Pond Evaporation Calculation 12/31/14
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 2013 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec or Avg.
Ovid Avg. Temp F 26.41 29.69 37.33 42.96 58.87 70.53 74.29 74.48 67.56 46.97 36.34 25.34 49.23
Ref date as of 12/31/2013 Total Precip " 0.36 0.62 0.45 1.27 1.56 1.91 1.49 1.47 2.49 0.98 0.52 0.15 13.27
Site Type: Alfalfa Total Alfalfa ETr " 1.89 2.36 4.35 5.83 8.55 10.48 9.72 8.4 6.45 4.07 2.63 2.16 66.89
Total Growing Degee Days from March 1 0 0 103 172 376 573 691 681 525 200 110 57 3488
Gross Pond Evap Total " 1.59 1.98 3.65 4.9 7.18 8.8 8.16 7.06 5.42 3.42 2.21 1.81 56.18
Net Pond Evap Total " 1.34 1.55 3.34 4.01 6.09 7.47 7.12 6.03 3.68 2.73 1.85 1.71 46.92
Crook Avg. Temp F 26.91 29.74 37.68 42.36 57.83 69.94 72.38 72.25 65.62 46.29 35.8 25.31 48.51
Ref date as of 12/31/2013 Total Precip " 0.24 0.43 0.24 1.24 2.53 1.09 2.6 1.23 4.2 1.01 0.36 0.1 15.27
Site Type: Alfalfa Total Alfalfa ETr " 1.98 2.41 4.51 5.29 7.59 10.34 8.75 7.58 5.52 3.88 2.63 2.15 62.63
Total Growing Degee Days from March 1 0 0 109 161 359 563 653 631 491 188 108 57 3320
Gross Pond Evap Inch 1.66 2.02 3.79 4.44 6.38 8.69 7.35 6.37 4.64 3.26 2.21 1.81 52.62
Net Pond Evap Inch 1.5 1.72 3.62 3.58 4.6 7.92 5.53 5.51 1.7 2.55 1.96 1.74 41.93
 
Sterling Avg. Temp F 27.23 30.23 38.13 42.99 58.99 71.38 73.04 72.19 66.03 46.69 36.85 25.54 49.11
Ref date as of 12/31/2013 Total Precip " 0.33 0.52 0.41 1.84 1.31 1.13 5.47 1.15 6.28 1.32 0.32 0.06 20.14
Site Type: Alfalfa Total Alfalfa ETr " 1.98 2.39 4.47 5.23 8.61 10.99 8.82 7.28 5.54 3.79 2.6 2.09 63.79
Total Growing Degee Days from March 1 0 0 121 159 373 587 667 641 497 188 122 55 3410
Gross Pond Evap Inch 1.66 2.01 3.75 4.39 7.23 9.23 7.41 6.12 4.65 3.18 2.18 1.76 53.57
Net Pond Evap Inch 1.43 1.64 3.47 3.11 6.32 8.44 3.58 5.31 0.26 2.26 1.96 1.71 39.49
 
Brush Avg. Temp F 26.18 28.45 36 42.2 57.68 69.87 71.45 71.51 64.94 46.48 37.24 25.6 48.13
Ref date as of 12/31/2013 Total Precip " 0.33 0.37 0.93 1.31 0.86 1.14 3.07 3.17 4.48 1.42 0.22 0.21 17.51
Site Type: Alfalfa Total Alfalfa ETr " 2.11 2.47 3.88 5.26 8.22 10.22 8.9 7.47 5.34 3.8 2.63 2 62.3
Total Growing Degee Days from March 1 0 0 107 158 357 559 637 637 481 201 123 58 3318
Gross Pond Evap Inch 1.77 2.07 3.26 4.42 6.9 8.58 7.48 6.27 4.49 3.19 2.21 1.68 52.32
Net Pond Evap Inch 1.54 1.82 2.61 3.5 6.3 7.79 5.33 4.06 1.35 2.2 2.06 1.53 40.09
 
