Attachment 12
Drift Creek Reservoir Model Model Development and Scenarios Report
Department of Civil and Environmental Engineering Maseeh College of Engineering and Computer Science Technical Report EWR-03-11, June 2011
Drift Creek Reservoir Model:
Model Development and Scenarios Report
by
Chris Berger
Scott Wells
Andrew McCulloch
and
Vanessa Wells
Technical Report EWR-03-11
Water Quality Research Group Department of Civil and Environmental Engineering
Maseeh College of Engineering and Computer Science Portland State University
Portland, Oregon 97201-0751
Prepared for East Valley Water District
June 2011
Table of Contents Table of Contents......................................................................................................................................... i List of Figures ............................................................................................................................................. ii List of Tables ............................................................................................................................................. iv Introduction................................................................................................................................................. 1 CE-QUAL-W2............................................................................................................................................ 3 Overview of Modeling Data Requirements ................................................................................................ 4 Model Bathymetry ...................................................................................................................................... 4 Meteorological Data.................................................................................................................................... 8
Air Temperature................................................................................................................................ 10 Dew Point.......................................................................................................................................... 14 Short Wave Solar Radiation.............................................................................................................. 17 Cloud Cover ...................................................................................................................................... 20 Wind Speed & Direction................................................................................................................... 23 Precipitation ...................................................................................................................................... 28
Reservoir Inflows...................................................................................................................................... 31 Temperature Input Files............................................................................................................................ 34 Constituent Input Files.............................................................................................................................. 35 Reservoir Operations ................................................................................................................................ 39 Scenarios ................................................................................................................................................... 40
Water Level........................................................................................................................................... 44 Flow ...................................................................................................................................................... 45 Temperature .......................................................................................................................................... 49
Scenarios 1-3..................................................................................................................................... 49 Scenarios 4-6..................................................................................................................................... 56 Scenario 7.......................................................................................................................................... 57
Dissolved Oxygen................................................................................................................................. 58 Algae and Nutrients .............................................................................................................................. 66
Summary ................................................................................................................................................... 73 References................................................................................................................................................. 76
i
List of Figures Figure 1. Topography of the Drift Creek Dam Project. The polygons show the model segments for the reservoir model. Elevations are in meters.................................................................................................. 2 Figure 2 CE-QUAL-W2 model predictions for Tenkiller Reservoir, OK, USA, for temperature as a function of depth and longitudinal distance on July 12, 2005. Field data are red symbols compared to the blue model profile predictions. ................................................................................................................... 3 Figure 3. Reservoir model grid, plan view. ................................................................................................ 5 Figure 4. Reservoir model grid, side view.................................................................................................. 6 Figure 5. Reservoir volume versus elevation curve................................................................................... 7 Figure 6. Reservoir surface area versus elevation. .................................................................................... 8 Figure 7. Photograph of the Aurora AGRIMET weather station (Bureau of Reclamation)...................... 9 Figure 8. Aurora AGRIMET weather station and Drift Creek dam site location.................................... 10 Figure 9. Aurora AGRIMET summer and winter average air temperatures (oC) 2004-2010. ................ 11 Figure 10. Aurora AGRIMET air temperature (oC) 2004-2006. ............................................................. 12 Figure 11. Aurora AGRIMET air temperature (oC) 2007-2009. ............................................................. 13 Figure 12. Aurora AGRIMET air temperature (oC) 2010........................................................................ 14 Figure 13. Aurora AGRIMET dew point temperature (oC) 2004-2006................................................... 15 Figure 14. Aurora AGRIMET dew point temperature (oC) 2007-2009................................................... 16 Figure 15. Aurora AGRIMET dew point temperature (oC) 2010. .......................................................... 17 Figure 16. Aurora AGRIMET short wave solar radiation (W/m2) 2004-2006........................................ 18 Figure 17. Aurora AGRIMET short wave solar radiation (W/m2) 2007-2009........................................ 19 Figure 18. Aurora AGRIMET short wave solar radiation (W/m2) 2010. ................................................ 20 Figure 19. Aurora AGRIMET calculated hourly averaged cloud cover 2004-2006. .............................. 21 Figure 20. Aurora AGRIMET calculated hourly averaged cloud cover 2007-2009. .............................. 22 Figure 21. Aurora AGRIMET calculated hourly averaged cloud cover 2010......................................... 23 Figure 22. Aurora AGRIMET hourly average wind rose plots (degrees azimuth & m/s) 2004-2009. ... 24 Figure 23. Aurora AGRIMET hourly average wind rose plots (degrees azimuth & m/s) 2010.............. 25 Figure 24. Aurora AGRIMET hourly average wind speed (m/s) 2004-2006.......................................... 26 Figure 25. Aurora AGRIMET hourly average wind speed (m/s) 2007-2009.......................................... 27 Figure 26. Aurora AGRIMET hourly average wind speed (m/s) 2010. .................................................. 28 Figure 27. Aurora AGRIMET hourly precipitation (mm) 2004-2006...................................................... 29 Figure 28. Aurora AGRIMET hourly precipitation (mm) 2007-2009..................................................... 30 Figure 29. Aurora AGRIMET hourly precipitation (mm) 2010 .............................................................. 31 Figure 30. Percent drainage areas of watershed upstream of model branches 1 and 2............................ 32 Figure 31. Flow rates of branch 1 inflows. .............................................................................................. 33 Figure 32. Flow rates of branch 2 inflows. .............................................................................................. 34 Figure 33. Temperature data measured at Victor Point Road along wtih 6th degree polynomial used to determine composite temperatures. .......................................................................................................... 35 Figure 34. Locations of stations used to develop constituent input files. ................................................ 36 Figure 35. Model predicted water level elevations for the low, average, and high flow year scenarios. 45 Figure 37. Total reservoir outflows for scenario 1-3. ............................................................................... 46 Figure 38. Spillway flows for the scenarios 1-3. ...................................................................................... 47 Figure 39. Agricultural release flows for the scenarios 1-3..................................................................... 48 Figure 40. Instream water right flows for the scenarios 1-3. ................................................................... 49 Figure 42. Model predicted dam outflow temperatures of the lower level outlet for scenarios 1 through 3. For these scenarios flows from the low level outlet were used to be used for IWR flows, or fish flows. Average daily temperature data measured at Victor Point Bridge were also plotted. .............................. 50
ii
