Focus Group Meeting: November 12, 2013

Truckee River Water Quality Standards Review

Overview of Topics for Discussion• Welcome and introductions • Feedback from previous workshop• Technical Updates– Updated (DRAFT final) model simulation results– Climate sensitivity runs– Mapping of restoration sites in context of model domain

• Next steps– Technical report development and review– NDEP timeline – Focus Group involvement in 2014

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Feedback from Previous Workshop?

Updated (Draft Final) Model Simulation Results

Summary of Final Adjustments

• Final Model Adjustments – wrapping up loose ends– Minor low flow year adjustments -- closer to 10th

percentile targets– Resolved DO concentration initial condition issue– Extended simulations across full range of WQ

concentrations– Shifted curves to actual instream (not target) nutrient

concentrations• Results: – No major surprises

Representative Flow Conditions

• Derived “target flows” based on TROM Future No Action output

• Two representative flow regimes – Low Flow (10th percentile) – Average Flow (50th percentile)

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Low Flow Regime:TROM 1977 FNA, 10th percentile targets, TRHSPF

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• Adjusted at WARMF-TRHSPF interface– July, August decreased flow– September increased flow

• Adjusted summer period for lower river

Adjusted at Sparks Jul - Sep Adjusted at TCID

Average Flow Regime:TROM 1985 FNA, 10th percentile targets, TRHSPF

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• No additional adjustment

Set of Simulations Orthophosphate (mg/L)

Total

Nitrogen

(mg/L)

0.030 0.040 0.050

PLPT std0.075 0.100

0.55 x0.65 x0.75

NDEP/PLPT std x x x x x0.85 x1.00 x

Total Phosphorus (mg/L)

Total Nitrogen

(mg/L)

0.030 0.040 0.050

NDEP std0.075 0.100 0.125

0.55 x 0.65 x 0.75

NDEP/PLPT std x x x x x x0.85 x 1.00 x

Spatial Aggregation for WQS Modeling

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Options for Calculating Percent Violation of DO WQS

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% of Hours: attainment is aggregation of all hours that have violated WQS

X hours violated 8760 hours/yr

% of Days: if 1+ hours violate WQS on a given day, that day is not in attainment

X days violated365 days/yr

Reviewing attainment as “% of days” is more

conservative approach

Normalized Nutrient Concentrations in DO Compliance Curves• Target concentrations set at upper model boundaries• Adjusted loads at major sources of load input (Steamboat Cr., N.

Truckee Drain, lower river agricultural input)• Slight variation in concentrations longitudinally• Plotted “actual” instead of “target” concentration on x-axis• For TN plots, also shifted Y-axis for Ortho-P curve

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Example of Curve Normalization

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Horizontal Shift for OP evaluation Vertical Shift of OP line for TN evaluation (Reach 4 only)

DRAFT Final Results Total P10th Percentile Flow: Reach Averaged

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% of Days % of Hours

TN = 0.75 TN = 0.75

DRAFT Final Results Ortho-P10th Percentile Flow: Reach Averaged

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% of Days % of Hours

TN = 0.75 TN = 0.75

DRAFT Final Results Total Nitrogen10th Percentile Flow: Reach Averaged

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% of Days % of Hours

Longitudinal Plot: Low Flow Year(DRAFT Final)

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TN = 0.75 mg/LOP = 0.05 mg/L

TN = 0.75 mg/LTP = 0.05 mg/L

DRAFT Final Results Total P50th Percentile Flow: Reach Averaged

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% of Days % of Hours

TN = 0.75 TN = 0.75

DRAFT Final Results Ortho P50th Percentile Flow: Reach Averaged

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% of Days % of Hours

TN = 0.75 TN = 0.75

DRAFT Final Results Total N50th Percentile Flow: Reach Averaged

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% of Days % of Hours

Longitudinal Plot: Average Flow Year(DRAFT Final)

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TN = 0.75 mg/LOP = 0.05 mg/L

TN = 0.75 mg/LTP = 0.05 mg/L

Summary of DO Compliance (DRAFT Final)Crosshairs run: TN 0.75 / TP 0.05 and TN 0.75 / OP 0.05

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Location

TP = 0.05 (OP ~ 0.028) OP = 0.05 (TP ~ 0.094)% of Days in

Violation% of Hours in

Violation% of Days in

Violation% of Hours in

ViolationLow Flow Ave Flow Low Flow Ave Flow Low Flow Ave Flow Low Flow Ave Flow

Aggregated

Reach 1 0.27 1.89 0.03 0.39 0.37 1.89 0.03 0.38

Reach 2 0.05 0.39 0.00 0.06 0.05 0.44 0.01 0.06

Reach 3 0.17 0.00 0.03 0.00 0.37 0.00 0.07 0.00

Reach 4 3.06 0.00 0.59 0.00 5.55 0.00 1.11 0.00

Most

Critical

Reaches

Vista 1.65 5.92 0.17 1.40 1.93 5.92 0.18 1.36

Tracy 1.10 3.23 0.16 0.70 1.10 3.49 0.17 0.71

Below Derby 2.50 0.00 0.63 0.00 2.50 0.00 0.65 0.00

Marble Bluff Dam 10.77 0.00 2.70 0.00 21.05 0.00 6.00 0.00

Summary of DO Compliance (DRAFT Final)Crosshairs run: TN 0.75 / TP 0.05 and TN 0.75 / OP 0.05

