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	2007	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	18.85	26.39	46.23	46.11	59.78	68.15	75.55	74.81	64.74	52.46	38.35	21.23	49.39
Ref date as of 12/31/2007	Total Precip "	0.14	0.15	1.37	5.18	1.98	1.42	2.7	0.99	1.44	0.61	0	0.2	16.18
Site Type: Alfalfa	Total Alfalfa ETr "	1.37	1.82	5.58	5.18	7.65	9.5	9.82	9.11	7.62	6.32	4.84	1.49	70.3
Total Growing Degee Days from March 1		0	0	197	175	375	536	720	710	452	283	159	15	3622
Gross Pond Evap	Total "	1.15	1.53	4.69	4.35	6.43	7.98	8.25	7.65	6.4	5.31	4.07	1.25	59.06
Net Pond Evap	Total "	1.05	1.42	3.73	0.73	5.04	6.99	6.36	6.96	5.39	4.88	4.07	1.11	47.73
Crook	Avg. Temp ° F	17.93	26.6	45.49	45.77	58.99	67.54	74.47	73.6	62.58	50.46	36.33	20.29	48.34
Ref date as of 12/31/2007	Total Precip "	0.12	0.19	1.07	2.52	2.99	1.23	0.19	0.44	0.54	0.36	0	0.04	9.69
Site Type: Alfalfa	Total Alfalfa ETr "	1.06	1.65	5.25	4.75	6.8	8.18	8.38	7.74	5.93	5.2	4.46	1.4	60.8
Total Growing Degee Days from March 1		0	0	211	176	355	511	689	677	422	282	165	17	3505
Gross Pond Evap	Inch	0.89	1.39	4.41	3.99	5.71	6.87	7.04	6.5	4.98	4.37	3.75	1.18	51.08
Net Pond Evap	Inch	0.81	1.25	3.66	2.23	3.62	6.01	6.91	6.19	4.6	4.12	3.75	1.15	44.3
Sterling	Avg. Temp ° F	14.76	25.56	45.68	46.44	59.36	68.83	75.68	73.96	63.16	50.57	36.35	19.16	48.29
Ref date as of 12/31/2007	Total Precip "	0.09	0.08	1.21	4.22	2.67	1.49	1.45	1.6	0.62	0.42	0	0	13.85
Site Type: Alfalfa	Total Alfalfa ETr "	1.22	1.75	5.63	5.58	7.93	10.18	10.09	8.64	7.1	5.64	4.34	1.46	69.56
Total Growing Degee Days from March 1		0	0	217	193	375	534	708	694	443	295	169	20	3648
Gross Pond Evap	Inch	1.02	1.47	4.73	4.69	6.66	8.55	8.48	7.26	5.96	4.74	3.65	1.23	58.44
Net Pond Evap	Inch	0.96	1.41	3.88	1.73	4.79	7.51	7.46	6.14	5.53	4.44	3.65	1.23	48.73
Brush	Avg. Temp ° F	13.96	25.47	46.25	47.3	59.58	68.37	75.66	74.34	64.42	50.61	37.12	19.05	48.51
Ref date as of 12/31/2007	Total Precip "	0.28	0.09	0.98	2.09	2.64	0.86	3.17	1.24	0.41	0.52	0	0	12.28
Site Type: Alfalfa	Total Alfalfa ETr "	1.15	1.53	5.51	5.69	7.87	9.1	9.65	8.19	7.19	5.05	3.64	1.43	66
Total Growing Degee Days from March 1		0	0	210	205	387	532	720	711	475	288	162	21	3711
Gross Pond Evap	Inch	0.97	1.29	4.63	4.78	6.61	7.64	8.11	6.88	6.04	4.24	3.06	1.2	55.45
Net Pond Evap	Inch	0.77	1.22	3.94	3.32	4.76	7.04	5.89	6.01	5.75	3.88	3.06	1.2	46.84
Fort Morgan	Avg. Temp ° F	13.89	24.9	45.51	47.28	59.45	68.83	75.69	73.75	64.03	51.1	37.07	19.37	48.41
Ref date as of 12/31/2007	Total Precip "	0	0	0	0.03	0.1	0.48	2.43	1.74	0.44	0.5	0.06	0.53	6.31
Site Type: Turf	Total Alfalfa ETr "	1.07	1.53	5.13	5.61	7.42	9.04	9.43	7.84	6.78	4.97	3.31	1.27	63.4
