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	2005	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	25.6	31.88	38.07	45.69	55.86	67.45	75.36	70.41	65.47	49.37	40.6	27.28	49.42
Ref date as of 12/31/2005	Total Precip "	0.26	0.23	0.98	2.28	2.03	3.27	2.22	2.64	0.08	3.06	0.25	0.18	17.48
Site Type: Alfalfa	Total Alfalfa ETr "	2.02	3.04	4.95	5.1	6.99	8.48	10.91	7.81	7.44	4.16	4.38	2.93	68.21
Total Growing Degee Days from March 1		0	0	106	152	308	525	672	609	475	220	154	47	3268
Gross Pond Evap	Total "	1.7	2.55	4.16	4.28	5.87	7.12	9.16	6.56	6.25	3.49	3.68	2.46	57.28
Net Pond Evap	Total "	1.51	2.39	3.47	2.69	4.45	4.83	7.61	4.71	6.19	1.35	3.5	2.34	45.04
Crook	Avg. Temp ° F	27.15	32.4	38.61	46.69	56.23	67.18	74.57	69.15	63.58	48.67	39.59	26.32	49.18
Ref date as of 12/31/2005	Total Precip "	0.17	0.16	0.84	2.33	3.08	3.74	2.52	2.83	0.08	2.13	0.16	0.14	18.18
Site Type: Alfalfa	Total Alfalfa ETr "	2.01	3.02	4.76	5.24	6.42	7.58	9.73	7.22	6.67	3.86	4.35	2.69	63.55
Total Growing Degee Days from March 1		0	0	113	183	311	504	632	581	468	235	159	40	3226
Gross Pond Evap	Inch	1.69	2.54	4	4.4	5.39	6.37	8.17	6.06	5.6	3.24	3.65	2.26	53.37
Net Pond Evap	Inch	1.57	2.42	3.41	2.77	3.24	3.75	6.41	4.08	5.55	1.75	3.54	2.16	40.65
Sterling	Avg. Temp ° F	27.93	32.74	39.1	46.64	56.93	67.8	75.01	69.3	63.1	48.99	39.02	25.91	49.37
Ref date as of 12/31/2005	Total Precip "	0.33	0.2	0.91	2.63	2.41	3.21	1.56	1.48	1.13	2.32	0.46	0.17	16.81
Site Type: Alfalfa	Total Alfalfa ETr "	2.06	3.05	5.15	5.6	6.59	8.45	10.12	7.66	6.48	4.44	4.23	2.54	66.37
Total Growing Degee Days from March 1		0	0	122	186	339	509	645	582	468	254	161	37	3303
Gross Pond Evap	Inch	1.73	2.56	4.33	4.7	5.54	7.1	8.5	6.43	5.44	3.73	3.55	2.13	55.74
Net Pond Evap	Inch	1.5	2.42	3.69	2.86	3.85	4.85	7.41	5.4	4.65	2.11	3.23	2.01	43.98
Brush	Avg. Temp ° F	28.47	33.3	39.15	46.55	57.29	67.29	74.81	68.85	64.21	49.33	40.05	26.15	49.62
Ref date as of 12/31/2005	Total Precip "	0.5	0.06	1.02	1.61	0.84	3.18	1.29	1.13	0.3	2.37	0.5	0.11	12.91
Site Type: Alfalfa	Total Alfalfa ETr "	1.82	3	5.26	5.61	7.36	8.65	10.4	7.6	6.66	4.14	4.12	2.21	66.83
Total Growing Degee Days from March 1		0	0	131	192	349	505	664	590	478	266	168	34	3377
Gross Pond Evap	Inch	1.53	2.52	4.42	4.71	6.18	7.27	8.74	6.38	5.59	3.48	3.46	1.86	56.14
Net Pond Evap	Inch	1.18	2.48	3.7	3.59	5.59	5.04	7.83	5.59	5.38	1.82	3.11	1.78	47.09
Fort Morgan	Avg. Temp ° F	28.59	33.71	39.3	46.69	57.71	67.17	75.29	69.07	64.28	49.47	39.64	26	49.74
Ref date as of 12/31/2005	Total Precip "	0.27	0.1	1.14	2.08	1.09	5.61	2.08	2.06	0.4	3.52	1.23	0.26	19.84
