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	2002	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	28.15	31.23	30.87	50.03	57.27	74.7	77.3	70.75	62.86	42.67	36.49	29.71	49.34
Ref date as of 12/31/2002	Total Precip "	0.08	0.06	0.12	0.5	0.41	2.97	1.06	1.55	0.93	1.65	0.17	0.07	9.57
Site Type: Alfalfa	Total Alfalfa ETr "	3.17	4.53	3.95	7.56	9.54	12.64	11.03	8.48	7.14	3.97	3.29	2.94	78.24
Total Growing Degee Days from March 1		0	0	72	246	346	634	720	629	447	178	82	44	3398
Gross Pond Evap	Total "	2.66	3.81	3.32	6.35	8.01	10.62	9.27	7.12	6	3.33	2.76	2.47	65.72
Net Pond Evap	Total "	2.61	3.76	3.23	6	7.73	8.54	8.52	6.04	5.35	2.18	2.64	2.42	59.02
Crook	Avg. Temp ° F	26.81	29.67	30.78	49.72	55.57	72.6	76.51	70.33	61.59	41.94	36.3	29.41	48.44
Ref date as of 12/31/2002	Total Precip "	0.02	0.14	0.32	0.34	0.79	2	0.89	3.87	0.58	2.5	0.27	0.01	11.73
Site Type: Alfalfa	Total Alfalfa ETr "	3.25	4.11	3.96	7.15	7.45	10.74	10.6	8.85	6.47	3.98	3.35	3.01	72.92
Total Growing Degee Days from March 1		0	0	86	256	319	567	680	615	427	175	82	43	3250
Gross Pond Evap	Inch	2.73	3.45	3.33	6.01	6.26	9.02	8.9	7.43	5.43	3.34	2.81	2.53	61.24
Net Pond Evap	Inch	2.72	3.35	3.1	5.77	5.71	7.62	8.28	4.73	5.03	1.59	2.63	2.52	53.05
Sterling	Avg. Temp ° F	26.52	29.23	31.32	50.07	56.14	72.6	76.65	70.24	61.67	42	35.55	29.25	48.44
Ref date as of 12/31/2002	Total Precip "	0	0.04	0.17	0.16	0.66	0.52	1.08	2.03	0.74	0.92	0.37	0	6.69
Site Type: Alfalfa	Total Alfalfa ETr "	3	3.78	4.09	7.36	7.43	10.58	10.79	8.99	6.41	3.66	2.92	2.77	71.78
Total Growing Degee Days from March 1		0	0	95	266	330	568	698	612	423	174	82	47	3295
Gross Pond Evap	Inch	2.52	3.18	3.44	6.18	6.24	8.89	9.06	7.55	5.38	3.07	2.45	2.33	60.29
Net Pond Evap	Inch	2.52	3.15	3.32	6.07	5.78	8.52	8.31	6.13	4.87	2.43	2.19	2.33	55.62
Brush	Avg. Temp ° F	26.91	29.85	32.21	50.67	56.6	72.32	77.03	70.66	62.85	43.04	35.41	29.68	48.94
Ref date as of 12/31/2002	Total Precip "	0.22	0	0.03	0.44	0.52	1.22	0.03	0.12	0.11	0.79	0.18	0.08	3.74
Site Type: Alfalfa	Total Alfalfa ETr "	2.87	3.86	4.33	7.46	7.66	10.67	11.4	9.75	7.23	4.15	2.83	2.6	74.81
Total Growing Degee Days from March 1		0	0	100	275	339	573	690	621	435	192	71	42	3338
Gross Pond Evap	Inch	2.41	3.24	3.64	6.27	6.43	8.96	9.58	8.19	6.07	3.49	2.38	2.18	62.84
Net Pond Evap	Inch	2.26	3.24	3.62	5.96	6.07	8.11	9.56	8.11	6	2.93	2.25	2.13	60.24
Fort Morgan	Avg. Temp ° F	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	79.3	71.09	62.96	43.63	35.52	29.86	53.73
