Pond Evaporation Calculation													1/28/09
Weather Station Data provided by Northern Colorado Water Conservancy District
See Weather Station Location Map at:
http://www.ncwcd.org/ims/ims_weather_form.asp
Notes:
Current month reflects values through "Reference Date".
Pond Evap. calculated per recent Division 1 Water Court decree language:
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	2004	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	25.75	28.73	42.95	48.26	58.98	63.82	69.92	66.01	63.44	50.01	34.37	29.22	48.46
Ref date as of 12/31/2004	Total Precip "	0.17	0.82	0.26	2.6	2.32	1.86	3.42	3.96	1.64	0.98	0.47	0.1	18.6
Site Type: Alfalfa	Total Alfalfa ETr "	2.65	2.63	5.96	6.15	8.3	8.2	8.12	6.9	7.23	3.77	2.43	2.58	64.92
Total Growing Degee Days from March 1		0	0	177	204	370	433	582	501	443	217	79	23	3029
Gross Pond Evap	Total "	2.23	2.21	5.01	5.17	6.97	6.89	6.82	5.8	6.07	3.17	2.04	2.17	54.55
Net Pond Evap	Total "	2.11	1.64	4.82	3.35	5.35	5.59	4.43	3.02	4.93	2.48	1.71	2.1	41.53
Crook	Avg. Temp ° F	26.75	29.07	43.7	48.43	58.82	63.72	69.42	66.32	62.38	50.68	34.69	29.05	48.59
Ref date as of 12/31/2004	Total Precip "	0.12	0.63	0.09	2.26	1.58	1.88	5.1	0.98	1.92	0.68	0.48	0.1	15.82
Site Type: Alfalfa	Total Alfalfa ETr "	2.68	2.53	5.99	5.91	7.6	7.46	7.94	7.3	6.38	4.12	2.47	2.29	62.67
Total Growing Degee Days from March 1		0	0	199	213	368	433	567	517	434	251	84	27	3093
Gross Pond Evap	Inch	2.25	2.13	5.03	4.96	6.38	6.27	6.67	6.13	5.36	3.46	2.07	1.92	52.63
Net Pond Evap	Inch	2.17	1.68	4.97	3.38	5.28	4.95	3.1	5.45	4.02	2.98	1.74	1.85	41.57
Sterling	Avg. Temp ° F	26.53	29.46	44.27	48.53	58.93	63.4	70.73	66.36	62.49	50.15	33.81	28.36	48.59
Ref date as of 12/31/2004	Total Precip "	0.12	0.24	0.09	1.32	1.9	4.29	1.57	2.23	2.09	0.66	0.84	0.23	15.58
Site Type: Alfalfa	Total Alfalfa ETr "	2.53	2.74	6.6	6.28	8.06	7.55	8.75	7.3	6.81	4.26	2.41	2.37	65.66
Total Growing Degee Days from March 1		0	0	209	212	374	438	579	523	437	251	75	27	3125
Gross Pond Evap	Inch	2.13	2.3	5.54	5.28	6.77	6.34	7.35	6.13	5.72	3.58	2.02	1.99	55.15
Net Pond Evap	Inch	2.04	2.13	5.48	4.35	5.44	3.34	6.25	4.57	4.26	3.12	1.44	1.83	44.25
Brush	Avg. Temp ° F	27.45	29.88	45.49	49.14	59.83	63.67	70.48	66.95	62.51	50.29	33.48	27.73	48.91
Ref date as of 12/31/2004	Total Precip "	0.18	0.62	0.1	1.8	0.66	3.26	0.74	2.54	0.51	0.64	0.43	0.04	11.52
Site Type: Alfalfa	Total Alfalfa ETr "	2.16	2.38	6.23	5.9	8.35	7.55	8.53	7.74	6.81	4.54	2.08	2.19	64.46
Total Growing Degee Days from March 1		0	0	226	225	400	439	589	536	446	262	74	28	3225
Gross Pond Evap	Inch	1.81	2	5.23	4.96	7.01	6.34	7.17	6.5	5.72	3.81	1.75	1.84	54.14
