Scientific Programfor

Tahoe ClarityTMDL

Phase 1

Tahoe TMDL Symposium - Day 1December 9, 2004

Restoration of Declining Clarityis TMDL Target

• Stimulation of algae by phosphorus & nitrogen

• Fine sediment (<20 µm) from erosion and dust

• Tahoe TMDL addresses interaction between 3 pollutants as they affect Secchi depth

Goals of Tahoe TMDLResearch Program

1. Fill in critical science gaps.

2. Integrate knowledge on air, watershed and lake processes within a modeling framework.

3. Determine science-base targets for pollutant load reduction.

4. Develop tools to guide management.

5. Establish research plan for water quality.

6. Quantify the EIP.

Science-Based LoadReduction Target

• Historic Tahoe data• Literature• New monitoring• Lab experiments• Field experiments• Demonstration projects• Statistical analyses• Modeling - with verification• Best professional judgment

Scientific ApproachesIncline Creek

Third Creek

Trout Creek

Upper Truckee River

Glenbrook Creek

Logan HouseCreek

EdgewoodCreek

General Creek

BlackwoodCreek

Ward Creek

Primary site

Secondary site

Incline Creek

Misc. site

LTIMP

TMDL Research Program�� Wholistic Wholistic approach approach -- land, air, water land, air, water

science + resource management + policy science + resource management + policy

�� Involves >200 peopleInvolves >200 people

�� Financial commitments of over $5,000,000Financial commitments of over $5,000,000

�� Largest scientific effort at Lake TahoeLargest scientific effort at Lake Tahoe

�� Significant at national levelSignificant at national level

�� Tools will last beyond TMDLTools will last beyond TMDL

�� Model for science/management planningModel for science/management planning

Diverse Collaborative Team�� UC Davis/Tahoe Research GroupUC Davis/Tahoe Research Group

�� U Nevada Reno & Desert Research InstituteU Nevada Reno & Desert Research Institute

�� USACE, USGS, USFS, USDA NSLUSACE, USGS, USFS, USDA NSL

�� California Air Resources Control Board (CARB)California Air Resources Control Board (CARB)

�� CalTransCalTrans, NDOT, NDOT

�� Lahontan, TRPA, CTC, Nevada State LandsLahontan, TRPA, CTC, Nevada State Lands

�� Consultants (Tetra Tech, Hydroikos, GeoSyntec)Consultants (Tetra Tech, Hydroikos, GeoSyntec)

�� OthersOthers

New Research and Monitoring Projects• Nearshore water quality – DRI

• Loading of fine sediment – Collective Effort

• Stream channel erosion – USDA National Sedimentation Lab

• Groundwater & Sewer line exfiltration – USACE

• Stormwater monitoring & land-use loading –TRG, DRI, Hydroikos

• Reconstruction of historic meteorology – UC Davis

• Watershed Modeling – Tetra Tech

• Biologically available phosphorus – UNR

• Lake Particles: Character & loss rates – UCD

• Application of Clarity Model – UCD

• BMP evaluation and implementation feasibility –GeoSyntec Consulting

• Air quality monitoring network – CARB

• Air quality emission sources – CARB

• Modeling of atmospheric deposition – CARB

• Data management framework (TIIMS) – TRPA

New Research and Monitoring Projects

WQStats

UrbanRunoff

StreamChannel GW Sewer

Exfil BMP HistMet

Air Quality

ClarityField BAP Near

Shore

Watershed Model Clarity Model

Draft Schedule for Technical TMDL(12/05/02)

4/05Technical TMDL Due

12/03

11/04

1/05

6/04

7/03

7/03

6/036/03

10/03

4/04

6/047/04

CaltransForestRunoff

ChemicalSignature

CEBMP

Research Integration

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Time

Jan Apr Jul Oct1999 2000 2001 2002

Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct

Abs o rptio n by pure wate r and dis s o lve d o rganic s

Sc atte ring due to ino rganic partic le s (s e dime nt

Sc atte ring due to o rganic partic le s (a lgae )

Abs o rptio n by o rganic partic le s (a lgae )

_

0 105 kilo me ter s

Erodi bilit y clas ses

1

2

3

4

5

A Science Program With Many First Time Products

Atmospheric• CARB - loading model• UCD - MM5 historic climate reconstruction

Upland•Tetra Tech - LSPC (Hydrology and Loading)•Hydroikos - Statistical Modeling•Geosyntech - SWMM (Pilot BMP modeling)