Figure 43. Model predicted mid-level outlet temperatures for scenarios 1-3. Water withdrawn from this outlet were used for agricultural releases.................................................................................................. 51 Figure 44. Predicted temperature profile for scenarios 1-3 on April 1.................................................... 52 Figure 45. Predicted temperature profile for scenarios 1-3 on June 30. .................................................. 53 Figure 46. Predicted temperature profiles for scenarios 1-3 on September 28........................................ 54 Figure 47. Predicted temperature profiles for runs scenarios 1-3 on October 1. ..................................... 55 Figure 48. Time-elevation contour plot of temperature for scenario 2, the average flow year scenario. 56 Figure 49. Temperatures of instream water right releases (IWR) for scenarios 4-6................................ 57 Figure 50. Temperatures of instream water right releases (IWR) for scenarios 2 and 8. ........................ 58 Figure 51. Time-elevation contour plot of model predicted dissolved oxygen concentrations for the average flow year scenario (scenario 2).................................................................................................... 59 Figure 52. Model predicted low level outlet dissolved oxygen concentrations for scenarios 1-3............ 60 Figure 53. Model predicted mid-level outlet dissolved oxygen concentrations for scenarios 1-3. .......... 61 Figure 54. Predicted dissolved oxygen profiles for scenarios 1-3 on April 1........................................... 62 Figure 55. Predicted dissolved oxygen profiles for scenarios 1-3 on June 30.......................................... 63 Figure 56. Predicted dissolved oxygen profiles for scenarios 1-3 on September 28................................ 64 Figure 57. Predicted dissolved oxygen profiles for scenarios 1-3 on October 1. ..................................... 65 Figure 58. Time series of dissolved oxygen fluxes for the average flow year scenario 2. The fluxes correspond to the entire reservoir. ............................................................................................................ 66 Figure 59. Predicted chlorophyll a profiles for scenarios 1-3 on April 1. ................................................ 67 Figure 60. Predicted chlorophyll a profiles for scenarios 1-3 on June 30. ............................................... 68 Figure 61. Predicted chlorophyll a profiles for scenarios 1-3 on September 28....................................... 69 Figure 62. Predicted chlorophyll a profiles for scenarios 1-3 on December 27. ...................................... 70 Figure 63. Time-elevation contour plot of model predicted total phosphorus concentrations for the average flow year scenario (scenario 2). The concentrations correspond model segment adjacent to the dam (segment 7). During the summer phosphorus concentrations were depleted in the epilimnion due to algae growth but increased in the hypolimnion because of the anaerobic release of nutrients. ............... 71 Figure 64. Model predicted low level outlet chlorophyll a concentrations for scenarios 1-3. ................. 72 Figure 65. Contour plot of model predicted temperatures for August 1 at 12 pm for the average flow year scenario (scenario 2). The low level and mid-level outlets were shown by the arrows. The metalimnion, separating the epilimnion and hypolimnion, was located approximately at the elevation of the mid-level outlet. .................................................................................................................................. 74 Figure 66. Contour plot of model predicted dissolved oxygen concentrations for August 1 at 12 pm for the average flow year scenario (scenario 2). The low level and mid-level outlets were shown by the arrows. Dissolved oxygen concentrations in most of the hypolimnion were zero by this time. ............. 75
iii
List of Tables Table 1. CE-QUAL-W2 applications between 2000-2006......................................................................... 3 Table 2. Data needs for modeling the reservoir and river system. ............................................................. 4 Table 3. Reservoir Model Grid Branch Summary ...................................................................................... 5 Table 4. Summary of reservoir model grid details. ................................................................................... 6 Table 5. Aurora AGRIMET station summary. .......................................................................................... 9 Table 6. Aurora AGRIMET air temperature (oC) summary statistics 2004-2010................................... 10 Table 7. Aurora AGRIMET dew point temperature (oC) summary statistics 2004-2010. ...................... 14 Table 8. Aurora AGRIMET short wave solar radiation (W/m2) summary statistics 2004-2010. ........... 17 Table 9. Cloud cover data calculated from Aurora AGRIMET solar data 2004-2010........................... 20 Table 10. Aurora AGRIMET wind speed (m/s) statistics summary 2004-2010. .................................... 23 Table 11. Aurora AGRIMET annual precipitation (mm) summary statistics ......................................... 28 Table 12. List of water quality measurement stations used to develop constituent inflow files. ............ 36 Table 13. Water quality data used to develop constituent input file of branch 1 of reservoir model. ..... 37 Table 14. Modeled constituent concentrations in constituent inflow file for reservoir branches 1 and 2.................................................................................................................................................................... 39 Table 15. Reservoir operations parameters.............................................................................................. 40 Table 16. Agricultural release flows........................................................................................................ 40 Table 17. Instream water right release rates. ............................................................................................ 40 Table 18. Model scenarios. ....................................................................................................................... 41 Table 19. W2 Model Water Quality Parameters....................................................................................... 42
iv
Introduction The focus of this present study was to evaluate the water quality impacts of the proposed Drift Creek Dam project located approximately 8 miles east of Salem, Oregon. The specific objectives of this study were:
• Develop a hydrodynamic and water quality model of the reservoir formed by Drift Creek Dam (see Figure 1).
• Develop, run, and evaluate a variety of modeling scenarios. These scenario runs include
evaluating the water quality impacts for a variety of scenarios, including low, average, and high flow years
This report was organized into the following sections:
1. Background on the model chosen for the analysis – CE-QUAL-W2 2. Data requirements for the model development 3. Reservoir grid development 4. Meteorological data 5. Hydrology for all model inflows 6. Temperatures for all model inflows 7. Concentration for all model inflows 8. Reservoir operations 9. Evaluation of water quality results from the reservoir the different model scenarios 10. Summary of model results
1
Figure 1. Topography of the Drift Creek Dam Project. The polygons show the model segments for the reservoir
model. Elevations were in meters.
2
CE-QUAL-W2 The model used for the reservoir formed by Drift Creek Dam was the public domain model, CE-QUAL-W2 (Cole and Wells, 2010). This model is a 2-dimensional (longitudinal-vertical) hydrodynamic and water quality model capable of predicting water surface elevation, velocity, temperature, nutrient concentrations, multiple algae, zooplankton, periphyton, and macrophyte species, dissolved oxygen, pH, alkalinity, multiple CBOD groups, multiple suspended solids groups, multiple generic constituents (such as tracer, bacteria, toxics), and multiple organic matter groups, both dissolved and particulate. The model is set up to predict these state variables at longitudinal segments and vertical layers (see Figure 2). Typical model longitudinal resolution is between 100-1000 m; vertical resolution is usually between 0.5 m and 2 m. The model can also be used in quasi-3-D mode, where embayments are treated as separate model branches off the main stem of the reservoir. The user manual and documentation can be found at the PSU website for the model: http://www.cee.pdx.edu/w2. Dr. Wells and his group have been the primary developers of this model for the ERDC (Engineer Research and Development Center), Environmental Laboratory, Waterways Experiments Station Corps of Engineers for the last 15 years. Since 2000, this model has been used extensively throughout the world in 116 different countries in lakes, reservoirs, estuaries, and river systems (see Table 1).
Figure 2 CE-QUAL-W2 model predictions for Tenkiller Reservoir, OK, USA, for temperature as a function of depth and longitudinal distance on July 12, 2005. Field data are red symbols compared to the blue model profile predictions.
Table 1. CE-QUAL-W2 applications between 2000-2006.
Water body Known Number of Applications Reservoirs 319+
Lakes 287+ Rivers 436+
3
Water body Known Number of Applications Estuaries 82+ Pit Lakes 10+
Overview of Modeling Data Requirements In order to set up this model, specific data were required to provide the forcing functions to the reservoir and river system. In addition, data were required for comparison to model predictions. A list of these data was shown in Table 2. Table 2. Data needs for modeling the reservoir and river system.
# Data Type Why necessary?
1 Bathymetric x-y-z data of the reservoir and rivers Construct model segments and layers
2 Flow rates (Q), temperatures (T), and concentrations of water quality state variables for all inflows
These are the model boundary conditions; continuous data are preferable, otherwise the model can use any temporal resolution available
3 Outlet structure details for the outlets and spillways, including rating curves for the spillways if available
The centerline elevation of the outlets and the weir crest elevations are of importance in predicting the vertical stratification in the reservoir system and the correct outflow during spill events (unless these are measured and known)
4 Flow rates and locations of outflows from the system, including the dam outlet, irrigation and other water withdrawals
These are model boundary conditions.
5
Meteorological data such as air temperature, dew point temperature (or relative humidity), wind speed and direction, solar radiation and cloud cover at an hourly frequency
These are model boundary conditions.
Each of the following sections in the report outline the data used for the development of the reservoir model.
Model Bathymetry Bathymetry data were generated from AutoCAD drawings of topographic contours of the area provided by Stuntzner Engineering & Forestry, LLC. These data were processed by the software SURFER to generate a complete bathymetric grid for the reservoir (Figure 1). One main branch and a smaller side branch were identified for the reservoir. A centerline of each model branch was generated and used to create polygons with equally spaced segment centers. SURFER was then used to generate 1 meter vertical layers within each segment.
4
A summary of the lengths, the number of active segments, and spacing for each branch in the reservoir was shown in Table 3. Model grid plan and side views were shown in Figure 3 and Figure 4.
Table 3. Reservoir Model Grid Branch Summary
Branch Number
Number of active
segments
Upstream active
segment
Downstream active
segment
Centerline Length of Branch, m
Average Segment Length,
m 1 6 2 7 3488.34 581.39 2 3 10 12 257.07 85.69
Figure 3. Reservoir model grid, plan view.
