Pond Evaporation Calculation 12/31/13
Weather Station Data provided by Northern Colorado Water Conservancy District
See Weather Station Location Map at:
http://www.northernwater.org/WaterConservation/WeatherandETData.aspx
Notes:
Current month reflects values through "Reference Date".
Pond Evap. calculated per recent Division 1 Water Court decree language: Lower South Platte Home Page
Gross Pond = .84(Alfalfa ETr) Pond Evaporation Reports Main Menu
Net Pond = .84(Alfalfa ETr) - .7(Total Precip)
Alfalfa reference ETr computed by Standard ASCE equation from daily weather data.
Winter pond evap. is a reference for unfrozen ponds.
For Growing Degree Days:
Tmax = 86 F, Tmin = 50 F and Tbase = 50 F
Totals
Weather Station 2012 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec or Avg.
Ovid Avg. Temp F 30.1 29.77 48.6 54.25 61.95 76.32 79.84 74.33 64.46 47.16 38.5 26.74 52.67
Ref date as of 12/31/2012 Total Precip " 0.09 0.31 0.57 1.94 0.82 0.64 2.35 0.07 0.47 0.64 0.14 0.41 8.45
Site Type: Alfalfa Total Alfalfa ETr " 2.78 2.64 7.38 7.38 9.67 13.35 12.14 10.44 7.83 4.49 3.03 2.06 83.19
Total Growing Degee Days from March 1 0 0 288 272 429 664 742 639 474 240 174 40 3962
Gross Pond Evap Total " 2.34 2.22 6.2 6.2 8.12 11.21 10.2 8.77 6.58 3.77 2.55 1.73 69.89
Net Pond Evap Total " 2.27 2 5.8 4.84 7.55 10.77 8.55 8.72 6.25 3.32 2.45 1.44 63.96
Crook Avg. Temp F 29.91 29.36 46.95 53.14 59.5 74.56 77.58 72.22 63.03 46.29 38.06 26.69 51.44
Ref date as of 12/31/2012 Total Precip " 0.13 0.55 0.51 1.71 1.09 0.37 3.12 0.92 0.79 0.8 0.16 0.41 10.56
Site Type: Alfalfa Total Alfalfa ETr " 2.74 2.72 7.15 7.12 8.74 11.98 10.23 8.86 6.8 4.17 2.92 1.98 75.41
Total Growing Degee Days from March 1 0 0 272 258 392 617 690 587 453 232 164 40 3705
Gross Pond Evap Inch 2.3 2.28 6.01 5.98 7.34 10.06 8.59 7.44 5.71 3.5 2.45 1.66 63.32
Net Pond Evap Inch 2.21 1.9 5.65 4.78 6.58 9.8 6.41 6.8 5.16 2.94 2.34 1.38 55.95
 
Sterling Avg. Temp F 30.82 28.58 47.61 54.76 60.72 75.72 78.64 74.01 64.04 46.89 38.76 27.35 52.33
Ref date as of 12/31/2012 Total Precip " 0.1 0.66 0.23 1.34 0.99 0.47 2.96 0.02 0.6 1.09 0.15 0.38 8.99
Site Type: Alfalfa Total Alfalfa ETr " 2.62 2.57 6.86 7.39 8.33 12.2 11.29 9.83 6.95 4.18 2.73 1.91 76.86
Total Growing Degee Days from March 1 0 0 279 284 405 640 728 631 458 242 172 46 3885
Gross Pond Evap Inch 2.2 2.16 5.76 6.21 7 10.25 9.48 8.26 5.84 3.51 2.29 1.6 64.56
Net Pond Evap Inch 2.13 1.7 5.6 5.27 6.3 9.92 7.41 8.24 5.42 2.75 2.19 1.34 58.27
 
Brush Avg. Temp F 31.78 28.54 47.69 53.93 60.01 73.61 75.71 71.79 63.08 45.75 36.93 26.06 51.24
Ref date as of 12/31/2012 Total Precip " 0.08 0.79 0.03 1.52 1.04 1.03 2.49 0.26 0.84 0.87 0.26 0.29 9.5
Site Type: Alfalfa Total Alfalfa ETr " 2.68 2.29 6.91 7.39 8.46 11.4 9.94 9.19 6.86 4.09 2.32 1.88 73.41
Total Growing Degee Days from March 1 0 0 282 294 401 593 695 600 456 233 137 37 3728
Gross Pond Evap Inch 2.25 1.92 5.8 6.21 7.11 9.58 8.35 7.72 5.76 3.44 1.95 1.58 61.67
Net Pond Evap Inch 2.2 1.37 5.78 5.14 6.38 8.86 6.61 7.54 5.17 2.83 1.77 1.38 55.03
 