Groundwater• USACE - groundwater loading model

Stream Channel Erosion• National Sedimentation Laboratory - CONCEPTS/AnnAGNPS

Lake Response• UCD - Lake Tahoe Clarity Model (hydrodynamics, water quality,

optical properties)

Widespread Use of Models

Watershed and Lake Clarity ModelsThese Tahoe-specific models allow us to:

(1) Estimate pollutant load from entire watershed(2) Evaluate loading based on management

scenarios(3) Assess lake response to management actions

LakeLake

1 12

2 7

1 65

1 7

3

1 54 2 4

3

1 54

6

����������� �

Urban

Rural

Legend

= Calibration/Validation Points Subwatershed

Figure 1: Land use representation (symbolized bynumbered boxes) and hydrologic routing(symbolized by lines and arrows) in the WatershedModel.

Stream Channel Erosion

�

0 31.5kilometers

Upper Truckee River

Relative contribution offine sediment fromstreambank erosion

Low

Moderate

High

First time that total sediment and fine sediment loading from stream channels has been studied.

Could be an important source at certain locations

Stream Particle Size Distribution

Monthly Particle Loads for Blackwood Creek WY 2002

1.E+11

1.E+12

1.E+13

1.E+14

1.E+15

1.E+16

1.E+17

Oct-01 Nov-01 Dec-01 Jan-02 Feb-02 Mar-02 Apr-02 May-02 Jun-02 Jul-02 Aug-02 Sep-02

Month of WY 2002

Part

icle

Loa

ds (N

um. o

f Par

ticle

s)

Fine (0.5 - 2.8 um)

Med (2.8 - 8.0 um)

Coarse (8.0 - 20.0 um)

• First time measured in Tahoe basin• Focuses on particle sizes that most affect Secchi depth• Used in both watershed and lake clarity models

Stormwater Monitoring• First basin-wide monitoring program for SWM• Similar scope as LTIMP• Covers a variety of land uses

Reliable GIS Land-Use LayersCooperative effort with TRPA, USFS, CTC and others to

make layers compatible for modeling

Annual Precipitation (in)

Selected grid cellswere missingPrecipitation

Aggregation doesnot considerimpaired cells.

Reconstructed HistoricalMeteorology

Needed to drive watershed model & other models when applied in forecasting mode

Biologically Available Phosphorus

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Tribut. Sus. Seds. Urban Runoff Seds. Erod. Bank Seds.

Source

Ave

rage

Bio

avai

l. P

(ug/

mg

sed.

) • First measurements done at Tahoe

• Not routinely preformed

• Input to Clarity Model

• Helps target priority P-reduction projects

Basin-Wide BMP Effectiveness Modeling

Bijou Park

Camp Richardson

Sand Harbor

Ward Creek

Bliss State Park

¨Tahoe Vista

¨Cedar Flats

Skyland

¨

East StatelinePoint

General Creek

Eagle Creek

Eagle Rock

Ward Creek_Tahoe City

¨

Dollar Creek

Glenbrook Creek

Bijou Creek

¨

Deadman Point

North LoganHouse Creek

Paradise Flat¨

Second Creek

¨

Wood Creek

¨Cave Rock

¨ Burnt Cedar Creek

¨

Carnelian Canyon¨

Burton Creek

Burke Creek

Mcfaul Creek

¨

Mill Creek

Sierra Creek

Meeks

¨

Tunnel Creek

Madden Creek

Zephyr Creek

¨

Kings Beach

¨

Secret HarborCreek

¨Quail Lake

Creek

¨

Tallac Creek

¨

Bliss Creek

Edgewood Creek

¨

Lonely Gulch Creek

¨

Carnelian Bay Creek

¨

Barton Creek

¨

Mkinney Creek

¨

Griff Creek Data on stormwater concentration, expected effluent concentration from Tahoe BMPs, and runoff are used to model pollutant reduction from intervening zones basin-wide

Ending CommentsPhase 1 TMDL Research Program has (will be) successful in achieving all its stated goals:

1. Fill critical science gaps.

2. Integrate knowledge within a modeling framework.

3. Science-base targets for pollutant load reduction.

4. Tools to guide management.

5. Research plan for water quality.

6. Quantify the EIP.