5
Figure 4. Reservoir model grid, side view
A summary of model grid statistics was displayed in Table 4. The model reservoir volume versus elevation curve was compared with curve provided Stuntzner Engineering & Forestry (2007) in Figure 5. Figure 6 compares reservoir surface area versus elevation curves.
Table 4. Summary of reservoir model grid details.
Number of water bodies
1
Number of branches 2 Number of segments 13
Minimum grid elevation
188.30 m
Maximum grid elevation
210.30 m
Number of layers 24 Layer thickness 1 m
Latitude 44.9149 Longitude -122.75
6
185
190
195
200
205
210
0.00E+00 2.00E+06 4.00E+06 6.00E+06 8.00E+06 1.00E+07 1.20E+07 1.40E+07 1.60E+07 1.80E+07
Elevation, m
Volume (cubic meters)
Surfer generated grid Stuntzner Engineering & Forestry, 2007
Figure 5. Reservoir volume versus elevation curve.
7
185
190
195
200
205
210
0.00E+00 2.00E+05 4.00E+05 6.00E+05 8.00E+05 1.00E+06 1.20E+06 1.40E+06 1.60E+06 1.80E+06
Elevation, m
Surface Area (square meters)
Surfer generated grid
Stuntzner Engineering & Forestry, 2007
Figure 6. Reservoir surface area versus elevation.
Meteorological Data Model scenarios were simulated using 2008 meteorological data. To determine model sensitivity to meteorological conditions, a scenario run was conducted using 2009 meteorological data. Meteorological data for 1/1/2004 through 12/31/2010 were gathered from an AGRIMET weather station located in Aurora, Oregon. The Aurora AGRIMET station was installed on 10/22/1998 (Figure 7). AGRIMET is a satellite based network of automated weather stations operated and maintained by the Bureau of Reclamation. Table 5 shows the Aurora AGRIMET station’s location, station ID, managing agency, elevation, coordinates and the weather constituents measured. Figure 8 shows the proximity of the Aurora AGRIMET station to the Drift Creek Dam and Salem, Oregon. The Aurora AGRIMET site is 35.2 km (21.87 mi) from the Drift Creek Dam site and 20.17 km (12.53 mi) from Salem, Oregon.
The majority of meteorological data was gathered as instantaneous hourly data with the exception of short wave solar radiation and precipitation data which were measured as hourly cumulative values and wind speed data which was recorded as average hourly values. Data gaps found in the Aurora AGRIMET station’s record were typically small and were filled by using linear interpolation or direct substitution.
8
Figure 7. Photograph of the Aurora AGRIMET weather station (Bureau of Reclamation).
Table 5. Aurora AGRIMET station summary.
Station Location
Station ID Agency Elevation
(ft-m) Latitude Longitude Meteorological Parameters
Aurora, OR ARAO
AGRIMET (Bureau of
Reclamation)
140 ft - 42.7 m 45.28194 122.75028
Air Temperature, Wind Speed, Wind Direction,
Precipitation, Solar Radiation, Dew Point
Temperature
9
Figure 8. Aurora AGRIMET weather station and Drift Creek dam site location
Air Temperature Air temperature data were collect from the Aurora AGRIMET station as instantaneous hourly values. Table 6 shows a statistical summary of the Aurora AGRIMET station’s air temperature data for 2004-2010. Figure 9 shows the average summer and average winter air temperatures from 2004 to 2010. Figure 10, Figure 11 and Figure 12 show hourly air temperature data measured at the Aurora AGRIMET station for 2004-2010. Summer temperatures fluctuated from 5.5 oC to 41.5 oC and average summer temperatures remained relatively constant, measuring around 19.5 oC. Winter temperatures ranged from -6.5 oC to 24.4 oC and average winter temperatures showed a general decline in temperatures through 2009 and a sharp increase for 2010.
Table 6. Aurora AGRIMET air temperature (oC) summary statistics 2004-2010
Year 2004 2005 2006 2007 2008 2009 2010 Max 39.4 35.1 39.3 39.5 39.1 41.5 36.8 Min -6.6 -6.7 -6.6 -6.1 -8.2 -12.1 -8.0
Median 11.6 11.6 11.0 10.9 10.4 10.7 11.1 Average 12.5 11.9 12.1 11.6 11.2 11.6 11.9
10
2004 2005 2006 2007 2008 2009 2010
16
17
18
19
20
Ave
rage
Sum
mer
Tem
pera
ture
, o C
4
5
6
7
8
Average
Winter Tem
perature, oCAverage Summer Temp.Average Winter Temp.
Figure 9. Aurora AGRIMET summer and winter average air temperatures (oC) 2004-2010.
11
0 73 146 219 292 365Julian Day
-20
-10
0
10
20
30
40
50A
ir Te
mpe
ratu
re, o C
1/1/04 3/14/04 5/26/04 8/7/04 10/19/04 12/31/04
367 440 513 586 659 732Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/05 3/15/05 5/27/05 8/8/05 10/20/05 1/1/06
732 805 878 951 1024 1097Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/06 3/15/06 5/27/06 8/8/06 10/20/06 1/1/07
Figure 10. Aurora AGRIMET air temperature (oC) 2004-2006.
12
1097 1170 1243 1316 1389 1462Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/07 3/15/07 5/27/07 8/8/07 10/20/07 1/1/08
1462 1535 1608 1681 1754 1827Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/08 3/14/08 5/26/08 8/7/08 10/19/08 12/31/08
1828 1901 1974 2047 2120 2193Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/09 3/15/09 5/27/09 8/8/09 10/20/09 1/1/10
Figure 11. Aurora AGRIMET air temperature (oC) 2007-2009.
13
2193 2266 2339 2412 2485 2558Julian Day
-20
-10
0
10
20
30
40
50
Air
Tem
pera
ture
, o C
1/1/10 3/15/10 5/27/10 8/8/10 10/20/10 1/1/11
Figure 12. Aurora AGRIMET air temperature (oC) 2010.
Dew Point Dew point temperature data were collect from the Aurora AGRIMET station as instantaneous hourly values. Table 7 shows a statistical summary of the dew point temperatures collected at the Aurora AGRIMET station from 2004-2010. Figure 13, Figure 14 and Figure 15 show hourly dew point temperature data that was measured at the Aurora AGRIMET station. Dew point temperatures fluctuated from -13.4 oC to 20.2 oC with annual averages around 6.5 oC. Annual lows were found during December through February, and annual highs were found from July through September.
Table 7. Aurora AGRIMET dew point temperature (oC) summary statistics 2004-2010.
Year 2004 2005 2006 2007 2008 2009 2010 Max 17.9 17.4 20.1 18.5 20.2 18.6 19.4 Min -13.4 -11.6 -22.0 -11.0 -15.7 -21.3 -11.4
Median 7.5 7.5 6.4 6.9 6.2 6.3 7.4 Average 7.3 6.5 5.9 6.6 6.1 5.9 7.3
14
0 73 146 219 292 365Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/04 3/14/04 5/26/04 8/7/04 10/19/04 12/31/04
367 440 513 586 659 732Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/05 3/15/05 5/27/05 8/8/05 10/20/05 1/1/06
732 805 878 951 1024 1097Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/06 3/15/06 5/27/06 8/8/06 10/20/06 1/1/07
Figure 13. Aurora AGRIMET dew point temperature (oC) 2004-2006.
15
1097 1170 1243 1316 1389 1462Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/07 3/15/07 5/27/07 8/8/07 10/20/07 1/1/08
1462 1535 1608 1681 1754 1827Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/08 3/14/08 5/26/08 8/7/08 10/19/08 12/31/08
1828 1901 1974 2047 2120 2193Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/09 3/15/09 5/27/09 8/8/09 10/20/09 1/1/10
Figure 14. Aurora AGRIMET dew point temperature (oC) 2007-2009.
16
2193 2266 2339 2412 2485 2558Julian Day
-30
-20
-10
0
10
20
30
Dew
Poi
nt T
empe
ratu
re, o C
1/1/10 3/15/10 5/27/10 8/8/10 10/20/10 1/1/11
Figure 15. Aurora AGRIMET dew point temperature (oC) 2010.