Net Pond Evap	Inch	1.69	1.57	5.16	3.7	6.55	4.06	6.65	4.72	5.36	3.37	1.45	1.81	46.09
Fort Morgan	Avg. Temp ° F	26.71	29.47	45.26	49.45	60.29	63.96	70.77	67.34	62.84	50.66	34.13	28.09	49.08
Ref date as of 12/31/2004	Total Precip "	0.09	0.77	0.08	1.68	1.08	3.4	0.59	1.81	0.84	0.86	0.44	0.61	12.25
Site Type: Turf	Total Alfalfa ETr "	1.94	2.19	5.87	5.95	8.32	7.31	8.39	7.68	6.46	4.38	2.09	2.09	62.67
Total Growing Degee Days from March 1		0	0	217	214	402	448	597	544	445	262	76	27	3232
Gross Pond Evap	Inch	1.63	1.84	4.93	5	6.99	6.14	7.05	6.45	5.43	3.68	1.76	1.76	52.66
Net Pond Evap	Inch	1.57	1.3	4.87	3.82	6.23	3.76	6.63	5.18	4.84	3.08	1.45	1.33	44.06
Wiggins	Avg. Temp ° F	25.91	28.85	45.3	49.41	60.65	64.5	70.51	66.76	62.03	49.57	33.67	27.54	48.73
Ref date as of 12/31/2004	Total Precip "	0.38	0.56	0.02	1.44	1.18	1.91	1.82	1.05	1.02	0.69	0.63	0.11	10.81
Site Type: Alfalfa	Total Alfalfa ETr "	1.74	2.12	6.45	6.13	8.77	7.93	8.22	7.38	6.13	4.15	1.99	2.02	63.03
Total Growing Degee Days from March 1		0	0	224	226	414	450	591	544	447	280	84	43	3303
Gross Pond Evap	Inch	1.46	1.78	5.42	5.15	7.37	6.66	6.9	6.2	5.15	3.49	1.67	1.7	52.95
Net Pond Evap	Inch	1.2	1.39	5.4	4.14	6.54	5.32	5.63	5.46	4.44	3	1.23	1.62	45.37
Fort Collins East	Avg. Temp ° F	27.84	27.59	44.6	47.07	58.29	61.13	68.05	63.79	58.1	47.3	33.44	29.11	47.19
Ref date as of 12/31/2004	Total Precip "	0.55	0.27	0.2	1.19	1.19	1.97	1.3	2.07	2.15	0.9	0.35	0.08	12.22
Site Type: Alfalfa	Total Alfalfa ETr "	2.47	2.34	6.38	5.62	7.63	5.61	7.78	6.63	5.72	3.77	2.4	2.47	58.82
Total Growing Degee Days from March 1		0	0	195	183	354	362	529	470	373	200	75	27	2768
Gross Pond Evap	Inch	2.07	1.97	5.36	4.72	6.41	4.71	6.54	5.57	4.8	3.17	2.02	2.07	49.41
Net Pond Evap	Inch	1.69	1.78	5.22	3.89	5.58	3.33	5.63	4.12	3.3	2.54	1.77	2.02	40.87
Eaton	Avg. Temp ° F	27.22	28.06	44.9	47.56	58.42	62.14	68.15	64.05	59.25	48	33.77	29.2	47.56
Ref date as of 12/31/2004	Total Precip "	0.28	0.31	0.03	1.05	1.76	2.4	0.91	1.43	2.02	1.06	0.37	0.04	11.66
Site Type: Alfalfa	Total Alfalfa ETr "	2.18	2.29	6.6	5.85	7.57	6.69	7.42	6.45	5.85	3.76	2.44	2.42	59.52
Total Growing Degee Days from March 1		0	0	206	191	360	384	547	481	392	207	77	29	2874
Gross Pond Evap	Inch	1.83	1.92	5.54	4.91	6.36	5.62	6.23	5.42	4.91	3.16	2.05	2.03	49.98
Net Pond Evap	Inch	1.64	1.71	5.52	4.18	5.13	3.94	5.6	4.42	3.5	2.42	1.79	2	41.85
Johnsons Corner	Avg. Temp ° F	29.81	29.87	46.04	47.67	58.47	62.15	68.05	65	59.99	48.82	35.36	30.79	48.5
Ref date as of 12/31/2004	Total Precip "	0.19	0.21	0.27	1.5	1.21	2.53	1.79	1.54	2.79	0.72	0.99	0.1	13.84
