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	2003	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	29.95	25.55	39.48	49.69	57.63	64.07	77.51	73.64	58.84	51.38	33.06	28.46	49.11
Ref date as of 12/31/2003	Total Precip "	0.25	0.45	1.33	2.33	2.01	1.88	2.49	1.05	1.51	0.17	0.33	0.2	14
Site Type: Alfalfa	Total Alfalfa ETr "	3.14	2.28	4.81	6.11	6.66	7.89	11.4	9.5	6.69	6.61	3.09	2.51	70.69
Total Growing Degee Days from March 1		0	0	147	230	331	472	709	659	385	341	65	19	3358
Gross Pond Evap	Total "	2.64	1.92	4.04	5.13	5.59	6.63	9.58	7.98	5.62	5.55	2.6	2.11	59.39
Net Pond Evap	Total "	2.46	1.6	3.11	3.5	4.19	5.31	7.83	7.25	4.56	5.43	2.36	1.97	49.57
Crook	Avg. Temp ° F	30.8	25.03	39.46	49.47	57.3	63.8	75.74	72.62	57.9	51.12	33.31	28.33	48.74
Ref date as of 12/31/2003	Total Precip "	0.16	0.32	1.83	1.99	1.74	3.79	1.54	1.05	0.7	0.07	0.21	0.12	13.52
Site Type: Alfalfa	Total Alfalfa ETr "	3.56	2.41	4.95	6.06	6.43	7.32	10.03	8.78	6.24	6.71	3.02	2.46	67.97
Total Growing Degee Days from March 1		0	0	152	234	326	464	679	640	386	350	69	20	3320
Gross Pond Evap	Inch	2.99	2.02	4.16	5.09	5.4	6.15	8.43	7.38	5.24	5.64	2.54	2.07	57.11
Net Pond Evap	Inch	2.88	1.8	2.88	3.7	4.18	3.5	7.35	6.64	4.75	5.59	2.39	1.98	47.64
Sterling	Avg. Temp ° F	30.89	26.04	40.06	49.93	57.6	63.66	75.86	72.5	57.3	50.59	32.96	27.27	48.72
Ref date as of 12/31/2003	Total Precip "	0.06	0.1	2.56	2.82	2.05	1.88	0.4	1.23	0.07	0.06	0.08	0.05	11.36
Site Type: Alfalfa	Total Alfalfa ETr "	3.35	2.29	4.95	6.29	6.57	7.31	10.75	9.06	6.22	6.39	2.99	2.42	68.59
Total Growing Degee Days from March 1		0	0	155	235	325	458	676	640	382	345	69	25	3310
Gross Pond Evap	Inch	2.81	1.92	4.16	5.28	5.52	6.14	9.03	7.61	5.22	5.37	2.51	2.03	57.6
Net Pond Evap	Inch	2.77	1.85	2.37	3.31	4.08	4.82	8.75	6.75	5.18	5.33	2.46	2	49.67
Brush	Avg. Temp ° F	32.05	26.9	40.4	50.76	57.72	63.01	76.75	73.73	59.66	51.89	33.6	28.15	49.55
Ref date as of 12/31/2003	Total Precip "	0.1	0.34	2.79	1.29	2.64	3.17	1.69	1.08	0.29	0.02	0.09	0.26	13.76
Site Type: Alfalfa	Total Alfalfa ETr "	3.15	2.27	4.77	6.85	6.57	6.99	10.6	9.3	6.76	6.11	2.75	2.44	68.56
Total Growing Degee Days from March 1		0	0	150	246	338	445	688	662	413	350	73	34	3399
Gross Pond Evap	Inch	2.65	1.91	4.01	5.75	5.52	5.87	8.9	7.81	5.68	5.13	2.31	2.05	57.59
Net Pond Evap	Inch	2.58	1.67	2.05	4.85	3.67	3.65	7.72	7.06	5.48	5.12	2.25	1.87	47.97
Fort Morgan	Avg. Temp ° F	32.3	27.49	40.88	51.3	58.99	63.95	76.85	73.4	59.21	51.78	33.24	27.58	49.75