Short Wave Solar Radiation Short wave solar radiation data was collected from the Aurora AGRIMET station as cumulative langleys per hour. Hourly short wave solar radiation was calculated by finding the difference between successive cumulative hourly readings then converting the units from langleys per hour to watts per square meter. Table 8 shows a statistical summary of all short wave solar radiation data. Figure 16, Figure 17 and Figure 18 show hourly short wave solar radiation data collected from the Aurora AGRIMET station. Annual highs for short wave solar radiation occurred May through July and measured around 1000 W/m2.
Table 8. Aurora AGRIMET short wave solar radiation (W/m2) summary statistics 2004-2010.
Year 2004 2005 2006 2007 2008 2009 2010 Max 1073.9 998.3 1074.3 989.3 1007.1 1025.6 998.0 Min 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Median 5.8 5.8 5.8 5.8 7.6 7.7 7.6 Average 157.0 154.5 160.9 154.0 149.8 156.8 144.9
17
0 73 146 219 292 365Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/04 3/14/04 5/26/04 8/7/04 10/19/04 12/31/04
366 439 512 585 658 731Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/05 3/15/05 5/27/05 8/8/05 10/20/05 1/1/06
732 805 878 951 1024 1097Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/06 3/15/06 5/27/06 8/8/06 10/20/06 1/1/07
Figure 16. Aurora AGRIMET short wave solar radiation (W/m2) 2004-2006.
18
1097 1170 1243 1316 1389 1462Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/07 3/15/07 5/27/07 8/8/07 10/20/07 1/1/08
1462 1535 1608 1681 1754 1827Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/08 3/14/08 5/26/08 8/7/08 10/19/08 12/31/08
1828 1901 1974 2047 2120 2193Julian Day
0
200
400
600
800
1000
1200
Sho
rt W
ave
Sol
ar R
adia
tion,
W/m
2
1/1/09 3/15/09 5/27/09 8/8/09 10/20/09 1/1/10
Figure 17. Aurora AGRIMET short wave solar radiation (W/m2) 2007-2009.
19
2193 2266 2339 2412 2485 2558Julian Day
0
200
400
600
800
1000
Sho
rt W
ave
Sola
r Rad
iatio
n, W
/m2
1/2/10 3/16/10 5/28/10 8/9/10 10/21/10 1/2/11
Figure 18. Aurora AGRIMET short wave solar radiation (W/m2) 2010.
Cloud Cover CE-QUAL-W2 uses cloud cover data and air temperature data to calculated long wave radiation. In the absence of measured cloud cover data, cloud cover data was back calculated. Using a fortran program developed by Dr. Robert Annear the theoretical clear sky solar radiation is calculated based on the geographic location of Aurora AGRIMET weather station and then compared against the observed solar radiation data. The difference is then calculated into a value ranging from 0 (no clouds) to 10 (complete cloud cover). Cloud cover data was calculated at hourly intervals from January 1st, 2004 to December 31st, 2010. Table 9 shows the annual mean and median cloud cover values for 2004 through 2010. Figure 19, Figure 20 and Figure 21 show line plots of daily average cloud cover. Hourly cloud cover ranged from 0 to 10 annually and annual average cloud cover was consistent around 2.5. Most years showed a slight increase in hourly cloud cover during spring months.
Table 9. Cloud cover data calculated from Aurora AGRIMET solar data 2004-2010
Year 2004 2005 2006 2007 2008 2009 2010 Average 2.6 2.5 2.5 2.6 2.8 2.6 2.8 Median 2.4 2.4 2.4 2.5 2.7 2.5 2.8
20
0 73 146 219 292 365Julian Day
0
2
4
6
8
10
Clo
ud C
over
1/1/04 3/14/04 5/26/04 8/7/04 10/19/04 12/31/04
367 440 513 586 659 732Julian Day
0
2
4
6
8
10
Clo
ud C
over
1/1/05 3/15/05 5/27/05 8/8/05 10/20/05 1/1/06
732 805 878 951 1024 1097Julian Day
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Figure 19. Aurora AGRIMET calculated hourly averaged cloud cover 2004-2006.
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1097 1170 1243 1316 1389 1462Julian Day
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1828 1901 1974 2047 2120 2193Julian Day
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Figure 20. Aurora AGRIMET calculated hourly averaged cloud cover 2007-2009.
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2193 2266 2339 2412 2485 2558Julian Day
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Figure 21. Aurora AGRIMET calculated hourly averaged cloud cover 2010.
Wind Speed & Direction Wind direction data were measured instantaneously every hour in degrees and then converted to radians in the direction of wind origin. Filling wind direction data gaps by linear interpolation would typically yield inaccurate results, therefore the wind direction data point measured prior to the data gap was used for direct substitution. Wind speed data was recorded as hourly average values. The minimum detection limit for the wind speed gage at the Aurora AgriMet site was 0.3 m/s. Any wind speed below these thresholds would register as a zero wind speed and the wind direction would be recorded as zero as well. Table 10 shows a statistical summary of wind speed data. Figure 22 and Figure 23 show annual rose plots of wind speed, wind direction and the density of measured wind speeds from a given direction. Figure 24, Figure 25 and Figure 26 show scatter plots of wind speed data. Daily average wind speeds ranged from 0.3 m/s to 5.5 m/s and annual averages of daily maximum wind speeds were around 2.5 m/s. Winds predominantly originated from the North or from South-South-West, with higher velocities from the South. Higher wind velocities were found during late winter and spring months.
Table 10. Aurora AGRIMET wind speed (m/s) statistics summary 2004-2010.
Year 2004 2005 2006 2007 2008 2009 2010 Max 5.5 6.2 8.4 7.1 6.4 7.9 7.1
Median 0.9 0.9 0.9 0.7 1.2 1.2 1.2 Average 1.1 1.1 1.2 1.0 1.4 1.5 1.5
23
030
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<=2>3 - 4>5 - 6>7
Wind Direction and Speed in 2004 (Deg. & m/s)0
30
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330
2%3%4%5%
<=2>3 - 4>5 - 6>7
Wind Direction and Speed in 2005 (Deg. & m/s)
030
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<=2>3 - 4>5 - 6>7
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030
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<=2>3 - 4>5 - 6>7
Wind Direction and Speed in 2009 (Deg. & m/s)
Figure 22. Aurora AGRIMET hourly average wind rose plots (degrees azimuth & m/s) 2004-2009.
24
030
60
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150180
210
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270
300
330
2%3%4%5%
<=2>3 - 4>5 - 6>7
Wind Direction and Speed in 2010 (Deg. & m/s)
Figure 23. Aurora AGRIMET hourly average wind rose plots (degrees azimuth & m/s) 2010.
25
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367 440 513 586 659 732Julian Day
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Figure 24. Aurora AGRIMET hourly average wind speed (m/s) 2004-2006.
26
1097 1170 1243 1316 1389 1462Julian Day
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1828 1901 1974 2047 2120 2193Julian Day
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peed
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1/1/09 3/15/09 5/27/09 8/8/09 10/20/09 1/1/10
Figure 25. Aurora AGRIMET hourly average wind speed (m/s) 2007-2009.
27
2193 2266 2339 2412 2485 2558Julian Day
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peed
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1/1/10 3/15/10 5/27/10 8/8/10 10/20/10 1/1/11
Figure 26. Aurora AGRIMET hourly average wind speed (m/s) 2010.
Precipitation A complete record of precipitation data was gathered from the Aurora AGRIMET station from 1/1/04 through 12/31/10. The data were measured as cumulative inches of precipitation per hour and were converted to millimeters of precipitation per hour. Table 11 shows total annual precipitation measured at the Aurora AGRIMET station. Figure 27, Figure 28 and Figure 29 show bar charts of hourly precipitation measured at the Aurora AGRIMET station. Annual hourly precipitation was fairly sporadic, trending towards higher hourly precipitation during winter and spring months and little to zero precipitation during summer months. Annual total precipitation ranged from 808 mm to 1300.5 mm with 2006 and 2010 being two of the more wet years and 2004 and 2008 being more dry than other years.