Fort Morgan Avg. Temp F 30.18 27.95 46.31 55.15 61.29 75.1 77.91 73.93 64.57 47.08 37.79 27.15 52.03
Ref date as of 12/31/2012 Total Precip " 0.03 0.85 0.03 2.1 1.42 1.96 1.86 0.5 1.18 1.13 0.59 0.28 11.93
Site Type: Turf Total Alfalfa ETr " 2.12 2.1 5.49 6.94 7.9 10.53 9.72 8.85 6.21 3.69 2.08 1.58 67.21
Total Growing Degee Days from March 1 0 0 261 318 427 622 718 642 479 241 133 45 3886
Gross Pond Evap Inch 1.78 1.76 4.61 5.83 6.64 8.85 8.16 7.43 5.22 3.1 1.75 1.33 56.46
Net Pond Evap Inch 1.76 1.17 4.59 4.36 5.64 7.47 6.86 7.08 4.39 2.31 1.33 1.13 48.09
 
Wiggins Avg. Temp F 30.56 28.11 46.15 52.64 58.77 72.89 75.6 72.06 62.56 44.82 34.99 24.93 50.34
Ref date as of 12/31/2012 Total Precip " 0.01 0.54 0.09 1.57 1.36 0.25 1.96 0.23 0.9 1.04 0.43 0.1 8.48
Site Type: Alfalfa Total Alfalfa ETr " 2.52 2.43 6.65 7.28 8.16 11.73 10.4 9.73 6.64 3.8 2.04 1.77 73.15
Total Growing Degee Days from March 1 0 0 263 281 389 577 681 606 449 212 108 33 3599
Gross Pond Evap Inch 2.12 2.04 5.59 6.12 6.85 9.85 8.74 8.17 5.58 3.19 1.71 1.49 61.45
Net Pond Evap Inch 2.11 1.66 5.52 5.02 5.9 9.68 7.36 8.01 4.95 2.46 1.41 1.42 55.5
 
Fort Collins East Avg. Temp F 33.76 29.71 47.29 52.59 58.38 71.53 73.82 69.61 61.45 45.92 37.74 26.72 50.71
Ref date as of 12/31/2012 Total Precip " 0.07 0.3 0.05 0.33 1.91 0.64 2.17 0.19 1.38 0.59 0.21 0.21 8.05
Site Type: Alfalfa Total Alfalfa ETr " 2.98 2.82 7.12 7.39 7.77 10.42 9.29 8.22 6.57 3.98 2.52 1.94 71.02
Total Growing Degee Days from March 1 0 0 269 280 362 558 659 569 437 210 117 35 3496
Gross Pond Evap Inch 2.5 2.37 5.98 6.21 6.53 8.75 7.8 6.9 5.52 3.34 2.12 1.63 59.65
Net Pond Evap Inch 2.45 2.16 5.95 5.98 5.19 8.3 6.28 6.77 4.55 2.93 1.97 1.48 54.01
 
Eaton Avg. Temp F 32.38 29.85 46.87 52.55 58.68 72.38 73.79 69.52 61.93 45.83 37.22 26.56 50.63
Ref date as of 12/31/2012 Total Precip " 0.06 0.32 0.08 0.73 1.5 1.18 2.19 0.06 1.31 0.85 0.22 0.17 8.67
Site Type: Alfalfa Total Alfalfa ETr " 2.86 2.76 6.98 7.49 8.34 11.16 9.25 8 6.28 3.82 2.23 1.81 70.98
Total Growing Degee Days from March 1 0 0 273 284 377 570 669 571 440 207 106 34 3531
Gross Pond Evap Inch 2.4 2.32 5.86 6.29 7.01 9.37 7.77 6.72 5.28 3.21 1.87 1.52 59.62
Net Pond Evap Inch 2.36 2.09 5.81 5.78 5.96 8.55 6.24 6.68 4.36 2.61 1.72 1.4 53.56
 