Site Type: Alfalfa	Total Alfalfa ETr "	2.24	2.14	6.18	5.48	7.43	6.85	7.36	6.82	5.85	3.64	2.14	2.14	58.27
Total Growing Degee Days from March 1		0	0	199	184	360	384	541	499	389	202	68	24	2850
Gross Pond Evap	Inch	1.88	1.8	5.19	4.6	6.24	5.75	6.18	5.73	4.91	3.06	1.8	1.8	48.94
Net Pond Evap	Inch	1.75	1.65	5	3.55	5.39	3.98	4.93	4.65	2.96	2.55	1.1	1.73	39.24
Gilcrest	Avg. Temp ° F	27.25	29.17	45.55	48.2	60.43	62.85	68.98	65.16	60.02	48.23	33.96	27.56	48.11
Ref date as of 12/31/2004	Total Precip "	0.17	0.28	0.12	2.11	1.64	1.94	0.78	3.11	2.43	0.77	0.31	0.06	13.72
Site Type: Alfalfa	Total Alfalfa ETr "	1.72	1.99	5.82	5.28	8.36	6.17	7.48	6.3	5.45	3.34	1.79	1.74	55.44
Total Growing Degee Days from March 1		0	0	212	195	402	405	579	520	409	230	77	28	3057
Gross Pond Evap	Inch	1.44	1.67	4.89	4.44	7.02	5.18	6.28	5.29	4.58	2.81	1.5	1.46	46.56
Net Pond Evap	Inch	1.33	1.48	4.8	2.96	5.87	3.82	5.74	3.12	2.88	2.27	1.29	1.42	36.98
Longmont South	Avg. Temp ° F	31.07	31.53	47.12	47.4	59.06	61.86	69.04	65.44	60.8	49.8	37.29	33.46	49.49
Ref date as of 12/31/2004	Total Precip "	0.64	0.45	0.33	3.03	1.12	2.54	2.23	2.19	2.29	0.96	1.13	0.18	17.09
Site Type: Alfalfa	Total Alfalfa ETr "	2.14	2.19	5.7	4.86	7.32	6.31	7.64	6.58	5.72	3.87	2.1	2.72	57.15
Total Growing Degee Days from March 1		0	0	209	171	368	379	553	501	395	215	81	40	2912
Gross Pond Evap	Inch	1.8	1.84	4.79	4.08	6.15	5.3	6.42	5.53	4.8	3.25	1.76	2.28	48
Net Pond Evap	Inch	1.35	1.52	4.56	1.96	5.36	3.52	4.86	3.99	3.2	2.58	0.97	2.16	36.03
Fort Collins NW	Avg. Temp ° F	25.05	26.76	40.4	43.41	54.91	58.78	63.35	59.7	53.86	43.78	29.49	27.07	43.88
Ref date as of 12/31/2004	Total Precip "	0.15	0.21	0.42	1.57	1.23	2.34	2.65	2.64	2.58	0.56	0.47	0.24	15.06
Site Type: Turf	Total Alfalfa ETr "	1.96	2.05	5.27	3.67	0.11	0	0	0	0	0.06	-0.6	0.76	13.88
Total Growing Degee Days from March 1		0	0	183	177	364	380	541	485	374	203	68	28	2803
Gross Pond Evap	Inch	1.65	1.72	4.43	3.08	0.09	0	0	0	0	0.05	0	0.64	11.66
Net Pond Evap	Inch	1.54	1.58	4.13	1.98	0	0	0	0	0	0	0	0.47	9.7
Fort Collins Central	Avg. Temp ° F	30.67	31.49	46.51	48.45	60.01	62.83	69.42	65.63	59.88	49.36	35.66	31.77	49.31
Ref date as of 12/31/2004	Total Precip "	0.18	0.31	0.37	1.7	1.58	2.64	1.93	3.49	2.84	0.92	0.8	0.25	17.01
Site Type: Turf	Total Alfalfa ETr "	2.15	2.19	5.37	5.01	6.92	5.83	6.69	5.71	4.84	3.3	1.94	2.11	52.06
Total Growing Degee Days from March 1		0	0	202	187	377	392	554	509	391	227	90	40	2969
Gross Pond Evap	Inch	1.81	1.84	4.51	4.21	5.81	4.9	5.62	4.8	4.07	2.77	1.63	1.77	43.74
Net Pond Evap	Inch	1.68	1.62	4.25	3.02	4.71	3.05	4.27	2.35	2.08	2.13	1.07	1.6	31.83