Ref date as of 12/31/2003	Total Precip "	0.03	0.07	2.26	1.6	2.92	2.5	1.84	0.91	0.31	0.03	0.08	0.05	12.6
Site Type: Turf	Total Alfalfa ETr "	3.04	2.3	4.61	6.67	7.15	7.29	10.36	8.69	6.1	5.78	2.53	2.36	66.88
Total Growing Degee Days from March 1		0	0	152	254	368	463	706	672	409	358	68	29	3479
Gross Pond Evap	Inch	2.55	1.93	3.87	5.6	6.01	6.12	8.7	7.3	5.12	4.86	2.13	1.98	56.17
Net Pond Evap	Inch	2.53	1.88	2.29	4.48	3.96	4.37	7.41	6.66	4.91	4.83	2.07	1.95	47.34
Wiggins	Avg. Temp ° F	31.25	26.51	40.19	50.56	57.78	63.19	75.55	71.64	58.51	51.63	32.48	26.51	48.82
Ref date as of 12/31/2003	Total Precip "	0.03	0.43	1.48	1.87	1.62	1.97	1.88	0.36	0.07	0.01	0.2	0.26	10.18
Site Type: Alfalfa	Total Alfalfa ETr "	2.94	2.38	4.55	6.96	6.47	6.97	9.86	8.12	5.98	5.89	2.5	2.2	64.82
Total Growing Degee Days from March 1		0	0	143	249	342	438	686	638	391	361	68	19	3335
Gross Pond Evap	Inch	2.47	2	3.82	5.85	5.43	5.85	8.28	6.82	5.02	4.95	2.1	1.85	54.44
Net Pond Evap	Inch	2.45	1.7	2.79	4.54	4.3	4.48	6.97	6.57	4.97	4.94	1.96	1.67	47.34
Fort Collins East	Avg. Temp ° F	31.92	26.33	38.63	47.66	55.4	60.9	73.64	70.05	56.76	51.56	33.44	28.14	47.87
Ref date as of 12/31/2003	Total Precip "	0.04	0.31	0.96	2.32	1.94	1	0.02	1.28	0.19	0.1	0.35	0.2	8.71
Site Type: Alfalfa	Total Alfalfa ETr "	3.29	2.37	4.72	5.82	6.44	6.6	9.51	8	6.13	6.53	2.7	2.57	64.68
Total Growing Degee Days from March 1		0	0	114	202	304	385	635	590	361	339	56	28	3014
Gross Pond Evap	Inch	2.76	1.99	3.96	4.89	5.41	5.54	7.99	6.72	5.15	5.49	2.27	2.16	54.33
Net Pond Evap	Inch	2.74	1.77	3.29	3.26	4.05	4.84	7.97	5.82	5.02	5.42	2.02	2.02	48.22
Eaton	Avg. Temp ° F	32.16	26.88	39.52	48.77	56.34	61.67	73.34	69.35	56.74	50.54	33.23	27	47.96
Ref date as of 12/31/2003	Total Precip "	0.04	0.15	0.82	2.46	2.57	2.19	0.1	1.5	0.23	0.02	0.23	0.08	10.39
Site Type: Alfalfa	Total Alfalfa ETr "	3.24	2.46	4.98	6.15	6.38	6.53	8.79	7.22	5.89	5.78	2.68	2.35	62.45
Total Growing Degee Days from March 1		0	0	134	222	325	402	647	592	367	329	62	19	3099
Gross Pond Evap	Inch	2.72	2.07	4.18	5.17	5.36	5.49	7.38	6.06	4.95	4.86	2.25	1.97	52.46
Net Pond Evap	Inch	2.69	1.96	3.61	3.44	3.56	3.95	7.31	5.01	4.79	4.84	2.09	1.92	45.17
Johnsons Corner	Avg. Temp ° F	33.36	28.04	40.04	49	55.92	61.71	74.34	70.84	58.24	53.13	35.04	30	49.14
Ref date as of 12/31/2003	Total Precip "	0	0.23	2.05	0.2	2.3	1.01	0.37	1.74	0.18	0.02	0.29	0.13	8.52
