1. M ODESTO I RRIGATION D ISTRICT | T URLOCK I RRIGATION D ISTRICT FERC PROJECT N O. 2299 Don Pedro Reservoir 3-Dimensional Temperature Model

2. Study Goals Accurately simulate reservoir temperature response to hydrological and meteorological conditions Assess effects of TID/MID flow control operations on temperature Provide model output that informs other studies, analyses and models  Output at reservoir release will be used as input to Lower Tuolumne River temperature model April 1, 2011 Don Pedro Project Relicensing, FERC Project No. 2299 2

3. MIKE3-FM Modeling Platform April 1, 2011 Don Pedro Project Relicensing, FERC Project No. 2299 3 Danish Hydraulic Institute (DHI) developed and technically supported http://mikebydhi.com/http://mikebydhi.com/ Superior features (theoretical basis, Graphical User Interface, animations, GIS-compatability documentation) Used world-wide in surface water studies Flexible computational mesh (FM) appropriate for dendritic shape of Don Pedro Reservoir and old dam

4. General Example of MIKE3-FM Model Computational Mesh April 1, 2011 Don Pedro Project Relicensing, FERC Project No. 2299 4

5. Modeling Study Tasks April 1, 2011 Don Pedro Project Relicensing, FERC Project No. 2299 5 Set-up 3-D Flexible Mesh  Bathymetry survey data Compile input data; primary inputs are:  Upstream river flow/temperature  Reservoir withdrawal flows  Meteorological drivers (air temp., wind, rel. humidity) Calibrate model  Temp. profiles prior to Dec. 2010  Powerhouse temp. Verify model  Met data, upstream river temp. and temp profiles Dec. 2010 through Summer 2011  Powerhouse temp. Simulate model scenarios

6. Model Validation Process April 1, 2011 Don Pedro Project Relicensing, FERC Project No. 2299 6 Calibration  Compare model results to observed temp. profile and powerhouse temp. data  Adjust model parameters within acceptable ranges to obtain good comparisons Verification  Compare model results to observed data for a different time period Peer Review  Peer modelers granted access to run MIKE3-FM model  Review comments and responses; reach resolution