Windsor	Avg. Temp ° F	26.2	27	41.72	45.42	57.1	60.1	65.98	61.99	56.26	45.71	31.81	28.05	45.61
Ref date as of 12/31/2004	Total Precip "	0.35	0.75	0.11	1.64	1.65	2.3	1.3	2.7	2.09	0.92	0.63	0.12	14.56
Site Type: Dryland Pasture	Total Alfalfa ETr "	2.31	2.3	6.58	6.05	8.39	7.23	8.38	7.34	6.13	3.99	2.36	2.31	63.37
Total Growing Degee Days from March 1		0	0	232	220	420	441	617	571	437	251	86	33	3308
Gross Pond Evap	Inch	1.94	1.93	5.53	5.08	7.05	6.07	7.04	6.17	5.15	3.35	1.98	1.94	53.23
Net Pond Evap	Inch	1.7	1.41	5.45	3.93	5.89	4.46	6.13	4.28	3.69	2.71	1.54	1.86	43.05
Greeley West	Avg. Temp ° F	28.52	29.67	46.26	48.73	60.43	63.62	70.61	67.12	61.56	49.3	35.05	30.03	49.24
Ref date as of 12/31/2004	Total Precip "	0.11	0.49	0.07	1.57	1.41	2.3	0.75	2.9	1.63	1.03	0.35	0.1	12.71
Site Type: Turf	Total Alfalfa ETr "	1.67	1.95	5.62	5.45	7.93	6.89	7.83	7.09	5.79	3.45	1.72	1.79	57.18
Total Growing Degee Days from March 1		0	0	205	204	392	413	592	544	417	224	72	31	3094
Gross Pond Evap	Inch	1.4	1.64	4.72	4.58	6.66	5.79	6.58	5.96	4.86	2.9	1.44	1.5	48.03
Net Pond Evap	Inch	1.33	1.3	4.67	3.48	5.67	4.18	6.05	3.93	3.72	2.18	1.2	1.43	39.14
Loveland	Avg. Temp ° F	30.42	30.51	46.5	48.5	60.07	62.8	69.74	66.47	60.99	50.07	35.73	31.38	49.43
Ref date as of 12/31/2004	Total Precip "	0.37	0.23	0.39	1.28	1.85	2.42	3.03	2.2	2.87	0.59	0.77	0.18	16.18
Site Type: Turf	Total Alfalfa ETr "	1.62	1.83	5.07	4.85	7.12	6.02	6.51	5.9	4.68	3.2	1.54	1.54	49.88
Total Growing Degee Days from March 1		0	0	199	180	381	401	581	535	405	215	76	22	2995
Gross Pond Evap	Inch	1.36	1.54	4.26	4.07	5.98	5.06	5.47	4.96	3.93	2.69	1.29	1.29	41.9
Net Pond Evap	Inch	1.1	1.38	3.99	3.18	4.69	3.36	3.35	3.42	1.92	2.28	0.75	1.17	30.59
Berthoud	Avg. Temp ° F	30.55	30.66	46.55	48.1	59.98	62.86	69.81	66.25	61.29	49.55	36.18	31.75	49.46
Ref date as of 12/31/2004	Total Precip "	0.21	0.26	0.34	1.77	1.24	2.75	3.51	1.91	2.08	0.22	0.64	0.04	14.97
Site Type: Turf	Total Alfalfa ETr "	2.14	2.21	5.94	5.6	8.41	7.37	8.41	7.28	6.23	3.78	2.15	2.21	61.73
Total Growing Degee Days from March 1		0	0	195	180	382	404	588	527	392	199	65	25	2957
Gross Pond Evap	Inch	1.8	1.86	4.99	4.7	7.06	6.19	7.06	6.12	5.23	3.18	1.81	1.86	51.86
Net Pond Evap	Inch	1.65	1.67	4.75	3.47	6.2	4.27	4.61	4.78	3.78	3.02	1.36	1.83	41.39
Longmont West	Avg. Temp ° F	31.3	32.13	47.72	48.69	60.45	63.3	70.23	66.8	61.74	50.31	36.67	33.31	50.22
Ref date as of 12/31/2004	Total Precip "	0.27	0.55	0.38	2.39	1.08	3.18	2.39	1.42	2.17	0.95	0.92	0.16	15.86
Site Type: Turf	Total Alfalfa ETr "	1.56	1.87	4.62	4.58	6.59	5.92	6.69	5.85	4.76	2.94	1.51	1.78	48.67
Total Growing Degee Days from March 1		0	0	207	179	389	406	594	535	409	212	80	39	3050
