Pond Evaporation Calculation 12/31/15
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 2014 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec or Avg.
Ovid Avg. Temp F 29.49 19.95 37.62 49.24 58.3 67.71 72.31 71.14 63.29 51.79 31.74 25.16 48.15
Ref date as of 12/31/2014 Total Precip " 0.5 1.11 0.49 0.68 2 5.39 0.53 1.89 1.28 0.8 0.41 0.48 15.56
Site Type: Alfalfa Total Alfalfa ETr " 2.99 1.64 4.35 7.24 7.68 8.57 8.88 7.62 6.08 4.9 2.38 1.44 63.77
Total Growing Degee Days from March 1 0 0 127 227 380 516 650 640 442 310 84 43 3419
Gross Pond Evap Total " 2.51 1.38 3.65 6.08 6.45 7.2 7.46 6.4 5.11 4.12 2 1.21 53.57
Net Pond Evap Total " 2.16 0.6 3.31 5.61 5.05 3.43 7.09 5.08 4.21 3.56 1.71 0.87 42.68
Crook Avg. Temp F 28.73 19.8 37.76 48.85 57.6 66.67 72.37 70.33 62.59 51.4 31.52 24.29 47.66
Ref date as of 12/31/2014 Total Precip " 0.43 0.72 0.46 0.61 2.54 4.37 1.37 3.58 2.95 0.42 0.43 0.63 18.51
Site Type: Alfalfa Total Alfalfa ETr " 2.76 1.54 4.34 6.9 7.31 8.55 8.66 7.09 5.66 4.55 2.29 1.37 61.02
Total Growing Degee Days from March 1 0 0 126 221 365 500 640 618 436 314 88 44 3352
Gross Pond Evap Inch 2.32 1.29 3.65 5.8 6.14 7.18 7.27 5.96 4.75 3.82 1.92 1.15 51.25
Net Pond Evap Inch 2.02 0.79 3.32 5.37 4.36 4.12 6.32 3.45 2.69 3.53 1.62 0.71 38.3
 
Sterling Avg. Temp F 28.73 21.3 39.2 49.41 58.21 67.41 72.47 70.16 62.4 51.64 31.59 23.72 48.02
Ref date as of 12/31/2014 Total Precip " 0.67 0.5 0.59 2.12 1.97 3.87 4.39 2.46 1.23 0.41 0.44 0.95 19.6
Site Type: Alfalfa Total Alfalfa ETr " 2.6 1.6 4.52 6.82 7.2 8.67 8.47 7.12 5.68 4.52 2.18 1.3 60.68
Total Growing Degee Days from March 1 0 0 139 222 364 524 651 622 438 329 93 41 3423
Gross Pond Evap Inch 2.18 1.34 3.8 5.73 6.05 7.28 7.11 5.98 4.77 3.8 1.83 1.09 50.96
Net Pond Evap Inch 1.72 0.99 3.38 4.24 4.67 4.57 4.04 4.26 3.91 3.51 1.52 0.43 37.24
 
Brush Avg. Temp F 26.95 22.49 39.57 49.6 57.66 67.11 71.9 68.69 62.06 51.62 31.46 23.04 47.68
Ref date as of 12/31/2014 Total Precip " 0.89 0.4 0.64 1.39 3.4 5.04 1.96 4.74 1.5 0.47 0.86 0.57 21.86
Site Type: Alfalfa Total Alfalfa ETr " 2.2 1.81 4.68 6.93 7.2 8.77 7.97 6.7 5.58 4.55 2.16 1.24 59.79
Total Growing Degee Days from March 1 0 0 151 224 360 519 641 596 435 323 96 33 3378
Gross Pond Evap Inch 1.85 1.52 3.93 5.82 6.05 7.37 6.69 5.63 4.69 3.82 1.81 1.04 50.22
Net Pond Evap Inch 1.23 1.24 3.48 4.85 3.67 3.84 5.32 2.31 3.64 3.49 1.21 0.64 34.92
 