Site Type: Alfalfa	Total Alfalfa ETr "	2.85	2.12	4.58	5.82	5.66	6.45	9	7.82	5.81	5.64	2.68	2.32	60.75
Total Growing Degee Days from March 1		0	0	122	217	314	406	662	623	365	336	57	22	3124
Gross Pond Evap	Inch	2.39	1.78	3.85	4.89	4.75	5.42	7.56	6.57	4.88	4.74	2.25	1.95	51.03
Net Pond Evap	Inch	2.39	1.62	2.41	4.75	3.14	4.71	7.3	5.35	4.75	4.72	2.05	1.86	45.05
Gilcrest	Avg. Temp ° F	31.83	27.66	40.06	49.42	57.74	63.18	74.31	70.51	57.92	51.3	33.49	27.1	48.71
Ref date as of 12/31/2003	Total Precip "	0	0.31	1.81	2.93	2.38	1.35	0.16	1.55	0.3	0.04	0.38	0.09	11.3
Site Type: Alfalfa	Total Alfalfa ETr "	2.9	2.14	4.41	5.82	6.55	7.07	8.49	7.02	5.2	4.95	2.24	2.07	58.86
Total Growing Degee Days from March 1		0	0	129	229	351	435	663	614	388	353	64	32	3258
Gross Pond Evap	Inch	2.44	1.8	3.7	4.89	5.5	5.94	7.13	5.9	4.37	4.16	1.88	1.74	49.45
Net Pond Evap	Inch	2.44	1.58	2.44	2.84	3.84	4.99	7.02	4.81	4.16	4.13	1.62	1.68	41.55
Longmont South	Avg. Temp ° F	36.83	29.3	42.37	50.08	56.75	62.31	74.81	71.28	58.37	54	36.46	31.42	50.33
Ref date as of 12/31/2003	Total Precip "	0.02	0.55	1.67	1.75	1.95	2.29	0.32	2.73	0.32	0.04	0.65	0.37	12.66
Site Type: Alfalfa	Total Alfalfa ETr "	3.69	2.39	5.12	5.85	6.22	6.6	8.98	7.66	5.08	4.98	2.75	2.33	61.65
Total Growing Degee Days from March 1		0	0	136	219	327	411	658	615	374	350	62	41	3193
Gross Pond Evap	Inch	3.1	2.01	4.3	4.91	5.22	5.54	7.54	6.43	4.27	4.18	2.31	1.96	51.77
Net Pond Evap	Inch	3.09	1.62	3.13	3.69	3.86	3.94	7.32	4.52	4.04	4.16	1.86	1.7	42.93
Fort Collins NW	Avg. Temp ° F	29.32	23.93	34.61	45.16	52.59	56.82	69.79	65.41	51.36	46.25	30.04	26.05	44.28
Ref date as of 12/31/2003	Total Precip "	0.02	0.34	2.02	2.23	2.22	1.36	0.37	2.85	0.16	0.03	0.45	0.24	12.29
Site Type: Turf	Total Alfalfa ETr "	2.66	1.97	3.86	5.13	6.08	6.05	8.62	6.89	4.97	4.48	0.69	-4.53	51.4
Total Growing Degee Days from March 1		0	0	108	200	317	397	673	618	358	336	53	35	3095
Gross Pond Evap	Inch	2.23	1.65	3.24	4.31	5.11	5.08	7.24	5.79	4.17	3.76	0.58	0	43.16
Net Pond Evap	Inch	2.22	1.42	1.83	2.75	3.55	4.13	6.98	3.79	4.06	3.74	0.26	0	34.73
Fort Collins Central	Avg. Temp ° F	34.62	28.61	40.26	49.51	57.17	62.51	76.17	71.64	58.4	52.71	35.54	31.12	49.86
Ref date as of 12/31/2003	Total Precip "	0.04	0.31	1.96	2.36	2.43	1.34	0.35	3.02	0.22	0.06	0.4	0.26	12.75
Site Type: Turf	Total Alfalfa ETr "	2.89	2.22	4.14	5.32	6.31	6.19	8.67	7.07	5.15	4.78	2.29	2.12	57.15
Total Growing Degee Days from March 1		0	0	116	205	328	414	678	628	381	357	66	39	3212