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Location

TP = 0.05 (OP ~ 0.028) OP = 0.05 (TP ~ 0.094)% of Days in

Violation% of Hours in

Violation% of Days in

Violation% of Hours in

ViolationLow Flow Ave Flow Low Flow Ave Flow Low Flow Ave Flow Low Flow Ave Flow

Aggregated

Reach 1 0.27 1.89 0.03 0.39 0.37 1.89 0.03 0.38

Reach 2 0.05 0.39 0.00 0.06 0.05 0.44 0.01 0.06

Reach 3 0.17 0.00 0.03 0.00 0.37 0.00 0.07 0.00

Reach 4 3.06 0.00 0.59 0.00 5.55 0.00 1.11 0.00

Most

Critical

Reaches

Vista 1.65 5.92 0.17 1.40 1.93 5.92 0.18 1.36

Tracy 1.10 3.23 0.16 0.70 1.10 3.49 0.17 0.71

Below Derby 2.50 0.00 0.63 0.00 2.50 0.00 0.65 0.00

Marble Bluff Dam 10.77 0.00 2.70 0.00 21.05 0.00 6.00 0.00

Shading denotes existing phosphorus WQS

Observations• Reaches 1, 2, 3 show low level of DO violation• Reach 4 is most critical at 10th percentile flow – Sensitive to the phosphorus concentration– Not sensitive to the TN concentration – No violations for 50th percentile flows

• DO violations in Reach 4 sensitive to other factors beyond P concentration– Flow condition– Channel geometry

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Integration of Results Over Full Flow Regime• Results to date have focused on low and average flow

conditions • Also evaluated integrated DO violations (DOv) across all flow

regimes:

DOvall= 0.2*DOvlow + 0.6* DOvave + 0.2*DOvhigh

• Spreadsheet calculation • 90th percentile year not simulated– Conservative assumption: DOvhigh = DOvave

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Integration Over Flow Regimes: Compare Target Flows

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Integrated Flow: Reached Averaged

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• % violations in Reach 4 (PLPT) much lower when integrating over all flows than for only the low flow year

TP Ortho-P

Interpretation of WQS Modeling Results• LimnoTech will summarize technical results in

a report• NDEP/EPA will determine recommendations

for any potential change from existing WQS

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Climate Sensitivity Runs

General Approach for Climate Sensitivity Runs• Simulated “cross hairs” run for each flow regime– TN 0.75 mg/L, Ortho-P 0.05 mg/L– TN 0.75 mg/L, TP 0.05 mg/L

• Adjusted TRHSPF temperature inputs: air water exchange– Applied a 1° C air temperature increase across entire year– First iteration run to estimate maximum water temperature

increase (near Marble Bluff Dam)– Applied ΔT ° C water temperature increase at WARMF /

TRHSPF interface (McCarran, North Truckee Drain, Steamboat Creek)

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Climate Sensitivity Simulation:10th Percentile Flow

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% of Days % of Hours

Modest increase in percent DO violations with increased air and water temperature

Climate Sensitivity Simulation:50th Percentile Flow

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% of Days % of Hours

Modest increase in percent DO violations with increased air and water temperature

Mapping of Restoration Sites

River Geomorphology and Restoration• Model is a conservative representation of

actual river– TRHSPF parameterized for pre-restoration

geometry condition• Mapped completed, ongoing and planned

restoration activity• Supplementary information to include in

technical report

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Vista (304)

Tracy (315)

Marble Bluff Dam (343)

Below Derby Dam (320)

Next Steps

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LimnoTech Technical Report • Introduction

– Watershed, justification for effort , WQS review process, stakeholder outreach• Summary of models (development, calibration)• Overview of WQS model application approach• Development of representative flow condition• Simulation of DO response to nutrient concentrations

– Low Flow Condition– Average Flow Condition– Integration Over full Flow Regime

• Discussion of results• Additional considerations

– River geometry properties– River restoration– Climate change sensitivity

• Observations and conclusions for revision of WQS• Appendices:

– Focus Group outreach, comments– Detailed technical information

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NDEP Timeline• 12/1/2013: Preliminary Draft LimnoTech report on modeling

• 1/1/2014: Review completed by Working Group

• 1/15/2014: Draft LimnoTech report on modeling results

• Mid Jan: NDEP Public workshop

• 2/15/2014: Review completed by Focus Group

• 3/1/2014: Final LimnoTech report on modeling results

• 4/1/2014: Draft NDEP Rationale/Petition for proposed standards changes

• 5/1/2014: NDEP Workshops – Focus Group, general public

• 6/30/2014: Final NDEP Rationale/Petition to LCB

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Focus Group Involvement 2014

• Focus Group Meeting: Jan 15, 2014– Overview of Technical Report document

• Review of Technical Report – Comments due 2/15/2014

• Additional Stakeholder / Focus Group meetings TBD in 2014

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Extras

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“Crosshairs” Simulation for Testing Orthophosphate (mg/L)

Total

Nitrogen

(mg/L)

0.030 0.040 0.050

PLPT std0.075 0.100

0.55 x0.65 x0.75

NDEP/PLPT std x x x x x0.85 x1.00 x

Total Phosphorus (mg/L)

Total Nitrogen

(mg/L)

0.030 0.040 0.050

NDEP std0.075 0.100 0.125

0.55 x 0.65 x 0.75

NDEP/PLPT std x x x x x x0.85 x 1.00 x

River Geomorphology and Restoration• Supplementary information to include with analysis• Potential relationship between channel geometry and

most critical segments• Developed and mapped “indicator” of potentially

vulnerable regions – Based on depth, velocity, slope

• Mapped restoration activity• Model is a conservative representation of actual river

– TRHSPF parameterized for pre-restoration geometry condition

Reach Geometry Index

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Vista (304)

Tracy (315)

Marble Bluff Dam (343)

Below Derby Dam (320)