Fort Morgan Avg. Temp F 27.14 29.4 37.2 42.9 58.98 71.31 72.52 72.13 65.42 46.24 36.77 24.64 48.72
Ref date as of 12/31/2013 Total Precip " 0.2 0.37 1.22 1.36 1.25 1.59 1.84 1.8 4.22 1.45 0.21 0.21 15.72
Site Type: Turf Total Alfalfa ETr " 1.92 2.26 3.63 4.92 8.29 9.88 8.87 7.7 5.24 3.39 2.25 1.57 59.92
Total Growing Degee Days from March 1 0 0 115 162 379 578 658 645 490 189 109 48 3373
Gross Pond Evap Inch 1.61 1.9 3.05 4.13 6.96 8.3 7.45 6.47 4.4 2.85 1.89 1.32 50.33
Net Pond Evap Inch 1.47 1.64 2.2 3.18 6.09 7.19 6.16 5.21 1.45 1.83 1.74 1.17 39.33
 
Wiggins Avg. Temp F 24.66 27.03 34.99 40.91 56.78 69.77 72.02 71.84 64.54 45.71 36.17 24.22 47.39
Ref date as of 12/31/2013 Total Precip " 0.25 0.26 0.87 1.37 0.68 0.74 0.69 1.02 3.66 1.25 0.16 0.26 11.21
Site Type: Alfalfa Total Alfalfa ETr " 2.01 2.34 3.76 5.04 7.83 11 9.69 8.12 5.4 3.75 2.63 1.74 63.31
Total Growing Degee Days from March 1 0 0 97 145 354 553 626 637 479 192 118 51 3252
Gross Pond Evap Inch 1.69 1.97 3.16 4.23 6.58 9.24 8.14 6.82 4.54 3.15 2.21 1.46 53.19
Net Pond Evap Inch 1.51 1.78 2.55 3.27 6.1 8.72 7.66 6.11 1.97 2.28 2.1 1.28 45.33
 
Fort Collins East Avg. Temp F 26.23 28.41 36.78 40.96 56.62 68.7 70 69.5 62.02 44.84 35.93 24.93 47.08
Ref date as of 12/31/2013 Total Precip " 0.24 0.32 0.5 2.27 1.9 1.44 1.52 0.6 4.72 1.27 0.18 0.23 15.19
Site Type: Alfalfa Total Alfalfa ETr " 2.22 2.63 4.66 5.19 8.37 10.27 8.05 7.12 4.94 3.53 2.76 2.03 61.77
Total Growing Degee Days from March 1 0 0 102 139 334 522 600 584 434 157 89 34 2995
Gross Pond Evap Inch 1.86 2.21 3.91 4.36 7.03 8.63 6.76 5.98 4.15 2.97 2.32 1.71 51.89
Net Pond Evap Inch 1.7 1.99 3.56 2.77 5.7 7.62 5.7 5.56 0.85 2.08 2.19 1.54 41.26
 
Eaton Avg. Temp F 25.8 28.45 36.64 41.15 56.66 68.86 69.9 70.12 62.22 44.84 35.48 24.19 47.03
Ref date as of 12/31/2013 Total Precip " 0.37 0.32 0.65 1.93 2.3 0.55 1.32 1.05 4.11 1.22 0.23 0.35 14.4
Site Type: Alfalfa Total Alfalfa ETr " 1.99 2.37 4.25 4.88 8.11 10.14 7.98 7.19 4.95 3.4 2.49 1.7 59.45
Total Growing Degee Days from March 1 0 0 102 146 341 537 613 605 444 169 98 35 3090
Gross Pond Evap Inch 1.67 1.99 3.57 4.1 6.81 8.52 6.7 6.04 4.16 2.86 2.09 1.43 49.94
Net Pond Evap Inch 1.41 1.77 3.12 2.75 5.2 8.13 5.78 5.3 1.28 2 1.93 1.18 39.85
 
Johnsons Corner Avg. Temp F 28.64 29.18 37.63 41.9 57.65 70.52 71.69 72.22 64.12 46.1 37.54 26.13 48.61
Ref date as of 12/31/2013 Total Precip " 0.15 0.86 0.93 2.76 1.77 0.64 0.68 0.27 5.65 0.98 0.38 0.5 15.57
Site Type: Alfalfa Total Alfalfa ETr " 2.14 2.3 4.03 4.65 7.13 9.82 8.24 8.08 5.21 3.48 2.57 2.03 59.68
Total Growing Degee Days from March 1 0 0 106 150 349 558 647 638 464 165 100 37 3214
Gross Pond Evap Inch 1.8 1.93 3.39 3.91 5.99 8.25 6.92 6.79 4.38 2.92 2.16 1.71 50.15
Net Pond Evap Inch 1.69 1.33 2.73 1.97 4.75 7.8 6.45 6.6 0.42 2.24 1.89 1.36 39.23
 