Site Type: Turf	Total Alfalfa ETr "	1.84	2.87	4.91	5.43	7.06	8.07	10.05	7.65	6.43	4	3.73	2.15	64.19
Total Growing Degee Days from March 1		0	0	117	188	345	507	674	587	479	257	155	32	3341
Gross Pond Evap	Inch	1.55	2.41	4.12	4.56	5.93	6.78	8.44	6.43	5.4	3.36	3.13	1.81	53.92
Net Pond Evap	Inch	1.36	2.34	3.33	3.11	5.17	2.85	6.99	4.98	5.12	0.9	2.27	1.62	40.04
Wiggins	Avg. Temp ° F	27.89	32.99	38.91	45.95	57.7	67.49	74.7	67.86	63.7	49.3	39.22	25.35	49.26
Ref date as of 12/31/2005	Total Precip "	0.12	0.19	0.36	1.73	1.55	4.83	1.77	1.21	0.35	2.62	0.55	0.06	15.34
Site Type: Alfalfa	Total Alfalfa ETr "	1.7	2.84	5.17	5.73	8.16	9.53	10.34	6.63	6.31	4.12	3.8	2.09	66.42
Total Growing Degee Days from March 1		0	0	144	211	371	509	640	562	474	270	156	33	3370
Gross Pond Evap	Inch	1.43	2.39	4.34	4.81	6.85	8.01	8.69	5.57	5.3	3.46	3.19	1.76	55.8
Net Pond Evap	Inch	1.34	2.25	4.09	3.6	5.77	4.62	7.45	4.72	5.06	1.63	2.81	1.71	45.05
Fort Collins East	Avg. Temp ° F	27.75	32.91	38.71	45.25	54.96	63.8	71.46	66.41	59.97	48.2	38.67	27.45	47.96
Ref date as of 12/31/2005	Total Precip "	0.33	0.28	0.97	2	2.3	3.32	0.15	0.66	0.15	2.74	0.14	0.08	13.12
Site Type: Alfalfa	Total Alfalfa ETr "	1.98	3.01	4.9	5.69	6.57	7.67	9.25	7.61	6.04	3.83	4	2.76	63.31
Total Growing Degee Days from March 1		0	0	102	176	295	437	592	526	411	224	123	40	2926
Gross Pond Evap	Inch	1.66	2.53	4.12	4.78	5.52	6.44	7.77	6.39	5.07	3.22	3.36	2.32	53.18
Net Pond Evap	Inch	1.43	2.33	3.44	3.38	3.91	4.12	7.67	5.93	4.97	1.3	3.26	2.26	44
Eaton	Avg. Temp ° F	28.34	33.88	38.93	46.44	56.15	64.78	72.16	66.4	61.24	47.99	38.33	26.54	48.43
Ref date as of 12/31/2005	Total Precip "	0.13	0.09	0.59	1.41	1.41	3.86	0.35	1.9	0.43	3.31	0.36	0.09	13.93
Site Type: Alfalfa	Total Alfalfa ETr "	1.98	3.21	4.99	6.27	6.88	7.86	9.39	7.08	6.26	3.58	3.63	2.55	63.68
Total Growing Degee Days from March 1		0	0	109	188	318	453	610	533	433	216	121	39	3020
Gross Pond Evap	Inch	1.66	2.7	4.19	5.27	5.78	6.6	7.89	5.95	5.26	3.01	3.05	2.14	53.5
Net Pond Evap	Inch	1.57	2.63	3.78	4.28	4.79	3.9	7.64	4.62	4.96	0.69	2.8	2.08	43.74
Johnsons Corner	Avg. Temp ° F	29.3	34.87	39.79	45.98	55.73	64.67	73.12	67.13	62.23	49.64	40.2	28.36	49.25
Ref date as of 12/31/2005	Total Precip "	0.46	0.33	0.83	1.92	2.2	3.16	1.2	1.56	0.22	2.9	0.18	0.11	15.07
Site Type: Alfalfa	Total Alfalfa ETr "	1.77	2.69	4.6	5.18	6.34	7.7	9.67	7.31	6.22	3.63	3.69	2.6	61.4
Total Growing Degee Days from March 1		0	0	99	169	308	464	632	545	434	219	123	46	3039