Fort Morgan Avg. Temp F 26.58 22.08 38.64 49.01 57.36 66.56 72.06 69.37 62.51 51.81 31.82 23.83 47.64
Ref date as of 12/31/2014 Total Precip " 0.74 0.33 0.58 1.31 2.44 6.01 2.01 5.19 2.68 0.73 0.98 0.61 23.61
Site Type: Turf Total Alfalfa ETr " 1.92 1.7 4.09 6.18 6.9 8.19 8.19 6.8 5.34 3.99 1.98 1.11 56.39
Total Growing Degee Days from March 1 0 0 136 212 356 508 644 604 442 317 96 33 3348
Gross Pond Evap Inch 1.61 1.43 3.44 5.19 5.8 6.88 6.88 5.71 4.49 3.35 1.66 0.93 47.37
Net Pond Evap Inch 1.09 1.2 3.03 4.27 4.09 2.67 5.47 2.08 2.61 2.84 0.98 0.51 30.84
 
Wiggins Avg. Temp F 25.97 21.78 38.38 48.5 56.92 65.72 70.23 67.5 60.92 49.88 29.61 21.85 46.44
Ref date as of 12/31/2014 Total Precip " 0.47 0.33 0.64 1.04 2.29 2 2.52 3.51 1.29 0.71 0.65 0.47 15.92
Site Type: Alfalfa Total Alfalfa ETr " 2.05 1.77 4.44 6.66 6.75 8.42 7.69 6.98 5.59 4.22 2.06 1.17 57.8
Total Growing Degee Days from March 1 0 0 134 212 345 492 603 563 424 300 77 29 3179
Gross Pond Evap Inch 1.72 1.49 3.73 5.59 5.67 7.07 6.46 5.86 4.7 3.54 1.73 0.98 48.54
Net Pond Evap Inch 1.39 1.26 3.28 4.87 4.07 5.67 4.7 3.41 3.79 3.05 1.28 0.65 37.42
 
Fort Collins East Avg. Temp F 28.15 24.45 38.47 47.77 55.34 64.84 69.74 67.03 60.52 50.94 32.69 26.83 47.23
Ref date as of 12/31/2014 Total Precip " 0.77 0.31 1.24 0.28 2.92 3.2 3.28 0.71 1 1.67 0.55 0.42 16.35
Site Type: Alfalfa Total Alfalfa ETr " 2.55 2.22 4.75 6.91 6.83 8.79 7.83 7.07 5.54 4.57 2.42 1.99 61.47
Total Growing Degee Days from March 1 0 0 114 193 301 472 594 545 401 287 94 44 3045
Gross Pond Evap Inch 2.14 1.86 3.99 5.8 5.74 7.38 6.58 5.94 4.65 3.84 2.03 1.67 51.62
Net Pond Evap Inch 1.6 1.65 3.12 5.61 3.69 5.14 4.28 5.44 3.95 2.67 1.65 1.38 40.18
 
Eaton Avg. Temp F 27.15 22.24 38.04 47.94 55.95 65.23 69.85 67.55 61.11 51.51 32.4 26.24 47.1
Ref date as of 12/31/2014 Total Precip " 0.83 0.25 0.91 0.3 2.81 2.48 3.64 0.92 1.12 0.57 0.78 0.58 15.19
Site Type: Alfalfa Total Alfalfa ETr " 2.27 1.73 4.39 6.91 6.92 8.58 7.4 6.71 5.43 4.35 2.28 1.69 58.66
Total Growing Degee Days from March 1 0 0 116 208 325 481 604 568 426 309 94 42 3173
Gross Pond Evap Inch 1.91 1.45 3.69 5.8 5.81 7.21 6.22 5.64 4.56 3.65 1.92 1.42 49.28
Net Pond Evap Inch 1.33 1.28 3.05 5.59 3.85 5.47 3.67 4.99 3.78 3.26 1.37 1.01 38.65
 
Johnsons Corner Avg. Temp F 27.82 25.11 39.3 48.54 56.04 65.4 70.78 68.06 61.68 52.89 33.45 28.36 48.12
Ref date as of 12/31/2014 Total Precip " 1.34 0.34 1.1 0.58 4.3 0.63 2.72 0.73 0.94 0.74 1 0.64 15.06
Site Type: Alfalfa Total Alfalfa ETr " 1.99 2.17 4.67 6.61 6.88 8.69 8.17 7.18 5.39 4.35 2.4 1.62 60.12
Total Growing Degee Days from March 1 0 0 124 200 318 483 611 559 415 301 99 44 3154
Gross Pond Evap Inch 1.67 1.82 3.92 5.55 5.78 7.3 6.86 6.03 4.53 3.65 2.02 1.36 50.49
Net Pond Evap Inch 0.73 1.58 3.15 5.15 2.77 6.86 4.96 5.52 3.87 3.14 1.32 0.91 39.96
 