Ref date as of 12/31/2002	Total Precip "	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	0	1.43	0.66	0.96	0.27	0.1	3.42
Site Type: Turf	Total Alfalfa ETr "	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	1.07	9.41	6.51	3.98	2.87	2.31	26.15
Total Growing Degee Days from March 1		0	0	#N/A	#N/A	#N/A	#N/A	64	644	447	200	79	41	1475
Gross Pond Evap	Inch	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	0.9	7.9	5.47	3.34	2.41	1.94	21.96
Net Pond Evap	Inch	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	0.9	6.9	5.01	2.67	2.22	1.87	19.57
Wiggins	Avg. Temp ° F	25.33	29.23	31.63	50.26	56.68	71.7	74.52	68.72	61.2	42.14	34.73	28.91	47.92
Ref date as of 12/31/2002	Total Precip "	0.28	0	0.1	0.4	0.44	1.05	0.03	0.66	0.7	0.97	0.22	0.11	4.96
Site Type: Alfalfa	Total Alfalfa ETr "	2.44	3.71	4.16	7.63	7.99	10.38	9.96	8.49	6.14	3.67	2.54	2.28	69.39
Total Growing Degee Days from March 1		0	0	103	273	336	567	673	599	410	178	72	38	3249
Gross Pond Evap	Inch	2.05	3.12	3.49	6.41	6.71	8.72	8.37	7.13	5.16	3.08	2.13	1.92	58.29
Net Pond Evap	Inch	1.85	3.12	3.42	6.13	6.4	7.98	8.35	6.67	4.67	2.4	1.98	1.84	54.81
Fort Collins East	Avg. Temp ° F	25.61	29.1	31.2	48.41	53.38	68.26	72.26	65.36	58.5	40.23	33.58	29.46	46.28
Ref date as of 12/31/2002	Total Precip "	0.33	0.03	0.26	0.1	1.11	0.94	0.73	1.13	0.94	0.44	0.37	0.02	6.4
Site Type: Alfalfa	Total Alfalfa ETr "	2.22	3.31	3.6	6.17	5.35	8.76	9.35	7.47	5.48	3.74	2.75	2.53	60.73
Total Growing Degee Days from March 1		0	0	75	230	277	513	608	509	363	148	60	30	2813
Gross Pond Evap	Inch	1.86	2.78	3.02	5.18	4.49	7.36	7.85	6.27	4.6	3.14	2.31	2.13	50.99
Net Pond Evap	Inch	1.63	2.76	2.84	5.11	3.72	6.7	7.34	5.48	3.95	2.83	2.05	2.11	46.52
Eaton	Avg. Temp ° F	25.57	29.55	31.69	49.13	54.85	69.78	72.88	66.29	60.08	40.98	33.88	29.88	47.05
Ref date as of 12/31/2002	Total Precip "	0.21	0	0.2	0.12	1.39	1.27	1.13	0.41	0.6	0.73	0.37	0.02	6.45
Site Type: Alfalfa	Total Alfalfa ETr "	2.33	3.86	4.25	7.48	7.05	9.28	8.27	6.45	6	3.73	2.67	2.51	63.88
Total Growing Degee Days from March 1		0	0	97	246	305	547	649	539	383	155	64	35	3020
Gross Pond Evap	Inch	1.96	3.24	3.57	6.28	5.92	7.8	6.95	5.42	5.04	3.13	2.24	2.11	53.66
Net Pond Evap	Inch	1.81	3.24	3.43	6.2	4.95	6.91	6.16	5.13	4.62	2.62	1.98	2.09	49.14
Johnsons Corner	Avg. Temp ° F	26.72	31.28	32.66	50.11	55.08	70.51	74.94	67.99	61.48	42.4	34.58	31.11	48.24
Ref date as of 12/31/2002	Total Precip "	0.61	0	0.25	0.29	2.54	0.54	0.26	0.41	1.44	0.87	0.53	0	7.74