Gross Pond Evap	Inch	1.49	2.26	3.86	4.35	5.33	6.47	8.12	6.14	5.22	3.05	3.1	2.18	51.57
Net Pond Evap	Inch	1.16	2.03	3.28	3.01	3.79	4.26	7.28	5.05	5.07	1.02	2.97	2.11	41.03
Gilcrest	Avg. Temp ° F	27.53	33.84	39.33	46.3	56.59	65.52	72.66	67.02	61.24	48.36	38.78	26.61	48.65
Ref date as of 12/31/2005	Total Precip "	0.17	0.11	0.44	1.66	1.3	3.55	1.19	0.72	0.25	2.86	0.39	0.12	12.76
Site Type: Alfalfa	Total Alfalfa ETr "	1.55	2.51	4.43	4.78	5.65	7.21	8.75	6.58	5.16	3.05	3.43	2.24	55.34
Total Growing Degee Days from March 1		0	0	112	177	328	477	632	554	441	240	144	46	3151
Gross Pond Evap	Inch	1.3	2.11	3.72	4.02	4.75	6.06	7.35	5.53	4.33	2.56	2.88	1.88	46.49
Net Pond Evap	Inch	1.18	2.03	3.41	2.85	3.84	3.57	6.52	5.02	4.16	0.56	2.61	1.8	37.55
Longmont South	Avg. Temp ° F	31.79	36.39	40.97	47.38	57.21	65.5	74.26	68.57	63.68	50.83	42.68	30.67	50.83
Ref date as of 12/31/2005	Total Precip "	0.85	0.23	1.16	2.15	1.56	2.54	0.52	1.66	0.33	2.41	0.22	0.26	13.89
Site Type: Alfalfa	Total Alfalfa ETr "	2.05	2.83	4.59	5.42	6.8	7.86	9.86	7.59	6.22	3.6	4.17	2.89	63.88
Total Growing Degee Days from March 1		0	0	106	189	322	465	646	566	466	243	155	64	3222
Gross Pond Evap	Inch	1.72	2.38	3.86	4.55	5.71	6.6	8.28	6.38	5.22	3.02	3.5	2.43	53.65
Net Pond Evap	Inch	1.13	2.22	3.04	3.05	4.62	4.82	7.92	5.21	4.99	1.34	3.35	2.25	43.94
Fort Collins NW	Avg. Temp ° F	24.89	29.65	34.74	41.59	50.47	59.92	68.36	61.31	55.36	43.44	32.56	24.27	43.88
Ref date as of 12/31/2005	Total Precip "	0.51	0.27	0.47	1.72	2.44	1.82	0.24	0.95	0.1	2.37	0.07	0.15	11.11
Site Type: Turf	Total Alfalfa ETr "	0.49	1.01	2.38	2.01	2.79	3.97	9.02	6.21	5.66	3.12	3.26	2.26	42.18
Total Growing Degee Days from March 1		0	0	97	170	300	455	633	541	435	223	115	40	3009
Gross Pond Evap	Inch	0.41	0.85	2	1.69	2.34	3.33	7.58	5.22	4.75	2.62	2.74	1.9	35.43
Net Pond Evap	Inch	0.05	0.66	1.67	0.48	0.64	2.06	7.41	4.55	4.68	0.96	2.69	1.79	27.64
Fort Collins Central	Avg. Temp ° F	30.73	35.32	40.54	47.09	56.83	65.45	74.05	67.84	62.27	49.44	40.35	29.43	49.95
Ref date as of 12/31/2005	Total Precip "	0.58	0.28	0.67	1.73	2.57	2.62	0.19	0.94	0.3	2.91	0.07	0.07	12.93
Site Type: Turf	Total Alfalfa ETr "	1.94	2.49	4.2	4.99	6.19	7.18	8.83	6.75	5.63	3.36	3.39	2.32	57.27
Total Growing Degee Days from March 1		0	0	104	179	313	467	638	560	450	250	139	54	3154
Gross Pond Evap	Inch	1.63	2.09	3.53	4.19	5.2	6.03	7.42	5.67	4.73	2.82	2.85	1.95	48.11
Net Pond Evap	Inch	1.22	1.9	3.06	2.98	3.4	4.2	7.28	5.01	4.52	0.79	2.8	1.9	39.06
Windsor	Avg. Temp ° F	26.15	31.68	36.05	41.92	51.76	59.88	68.25	62.43	57.82	45.16	35.31	25.68	45.17