Gilcrest Avg. Temp F 25.63 24.17 39.07 48.89 56.33 66.05 71.09 68.78 62.77 52.51 32.64 26.43 47.86
Ref date as of 12/31/2014 Total Precip " 1.03 0.25 1 0.83 3.65 1.69 3.02 0.78 1.45 0.49 0.59 0.51 15.29
Site Type: Alfalfa Total Alfalfa ETr " 1.68 2 4.59 6.6 6.82 8.44 8.22 6.9 5.46 4.04 2.27 1.5 58.52
Total Growing Degee Days from March 1 0 0 128 214 329 501 616 586 445 322 110 45 3296
Gross Pond Evap Inch 1.41 1.68 3.86 5.54 5.73 7.09 6.9 5.8 4.59 3.39 1.91 1.26 49.16
Net Pond Evap Inch 0.69 1.51 3.16 4.96 3.17 5.91 4.79 5.25 3.57 3.05 1.49 0.9 38.45
 
Longmont South Avg. Temp F 29.8 26.83 40.19 48.97 56.08 65.11 70.68 68.37 62.57 54.17 36.02 28.93 48.98
Ref date as of 12/31/2014 Total Precip " 1.16 0.36 1.09 1.05 2.04 0.51 2.55 0.74 1.29 0.89 0.69 0.63 13
Site Type: Alfalfa Total Alfalfa ETr " 2.73 2.55 5.31 6.55 6.65 8.75 7.92 7.04 5.42 4.68 3.1 1.75 62.45
Total Growing Degee Days from March 1 0 0 132 196 318 473 590 569 436 306 119 46 3185
Gross Pond Evap Inch 2.29 2.14 4.46 5.5 5.59 7.35 6.65 5.91 4.55 3.93 2.6 1.47 52.44
Net Pond Evap Inch 1.48 1.89 3.7 4.77 4.16 6.99 4.87 5.4 3.65 3.31 2.12 1.03 43.37
 
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 29.87 26.73 39.29 48.68 56.27 65.57 70.86 68.51 60.99 52.01 34.44 29.18 48.53
Ref date as of 12/31/2014 Total Precip " 0.43 0.7 1.5 0.44 4.07 1.36 3.58 0.84 1.32 0.98 0.92 0.35 16.49
Site Type: Turf Total Alfalfa ETr " 2.08 2.13 4.09 5.8 5.97 7.26 6.53 6.13 4.29 3.48 2.06 1.43 51.25
Total Growing Degee Days from March 1 0 0 121 194 315 476 611 569 418 316 119 58 3197
Gross Pond Evap Inch 1.75 1.79 3.44 4.87 5.01 6.1 5.49 5.15 3.6 2.92 1.73 1.2 43.05
Net Pond Evap Inch 1.45 1.3 2.39 4.56 2.17 5.15 2.98 4.56 2.68 2.24 1.09 0.96 31.53
 
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 27.25 24.05 38.84 48.77 56.76 66.17 71.45 68.86 62.36 52 33.09 27.36 48.08
Ref date as of 12/31/2014 Total Precip " 1.17 0.39 1.12 0.59 4 1.62 3.62 0.66 1.46 1.38 0.87 0.57 17.45
Site Type: Turf Total Alfalfa ETr " 1.82 1.93 4.06 6.25 6.56 7.79 7.39 6.51 5.02 3.67 1.98 1.43 54.41
Total Growing Degee Days from March 1 0 0 122 211 335 500 632 591 439 306 97 38 3271
Gross Pond Evap Inch 1.53 1.62 3.41 5.25 5.51 6.54 6.21 5.47 4.22 3.08 1.66 1.2 45.7
Net Pond Evap Inch 0.71 1.35 2.63 4.84 2.71 5.41 3.67 5.01 3.19 2.12 1.05 0.8 33.49
 
Loveland Avg. Temp F 29.11 26.64 40.14 49.3 56.97 66.15 71.43 68.98 61.71 52.75 34.24 28.32 48.81
Ref date as of 12/31/2014 Total Precip " 0.67 0.76 1.04 0.41 6.15 0.58 2.45 1.73 1.37 0.98 0.67 0.43 17.24
Site Type: Turf Total Alfalfa ETr " 1.87 2.16 4.07 5.59 5.88 6.94 6.41 5.8 4.3 3.51 2.14 1.27 49.94
Total Growing Degee Days from March 1 0 0 152 223 349 510 648 599 435 332 114 55 3417
Gross Pond Evap Inch 1.57 1.81 3.42 4.7 4.94 5.83 5.38 4.87 3.61 2.95 1.8 1.07 41.95
Net Pond Evap Inch 1.1 1.28 2.69 4.41 0.63 5.42 3.67 3.66 2.65 2.26 1.33 0.77 29.87
 