Total Growing Degee Days from March 1		0	0	198	197	373	537	721	705	467	291	149	18	3656
Gross Pond Evap	Inch	0.9	1.29	4.31	4.71	6.23	7.59	7.92	6.59	5.7	4.17	2.78	1.07	53.26
Net Pond Evap	Inch	0.9	1.29	4.31	4.69	6.16	7.26	6.22	5.37	5.39	3.82	2.74	0.7	48.85
Wiggins	Avg. Temp ° F	12.07	23.43	44.77	46.76	58.83	68.56	75.32	73.32	63.06	50.81	36.8	18.58	47.69
Ref date as of 12/31/2007	Total Precip "	0.34	0.11	0.95	1.56	1.53	1.96	1.35	2.2	0.46	0.49	0.09	0.14	11.18
Site Type: Alfalfa	Total Alfalfa ETr "	1.16	1.47	5.26	5.91	7.98	10.14	10.09	8.31	7.09	5.69	3.59	1.38	68.07
Total Growing Degee Days from March 1		0	0	195	200	378	527	704	687	459	293	150	17	3610
Gross Pond Evap	Inch	0.97	1.23	4.42	4.96	6.7	8.52	8.48	6.98	5.96	4.78	3.02	1.16	57.18
Net Pond Evap	Inch	0.74	1.16	3.75	3.87	5.63	7.15	7.53	5.44	5.63	4.44	2.95	1.06	49.35
Fort Collins East	Avg. Temp ° F	18.15	27.99	43.54	45.81	56.32	67.13	72.81	70.3	60.06	49.59	36.88	21.79	47.53
Ref date as of 12/31/2007	Total Precip "	0.11	0.16	1.22	1.62	1.36	0.1	1.41	3.31	1.11	1.5	0.15	0.49	12.54
Site Type: Alfalfa	Total Alfalfa ETr "	1.62	2.07	5.27	5.36	6.77	9.15	8.8	7.17	5.54	5.06	3.14	1.72	61.67
Total Growing Degee Days from March 1		0	0	185	170	334	490	650	616	401	257	129	17	3249
Gross Pond Evap	Inch	1.36	1.74	4.43	4.5	5.69	7.69	7.39	6.02	4.65	4.25	2.64	1.44	51.8
Net Pond Evap	Inch	1.28	1.63	3.57	3.37	4.73	7.62	6.41	3.71	3.88	3.2	2.53	1.1	43.03
Eaton	Avg. Temp ° F	17.38	27.61	44.22	46.48	56.84	67.49	72.94	70.11	60.77	48.93	36.28	20.98	47.5
Ref date as of 12/31/2007	Total Precip "	0.09	0.08	1.07	1.27	1.85	0.29	0.26	0.32	0.98	0.47	0.16	0.36	7.2
Site Type: Alfalfa	Total Alfalfa ETr "	1.32	1.93	5.4	5.98	6.89	9.46	8.73	6.91	5.74	4.84	3.12	1.45	61.77
Total Growing Degee Days from March 1		0	0	188	185	340	503	666	632	410	256	133	16	3329
Gross Pond Evap	Inch	1.11	1.62	4.54	5.02	5.79	7.95	7.33	5.8	4.82	4.07	2.62	1.22	51.89
Net Pond Evap	Inch	1.05	1.57	3.79	4.13	4.49	7.74	7.15	5.58	4.14	3.74	2.51	0.97	46.86
Johnsons Corner	Avg. Temp ° F	18.96	27.28	45.27	46.28	56.26	67.41	73.87	71.23	61.29	51.45	39.07	23.08	48.45
Ref date as of 12/31/2007	Total Precip "	0.38	0.08	1.11	1.57	0.83	0.35	0.4	3.12	1.12	1.05	0.11	0.51	10.63
Site Type: Alfalfa	Total Alfalfa ETr "	1.36	1.79	4.92	5.14	6.48	7.63	9.14	7.9	5.75	5.05	3.07	1.46	59.69
Total Growing Degee Days from March 1		0	0	180	169	341	502	685	649	412	273	140	14	3365
Gross Pond Evap	Inch	1.14	1.5	4.13	4.32	5.44	6.41	7.68	6.64	4.83	4.24	2.58	1.23	50.14
Net Pond Evap	Inch	0.88	1.45	3.36	3.22	4.86	6.16	7.4	4.45	4.05	3.51	2.5	0.87	42.71
Gilcrest	Avg. Temp ° F	12.44	23.9	44.27	46.68	57.09	68.07	73.81	71.23	61.95	49.81	36.33	18.94	47.04