Table 11. Aurora AGRIMET annual precipitation (mm) summary statistics
Year 2004 2005 2006 2007 2008 2009 2010 Total 808.5 1052.1 1300.5 1003.8 860.0 970.8 1290.0
28
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Hou
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366 439 512 585 658 731Julian Day
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1/1/06 3/15/06 5/27/06 8/8/06 10/20/06 1/1/07
Figure 27. Aurora AGRIMET hourly precipitation (mm) 2004-2006.
29
1097 1170 1243 1316 1389 1462Julian Day
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1828 1901 1974 2047 2120 2193Julian Day
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1/1/09 3/15/09 5/27/09 8/8/09 10/20/09 1/1/10
Figure 28. Aurora AGRIMET hourly precipitation (mm) 2007-2009.
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Figure 29. Aurora AGRIMET hourly precipitation (mm) 2010
Reservoir Inflows Reservoir inflows were estimated using a regression equation that predicted daily flow rate predictions for Drift Creek at Victor Point Road (Tanovan, 2010). The regression equation correlated flow rates measured at Victor Point Road with measurements from the United States Geological Survey (USGS) station Pudding River at Aurora, OR (station number 14202000). The water years 1934, 1945, and 1948 were identified in Tanovan (2010) as the average, low, and high flow years. For modeling purposes it was assumed that flow rates at Victor Point Road, which was located several hundred feet downstream of the proposed dam site, were equivalent to reservoir inflows. The applied regression equation was
where was the daily average flow rate (cfs) at Victor Point Road and was the daily average flow rate measured on the Pudding River at Aurora. The model consists of two branches, and inflows into each respective branch were determined by multiplying the flow rate for Victor Point Road by the percentage of watershed area upstream of each branch. Inflows to branch 1 account for 97% of the watershed area and 3% of the watershed area was located upstream of branch 2 (Figure 30). Branch 1 and 2 flow rates were shown in Figure 31 and Figure 32, respectively.
31
Figure 30. Percent drainage areas of watershed upstream of model branches 1 and 2.
32
Figure 31. Flow rates of branch 1 inflows.
33
Figure 32. Flow rates of branch 2 inflows.
Temperature Input Files Temperature inflow files for the reservoir branches were developed using average stream flow data measured at Victor Point Bridge and fitting a 6th degree polynomial to determine composite inflow temperatures. Data measured between 12/4/2008 and 11/24/2010 were used to develop the composite temperatures. Figure 33 plots the temperature data, the fitted polynomial, and 2009 temperature data that were discarded as outliers.
34
Figure 33. Temperature data measured at Victor Point Road along with 6th degree polynomial used to determine composite temperatures.
Constituent Input Files The constituent boundary conditions were developed using data collected at USGS stations located nearby. These data included conductivity, dissolved oxygen, pH, nitrite nitrogen, nitrate nitrogen, ammonia nitrogen, orthophosphate, phosphorus, alkalinity, organic nitrogen and organic carbon. Table 12 lists the stations where the data used to develop the constituent input files were collected. The locations of these stations relative to the dam site were shown in Figure 34.
35
Table 12. List of water quality measurement stations used to develop constituent inflow files.
Station ID Station Name Latitude Longitude USGS 445322122475303 Pudding River Tributary at
Cascade Highway near Silverton, OR
44°53'22" 122°47'53"
USGS 445814122505602 Pudding River at Kaufman Road, Oregon
44°58'14" 122°50'56"
USGS 445633122485103 Beaver Creek at Sunnyview Road near Silverton, OR
44°56'33" 122°48'51"
USGS 445811122503503 Beaver Creek at Kaufman Road near Silverton, OR
44°58'11" 122°50'35"
Figure 34. Locations of stations used to develop constituent input files.
The constituent input files for the reservoir model was developed from median values of water quality data measured at the sampling sites. The data and median constituent concentrations for these stations were listed in Table 13. The samples were collected in either 1993 or 1994. The Pudding River at Kaufman Road station had 2 sampling dates, whereas the other stations only had one. There was only
36
one measurement of organic carbon, which occurred on 4/26/1993 at the Pudding River at Kaufman Road station.
Table 13. Water quality data used to develop constituent input file of branch 1 of reservoir model.
Parameter/Station Pudding R. Tributary at
Cascade HWY
Pudding River at
Kaufman Road
Pudding River at
Kaufman Road
Beaver Creek at Sunnyview
Road
Beaver Creek at Kaufman
Road
Median Value
Sample Date 8/15/1994 4/26/1993 8/15/1994 8/15/1994 8/15/1994 Conductivity, µS/cm 44 56 314 44 67 56 Dissolved Oxygen, mg/l 8.7 10.6 7.7 7.2 6.9 7.7 pH 7.5 6.6 6.9 7.3 6.7 6.9 Total Phosphorus, mg/l 0.05 0.08 0.05 0.09 0.065 Orthophosphate, mg/l 0.01 0.01 0.01 0.01 0.01 0.01 Ammonia Nitrogen, mg/l 0.02 0.01 0.06 0.02 0.05 0.02 Total Organic Carbon, mg/l 1 1
Nitrite nitrogen, mg/l 0.01 0.01 0.01 0.01 0.01 0.01 Nitrate nitrogen, mg/l 1.2 2.5 0.47 0.92 0.68 0.92 Total Organic Nitrogen, mg/l 0.38 0.34 0.18 0.45 0.36
The equations used in developing the constituent files were shown below. Algae:
hla_ratioAlgae_to_C_lg ×Φ=Φ aChlaea Algae_to_Chla_Ratio = 0.2 this is the Ratio between algal biomass and chlorophyll a in terms of milligrams (mg) algae per micrograms (μg) chlorophyll a
aChl _Φ : chlorophyll a concentration, assumed to equal 1 μg/l
aea lgΦ : Algae concentration Total Organic Matter (TOM):
aeaC
TOCTOM lgΦ−
Φ=Φ
δ
45.0=Cδ , carbon-biomass ratio
TOCΦ : Total organic carbon, from data labile dissolved organic matter (LDOM):
TOMLDOMLDOM f Φ=Φ
LDOMf =0.25, fraction of organic matter that is LDOM
refractory dissolved organic matter (RDOM): TOMRDOMRDOM f Φ=Φ
RDOMf =0.25, fraction of organic matter that is RDOM
labile particulate organic matter (LPOM): 37
TOMLPOMLPOM f Φ=Φ LPOMf =0.25, fraction of organic matter that is LPOM
refractory particulate organic matter (RPOM): TOMRPOMRPOM f Φ=Φ
RPOMf =0.25, fraction of organic matter that is RPOM
labile dissolved organic matter – phosphorus (LDOM-P): ( )( ) LDOMTOMaeaPPOTPPLDOM Φ×Φ×Φ−Φ−Φ=Φ ∑− /algplg4
algp : phosphorus fraction of each algae group
TPΦ : Total Phosphorus, from data PPO 4Φ : orthophosphate, from data
refractory dissolved organic matter – phosphorus (RDOM-P): ( )( ) RDOMTOMaeaPPOTPPRDOM Φ×Φ×Φ−Φ−Φ=Φ ∑− /algplg4
labile particulate organic matter – phosphorus (LPOM-P): ( )( ) LPOMTOMaeaPPOTPPLPOM Φ×Φ×Φ−Φ−Φ=Φ ∑− /algplg4
refractory particulate organic matter – phosphorus (RPOM-P): ( )( ) RPOMTOMaeaPPOTPPRPOM Φ×Φ×Φ−Φ−Φ=Φ ∑− /algplg4
labile dissolved organic matter – nitrogen (LDOM-N):
( )( ) LDOMTOMaeaTONNLDOM Φ×Φ×Φ−Φ=Φ ∑− /algnlg algn : nitrogen fraction of algae group
TONΦ : Total Organic Nitrogen, from data
refractory dissolved organic matter – nitrogen (RDOM-N): ( )( ) RDOMTOMaeaTONNRDOM Φ×Φ×Φ−Φ=Φ ∑− /algnlg
labile particulate organic matter – nitrogen (LPOM-N): ( )( ) LPOMTOMaeaTONNLPOM Φ×Φ×Φ−Φ=Φ ∑− /algnlg
refractory particulate organic matter – nitrogen (RPOM-N): ( )( ) RPOMTOMaeaTONNRPOM Φ×Φ×Φ−Φ=Φ ∑− /algnlg
Total Inorganic Carbon: ( )TemppHfunction alkTIC ,,Φ=Φ
alkΦ : alkalinity, from data There were no alkalinity data available nearby at the sampling stations so a value of 27 mg/l CaCO3 was assumed. This value was based on average alkalinity concentrations measured in the Clackamas River, Oregon watershed in 2000 and 2001. Table 14 lists the constituent concentrations for the branch inflows.
