Lower Snake Modeling and LGR Monitoring Year 1 Report Summary Christopher Cook BPA Project

2 Current Geographic Extent: Lower Granite Pool to Columbia R.

3 Note: USACE is reviewing data

Temperature Monitoring Locations

5 Pressure sensors at Sites 2, 3, 4, & 7 Spring/Summer 2002 => pool had little slope

6 Note: black lines indicate depths of loggers Most downstream site. Approximately 9 miles from LGR. Most downstream Clearwater R. site. Attached to railroad trestle. Appendix A and provided to USACE

7 Water velocity (ADCP) measurements: 2 surveys of 52 pts Note: Data provided to USACE

8 LGR Velocity and Thermal Structure Mode 1: Weak to No Stratification Mode 2: Strong Stratification Typical mode 1 pattern. Rivers flow parallel to each other at the confluence. Satellite Image 4/4/2002 Temp delta = 1.5° C

9 18 Degree Isotherm20 Degree Isotherm 14 Degree Isotherm °C °C °C Typical mode 2 pattern. Clearwater subducts under the Snake River. Satellite Image 7/21/2002 Temp delta = 10° C Density Driven Flow Colder Clearwater R flow can migrate up the Snake R. Migration halts when a balance between momentum and buoyancy is reached.

10 3-D Modeling of LGR Examples of the numerical grid, colored by bathymetry

11 Velocity Results compared to August 2002 ADCP survey R2R2 avg. RMSMSEMAEbias Easting velocity Northing velocity Velocity Magnitude

12 3-D Model => a work in progress Ongoing model fixes Calculation error at downstream boundary Doesn’t impact results at PNNL sites…issues downriver by the dam As of today, bug (appears) to be fixed and seems to be working properly. Need to improve water balance. Will apply CE-QUAL- W2 to calculate Q for synthetic tributary. Temperature difference plots in report Could be better. Next steps are to adjust surface heat exchange parameters for an improved fit – need to fix boundary 1 st.

13 CE-QUAL-W2 Modeling of the Lower Snake River Year 1 applied CE-QUAL to LGS, LMN, and IHR Bathymetry dataset is from MASS1 (0.5 mile dx, 1m dz) CE-QUAL volumes compared to Water Control Manual LGS & IHR < 5%; LMN < 10% LGS IHR LMN

14 CE-QUAL-W2 Boundary Conditions Inflow discharge and temperature data Upstream data specified hourly Obtained from USACE database LMN => Tucannon and Palouse Rivers Q (daily) from USGS. Temp (hourly) from USACE Meteorology All reservoirs used Rice Bar AgriMet data (mid-LGS) IHR results may be improved by using closer station PAWS station (Fishhook) Downstream flow boundary Specified hourly & obtained from USACE database Distributed tributary used to achieve correct elevation at downstream. Iterative process. Average adjustments were less than ±3% of river Q.

15

16

17

18 Year 2 Data Collection Temperature Loggers Same 11 sites as last year 2 additional: Red Wolf (replace USGS) & US-12 Installed April 28 – May 1 Maintenance trips: weeks of June 16, July 21 Removed week of Sept 22 ADCP survey Increased coverage of confluence zone Survey trips May cross-sections x 3 pts surveyed Aug 11-13, Aug Increased monitoring of confluence zone Upstream migration of Clearwater Satellite and IR Camera monitoring to improve understanding of mixing zone (shape, location, etc.).

19 Year 2 Modeling CE-QUAL-W2 Test sensitivity to met conditions Cloud cover Fishhook data at IHR Wind variations (topographic steering issue) Validate against mid-pool temperature time series Simulate LGR pool in support of 3-D modeling 3-D CFD of LGR Confirm working properly Adjust parameters for best fit Validate against Year 2 data