Ref date as of 12/31/2007	Total Precip "	0.29	0.06	0.89	1.64	1.67	0.52	1.36	2.26	1.32	0.66	0.13	0.42	11.22
Site Type: Alfalfa	Total Alfalfa ETr "	0.87	1.18	4.16	4.89	5.99	8.59	8.23	7.02	5.75	4.61	2.76	1.33	55.38
Total Growing Degee Days from March 1		0	0	184	186	343	512	678	655	439	284	137	16	3434
Gross Pond Evap	Inch	0.73	0.99	3.49	4.11	5.03	7.22	6.91	5.9	4.83	3.87	2.32	1.12	46.52
Net Pond Evap	Inch	0.53	0.95	2.87	2.96	3.86	6.85	5.96	4.31	3.91	3.41	2.23	0.82	38.66
Longmont South	Avg. Temp ° F	21.48	29.34	45.88	46.76	57.07	67.63	73.97	71.75	62.98	51.87	40.53	25.07	49.53
Ref date as of 12/31/2007	Total Precip "	0.26	0.25	1.14	1.3	0.77	0.47	0.6	1.33	2.06	1.31	0.15	0.35	9.99
Site Type: Alfalfa	Total Alfalfa ETr "	1.74	2.2	5	5.28	6.29	8.4	8.86	7.89	6.63	4.98	3.68	1.9	62.85
Total Growing Degee Days from March 1		0	0	194	175	336	497	671	644	440	277	158	23	3415
Gross Pond Evap	Inch	1.46	1.85	4.2	4.44	5.28	7.06	7.44	6.63	5.57	4.18	3.09	1.6	52.8
Net Pond Evap	Inch	1.28	1.67	3.4	3.53	4.74	6.73	7.02	5.7	4.13	3.27	2.99	1.35	45.81
Fort Collins NW	Avg. Temp ° F	14.99	26.29	38.6	41.41	49.23	59.94	67.27	63.54	54.93	42.92	31.16	20.6	42.57
Ref date as of 12/31/2007	Total Precip "	0.22	0.13	1.22	0.6	0.91	0.39	0.58	1.81	0.74	1.74	0.33	0.67	9.34
Site Type: Turf	Total Alfalfa ETr "	1.28	1.95	3.38	3.91	5.73	8.04	8.31	6.76	5.28	4.06	2.35	1.44	52.49
Total Growing Degee Days from March 1		0	0	222	197	329	495	669	624	409	252	125	19	3341
Gross Pond Evap	Inch	1.08	1.64	2.84	3.28	4.81	6.75	6.98	5.68	4.44	3.41	1.97	1.21	44.09
Net Pond Evap	Inch	0.92	1.55	1.99	2.86	4.18	6.48	6.57	4.41	3.92	2.19	1.74	0.74	37.55
Fort Collins Central	Avg. Temp ° F	21.52	30.04	45.29	47.21	57.41	67.59	74.44	71.41	61.91	50.36	38.68	25.15	49.25
Ref date as of 12/31/2007	Total Precip "	0.29	0.21	1.34	0.87	1.2	0.45	0.49	3.85	1.46	1.68	0.17	0.66	12.67
Site Type: Turf	Total Alfalfa ETr "	1.45	2.04	4.57	4.8	6.05	7.76	8.15	6.64	5.49	4.36	2.88	1.76	55.95
Total Growing Degee Days from March 1		0	0	194	174	342	501	691	650	440	290	156	25	3463
Gross Pond Evap	Inch	1.22	1.71	3.84	4.03	5.08	6.52	6.85	5.58	4.61	3.66	2.42	1.48	47
Net Pond Evap	Inch	1.02	1.57	2.9	3.42	4.24	6.2	6.5	2.88	3.59	2.49	2.3	1.02	38.13
Windsor	Avg. Temp ° F	15.74	25.83	41.23	42.91	51.45	62.11	68.9	66.3	56.49	45.14	34.02	20.03	44.18
Ref date as of 12/31/2007	Total Precip "	0.73	0.21	1.64	1.36	0.9	0.07	1.05	1.93	1.6	1.01	0.26	1.03	11.79
Site Type: Dryland Pasture	Total Alfalfa ETr "	1.09	1.69	4.85	5.28	6.55	8.87	9.21	7.82	6.01	4.58	3.03	1.32	60.3
Total Growing Degee Days from March 1		0	0	198	199	377	537	713	684	452	290	150	21	3621