Johnsons Corner Avg. Temp F 34.89 29.44 48.67 53.44 59.35 74.29 75.36 72.37 64.45 47.58 39.31 28.88 52.34
Ref date as of 12/31/2012 Total Precip " 0.31 0.77 0.15 0.68 1.39 0.32 2.61 0.13 1.19 0.82 0.44 0.38 9.19
Site Type: Alfalfa Total Alfalfa ETr " 2.65 2.48 6.69 7.02 8.15 11.63 9.75 9.05 6.81 4.08 2.32 1.9 72.53
Total Growing Degee Days from March 1 0 0 266 286 379 593 700 624 461 219 104 38 3670
Gross Pond Evap Inch 2.23 2.08 5.62 5.9 6.85 9.77 8.19 7.6 5.72 3.43 1.95 1.6 60.94
Net Pond Evap Inch 2.01 1.54 5.51 5.42 5.87 9.55 6.36 7.51 4.89 2.85 1.64 1.33 54.48
 
Gilcrest Avg. Temp F 33.34 28.49 47.6 53.46 59.35 74.76 76.52 72.63 64.03 47.49 37.74 27.82 51.94
Ref date as of 12/31/2012 Total Precip " 0.04 0.43 0.04 1.01 1.31 0.66 2.12 1.52 2.24 1.23 0.43 0.23 11.26
Site Type: Alfalfa Total Alfalfa ETr " 2.27 2.34 6.61 6.91 7.61 11.08 9.54 8.37 5.73 3.65 1.99 1.77 67.87
Total Growing Degee Days from March 1 0 0 278 301 389 597 714 628 474 240 112 43 3776
Gross Pond Evap Inch 1.91 1.97 5.55 5.8 6.39 9.31 8.01 7.03 4.81 3.07 1.67 1.49 57.01
Net Pond Evap Inch 1.88 1.66 5.52 5.1 5.48 8.85 6.53 5.97 3.25 2.21 1.37 1.33 49.15
 
Longmont South Avg. Temp F 37.54 29.56 50.16 54.5 60.35 74.63 75.88 73.1 65.15 48.92 41.73 31.11 53.55
Ref date as of 12/31/2012 Total Precip " 0.27 0.76 0.05 1.02 1.62 0.31 1.6 0.15 1.19 1.04 0.38 0.24 8.63
Site Type: Alfalfa Total Alfalfa ETr " 3.51 2.61 7.23 7.54 8.08 11.24 9.62 8.89 6.63 4.21 2.82 2.39 74.77
Total Growing Degee Days from March 1 0 0 272 299 388 611 706 640 462 240 144 54 3816
Gross Pond Evap Inch 2.95 2.19 6.07 6.33 6.79 9.44 8.08 7.47 5.57 3.54 2.37 2.01 62.81
Net Pond Evap Inch 2.76 1.66 6.04 5.62 5.65 9.22 6.96 7.36 4.74 2.81 2.1 1.84 56.76
 
Fort Collins NW Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 12/31/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Fort Collins Central Avg. Temp F 35.04 30.24 48.51 53.29 58.58 72.34 74.17 70.45 62.17 46.42 38.69 28.15 51.5
Ref date as of 12/31/2012 Total Precip " 0.07 0.92 0.02 0.32 1.62 0.25 3.41 0.02 1.79 0.55 0.1 0.08 9.15
Site Type: Turf Total Alfalfa ETr " 2.39 2.48 6.12 6.25 7.15 8.97 7.67 6.82 5.29 3.12 2.07 1.49 59.82
Total Growing Degee Days from March 1 0 0 265 277 368 564 674 585 444 223 135 37 3572
Gross Pond Evap Inch 2.01 2.08 5.14 5.25 6.01 7.53 6.44 5.73 4.44 2.62 1.74 1.25 50.24
Net Pond Evap Inch 1.96 1.44 5.13 5.03 4.87 7.36 4.06 5.71 3.19 2.24 1.67 1.2 43.86
 