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Table 14. Modeled constituent concentrations in constituent inflow file for reservoir branches 1 and 2.
Constituent Concentration Conductivity, µS/cm 56.0 Orthophosphate, mg/l 0.01 Ammonia nitrogen, mg/l 0.02 Nitrate-nitrite nitrogen, mg/l 0.925 Labile Dissolved Organic Matter, mg/l 0.506 Refractory Dissolved Organic Matter, mg/l 0.506 Labile Particulate Organic Matter, mg/l 0.506 Refractory Particulate Organic Matter, mg/l 0.506 Algae, mg/l 0.2 Dissolved Oxygen, mg/l 7.7 Total Inorganic Carbon, mg/l 8.44 Alkalinity, mg/l 27.0 Labile Dissolved Organic Matter-Phosphorus, mg/l 0.0149 Refractory Dissolved Organic Matter –Phosphorus, mg/l 0.0149 Labile Particulate Organic Matter –Phosphorus, mg/l 0.0149 Refractory Particulate Organic Matter –Phosphorus, mg/l 0.0149 Labile Dissolved Organic Matte-Nitrogen, mg/l 0.0890 Refractory Dissolved Organic Matter –Nitrogen, mg/l 0.0890 Labile Particulate Organic Matter –Nitrogen, mg/l 0.0890 Refractory Particulate Organic Matter -Nitrogen, mg/l 0.0890
Reservoir Operations Dam and reservoir parameters are listed in Table 15. The estimated agricultural release flows, which were provided by the East Valley Water District and assumed a total release for the year of 8000 acre-feet, were shown in Table 16. Dam release flows for instream water rights (ISWR) were based on year 2009 release rates provided by Tanovan (2009). If the ISWR monthly release rate was less than 1 cfs, a minimum release rate of 1 cfs was used. The spillway was modeled as a broad-crested weir. Using the equation for a weir with a well-rounded upstream edge (Streeter and Wylie, 1985):
where was the flow rate (cms), was the weir width (m), and was the head. The spillway width was 15.24 m (50 ft) giving
This equation was input directly into the model to calculate spillway flow rate. The head was internally calculated by the model by subtracting the spillway crest elevation from the model predicted water surface elevation at the dam segment.
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Table 15. Reservoir operations parameters.
Parameter Value Spillway crest elevation 677 ft or 206.35 m Spillway width 50 ft or 15.24 m Spillway type ogee Mid-level Outlet Intake Elevation 645 ft or 196.60 m Low-level Outlet Intake Elevation 620 ft or 188.98 m Maximum Flow Rate of Outlets 630 cfs or 17.84 m3/s Maximum Pool Elevation 684 ft or 208.49 Table 16. Agricultural release flows.
Month Percentage of
Annual Agricultural Release
Flow Rate (cfs) Flow Rate (m3/s) Flow Rate (acre-feet per day)
May 10% 13.00 0.368 25.8 June 10% 13.50 0.382 26.7 July 20% 26.00 0.736 51.6 August 30% 39.00 1.104 77.41 September 30% 40.33 1.142 80.0 Table 17. Instream water right release rates.
Month Instream Water Right
Release (Tanovan, 2010), cfs
Modeled ISWR Release Rate, cfs
Modeled ISWR Release m3/s
January, 2009 0.00 1.00 0.0283 February, 2009 28.91 28.91 0.8186 March, 2009 3.60 3.60 0.1019 April, 2009 28.56 28.56 0.8087 May, 2009 19.68 19.68 0.5573 June, 2009 7.25 7.25 0.2053 July, 2009 1.35 1.35 0.0382 August, 2009 0.24 1.00 0.0283 September, 2009 0.49 1.00 0.0283 October, 2009 3.02 3.02 0.0855 November, 2009 16.55 16.55 0.4686 December, 2009 16.92 16.92 0.4791
Scenarios Low, average, and high flow year scenarios were simulated (Table 18). The low flow year was 1945, the average flow year was chosen to be 1934, and the high flow year was 1948. For scenarios 1 through 3, in order to optimize cold pool of water in the hypolimnion agricultural flows were withdrawn from the mid-level outlet and instream water right (IWR) flows were withdrawn from the lower outlet. Other
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scenarios investigated the impact of withdrawing agricultural and IWR water solely from the mid-level outlet (scenario 4), withdrawing water solely from the low level outlet (scenario 5), and withdrawing 50% of the combined flows from the low-level and 50% from the mid-level outlets (scenario 6). The scenarios were run using year 2008 meteorological conditions. To help determine the sensitivity of model predictions to different meteorological conditions, scenario 7 used year 2009 meteorological conditions. The scenarios simulated the period between January 1 and December 31. January 1 was chosen as the simulation start date because the reservoir would likely be vertically well mixed on this date. The values of water quality coefficients used in the model were listed in Table 19.
Table 18. Model scenarios.
Scenario Number
Scenario Name Comments
1 Low Flow Year The low flow year was 1945. Year 2008 meteorological conditions were used. IWR flows were released from the low level outlet and Agricultural flows released from the middle level outlet.
2 Average Flow Year
The average flow year was 1934. Year 2008 meteorological conditions were used. IWR flows were released from the low level outlet and Agricultural flows released from the middle level outlet.
3 High Flow Year The high flow year was 1948. Year 2008 meteorological conditions were used. IWR flows were released from the low level outlet and Agricultural flows released from the middle level outlet.
4 Average Flow Year, Middle Withdrawal
The average flow year was 1934. Year 2008 meteorological conditions were used. All IWR and Agricultural flows released from middle level Outlet
5 Average Flow Year, Lower Withdrawal
The average flow year was 1934. Year 2008 meteorological conditions were used. All IWR and Agricultural flows released from lower level Outlet
6 Average Flow Year, 50-50 Withdrawal
The average flow year was 1934. Year 2008 meteorological conditions were used. IWR and Agricultural flows released 50%-50% from middle and lower level outlets
7 Average Flow Year, 2009 meteorological conditions
The average flow year was 1934. Year 2009 meteorological conditions were used. IWR flows were released from the low level outlet and Agricultural flows released from the middle level outlet.
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Table 19. W2 Model Water Quality Parameters.