Ref date as of 12/31/2005	Total Precip "	0.57	0.25	0.98	2.24	1.93	3.93	0.87	1.66	0.22	3.51	0.17	0.26	16.59
Site Type: Dryland Pasture	Total Alfalfa ETr "	1.94	3.02	5.03	5.98	7.14	7.96	10.41	7.77	6.4	3.66	4.01	2.47	65.79
Total Growing Degee Days from March 1		0	0	132	215	358	508	681	606	488	261	140	50	3439
Gross Pond Evap	Inch	1.63	2.54	4.23	5.02	6	6.69	8.74	6.53	5.38	3.07	3.37	2.07	55.27
Net Pond Evap	Inch	1.23	2.36	3.54	3.46	4.65	3.94	8.14	5.36	5.22	0.62	3.25	1.89	43.66
Greeley West	Avg. Temp ° F	28.73	34.99	40.25	47.31	57.98	66.7	75.43	69.33	64.13	49.96	39.91	27.5	50.19
Ref date as of 12/31/2005	Total Precip "	0.18	0.2	0.43	1.5	1.47	3.64	0.45	0.71	0.22	3.45	0.31	0.08	12.64
Site Type: Turf	Total Alfalfa ETr "	1.36	2.42	4.37	5.44	6.93	8.02	9.71	7.25	5.96	3.24	3.06	1.94	59.7
Total Growing Degee Days from March 1		0	0	108	191	342	497	673	593	475	239	129	37	3284
Gross Pond Evap	Inch	1.14	2.03	3.67	4.57	5.82	6.74	8.16	6.09	5.01	2.72	2.57	1.63	50.15
Net Pond Evap	Inch	1.02	1.89	3.37	3.52	4.79	4.19	7.84	5.59	4.85	0.31	2.35	1.57	41.29
Loveland	Avg. Temp ° F	30.12	35.46	40.32	46.93	57.21	65.93	74.84	68.44	63.25	50.01	40.76	29.02	50.19
Ref date as of 12/31/2005	Total Precip "	0.64	0.35	0.48	1.48	1.88	2.38	0.52	1.14	0.36	2.63	0.06	0.13	12.05
Site Type: Turf	Total Alfalfa ETr "	1.37	2.08	3.87	4.85	6.17	7.17	8.74	6.37	5.11	2.89	2.7	2.01	53.33
Total Growing Degee Days from March 1		0	0	100	180	328	489	673	584	464	239	124	52	3233
Gross Pond Evap	Inch	1.15	1.75	3.25	4.07	5.18	6.02	7.34	5.35	4.29	2.43	2.27	1.69	44.79
Net Pond Evap	Inch	0.7	1.5	2.91	3.04	3.87	4.36	6.98	4.55	4.04	0.59	2.23	1.6	36.37
Berthoud	Avg. Temp ° F	30.08	35.51	40.12	46.73	56.95	65.48	74.82	68.47	63.86	50.4	41.24	29.16	50.24
Ref date as of 12/31/2005	Total Precip "	0.42	0.18	0.57	1.68	1.83	3.58	1.45	1.85	0.2	3.27	0.08	0.15	15.26
Site Type: Turf	Total Alfalfa ETr "	1.77	2.68	4.63	5.34	7.05	7.81	9.57	7.78	6.63	3.8	3.67	2.55	63.28
Total Growing Degee Days from March 1		0	0	98	171	317	475	674	577	458	227	122	45	3164
Gross Pond Evap	Inch	1.49	2.25	3.89	4.49	5.92	6.56	8.04	6.54	5.57	3.19	3.08	2.14	53.16
Net Pond Evap	Inch	1.19	2.13	3.49	3.31	4.64	4.05	7.02	5.24	5.43	0.9	3.03	2.04	42.47
Longmont West	Avg. Temp ° F	31.2	36.52	40.91	47.32	57.88	66.27	75.49	69.34	64.41	50.74	42.27	30.02	51.03
Ref date as of 12/31/2005	Total Precip "	0.66	0.28	0.95	2.21	1.48	2.75	0.72	0.84	0.7	2.25	0.25	0.2	13.29
Site Type: Turf	Total Alfalfa ETr "	1.34	2.05	3.51	4.48	6.22	6.77	8.23	6.21	5.09	2.88	2.55	1.74	51.07