Gilcrest Avg. Temp F 26.15 28.47 37.44 42.94 58.51 71.29 72.46 72.3 64.01 45.43 36.35 24.38 48.31
Ref date as of 12/31/2013 Total Precip " 0.16 0.74 0.9 1.92 1.54 1.5 1.12 1.21 8.06 1.11 0.22 0.4 18.88
Site Type: Alfalfa Total Alfalfa ETr " 1.78 2.28 3.92 4.6 7.6 10.16 8.57 7.81 5.17 3.3 2.4 1.72 59.31
Total Growing Degee Days from March 1 0 0 113 160 371 570 663 650 471 175 111 42 3326
Gross Pond Evap Inch 1.5 1.92 3.29 3.86 6.38 8.53 7.2 6.56 4.34 2.77 2.02 1.44 49.81
Net Pond Evap Inch 1.38 1.4 2.66 2.52 5.31 7.48 6.41 5.71 0 2 1.86 1.16 37.89
 
Longmont South Avg. Temp F 30.47 30.69 39.24 43.11 58.31 70.7 72.07 71.48 63.4 45.82 38.85 28.08 49.35
Ref date as of 12/31/2013 Total Precip " 0.2 0.69 0.84 2.38 1.8 0.37 0.69 1.27 8.92 1.24 0.28 0.36 19.04
Site Type: Alfalfa Total Alfalfa ETr " 2.55 2.65 4.26 5.15 7.84 9.77 8.46 7.64 5.17 3.24 2.84 2.48 62.05
Total Growing Degee Days from March 1 0 0 119 159 359 551 643 630 439 154 113 49 3216
Gross Pond Evap Inch 2.14 2.23 3.58 4.33 6.59 8.21 7.11 6.42 4.34 2.72 2.39 2.08 52.14
Net Pond Evap Inch 2 1.74 2.99 2.66 5.33 7.95 6.62 5.53 0 1.85 2.19 1.83 40.69
 
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 27.91 29.47 37.93 41.48 57.3 69.08 70.89 70.52 62.44 45.01 36.92 25.87 47.9
Ref date as of 12/31/2013 Total Precip " 0.11 0.35 0.47 1.74 2.32 0.41 1.62 0.57 6.49 1.74 0.2 0.27 16.29
Site Type: Turf Total Alfalfa ETr " 1.72 2.15 3.87 4.24 6.92 8.34 6.98 6.08 4.19 2.91 2.16 1.55 51.11
Total Growing Degee Days from March 1 0 0 101 140 337 532 627 599 444 170 108 50 3108
Gross Pond Evap Inch 1.44 1.81 3.25 3.56 5.81 7.01 5.86 5.11 3.52 2.44 1.81 1.3 42.92
Net Pond Evap Inch 1.37 1.56 2.92 2.34 4.19 6.72 4.73 4.71 0 1.23 1.67 1.11 32.55
 
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 25.82 28 36.51 41.4 57.51 70.17 71.89 72.21 64.02 45.71 36.31 24.27 47.82
Ref date as of 12/31/2013 Total Precip " 0.23 0.63 0.83 2.12 1.55 0.36 1.43 2.47 5.43 1.16 0.36 0.48 17.05
Site Type: Turf Total Alfalfa ETr " 1.58 2.09 3.82 4.48 7.48 9.15 8.04 7.13 4.87 3.13 2.09 1.39 55.25
Total Growing Degee Days from March 1 0 0 93 144 354 562 656 646 476 172 99 33 3235
Gross Pond Evap Inch 1.33 1.76 3.21 3.76 6.28 7.69 6.75 5.99 4.09 2.63 1.76 1.17 46.42
Net Pond Evap Inch 1.17 1.31 2.63 2.28 5.2 7.43 5.75 4.26 0.29 1.82 1.5 0.83 34.47
 