Gross Pond Evap	Inch	1.31	1.57	3.88	3.85	5.54	4.97	5.62	4.91	4	2.47	1.27	1.5	40.89
Net Pond Evap	Inch	1.12	1.19	3.61	2.17	4.78	2.75	3.95	3.92	2.48	1.8	0.62	1.38	29.77
Fort Lupton	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 12/31/2006	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 NW	Avg. Temp ° F	33.75	31.67	47.31	47.5	60.22	63.11	70.01	65.91	62.17	49.84	37.21	35.52	50.35
Ref date as of 12/31/2004	Total Precip "	0.4	1.06	0.71	4.57	1.16	4.39	3.16	3.28	1.51	2.38	1.21	0.38	24.21
Site Type: Turf	Total Alfalfa ETr "	2.58	2.17	5.59	4.86	7.81	7.01	8.01	6.8	6.09	3.96	1.98	2.83	59.69
Total Growing Degee Days from March 1		0	0	209	180	397	423	581	528	424	223	80	40	3085
Gross Pond Evap	Inch	2.17	1.82	4.7	4.08	6.56	5.89	6.73	5.71	5.12	3.33	1.66	2.38	50.15
Net Pond Evap	Inch	1.89	1.08	4.2	0.88	5.75	2.82	4.52	3.42	4.06	1.66	0.82	2.11	33.21
Boulder East	Avg. Temp ° F	33.85	33.71	49.13	49.03	61.68	64.61	71.53	67.8	63.65	51.4	38.18	35.23	51.65
Ref date as of 12/31/2004	Total Precip "	0.33	0.84	0.59	3.86	1.5	3.32	2.84	2.77	1.79	1.62	0.99	0.14	20.59
Site Type: Turf	Total Alfalfa ETr "	2.3	2.3	5.64	4.98	7.76	7	7.56	6.51	5.69	3.71	1.81	2.55	57.81
Total Growing Degee Days from March 1		0	0	214	175	398	433	609	544	418	213	80	41	3125
Gross Pond Evap	Inch	1.93	1.93	4.74	4.18	6.52	5.88	6.35	5.47	4.78	3.12	1.52	2.14	48.56
Net Pond Evap	Inch	1.7	1.34	4.32	1.48	5.47	3.56	4.36	3.53	3.53	1.98	0.83	2.04	34.14
Boulder Flatiron	Avg. Temp ° F	31.8	31.79	46.74	47.24	59.07	61.91	68.36	64.63	59.67	48.93	36.28	33.5	49.16
Ref date as of 12/31/2004	Total Precip "	0.28	0.62	0.43	4.28	1.12	3.8	2.83	2.5	2.22	1.42	0.79	0.24	20.53
Site Type: Turf	Total Alfalfa ETr "	2.01	1.97	4.72	4.06	6.04	5.27	5.61	4.71	3.79	2.57	1.44	1.96	44.15
Total Growing Degee Days from March 1		0	0	206	165	370	390	539	491	392	206	77	38	2874
Gross Pond Evap	Inch	1.69	1.65	3.96	3.41	5.07	4.43	4.71	3.96	3.18	2.16	1.21	1.65	37.08
Net Pond Evap	Inch	1.49	1.22	3.66	0.41	4.29	1.77	2.73	2.21	1.63	1.16	0.66	1.48	22.71
Boulder SW	Avg. Temp ° F	35.95	33.87	48.84	48.11	60.55	62.51	69.82	66.59	63	51.51	39.2	37.93	51.49
Ref date as of 12/31/2004	Total Precip "	0.3	0.88	0.46	4.34	1.25	3.78	3.66	2.42	1.84	2.12	0.99	0.29	22.33
Site Type: Turf	Total Alfalfa ETr "	3.21	2.52	6.05	4.88	7.67	6.5	7.07	6.41	5.84	4.32	2.33	3.46	60.26
Total Growing Degee Days from March 1		0	0	192	151	368	391	578	515	415	196	67	40	2913
Gross Pond Evap	Inch	2.7	2.12	5.08	4.1	6.44	5.46	5.94	5.38	4.91	3.63	1.96	2.91	50.63
Net Pond Evap	Inch	2.49	1.5	4.76	1.06	5.57	2.81	3.38	3.69	3.62	2.14	1.26	2.7	34.98