Gross Pond Evap	Inch	0.92	1.42	4.07	4.44	5.5	7.45	7.74	6.57	5.05	3.85	2.55	1.11	50.67
Net Pond Evap	Inch	0.4	1.27	2.93	3.48	4.87	7.4	7	5.22	3.93	3.14	2.36	0.39	42.39
Greeley West	Avg. Temp ° F	17.46	26.93	45.09	47.31	58.48	68.98	75.75	72.72	62.96	50.88	37.97	21.52	48.84
Ref date as of 12/31/2007	Total Precip "	0.34	0.08	1.16	1.63	1.08	0.61	0.94	2.54	1.24	0.57	0.18	0.66	11.03
Site Type: Turf	Total Alfalfa ETr "	0.97	1.53	4.34	5.22	6.61	8.63	8.84	7.33	5.72	4.43	2.49	1.18	57.29
Total Growing Degee Days from March 1		0	0	185	191	362	529	715	690	445	282	140	18	3557
Gross Pond Evap	Inch	0.81	1.29	3.65	4.38	5.55	7.25	7.43	6.16	4.8	3.72	2.09	0.99	48.12
Net Pond Evap	Inch	0.58	1.23	2.83	3.24	4.8	6.82	6.77	4.38	3.94	3.32	1.97	0.53	40.41
Loveland	Avg. Temp ° F	20.63	29.51	45.24	46.91	57.48	67.73	74.75	72.24	62.58	51.08	39.15	24	49.28
Ref date as of 12/31/2007	Total Precip "	0.47	0.26	1.3	1.42	1.26	0.21	0.83	1.21	1.35	1.39	0.13	0.67	10.5
Site Type: Turf	Total Alfalfa ETr "	1.17	1.81	4.07	4.6	5.95	7.59	8.08	6.77	5.47	3.99	2.43	1.42	53.35
Total Growing Degee Days from March 1		0	0	179	168	344	512	709	679	447	274	141	13	3466
Gross Pond Evap	Inch	0.98	1.52	3.42	3.86	5	6.38	6.79	5.69	4.59	3.35	2.04	1.19	44.81
Net Pond Evap	Inch	0.65	1.34	2.51	2.87	4.12	6.23	6.21	4.84	3.65	2.38	1.95	0.72	37.47
Berthoud	Avg. Temp ° F	20.83	28.14	45.41	46.32	57.14	67.71	74.69	72.08	62.68	51.69	39.33	23.43	49.12
Ref date as of 12/31/2007	Total Precip "	0.29	0.1	1.79	2.13	1.56	0.18	1.02	3.03	1.27	1.22	0.08	0.59	13.26
Site Type: Turf	Total Alfalfa ETr "	1.54	1.96	5	5.12	7.03	9.1	9.63	8.35	6.54	5.08	3.19	1.44	63.98
Total Growing Degee Days from March 1		0	0	175	162	331	507	711	672	434	263	128	15	3398
Gross Pond Evap	Inch	1.29	1.65	4.2	4.3	5.91	7.64	8.09	7.01	5.49	4.27	2.68	1.21	53.74
Net Pond Evap	Inch	1.09	1.58	2.95	2.81	4.81	7.52	7.38	4.89	4.6	3.41	2.62	0.8	44.46
Longmont West	Avg. Temp ° F	22.48	30.35	45.96	47.35	58.05	68.76	75.58	73.28	63.46	52.46	40.91	25.58	50.35
Ref date as of 12/31/2007	Total Precip "	0.41	0.39	1.44	1.49	1.23	0.26	0.32	1.43	1.48	1.22	0.17	0.67	10.51
Site Type: Turf	Total Alfalfa ETr "	1.29	1.97	3.91	4.55	6.03	7.5	7.97	6.87	4.94	3.72	2.37	1.42	52.54
Total Growing Degee Days from March 1		0	0	184	174	344	533	727	700	453	279	157	25	3576
Gross Pond Evap	Inch	1.08	1.65	3.28	3.82	5.07	6.3	6.69	5.77	4.15	3.12	1.99	1.19	44.11
Net Pond Evap	Inch	0.8	1.38	2.28	2.78	4.2	6.12	6.47	4.77	3.11	2.27	1.87	0.72	36.77
Fort Lupton	Avg. Temp ° F	17.93	26.66	45.18	46.68	57.58	68.18	74.86	72.18	63.21	52.77	40.51	24.98	49.23
Ref date as of 12/31/2007	Total Precip "	0.2	0.08	0.66	1.28	1.26	1.12	0.83	2.69	0.48	0.72	0.15	0.33	9.8