Loveland Avg. Temp F 28.32 29.13 38.07 42.25 57.86 70 72.04 72.14 63.96 46.33 38.31 26.64 48.75
Ref date as of 12/31/2013 Total Precip " 0.03 0.43 0.42 2.22 2.02 1.14 1.39 0.4 7.2 1.08 0.36 0.23 16.92
Site Type: Turf Total Alfalfa ETr " 1.7 2.09 3.72 4.27 6.67 7.74 6.73 5.95 4.21 2.95 2.14 1.58 49.75
Total Growing Degee Days from March 1 0 0 114 164 363 577 682 656 483 192 124 54 3409
Gross Pond Evap Inch 1.43 1.76 3.12 3.59 5.6 6.5 5.65 5 3.54 2.48 1.8 1.33 41.8
Net Pond Evap Inch 1.41 1.45 2.83 2.03 4.19 5.7 4.68 4.72 0 1.72 1.55 1.17 31.45
 
Berthoud Avg. Temp F 28.52 28.74 36.94 40.95 56.99 69.3 70.7 71.47 63.51 45.59 37.75 26.71 48.1
Ref date as of 12/31/2013 Total Precip " 0.1 0.7 0.77 2.9 1.92 0.4 1.39 0.23 5.48 1.14 0.3 0.48 15.81
Site Type: Turf Total Alfalfa ETr " 1.87 2.16 3.72 4.29 7.06 8.39 7.37 7.19 4.8 3.17 2.36 1.86 54.24
Total Growing Degee Days from March 1 0 0 88 130 333 546 639 638 449 152 88 32 3095
Gross Pond Evap Inch 1.57 1.81 3.12 3.6 5.93 7.05 6.19 6.04 4.03 2.66 1.98 1.56 45.54
Net Pond Evap Inch 1.5 1.32 2.59 1.57 4.59 6.77 5.22 5.88 0.2 1.86 1.77 1.23 34.5
 
Longmont West Avg. Temp F 29.25 30.07 38.62 42.61 58.45 70.57 72.32 72.76 64.42 46.5 39.82 28.82 49.52
Ref date as of 12/31/2013 Total Precip " 0.06 0.34 0.54 1.87 1.68 0.14 0.63 0.67 7.84 1.18 0.16 0.19 15.3
Site Type: Turf Total Alfalfa ETr " 1.8 2.09 3.52 4.28 6.76 7.97 7.26 6.61 4.21 2.73 2.28 1.75 51.26
Total Growing Degee Days from March 1 0 0 100 143 347 565 667 655 471 176 119 55 3298
Gross Pond Evap Inch 1.51 1.76 2.96 3.6 5.68 6.69 6.1 5.55 3.54 2.29 1.92 1.47 43.07
Net Pond Evap Inch 1.47 1.52 2.58 2.29 4.5 6.6 5.66 5.08 0 1.47 1.8 1.34 34.31
 
Fort Lupton Avg. Temp F 28.74 29.89 37.9 42.36 57.59 70.38 72.34 72.59 65.04 47.15 40.03 28.53 49.38
Ref date as of 12/31/2013 Total Precip " 0.32 0.73 0.8 1.57 1.27 0.41 0.75 0.96 8.5 0.98 0.25 0.32 16.86
Site Type: Turf Total Alfalfa ETr " 2.08 2.43 4.01 4.95 7.66 10.31 9.03 8.17 5.4 3.65 2.82 2.22 62.73
Total Growing Degee Days from March 1 0 0 103 154 360 562 653 666 491 182 142 60 3373
Gross Pond Evap Inch 1.75 2.04 3.37 4.16 6.43 8.66 7.59 6.86 4.54 3.07 2.37 1.86 52.7
Net Pond Evap Inch 1.52 1.53 2.81 3.06 5.55 8.37 7.06 6.19 0 2.38 2.19 1.64 42.3
 
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 24.83 27.47 36.34 41.56 57.76 69.96 70.82 70.59 63.17 45.22 35.62 23.49 47.24
Ref date as of 12/31/2013 Total Precip " 0.04 0.24 0.33 0.77 1.57 0.33 1.13 1.4 4.03 1.05 0.11 0.11 11.11
Site Type: Fully irrigated Total Alfalfa ETr " 2.17 2.66 4.44 5.31 8.71 11.01 8.96 7.26 5.3 3.42 2.95 1.99 64.18
Total Growing Degee Days from March 1 0 0 98 147 362 554 622 618 472 180 105 32 3190
Gross Pond Evap Inch 1.82 2.23 3.73 4.46 7.32 9.25 7.53 6.1 4.45 2.87 2.48 1.67 53.91
Net Pond Evap Inch 1.79 2.07 3.5 3.92 6.22 9.02 6.74 5.12 1.63 2.14 2.4 1.59 46.14