Variable Description Units Typical values* Values
AX Longitudinal eddy viscosity (for momentum dispersion) m2/sec 1 1
DX
Longitudinal eddy diffusivity (for dispersion of heat and constituents) m2/sec 1 1
CBHE Coefficient of bottom heat exchange Wm2/sec 0.30 0.30
TSED Sediment (ground) temperature oC 12.0
WSC Wind sheltering coefficient 0.85 0.9
BETA
Fraction of incident solar radiation absorbed at the water surface 0.45 0.45
EXH20 Extinction for water /m 0.25-0.45 0.25 AG Algal growth rate /day 1-3 2 AM Algal mortality rate /day 0.1
AE Algal excretion rate /day 0.014-0.044 0.04
AR Algal dark respiration /day 0.01-0.92 0.04 AS Algal settling rate /day 0.02-1.00 0.1
ASAT
Algae Saturation intensity at maximum photosynthetic rate W/m2 10-170 100
APOM
Fraction of algal biomass lost by mortality to detritus for algae 0.8 0.8
ACHLA
Ratio between algae biomass and chlorophyll a in terms of mg algae/ug chl a
mg algae/ug
chl a 0.01 to
0.4 0.2
AT1 Lower temperature for algal growth oC 5
AT2 Lower temperature for maximum algal growth oC 20
AT3 Upper temperature for maximum algal growth oC 30
AT4 Upper temperature for algal growth oC 40
AK1 Fraction of algal growth rate at AT1 0.1 0.1
42
Variable Description Units Typical values* Values
AK2 Fraction of maximum algal growth rate at AT2 0.99 0.99
AK3 Fraction of maximum algal growth rate at AT3 0.99 0.99
AK4 Fraction of algal growth rate at AT4 0.1 0.1
ALGP
Stoichiometric equivalent between organic matter and phosphorus for algae 0.005 0.005
ALGN
Stoichiometric equivalent between organic matter and nitrogen for algae 0.08 0.08
ALGC
Stoichiometric equivalent between organic matter and carbon for algae 0.4-0.5 0.45
LDOMDK Labile DOM decay rate /day 0.04-0.12 0.10
LRDDK Labile to refractory decay rate /day 0.001 0.001
RDOMDK Maximum refractory decay rate /day 0.001 0.001
LPOMDK Labile Detritus decay rate /day 0.04-0.1 0.10 POMS Detritus settling rate m/day 0.2-2 0.5
RPOMDK Refractory detritus decay rate /day 0.001 0.001
OMT1 Lower temperature for organic matter decay oC 4 4
OMT2
Lower temperature for maximum organic matter decay oC 30 30
OMK1 Fraction of organic matter decay rate at OMT1 0.1 0.1
OMK2 Fraction of organic matter decay rate at OMT2 0.99 0.99
PO4R
Anaerobic sediment release rate of phosphorus as
fraction of SOD 0.001
AHSP Algal half-saturation constant for phosphorus g/m3
0.002-0.01 0.003
NH4DK Ammonia decay rate (nitrification rate) /day 0.001-1.3 0.12
AHSN Algal half-saturation constant for nitrogen g/m3 0.014 0.014
NH4T1 Lower temperature for ammonia decay oC 5 5
43
Variable Description Units Typical values* Values
NH4T2 Lower temperature for maximum ammonia decay oC 20 25
NH4K1 Fraction of nitrification rate at NH4T1 0.1 0.1
NH4K2 Fraction of nitrification rate at NH4T2 0.99 0.99
NO3DK Nitrate decay rate (denitrification rate) /day 0.05-0.15 0.05
NO3T1 Lower temperature for nitrate decay oC 5 5
NO3T2 Lower temperature for maximum nitrate decay oC 20 25
NO3K1 Fraction of denitrification rate at NO3T1 0.1 0.1
NO3K2 Fraction of denitrification rate at NO3T2 0.99 0.99
O2NH4
Oxygen stoichiometric equivalent for ammonia decay 4.57 4.57
O2OM
Oxygen stoichiometric equivalent for organic matter decay 1.4 1.4
O2AR
Oxygen stoichiometric equivalent for dark respiration 1.1 1.1
O2AG Oxygen stoichiometric equivalent for algal growth 1.4 1.8
O2LIM
Dissolved oxygen concentration at which anaerobic processes begin g/m3 0.1 0.1
SEDK First order sediment compartment decay rate /day 0.05
SOD Zeroth order sediment oxygen demand g/m2/day 0.3-6 0.5
SEDBR Sediment burial rate /day 0.02 * Cole and Wells (2010)
Water Level The water level predictions of the low (scenario 1), average (scenario 2), and high (scenario 3) flow year scenarios were shown in Figure 35. The initial water surface elevation was set to 206.35 m. Scenarios 4 through 7 simulate average flow year conditions, and water level predictions for those scenarios were the same as scenario 2. 44
Figure 35. Model predicted water level elevations for the low, average, and high flow year scenarios.
Flow Figure 36 shows the total dam outflow rates for the scenarios 1-3. Spillway flows for low, average, and high flow year scenarios were plotted in Figure 37. Agricultural release flows and Instream water right flows for scenario 1-3 were shown in Figure 38 and Figure 39, respectively. Outflow rates of the average flow year scenarios 4-7 were identical to that of scenario 2.
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Figure 36. Total reservoir outflows for scenario 1-3.
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Figure 37. Spillway flows for the scenarios 1-3.
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Figure 38. Agricultural release flows for the scenarios 1-3.
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Figure 39. Instream water right flows for the scenarios 1-3.
Temperature
Scenarios 1-3 Instream water right (IWR) release temperatures for scenarios 1, 2, and 3 (the low, average, and high flow year scenarios) were plotted along with data measured at Victor Point Bridge in Figure 40. Agricultural releases occurred through the mid-level outlet and IWR flows through the low level outlet for these scenarios. Victor Point Bridge was located within several hundred feet of the proposed dam site. The temperatures of the instream water right flows released from the lower level outlet were generally much less than temperatures measured in multiple years at the Victor Point Bridge location. Model predicted outflow temperatures of the mid-level outlet were plotted in Figure 41. Model predicted temperature profiles of scenarios were plotted in Figure 42 through Figure 45. As expected, stratification was significant during summer and early fall (Figure 43 and Figure 44) with temperatures being approximately eight degrees or more warmer in the epilimnion than the hypolimnion. A time-elevation contour plot of temperature for scenario 2 was shown in Figure 46. The contour plot corresponds to temperatures predicted in the segment adjacent to the dam. The contour plot also shows the dropping water level in the reservoir, and that although the pool of cooler water in the hypolimnion was diminished, it was never completely depleted.
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Figure 40. Model predicted dam outflow temperatures of the lower level outlet for scenarios 1 through 3. For these
scenarios flows from the low level outlet were used to be used for IWR flows, or fish flows. Average daily temperature data measured at Victor Point Bridge were also plotted.
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Figure 41. Model predicted mid-level outlet temperatures for scenarios 1-3. Water withdrawn from this outlet were used for agricultural releases.
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Figure 42. Predicted temperature profile for scenarios 1-3 on April 1.
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Figure 43. Predicted temperature profile for scenarios 1-3 on June 30.
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Figure 44. Predicted temperature profiles for scenarios 1-3 on September 28.
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Figure 45. Predicted temperature profiles for runs scenarios 1-3 on October 1.
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Figure 46. Time-elevation contour plot of temperature for scenario 2, the average flow year scenario.
Scenarios 4-6 Temperatures of IWR releases for the scenarios where combined agricultural and IWR releases were withdrawn from the mid-level outlet (Scenario 4), or the low level outlet (Scenario 5), or 50% from the low level outlet and 50% from the mid-level outlet (Scenario 6) were plotted in Figure 47. Scenario 4, where only the mid-level outlet was used, temperatures were highest because this outlet was closer to warm water near the surface. Scenario 6, with 50% of combined agricultural and IWR releases withdrawn from the low level outlet and 50% from the mid-level outlet, actually released cooler water than scenario 5 (where combined flows were released solely from the low-level outlet) because the cold water pool at the bottom of the reservoir lasted longer. In general IWR releases for scenarios 4-6 all exceeded typical Drift Creek water temperatures in August and September, showing the importance of dedicating the low level outlet for IWR releases and the mid-level outlet for agricultural releases.
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Figure 47. Temperatures of instream water right releases (IWR) for scenarios 4-6.
Scenario 7 Scenario 7 was an average flow year scenario that used year 2009 rather than year 2008 meteorological conditions. All other model inputs for scenario 7 were the same as that of scenario 2. IWR flows were released from the low level outlet and Agricultural flows released from the middle level outlet for scenario 7. The model predicted temperatures of outflows from the low level outlet, which was to be used for IWR releases, were shown for scenarios 2 and 7 in Figure 48. Using year 2009 meteorological conditions did not increase the temperature of the outflows.
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Figure 48. Temperatures of instream water right releases (IWR) for scenarios 2 and 7.