Site Type: Turf	Total Alfalfa ETr "	1.61	2.05	5.23	5.92	7.56	9.89	10.2	8.53	7.18	5.59	3.73	2.03	69.52
Total Growing Degee Days from March 1		0	0	191	195	351	521	700	680	460	302	160	21	3581
Gross Pond Evap	Inch	1.35	1.72	4.39	4.97	6.35	8.31	8.57	7.17	6.03	4.7	3.13	1.71	58.4
Net Pond Evap	Inch	1.21	1.67	3.93	4.08	5.47	7.52	7.99	5.28	5.7	4.19	3.03	1.47	51.54
Boulder NW	Avg. Temp ° F	25.02	33.17	46.68	46.9	57.9	68.54	75.52	73.37	63.19	52.85	42.74	28.52	51.2
Ref date as of 12/31/2007	Total Precip "	0.54	0.32	1.66	1.14	1.17	0.42	0.64	1.14	1.16	0.97	0.24	0.96	10.36
Site Type: Turf	Total Alfalfa ETr "	1.73	2.62	4.88	5.01	6.64	8.42	9.29	8.03	6.01	4.83	3.58	2.06	63.1
Total Growing Degee Days from March 1		0	0	196	182	357	517	709	685	459	296	166	23	3590
Gross Pond Evap	Inch	1.45	2.2	4.1	4.21	5.58	7.07	7.8	6.75	5.05	4.06	3.01	1.73	53.01
Net Pond Evap	Inch	1.08	1.98	2.94	3.41	4.76	6.78	7.36	5.95	4.24	3.38	2.84	1.06	45.78
Boulder East	Avg. Temp ° F	24.11	32.74	47.37	48.1	59.1	69.99	76.88	74.96	65.03	53.82	42.61	27.87	51.88
Ref date as of 12/31/2007	Total Precip "	0.44	0.22	1.36	1.55	1.27	4.63	0.39	1.28	2.51	1.32	0.16	0.9	16.03
Site Type: Turf	Total Alfalfa ETr "	1.52	2.45	4.56	5.16	6.35	8.16	8.85	7.59	5.89	4.47	2.98	2	59.98
Total Growing Degee Days from March 1		0	0	192	177	337	532	733	711	473	285	167	28	3635
Gross Pond Evap	Inch	1.28	2.06	3.83	4.33	5.33	6.85	7.43	6.38	4.95	3.75	2.5	1.68	50.37
Net Pond Evap	Inch	0.97	1.9	2.88	3.25	4.45	3.61	7.16	5.48	3.19	2.83	2.39	1.05	39.16
Boulder Flatiron	Avg. Temp ° F	22	31.59	45.17	46.33	56.48	66.29	72.93	71.24	61.29	50.67	40.03	26.6	49.22
Ref date as of 12/31/2007	Total Precip "	0.4	0.1	1.43	2.03	1.43	0.49	0.64	1.37	1.91	1.31	0.14	0.75	12
Site Type: Turf	Total Alfalfa ETr "	1.5	2.28	4.16	4.52	5.45	6.51	6.71	5.68	4.25	3.23	2.26	1.72	48.27
Total Growing Degee Days from March 1		0	0	186	167	321	471	643	638	426	265	151	26	3294
Gross Pond Evap	Inch	1.26	1.92	3.49	3.8	4.58	5.47	5.64	4.77	3.57	2.71	1.9	1.44	40.55
Net Pond Evap	Inch	0.98	1.85	2.49	2.38	3.58	5.13	5.19	3.81	2.23	1.8	1.8	0.92	32.16
Boulder SW	Avg. Temp ° F	27.47	33.91	47.31	46.99	57.64	68.08	74.36	72.92	64.25	54.46	45.09	30.81	51.94
Ref date as of 12/31/2007	Total Precip "	0.72	0.22	1.6	2.86	1.74	0.43	0.6	2.72	1.7	1.43	0.23	0.74	14.99
Site Type: Turf	Total Alfalfa ETr "	2.31	2.92	4.94	4.98	6.32	8.3	8.59	7.36	6.37	5.18	4.14	2.73	64.14
Total Growing Degee Days from March 1		0	0	166	154	312	512	675	666	453	256	160	26	3380
Gross Pond Evap	Inch	1.94	2.45	4.15	4.18	5.31	6.97	7.22	6.18	5.35	4.35	3.48	2.29	53.87
Net Pond Evap	Inch	1.44	2.3	3.03	2.18	4.09	6.67	6.8	4.28	4.16	3.35	3.32	1.78	43.4