1. November 2, 2011 Laura Weintraub, Dave Dilks
Background on Water Quality Models for the Truckee River WQS Review Process
November 2, 2011
Laura Weintraub, Dave Dilks

2. 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

3. Need for Water Quality Modeling in WQS Review Process

4. Conceptual Watershed/Water Quality Model

5. Model Linkage – Observed Conditions
Climate
Soil Types
WWTPs
Pollutant
Land Use
Loads
Watershed
Water Quality
Management Practices
Water
Model
Model
Quality
Water
Reservoir Releases
Quantity
WARMF
TRHSPF

6. 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

7. Compliance with Dissolved Oxygen (DO) Standard is Key Element for Aquatic Life Beneficial Use
Sunlight
Temperature
Flow
Dissolved Oxygen
Aeration
Nutrients (N&P)
Organic Matter
Algae
Truckee River downstream of Lake Tahoe

8. Use of Models in the WQS/TMDL Process
Climate
WWTPs
Nonpoint
Loads
Land Use
Watershed
Water Quality
Water
Management
Model
Model
Quality
Practices

9. Use of Models in the WQS/TMDL Process
Climate
WWTPs
Nonpoint
Loads
Land Use
Watershed
Water Quality
Water
Management
Model
Model
Quality
Practices No
Adjust Point Sources
Meets WQS?
or Land Management
Practices
Yes
Done

10. WARMF Development and Calibration

11. 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
Message: new watershed model not available in 1994

12. Key Processes of WARMF 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
Subsurface Processes
Mineral Weathering
AMD
Septic Systems
Organic Matter Decay
Nitrification
Cation Exchange
Plant Uptake

13. WARMF Input Data Data Type Data Source Details Topography
USGS DEM (Digital Elevation Model)
Basis for watershed delineation
Meteorology
NCDC, SNOTEL
Daily 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)

14. WARMF Calibration / Application
Model Calibration:
Model Confirmation / Verification:
Calibration Report: Systech, 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

15. TRHSPF Development and Calibration

16. 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
Message: new, updated public domain model
Stakeholder-based model selection process
Higher temporal and spatial resolution than WARMF
Predicts diurnal fluctuations of DO

17. TRHSPF Model Domain
43 segments from E. McCarran Blvd to Marble Bluff Dam
Average reach length 1.31 miles
Time step = 0.5 hr

18. Key Processes Modeled in TRHSPF
Stream hydraulics
Water quality
Temperature, nitrogen, phosphorus, algae, oxygen

19. 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

20. TRHSPF Input Data Data Type Data Source Details Climate (Hourly)
NCDC, WRCC
Air 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
WQ input updated for 16 parameters
Diversions
FWM, TROA Information System
Flow for 10 diversions
Groundwater
Repeat 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
The number of parameter updates for TMWRF and GW were different. GW is assumed to have negligible organic refractory nutrients (ORC, ORN, and ORP) and assumed to be zero.
The 18 parameters listed for the TMWRF grab data include calculated parameters.

21. 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 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

22. Model Updates

23. 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

24. 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
Need to check data of Washoe County data

25. Include table of % / area of each LULC category?

26. Late 1990’s previously in WARMF

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

28. 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

29. TRHSPF DO Results at Tracy / Clark

30. TRHSPF DO Results at Marble Bluff Dam

31. Summary of Model Update
Confirmation of WARMF and TRHSPF for 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

32. 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

33. Model Linkage – Observed Conditions
Climate
Soil Types
WWTPs
Pollutant
Land Use
Loads
Watershed
Water Quality
Management Practices
Water
Model
Model
Quality
Water
Reservoir Releases
Quantity
WARMF
TRHSPF

34. Model Linkage – Future Conditions
Flow Management
Model
Climate
Soil Types
WWTPs
Pollutant
Loads
Land Use
Watershed
Water Quality
Water
Model
Model
Management
Quality
Practices
Water
Quantity
WARMF
TRHSPF

35. Water Quality Model Linkage

36. 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

37. 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

38. Questions?