Dissolved Oxygen Dissolved oxygen concentrations during summer and early fall typically became zero in the hypolimnion for scenarios 1-3. Figure 49 shows the time-elevation contour plot of dissolved oxygen for the average flow year scenario (scenario 2). The predictions were for the model segment 7, which was adjacent to the dam. Nutrient concentrations in the reservoir inflows were high enough to produce a eutrophic system. The narrow band of super-saturated dissolved oxygen concentrations was caused by high algae productivity during the summer. The dissolved oxygen concentrations from the low level outlet were shown in Figure 50 for scenarios 1-3. Dissolved oxygen concentrations in the low level outlet are zero for a few months in the summer, indicating that the outlet withdraws water from the hypolimnion during this period. Since IWR releases come solely from the low level outlet for scenarios 1-3, some sort of reaeration device would be required to raise oxygen concentrations in the stream downstream of the dam to acceptable levels. Dissolved oxygen concentrations in the mid-level outlet flows, which were used for agricultural releases, were plotted in Figure 51. Concentrations for the average flow year scenario were higher because of the lower water level for this scenario, placing the outlet closer to the surface where dissolved oxygen concentrations were higher. Model predicted dissolved oxygen profiles for the scenarios 1-3 were plotted in Figure 52 through Figure 55. The band of higher DO due to algae productivity was apparent at a depth of 3-8 meter in Figure 53. Figure 54
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shows DO concentrations at zero in the hypolimnion on September 28th. Decay of organic matter in the water column was the largest sink of dissolved oxygen, even exceeding sediment oxygen demand (Figure 56). Algae productivity was a large source of dissolved oxygen in the epilimnion, but the high productivity in the epilimnion did not affect dissolved oxygen concentrations in the hypolimnion of the stratified system.
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Figure 49. Time-elevation contour plot of model predicted dissolved oxygen concentrations for the average flow year scenario (scenario 2).
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Figure 50. Model predicted low level outlet dissolved oxygen concentrations for scenarios 1-3.
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Figure 51. Model predicted mid-level outlet dissolved oxygen concentrations for scenarios 1-3.
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Figure 52. Predicted dissolved oxygen profiles for scenarios 1-3 on April 1.
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Figure 53. Predicted dissolved oxygen profiles for scenarios 1-3 on June 30.
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Figure 54. Predicted dissolved oxygen profiles for scenarios 1-3 on September 28.
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Figure 55. Predicted dissolved oxygen profiles for scenarios 1-3 on October 1.
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Figure 56. Time series of dissolved oxygen fluxes for the average flow year scenario 2. The fluxes correspond to the
entire reservoir.
Algae and Nutrients Model predicted chlorophyll a concentrations were plotted in Figure 57 through Figure 60. CE-QUAL-W2 outputs algae predictions in dry mass concentrations, and these were converted to chlorophyll a concentrations by assuming a ratio of 0.2 between algae biomass and chlorophyll a in terms of mg algae/ug chlorophyll a. This value was near the mid-point in the range recommended by the EPA (1985). Predicted chlorophyll a concentrations were generally less than 10 ug/l. The increase in chlorophyll a concentration that occurs starting at a depth of 5 m was caused by increased availability of nutrients that occurs near the hypolimnion (Figure 58 and Figure 59). Phosphorus, the limit nutrient, had larger concentrations in the hypolimnion because of the anaerobic release of nutrients (Figure 61). During the summer phosphorus was depleted in the epilimnion due to algae growth. On the other hand, light intensity diminishes as depth increases and this reduces the amount of energy available for photosynthesis. The “bulge” in chlorophyll a concentration that occurred between 5 and 9 m was the depth where light was still plentiful enough for photosynthesis and nutrients were available for growth.
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Chlorophyll a concentrations in the low level outlet were plotted in Figure 62 for scenarios 1-3. The low level outlet provides IWR flows for these scenarios which go directly into the creek downstream of the dam. In the IWR flows chlorophyll a concentrations were generally below 5 ug/l.
Figure 57. Predicted chlorophyll a profiles for scenarios 1-3 on April 1.
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Figure 58. Predicted chlorophyll a profiles for scenarios 1-3 on June 30.
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Figure 59. Predicted chlorophyll a profiles for scenarios 1-3 on September 28.
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Figure 60. Predicted chlorophyll a profiles for scenarios 1-3 on December 27.
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Figure 61. Time-elevation contour plot of model predicted total phosphorus concentrations for the average flow year scenario (scenario 2). The concentrations correspond model segment adjacent to the dam (segment 7). During the summer phosphorus concentrations were depleted in the epilimnion due to algae growth but increased in the hypolimnion because of the anaerobic release of nutrients.
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Figure 62. Model predicted low level outlet chlorophyll a concentrations for scenarios 1-3.
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Summary A CE-QUAL-W2 water quality model of the reservoir formed by the Drift Creek Dam was developed. The model simulates flow, water level, temperature, dissolved oxygen, organic matter, nutrients and algae. Model bathymetry was developed from AutoCAD drawings of topographic contours of the area provided by Stuntzner Engineering & Forestry, LLC. Flow and temperature inputs to the model were developed from data collected from stations on Drift Creek near the dam site. Water quality inputs were developed using data collected from neighboring watersheds. The Aurora Agrimet station, which was located approximately 22 miles from the dam site, provided data for meteorological inputs. Water releases from the dam were based on estimated agricultural needs and instream water right (IWR) requirements.
Low, average, and high flow year scenarios were simulated and different strategies of withdrawing water from the proposed low level and mid-level outlets were investigated. An additional scenario where year 2009 meteorological inputs was also simulated. The results of the scenarios helped provide the following conclusions:
• In order for the temperature IWR flows to remain at or below existing temperatures in Drift Creek, agricultural releases must come from the mid-level outlet and IWR releases from the low level outlet. This release strategy allows the cold water pool in the hypolimnion to be preserved through fall.
• If IWR flows come from the low level outlet, dissolved oxygen concentrations in the IWR release flows will be at zero for a few months in the summer making the use of a reaeration device to oxygenate the water necessary.
• The reservoir refilled by January 1 for the low, average, and high flow year scenarios using the current release rates
• Simulating year 2009 meteorological conditions did not affect the availability of cold water for IWR flows.
Contour plots of temperature and dissolved oxygen on August 1st for the average flow year scenario (scenario 2) were shown in Figure 63 and Figure 64, respectively. The model predicts a well defined metalimnion approximately at the depth of the mid-level outlet. Below the elevation of the mid-level outlet was the hypolimnion containing cooler water with low dissolved concentrations.
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Figure 63. Contour plot of model predicted temperatures for August 1 at 12 pm for the average flow year scenario (scenario 2). The low level and mid-level outlets were shown by the arrows. The metalimnion, separating the epilimnion and hypolimnion, was located approximately at the elevation of the mid-level outlet.
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Distance, m
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Figure 64. Contour plot of model predicted dissolved oxygen concentrations for August 1 at 12 pm for the average flow year scenario (scenario 2). The low level and mid-level outlets were shown by the arrows. Dissolved oxygen concentrations in most of the hypolimnion were zero by this time.
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References Cole, T. and Buchak, E. (1995) “CE-QUAL-W2 Version 2,” Instruction Report E-95-1, Corps of Engineers, ERDC, Vicksburg, MS. Cole, T. and Wells, S. (2010). “CE-QUAL-W2: A Two-Dimensional, Laterally Averaged, Hydrodynamic and Water Quality Model, Version 3.7” Department of Civil and Environmental Engineering, Portland State University, Portland, OR. EPA 1985. Rates, Constants and Kinetics in Surface Water Quality Modeling, Environmental Research Laboratory, EPA/600/3-85/040, Athens, Ga. Streeter, V. L. and Wylie E. B. (1985). “Fluid Mechanics, Eight Edition,” McGraw-Hill Book Company, New York. Stuntzner Engineering & Forestry. (2007). Eric Urstadt memorandum (March 23, 2007) to East Valley Water District. Tanovan, Bolyvong (2011). “Drift Creek Site A., Near Silverton OR Runoff Yield Analysis, Update #2”, Report prepared for East Valley Water District, Mt. Angel, OR.
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