Gross Pond Evap	Inch	2.43	1.86	3.48	4.47	5.3	5.2	7.28	5.94	4.33	4.02	1.92	1.78	48.01
Net Pond Evap	Inch	2.4	1.65	2.11	2.82	3.6	4.26	7.04	3.82	4.17	3.97	1.64	1.6	39.08
Windsor	Avg. Temp ° F	29.35	23.47	34.15	43.23	52.39	58.44	71.93	68.61	54.31	49.28	31.73	27.06	45.33
Ref date as of 12/31/2003	Total Precip "	0.01	0.5	1.24	1.57	2.11	1.44	0.49	2.25	0.15	0	0.44	0.43	10.63
Site Type: Dryland Pasture	Total Alfalfa ETr "	2.75	2.09	4.8	6.08	4.38	0	5.69	8.87	6.15	6.6	2.68	2.27	52.36
Total Growing Degee Days from March 1		0	0	119	208	336	461	720	674	423	380	71	26	3418
Gross Pond Evap	Inch	2.31	1.76	4.03	5.11	3.68	0	4.78	7.45	5.17	5.54	2.25	1.91	43.99
Net Pond Evap	Inch	2.3	1.41	3.16	4.01	2.2	0	4.44	5.88	5.06	5.54	1.94	1.61	37.55
Greeley West	Avg. Temp ° F	33.29	28.38	40.64	50.22	58.19	63.38	77.29	72.87	59.31	53.09	34.41	28.39	49.96
Ref date as of 12/31/2003	Total Precip "	0.02	0.14	1.28	3.44	2.38	2.42	0.86	1.92	0.31	0.02	0.27	0.11	13.17
Site Type: Turf	Total Alfalfa ETr "	2.47	2.15	4.42	6.05	6.82	6.93	9.7	8.23	5.79	5.07	2.24	1.78	61.65
Total Growing Degee Days from March 1		0	0	127	230	357	434	707	648	399	353	62	23	3340
Gross Pond Evap	Inch	2.07	1.81	3.71	5.08	5.73	5.82	8.15	6.91	4.86	4.26	1.88	1.5	51.78
Net Pond Evap	Inch	2.06	1.71	2.82	2.67	4.06	4.13	7.55	5.57	4.65	4.24	1.69	1.42	42.57
Loveland	Avg. Temp ° F	35.05	28.95	41.41	50.2	57.69	62.6	76.98	72.76	59.03	53.63	35.91	31.25	50.46
Ref date as of 12/31/2003	Total Precip "	0.06	1	4.11	2.46	2.27	3.55	1.08	3.18	0.29	0.03	0.5	0.19	18.72
Site Type: Turf	Total Alfalfa ETr "	2.61	2.15	4.14	5.36	5.99	6.05	8.39	7.09	4.93	4.33	2.08	1.94	55.06
Total Growing Degee Days from March 1		0	0	135	230	350	424	708	659	390	356	58	35	3345
Gross Pond Evap	Inch	2.19	1.81	3.48	4.5	5.03	5.08	7.05	5.96	4.14	3.64	1.75	1.63	46.26
Net Pond Evap	Inch	2.15	1.11	0.6	2.78	3.44	2.6	6.29	3.73	3.94	3.62	1.4	1.5	33.16
Berthoud	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 12/31/2004	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
Longmont West	Avg. Temp ° F	36.47	29.56	42.37	50.66	58.04	63.24	77.19	72.77	59.68	54.49	37.18	32.73	51.2
Ref date as of 12/31/2003	Total Precip "	0.03	0.44	2.21	1.73	2.43	1.96	0.23	2.72	0.18	0.03	0.4	0.22	12.58
Site Type: Turf	Total Alfalfa ETr "	2.15	1.72	3.83	5.07	5.82	6.24	8.17	6.8	4.82	3.88	1.93	1.83	52.26
Total Growing Degee Days from March 1		0	0	132	222	348	426	725	672	390	359	64	41	3379