Windsor Avg. Temp F 34.73 30.75 49.32 54.56 60.53 75.1 80.1 #N/A #N/A #N/A #N/A #N/A 55.01
Ref date as of 7/1/2012 Total Precip " 0.02 0.47 0.03 1.07 1.6 0.05 0 #N/A #N/A #N/A #N/A #N/A 3.24
Site Type: Dryland Pasture Total Alfalfa ETr " 2.56 2.44 6.69 6.86 6.23 6.65 0 #N/A #N/A #N/A #N/A #N/A 31.43
Total Growing Degee Days from March 1 0 0 285 312 399 622 22 #N/A #N/A #N/A #N/A #N/A 1640
Gross Pond Evap Inch 2.15 2.05 5.62 5.76 5.23 5.59 0 #N/A #N/A #N/A #N/A #N/A 26.4
Net Pond Evap Inch 2.14 1.72 5.6 5.01 4.11 5.55 0 #N/A #N/A #N/A #N/A #N/A 24.13
 
Greeley West Avg. Temp F 32.49 29.05 47.45 53.31 59.35 73.87 75.65 71.91 63.46 46.07 36.91 26.93 51.37
Ref date as of 12/31/2012 Total Precip " 0.1 0.45 0.06 0.67 1.3 0.46 1.32 0.15 2.2 1.11 0.44 0.33 8.59
Site Type: Turf Total Alfalfa ETr " 2.17 2.38 5.96 6.65 7.59 9.98 9.08 7.81 5.68 3.34 1.78 1.5 63.92
Total Growing Degee Days from March 1 0 0 273 296 387 605 705 621 456 208 93 29 3673
Gross Pond Evap Inch 1.82 2 5.01 5.59 6.38 8.38 7.63 6.56 4.77 2.81 1.5 1.26 53.71
Net Pond Evap Inch 1.75 1.68 4.96 5.12 5.47 8.06 6.7 6.46 3.23 2.03 1.19 1.03 47.68
 
Loveland Avg. Temp F 35 29.68 48.99 54.2 59.72 73.75 75.8 72.24 64.46 47.22 39.67 29.01 52.48
Ref date as of 12/31/2012 Total Precip " 0.17 0.14 0 0.38 1.64 0.07 2.09 0.09 1.16 0.67 0.32 0.04 6.77
Site Type: Turf Total Alfalfa ETr " 2.29 2.26 5.67 6.22 7.12 9.09 8.13 7.25 5.4 3.23 1.91 1.58 60.15
Total Growing Degee Days from March 1 0 0 289 317 393 616 722 643 482 230 126 42 3860
Gross Pond Evap Inch 1.92 1.9 4.76 5.22 5.98 7.64 6.83 6.09 4.54 2.71 1.6 1.33 50.52
Net Pond Evap Inch 1.8 1.8 4.76 4.96 4.83 7.59 5.37 6.03 3.72 2.24 1.38 1.3 45.78
 
Berthoud Avg. Temp F 34.92 29.16 49.03 53.66 59.43 73.87 75.01 72.04 63.88 46.95 39.31 28.73 52.17
Ref date as of 12/31/2012 Total Precip " 0.2 0.63 0.04 0.59 1.42 0.18 2.95 0.18 1.16 0.84 0.34 0.15 8.68
Site Type: Turf Total Alfalfa ETr " 2.35 2.36 6 6.5 7.58 10 8.86 8.22 5.88 3.44 2 1.75 64.94
Total Growing Degee Days from March 1 0 0 259 286 365 608 717 637 444 199 94 33 3642
Gross Pond Evap Inch 1.97 1.98 5.04 5.46 6.37 8.4 7.44 6.9 4.94 2.89 1.68 1.47 54.54
Net Pond Evap Inch 1.83 1.54 5.01 5.05 5.37 8.27 5.38 6.78 4.13 2.3 1.44 1.37 48.47
 
Longmont West Avg. Temp F 37.89 31.44 51.42 55.95 61.44 75.83 77.23 73.09 64.16 47.73 40.38 30.32 53.91
Ref date as of 12/31/2012 Total Precip " 0.13 0.39 0 0.65 1.44 0.11 1.63 0.15 1.32 0.73 0.33 0.13 7.01
Site Type: Turf Total Alfalfa ETr " 2.41 2.27 5.58 6.33 6.86 8.84 8.07 7.16 5.15 3.08 1.94 1.7 59.39
Total Growing Degee Days from March 1 0 0 276 308 395 645 751 652 447 215 122 41 3852
Gross Pond Evap Inch 2.02 1.91 4.69 5.32 5.76 7.43 6.78 6.01 4.33 2.59 1.63 1.43 49.9
Net Pond Evap Inch 1.93 1.63 4.69 4.86 4.75 7.35 5.64 5.91 3.4 2.08 1.4 1.34 44.98
 