Total Growing Degee Days from March 1		0	0	102	176	329	496	695	595	479	240	144	57	3313
Gross Pond Evap	Inch	1.13	1.72	2.95	3.76	5.22	5.69	6.91	5.22	4.28	2.42	2.14	1.46	42.9
Net Pond Evap	Inch	0.66	1.53	2.28	2.22	4.19	3.76	6.41	4.63	3.79	0.84	1.97	1.32	33.6
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	33.41	35.8	40.1	46.69	57.31	65.85	76.47	70.46	64.99	51.4	43.54	32.38	51.53
Ref date as of 12/31/2005	Total Precip "	1.01	0.28	0.82	2.48	1.89	2.51	0.51	1.54	0.14	2.34	0.3	0.24	14.06
Site Type: Turf	Total Alfalfa ETr "	2.32	2.72	4.26	5.03	6.9	7.87	10.2	7.96	6.58	3.8	3.59	2.83	64.06
Total Growing Degee Days from March 1		0	0	98	194	337	491	687	601	497	259	141	56	3361
Gross Pond Evap	Inch	1.95	2.28	3.58	4.23	5.8	6.61	8.57	6.69	5.53	3.19	3.02	2.38	53.83
Net Pond Evap	Inch	1.24	2.09	3	2.49	4.47	4.85	8.21	5.61	5.43	1.55	2.81	2.21	43.96
Boulder East	Avg. Temp ° F	33.32	37.1	41.72	48.34	58.88	67.29	77.82	70.87	66.16	52.15	44.08	32.25	52.5
Ref date as of 12/31/2005	Total Precip "	0.71	0.17	0.69	2.22	1.28	2.44	0.6	1.52	0.18	2.38	0.2	0.2	12.59
Site Type: Turf	Total Alfalfa ETr "	1.96	2.6	4.41	5.14	6.86	7.67	9.81	7.35	6.01	3.29	3.44	2.72	61.26
Total Growing Degee Days from March 1		0	0	97	182	334	502	722	609	499	249	155	60	3409
Gross Pond Evap	Inch	1.65	2.18	3.7	4.32	5.76	6.44	8.24	6.17	5.05	2.76	2.89	2.28	51.44
Net Pond Evap	Inch	1.15	2.07	3.22	2.76	4.87	4.73	7.82	5.11	4.92	1.1	2.75	2.14	42.64
Boulder Flatiron	Avg. Temp ° F	31.57	34.9	39.77	46.3	56.48	64.61	72.08	66.84	61.32	49.05	41.4	30.77	49.59
Ref date as of 12/31/2005	Total Precip "	0.71	0.12	0.49	2.19	1.34	2.71	0.58	1.43	0.22	2.82	0.24	0.15	13
Site Type: Turf	Total Alfalfa ETr "	1.66	2.15	3.48	4.17	5.48	6.03	6.62	5.01	3.98	2.45	2.77	2.25	46.05
Total Growing Degee Days from March 1		0	0	91	171	310	456	608	537	448	231	145	59	3056
Gross Pond Evap	Inch	1.39	1.81	2.92	3.5	4.6	5.07	5.56	4.21	3.34	2.06	2.33	1.89	38.68
Net Pond Evap	Inch	0.9	1.72	2.58	1.97	3.67	3.17	5.15	3.21	3.19	0.08	2.16	1.79	29.59
Boulder SW	Avg. Temp ° F	35.29	37.53	41.24	47.32	57.5	66.03	75.63	69.34	65.51	52.54	45.71	34.25	52.32
Ref date as of 12/31/2005	Total Precip "	0.95	0.18	0.85	2.69	2.15	2.29	0.35	1.64	0.49	2.85	0.26	0.13	14.83
Site Type: Turf	Total Alfalfa ETr "	2.67	2.92	4.64	5.18	6.84	8.24	10.07	7.52	6.8	3.96	4.39	3.35	66.58
Total Growing Degee Days from March 1		0	0	76	151	310	485	699	590	486	230	129	54	3210
Gross Pond Evap	Inch	2.24	2.45	3.9	4.35	5.75	6.92	8.46	6.32	5.71	3.33	3.69	2.81	55.93
Net Pond Evap	Inch	1.58	2.33	3.3	2.47	4.24	5.32	8.21	5.17	5.37	1.33	3.51	2.72	45.55