Site Type: Alfalfa	Total Alfalfa ETr "	1.98	3.17	3.62	6.76	6.6	9.55	9.46	7.46	5.67	3.39	2.19	2.03	61.88
Total Growing Degee Days from March 1		0	0	77	245	302	547	683	565	400	164	64	37	3084
Gross Pond Evap	Inch	1.66	2.66	3.04	5.68	5.54	8.02	7.95	6.27	4.76	2.85	1.84	1.71	51.98
Net Pond Evap	Inch	1.24	2.66	2.87	5.48	3.77	7.64	7.76	5.98	3.75	2.24	1.47	1.71	46.57
Gilcrest	Avg. Temp ° F	24.9	30.24	32.17	50.35	55.24	69.8	72.72	66.89	60.04	41.79	33.77	29.69	47.3
Ref date as of 12/31/2002	Total Precip "	0.5	0.02	0.22	0.14	1.86	0.7	0.8	0.52	0.69	0.37	0.58	0	6.4
Site Type: Alfalfa	Total Alfalfa ETr "	1.78	3.17	3.69	7	6.34	8.55	7.97	6.81	5.02	3.21	2.08	2.14	57.76
Total Growing Degee Days from March 1		0	0	83	262	309	540	644	562	406	172	73	41	3092
Gross Pond Evap	Inch	1.5	2.66	3.1	5.88	5.33	7.18	6.69	5.72	4.22	2.7	1.75	1.8	48.53
Net Pond Evap	Inch	1.15	2.65	2.95	5.78	4.02	6.69	6.13	5.36	3.73	2.44	1.34	1.8	44.04
Longmont South	Avg. Temp ° F	30.17	33.48	34.87	51.4	55.64	70.46	76.54	69.19	62.6	43.49	37.01	33.37	49.85
Ref date as of 12/31/2002	Total Precip "	0.64	0.42	0.58	0.21	2.18	0.94	0.04	0.63	0.97	1.04	0.51	0.02	8.18
Site Type: Alfalfa	Total Alfalfa ETr "	2.63	3.73	4.09	7.09	6.56	8.87	10.26	8.51	6.31	3.59	2.97	2.72	67.33
Total Growing Degee Days from March 1		0	0	96	266	309	539	689	579	425	172	83	53	3211
Gross Pond Evap	Inch	2.21	3.13	3.44	5.96	5.51	7.45	8.62	7.15	5.3	3.02	2.49	2.28	56.56
Net Pond Evap	Inch	1.76	2.84	3.03	5.81	3.98	6.79	8.59	6.71	4.62	2.29	2.14	2.27	50.83
Fort Collins NW	Avg. Temp ° F	23.91	26.9	28.51	46.21	51.15	65.61	69.92	63.82	55.58	37.21	31.08	27.73	43.97
Ref date as of 12/30/2002	Total Precip "	0.44	0.07	0.34	0.29	1.88	0.5	0.01	0.77	1.64	0.46	0.48	0	6.88
Site Type: Turf	Total Alfalfa ETr "	1.86	2.94	3.35	5.93	6.31	8.66	8.9	7.4	4.98	2.75	2.25	1.75	57.08
Total Growing Degee Days from March 1		0	0	73	230	288	545	674	562	386	146	61	30	2995
Gross Pond Evap	Inch	1.56	2.47	2.81	4.98	5.3	7.27	7.48	6.22	4.18	2.31	1.89	1.47	47.94
Net Pond Evap	Inch	1.25	2.42	2.58	4.78	3.98	6.92	7.47	5.68	3.04	1.99	1.55	1.47	43.13
Fort Collins Central	Avg. Temp ° F	#N/A	#N/A	#N/A	49.21	55.27	70.37	74.72	67.96	60.64	42	35.68	31.88	54.19
Ref date as of 12/31/2002	Total Precip "	#N/A	#N/A	#N/A	0	1.87	0.72	0.19	0.4	1.47	0.72	0.38	0	5.75
Site Type: Turf	Total Alfalfa ETr "	#N/A	#N/A	#N/A	2.82	6.25	8.82	8.63	7.4	5.15	3.15	2.41	2.13	46.76
Total Growing Degee Days from March 1		0	0	#N/A	102	297	541	652	555	391	157	75	40	2810