Gross Pond Evap	Inch	1.81	1.44	3.22	4.26	4.89	5.24	6.86	5.71	4.05	3.26	1.62	1.54	43.9
Net Pond Evap	Inch	1.79	1.14	1.67	3.05	3.19	3.87	6.7	3.81	3.92	3.24	1.34	1.38	35.1
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	38.2	28.85	42.25	50.41	57.39	62.58	77.65	72.91	59.95	55.78	37.6	34.21	51.48
Ref date as of 12/31/2003	Total Precip "	0.06	0.9	2.75	1.19	2.68	1.96	0.5	1.68	0.26	0.12	0.8	0.43	13.33
Site Type: Turf	Total Alfalfa ETr "	3.17	2.04	4.69	5.96	6.62	6.46	10.19	8.3	5.99	5.41	2.77	2.58	64.18
Total Growing Degee Days from March 1		0	0	128	234	351	422	716	662	403	367	62	46	3391
Gross Pond Evap	Inch	2.66	1.71	3.94	5.01	5.56	5.43	8.56	6.97	5.03	4.54	2.33	2.17	53.91
Net Pond Evap	Inch	2.62	1.08	2.01	4.17	3.68	4.05	8.21	5.8	4.85	4.46	1.77	1.87	44.57
Boulder East	Avg. Temp ° F	38.36	30.31	43.69	51.5	58.38	63.73	78.84	73.75	60.73	56.31	38.83	33.89	52.36
Ref date as of 12/31/2003	Total Precip "	0.03	0.71	2.39	1.54	2.27	1.13	0.38	2.5	0.32	0.07	0.56	0.41	12.31
Site Type: Turf	Total Alfalfa ETr "	2.87	2.07	4.68	5.58	6.45	6.54	9.58	7.53	5.53	4.55	3	2.49	60.87
Total Growing Degee Days from March 1		0	0	125	211	341	421	736	677	393	353	71	47	3375
Gross Pond Evap	Inch	2.41	1.74	3.93	4.69	5.42	5.49	8.05	6.33	4.65	3.82	2.52	2.09	51.14
Net Pond Evap	Inch	2.39	1.24	2.26	3.61	3.83	4.7	7.78	4.58	4.42	3.77	2.13	1.8	42.51
Boulder Flatiron	Avg. Temp ° F	36.04	28.91	42.14	49.07	55.71	61.01	72.03	68.79	56.6	51.62	36.02	31.7	49.14
Ref date as of 12/31/2003	Total Precip "	0.03	0.22	2.33	1.86	2.36	1.38	0.94	2.95	0.68	0.44	0.66	0.32	14.17
Site Type: Turf	Total Alfalfa ETr "	2.35	1.75	3.91	4.53	5.18	5.05	6.48	5.32	3.95	3.52	1.84	1.97	45.85
Total Growing Degee Days from March 1		0	0	118	196	316	375	612	584	361	334	50	46	2992
Gross Pond Evap	Inch	1.97	1.47	3.28	3.81	4.35	4.24	5.44	4.47	3.32	2.96	1.55	1.65	38.51
Net Pond Evap	Inch	1.95	1.32	1.65	2.5	2.7	3.28	4.79	2.4	2.84	2.65	1.08	1.43	28.59
Boulder SW	Avg. Temp ° F	40.06	30.09	43.41	50.24	57.23	61.78	76.74	72.16	60.46	57.04	39.34	36.61	52.1
Ref date as of 12/31/2003	Total Precip "	0.1	0.99	2.85	2.08	2.26	1.42	0.72	0.02	0	0.06	0.57	0.44	11.51
Site Type: Turf	Total Alfalfa ETr "	3.69	2.29	5.18	5.52	6.32	6.06	9.12	7.72	5.59	5.34	3.2	3.3	63.33
Total Growing Degee Days from March 1		0	0	108	190	310	370	694	661	376	341	52	41	3143
Gross Pond Evap	Inch	3.1	1.92	4.35	4.64	5.31	5.09	7.66	6.48	4.7	4.49	2.69	2.77	53.2
Net Pond Evap	Inch	3.03	1.23	2.36	3.18	3.73	4.1	7.16	6.47	4.7	4.44	2.29	2.46	45.15