Fort Lupton Avg. Temp F 37.02 30.6 51.04 55.43 61.44 75.64 76.5 73.1 64.87 47.86 40.27 29.98 53.65
Ref date as of 12/31/2012 Total Precip " 0.22 0.62 0.18 0.93 1.27 0.41 1.15 0.19 1.58 1.36 0.62 0.23 8.76
Site Type: Turf Total Alfalfa ETr " 2.91 2.58 6.86 7.39 8.64 11.6 10.22 9.16 6.33 3.84 2.47 2.06 74.06
Total Growing Degee Days from March 1 0 0 295 329 412 637 732 651 471 231 125 50 3933
Gross Pond Evap Inch 2.44 2.17 5.76 6.21 7.26 9.74 8.58 7.69 5.32 3.23 2.07 1.73 62.2
Net Pond Evap Inch 2.29 1.73 5.64 5.56 6.37 9.46 7.78 7.56 4.21 2.27 1.64 1.57 56.08
 
Boulder NW Avg. Temp F 37.65 29.64 50.39 53.79 60.03 74.83 75.52 73.33 64.89 49.14 44.06 32.86 53.84
Ref date as of 12/31/2012 Total Precip " 0.17 0.9 0.01 1.2 1.64 0.63 3.28 0.24 2.33 1.02 0.24 0.26 11.92
Site Type: Turf Total Alfalfa ETr " 3.02 2.28 5.99 6.28 7.09 8.53 8 7.62 5.53 3.55 2.65 2.06 62.6
Total Growing Degee Days from March 1 0 0 273 293 393 633 718 655 468 224 146 51 3854
Gross Pond Evap Inch 2.54 1.92 5.03 5.28 5.96 7.17 6.72 6.4 4.65 2.98 2.23 1.73 52.61
Net Pond Evap Inch 2.42 1.29 5.02 4.44 4.81 6.72 4.42 6.23 3.01 2.27 2.06 1.55 44.24
 
Boulder East Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder Flatiron Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder SW Avg. Temp F 40.24 31.02 51.87 54.59 59.64 74.08 74.75 72.96 65.1 49.83 46.06 34.28 54.54
Ref date as of 12/31/2012 Total Precip " 0.15 0.79 0 1.31 1.63 0.42 3.96 0.27 2.24 1.13 0.1 0.18 12.18
Site Type: Turf Total Alfalfa ETr " 3.62 2.47 6.34 6.71 7.29 9.64 8.4 7.83 5.83 3.74 3.02 2.29 67.18
Total Growing Degee Days from March 1 0 0 238 266 348 565 700 622 435 203 133 44 3554
Gross Pond Evap Inch 3.04 2.07 5.33 5.64 6.12 8.1 7.06 6.58 4.9 3.14 2.54 1.92 56.44
Net Pond Evap Inch 2.94 1.52 5.33 4.72 4.98 7.8 4.28 6.39 3.33 2.35 2.47 1.8 47.91
Greeley04 Avg. Temp F 30.55 29.19 46.43 53.33 59.38 73.17 74.55 70.43 62.28 45.79 35.94 25.94 50.58
Ref date as of 12/31/2012 Total Precip " 0.01 0.42 0.02 0.91 1.11 0.76 1.64 0.29 1.03 1 0.18 0.06 7.43
Site Type: Fully irrigated Total Alfalfa ETr " 2.98 2.92 7.24 8.07 9.1 11.52 9.74 8.3 6.23 4.2 2.27 2.33 74.9
Total Growing Degee Days from March 1 0 0 282 300 391 592 687 597 456 221 97 31 3654
Gross Pond Evap Inch 2.5 2.45 6.08 6.78 7.64 9.68 8.18 6.97 5.23 3.53 1.91 1.96 62.91
Net Pond Evap Inch 2.5 2.16 6.07 6.14 6.87 9.14 7.03 6.77 4.51 2.83 1.78 1.92 57.72