Gross Pond Evap	Inch	#N/A	#N/A	#N/A	2.37	5.25	7.41	7.25	6.22	4.33	2.65	2.02	1.79	39.29
Net Pond Evap	Inch	#N/A	#N/A	#N/A	2.37	3.94	6.9	7.12	5.94	3.3	2.14	1.76	1.79	35.26
Windsor	Avg. Temp ° F	23.97	27.19	28.06	45.78	51.55	65.78	71.21	64.37	57.36	38.57	31.75	27.39	44.42
Ref date as of 12/31/2002	Total Precip "	0.68	0.06	0.55	0.19	2.39	0.67	0.11	0.42	1.27	0.72	0.82	0	7.88
Site Type: Dryland Pasture	Total Alfalfa ETr "	2.08	3.34	3.62	7.02	6.89	9.77	10.69	8.49	5.89	3.6	2.22	2.08	65.69
Total Growing Degee Days from March 1		0	0	86	262	321	562	692	583	416	172	66	30	3190
Gross Pond Evap	Inch	1.75	2.81	3.04	5.9	5.79	8.21	8.98	7.13	4.95	3.02	1.86	1.75	55.19
Net Pond Evap	Inch	1.27	2.76	2.66	5.76	4.11	7.74	8.9	6.84	4.06	2.52	1.29	1.75	49.66
Greeley West	Avg. Temp ° F	25.51	31.12	32.56	50.65	56.63	71.73	75.96	69.18	62.35	42.88	35.32	31.24	48.76
Ref date as of 12/31/2002	Total Precip "	0.64	0.02	0.26	0.1	1.86	1.15	0.93	0.36	0.45	0.45	0.61	0.08	6.91
Site Type: Turf	Total Alfalfa ETr "	1.62	2.94	3.58	6.93	7.11	9.7	9.63	8.06	5.92	3.43	2.21	1.91	63.04
Total Growing Degee Days from March 1		0	0	83	265	333	568	691	594	425	172	73	36	3240
Gross Pond Evap	Inch	1.36	2.47	3.01	5.82	5.97	8.15	8.09	6.77	4.97	2.88	1.86	1.6	52.95
Net Pond Evap	Inch	0.91	2.46	2.83	5.75	4.67	7.34	7.44	6.52	4.66	2.57	1.43	1.55	48.13
Loveland	Avg. Temp ° F	28.85	32.49	33.64	50.77	55.54	71.36	76.76	69.55	62.24	43.03	35.79	32.47	49.37
Ref date as of 12/31/2002	Total Precip "	1.22	0.73	1.31	0.24	2.65	0.58	0.12	0.39	2.05	1.54	0.68	0.05	11.56
Site Type: Turf	Total Alfalfa ETr "	2.14	3.15	3.49	6.2	6.5	8.66	8.94	7.48	5.21	3.01	2.23	1.97	58.98
Total Growing Degee Days from March 1		0	0	83	255	309	571	713	594	421	169	79	42	3236
Gross Pond Evap	Inch	1.8	2.65	2.93	5.21	5.46	7.27	7.51	6.28	4.38	2.53	1.87	1.65	49.54
Net Pond Evap	Inch	0.94	2.14	2.01	5.04	3.61	6.87	7.43	6.01	2.94	1.45	1.4	1.62	41.46
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	30.38	33.35	34.71	51.61	55.88	71.23	76.88	69.4	62.8	43.59	37	33.43	50.02
Ref date as of 12/31/2002	Total Precip "	0.72	0.1	0.28	0.22	2.8	0.79	0.61	0.43	0.85	0.6	0.79	0	8.19
Site Type: Turf	Total Alfalfa ETr "	1.86	2.71	3.36	5.83	5.94	8.05	8.41	6.89	4.88	2.73	1.89	1.57	54.12
Total Growing Degee Days from March 1		0	0	94	266	311	574	730	594	430	166	83	50	3298
Gross Pond Evap	Inch	1.56	2.28	2.82	4.9	4.99	6.76	7.06	5.79	4.1	2.29	1.59	1.32	45.46
