No

Adjust Point Sourcesor Land Management

PracticesYes

Done

WWTPs

WARMF Development and Calibration

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WARMF: Watershed Model• Peer reviewed, public

domain• Predicts watershed flow and

pollutant loads based on– land use– meteorological conditions– water management– watershed improvements

• 125 catchments (subwatersheds)

• Time step = 1 day

Key Processes of WARMF

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Subsurface ProcessesMineral WeatheringAMDSeptic SystemsOrganic Matter DecayNitrificationCation ExchangePlant Uptake

• Driven by meteorology and land use – Simulates nonpoint source loads; point source loads are input

• Simulates hydrology, mass balance, acid-base chemistry, erosion / sediment transport, pollutant build-up / wash-off, water quality, algal nutrient dynamics (simplified)

• Evaluates changes in nonpoint loading with varying land use, meteorological conditions, water use

WARMF Input Data

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Data Type Data Source Details

Topography USGS DEM (Digital Elevation Model) Basis for watershed delineation

Meteorology NCDC, SNOTELDaily data of precipitation, min/max temp, cloud cover, wind speed, air pressure, dew point temperature

Air Quality NADP/CASTNET Weekly data of dry and wet deposition

Managed flow (diversions)

FWM, TROA Information System, USGS

Flow for all active agricultural and M&I diversions (46)

Reservoir USGS, USBR, CDEC Flow release, elevation, and bathymetry for 6 managed reservoirs

Point sources TMWRF, NDEP, TTSA 2 major and 5 minor sources; flow and WQ records

Land Use / Land Cover NLCD, Washoe County Spatial data circa late 1990’s; 12 LULC categories

Observed Hydrology USGS, TRIG All USGS gages (~ 30) within watershed

Observed Water Quality TMWRF, TRIG, NDEP, STORET, LRWQCB, TTSA

Real-time and grab water quality samples at stations throughout watershed (~40 stations)

WARMF Calibration / Application• Model Calibration: 1990-1997 • Model Confirmation / Verification:

– 1985-1990 – 1998-2004

• Calibration Report: Systech, 2007. Adaptation of the WARMF Watershed Decision Support System to the Truckee River Basin of California and Nevada, 2007 Calibration Report, Prepared for City of Reno and City of Sparks, NV, Prepared by Systech Engineering, December 2007.

• Report available on TRIG

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TRHSPF Development and Calibration

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TRHSPF: River Water Quality Model• Long history of HSPF applications in Truckee River (USGS)• Updated to include periphyton based on DSSAMt science• Open code, EPA-supported, peer reviewed• Inputs are flow, watershed loads, point sources• Predicts water quality response of river

– nutrients periphyton dissolved oxygen

TRHSPF Model Domain• 43 segments from E. McCarran Blvd to

Marble Bluff Dam• Average reach length 1.31 miles•Time step = 0.5 hr

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Key Processes Modeled in TRHSPF

• Stream hydraulics• Water quality

– Temperature, nitrogen, phosphorus, algae, oxygen

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Key Processes Modeled in TRHSPF (continued)

• Mass transport (Nitrogen, Phosphorus, TDS)• Nutrient dynamics• Productivity (algae growth and decay)

– Performed literature review on benthic algae modeling

– HSPF Enhancements based on DSAMMt algorithms

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TRHSPF Input Data

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Data Type Data Source Details

Climate (Hourly) NCDC, WRCCAir Temperature, Dew Point, Wind, Cloud Cover, Solar Radiation (by reach)

Streamflow USGS Flow for 6 locations

Water Quality TMWRF (YSI & Grab)

WQ (YSI) updated for 3 parameters at 9 locations.

WQ (Grab) for 18 parameters at 9 locations.

TMWRF TMWRF WQ input updated for 16 parameters

Diversions FWM, TROA Information System Flow for 10 diversions

GroundwaterRepeat of time series based on

Nowlin (1987) / Brock (1992) / Pohll (2001)

WQ input updated for 13 parameters

Upstream / tributary loads Historical data or WARMF output TR at Reno, Steamboat

Creek, N. Truckee Drain

TRHSPF Calibration / Application• Model Calibration: July 2000 – August 2002

– Many parameters estimated from data– Concurrent algae biomass and water quality data available for

calibration– Acceptable comparison confidence that algorithms can predict

benthic algae reasonably well• Model Confirmation / Verification: 1990, 1995, 1996• Calibration Report: LimnoTech. 2008. Final Draft Calibration of the

Truckee River HSPF Water Quality Model. Prepared for the Cities of Reno and Sparks, Nevada, January, 2008.