Berthoud Avg. Temp F 28.01 25.03 39.34 48.48 55.89 65.08 70.62 68.32 61.72 53.03 34.15 28.85 48.21
Ref date as of 12/31/2014 Total Precip " 1.36 0.32 0.97 0.58 5.24 0.78 2.77 0.7 0.96 0.45 0.96 0.61 15.7
Site Type: Turf Total Alfalfa ETr " 1.87 2.04 4.47 6.09 6.36 7.89 7.46 6.7 4.92 3.92 2.24 1.39 55.35
Total Growing Degee Days from March 1 0 0 116 200 315 474 617 574 414 287 98 39 3134
Gross Pond Evap Inch 1.57 1.71 3.75 5.12 5.34 6.63 6.27 5.63 4.13 3.29 1.88 1.17 46.49
Net Pond Evap Inch 0.62 1.49 3.08 4.71 1.67 6.08 4.33 5.14 3.46 2.98 1.21 0.74 35.51
 
Longmont West Avg. Temp F 30.43 27.8 41.39 50.29 57.49 66.82 72.02 69.26 61.6 52.73 34.68 28.5 49.42
Ref date as of 12/31/2014 Total Precip " 0.42 0.26 0.86 0.76 2.45 0.77 3.48 2.05 1.17 0.69 0.46 0.43 13.8
Site Type: Turf Total Alfalfa ETr " 1.91 2.08 4.18 5.71 6.11 7.51 6.89 6.08 4.1 3.43 2.23 1.23 51.46
Total Growing Degee Days from March 1 0 0 143 205 329 506 643 590 421 300 110 46 3293
Gross Pond Evap Inch 1.6 1.75 3.51 4.8 5.13 6.31 5.79 5.11 3.44 2.88 1.87 1.03 43.22
Net Pond Evap Inch 1.31 1.57 2.91 4.26 3.42 5.77 3.35 3.67 2.63 2.4 1.55 0.73 33.57
 
Fort Lupton Avg. Temp F 30.23 27.2 41.11 50.03 57.62 67.09 72.62 69.24 63.38 53.94 35.1 28.81 49.7
Ref date as of 12/31/2014 Total Precip " 0.77 0.37 1.2 0.9 3.34 2.09 2.66 1.65 2.43 0.61 0.72 0.54 17.28
Site Type: Turf Total Alfalfa ETr " 2.31 2.39 4.85 6.48 7.11 8.98 8.33 6.96 5.47 4.26 2.62 1.61 61.37
Total Growing Degee Days from March 1 0 0 148 220 348 520 657 610 448 319 120 49 3439
Gross Pond Evap Inch 1.94 2.01 4.07 5.44 5.97 7.54 7 5.85 4.59 3.58 2.2 1.35 51.54
Net Pond Evap Inch 1.4 1.75 3.23 4.81 3.63 6.08 5.14 4.69 2.89 3.15 1.7 0.97 39.44
 
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 #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 12/30/2015 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
Greeley04 Avg. Temp F 25.95 22.36 38.36 48.45 56.78 65.49 69.82 67.66 61.37 51.26 31.79 25.25 47.05
Ref date as of 12/31/2014 Total Precip " 0.27 0.07 0.66 0.63 4.88 2.38 4.37 0.73 1.36 0.5 0.41 0.05 16.31
Site Type: Fully irrigated Total Alfalfa ETr " 2.51 2.14 4.58 7.31 7.49 8.92 7.04 6.08 5.13 3.97 2.72 1.81 59.7
Total Growing Degee Days from March 1 0 0 125 219 346 500 589 569 436 318 97 38 3237
Gross Pond Evap Inch 2.11 1.8 3.85 6.14 6.29 7.49 5.91 5.11 4.31 3.33 2.28 1.52 50.14
Net Pond Evap Inch 1.92 1.75 3.39 5.7 2.88 5.83 2.85 4.6 3.36 2.98 2 1.49 38.75