Net Pond Evap	Inch	1.06	2.21	2.63	4.74	3.03	6.21	6.64	5.49	3.5	1.87	1.03	1.32	39.73
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	#N/A	#N/A	#N/A	51.74	54.32	71.95	77.72	70.14	62.93	43.58	38.31	34.87	56.17
Ref date as of 12/31/2002	Total Precip "	#N/A	#N/A	#N/A	0.17	2.87	1.28	0.03	0.96	1.82	1.07	1.01	0	9.21
Site Type: Turf	Total Alfalfa ETr "	#N/A	#N/A	#N/A	4.37	6.15	9.64	10.27	8.15	6.1	3.26	2.83	2.57	53.34
Total Growing Degee Days from March 1		0	0	#N/A	172	291	577	704	605	440	178	83	55	3105
Gross Pond Evap	Inch	#N/A	#N/A	#N/A	3.67	5.17	8.1	8.63	6.85	5.12	2.74	2.38	2.16	44.82
Net Pond Evap	Inch	#N/A	#N/A	#N/A	3.55	3.16	7.2	8.61	6.17	3.85	1.99	1.67	2.16	38.36
Boulder East	Avg. Temp ° F	32.71	34.89	36.3	52.77	56.95	72.67	78.37	70.91	64.26	44.44	38.88	35.1	51.52
Ref date as of 12/31/2002	Total Precip "	0.63	0.18	0.52	0.16	3.18	1.15	0.24	0.37	1.38	1.1	0.79	0	9.7
Site Type: Turf	Total Alfalfa ETr "	2.65	3.3	4.06	6.9	6.63	8.88	9.67	7.95	5.99	3.02	2.67	2.2	63.92
Total Growing Degee Days from March 1		0	0	86	266	311	588	744	619	440	160	80	50	3344
Gross Pond Evap	Inch	2.23	2.77	3.41	5.8	5.57	7.46	8.12	6.68	5.03	2.54	2.24	1.85	53.7
Net Pond Evap	Inch	1.79	2.65	3.05	5.68	3.34	6.65	7.95	6.42	4.07	1.77	1.69	1.85	46.91
Boulder Flatiron	Avg. Temp ° F	#N/A	#N/A	39.85	50.03	53.92	67.57	71.67	65.89	60.29	41.59	36.71	32.61	52.01
Ref date as of 12/31/2002	Total Precip "	#N/A	#N/A	0.04	0.15	2.52	1.73	0.98	1.04	1.79	0.99	0.59	0	9.83
Site Type: Turf	Total Alfalfa ETr "	#N/A	#N/A	1.53	5.48	5.22	6.64	6.89	5.57	4.12	2.22	2.05	1.74	41.46
Total Growing Degee Days from March 1		0	0	54	244	286	499	596	527	389	147	78	46	2866
Gross Pond Evap	Inch	#N/A	#N/A	1.29	4.6	4.38	5.58	5.79	4.68	3.46	1.86	1.72	1.46	34.82
Net Pond Evap	Inch	#N/A	#N/A	1.26	4.5	2.62	4.37	5.1	3.95	2.21	1.17	1.31	1.46	27.95
Boulder SW	Avg. Temp ° F	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	77.81	70.06	63.73	44.48	40.51	37.23	55.64
Ref date as of 12/31/2002	Total Precip "	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	0.16	0.81	1.54	1.23	0.97	0.01	4.72
Site Type: Turf	Total Alfalfa ETr "	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	9.7	8.09	6.51	3.27	3.48	3.28	34.33
Total Growing Degee Days from March 1		0	0	#N/A	#N/A	#N/A	#N/A	761	598	446	144	70	44	2063
Gross Pond Evap	Inch	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	8.15	6.8	5.47	2.75	2.92	2.76	28.85
Net Pond Evap	Inch	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	8.04	6.23	4.39	1.89	2.24	2.75	25.54