• Report available on TRIG

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Model Updates

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Truckee River Water Quality Model Updates

• 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:

– Extended models to run through 12/2008 – updated all databases– Capture changes in loading due to Truckee Meadows development– Conducted model confirmation runs – held model calibration parameters

constant– Documenting changes to models and databases, results of model

confirmation• Share model information with the focus stakeholder group

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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

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Late 1990’s previously in WARMF

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New 2006/2007 layer imported to WARMF(increased development)

Evaluation of Linked WARMF/TRHSPF Modeling Framework

• Previously used data to drive TRHSPF upstream boundary – now using WARMF results

• Comparison of TRHSPF results to data isn’t just evaluation of TRHSPF, but evaluation of linked WARMF/TRHSPF

• Allows for modeling of river WQ response based on changes in watershed

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TRHSPF DO Results at Tracy / Clark

0

2

4

6

8

10

12

14

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1/1/2000 6/29/2000 12/26/2000 6/24/2001 12/21/2001 6/19/2002 12/16/2002

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Tracy/Clark(2000-2002)

Observed Data Modeled Range

0

2

4

6

8

10

12

14

16

18

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1/1/2003 6/30/2003 12/27/2003 6/24/2004 12/21/2004 6/19/2005 12/16/2005

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Tracy/Clark(2003-2005)

Observed Data Modeled Range

0

2

4

6

8

10

12

14

16

1/1/2006 6/30/2006 12/27/2006 6/25/2007 12/22/2007 6/19/2008 12/16/2008

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Tracy/Clark(2006-2008)

Observed Data Modeled Range

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TRHSPF DO Results at Marble Bluff Dam

0

2

4

6

8

10

12

14

16

1/1/2000 6/29/2000 12/26/2000 6/24/2001 12/21/2001 6/19/2002 12/16/2002

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Marble Bluff Dam(2000-2002)

Observed Data Modeled Range

0

2

4

6

8

10

12

14

16

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1/1/2003 6/30/2003 12/27/2003 6/24/2004 12/21/2004 6/19/2005 12/16/2005

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Marble Bluff Dam(2003-2005)

Observed Data Modeled Range

0

2

4

6

8

10

12

14

16

1/1/2006 6/30/2006 12/27/2006 6/25/2007 12/22/2007 6/19/2008 12/16/2008

Diss

olve

d O

xyge

n (m

g/L)

Dissolved Oxygen at Marble Bluff Dam(2006-2008)

Observed Data Modeled Range

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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• Model confirmation report being finalized

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Intended Use of Models for WQS Review

• Provide linkage between nutrient loading to the Truckee River and resulting dissolved oxygen levels

• Account for other factors (flow, temperature, light, organic matter, aeration)

• Understand balance of nutrient concentrations which result in DO WQS attainment under a range of flow conditions

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Model Linkage – Observed Conditions

WatershedModel

WaterQuantity

Water QualityModel

Land Use

ClimateSoil Types

Management Practices

Reservoir Releases

WaterQuality

Pollutant Loads

WWTPs

WARMF TRHSPF

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Model Linkage – Future Conditions

WatershedModel

WaterQuantity

Water QualityModel

Land Use

ClimateSoil Types

ManagementPractices

WaterQuality

Pollutant Loads

WWTPs

WARMF TRHSPF

Flow ManagementModel

Water Quality Model Linkage

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WARMF

TRHSPF

RiverWare or TROM

Reservoir Releases, Diversions

Diversions Tributary Flows, Nonpoint Sources

In-stream Water Quality

Demands, Water Operations, In-stream Flow Targets Meteorology, Land Use,

TMWRF Effluent and Re-use

TMWRF Effluent

Selection of Flow Management Model• Flow management model will provide a mechanism

to determine a representative low flow condition with current river operations and historical climate

• TROM (Truckee River Operations Model)– Long history of application in Truckee River– Previously coupled with WARMF/TRHSPF for test

simulation• RiverWare

– Newer model; water accounting version functional– Still under development

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Next Technical Steps in WQS Review Process

• Finalize model update report; distribute to stakeholders

• Solicit feedback from stakeholder group• 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

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Questions?

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