Pond Evaporation Calculation													12/31/13
Weather Station Data provided by Northern Colorado Water Conservancy District
See Weather Station Location Map at:
http://www.northernwater.org/WaterConservation/WeatherandETData.aspx
Notes:
Current month reflects values through "Reference Date".
Pond Evap. calculated per recent Division 1 Water Court decree language:							Lower South Platte Home Page
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	2012	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	30.1	29.77	48.6	54.25	61.95	76.32	79.84	74.33	64.46	47.16	38.5	26.74	52.67
Ref date as of 12/31/2012	Total Precip "	0.09	0.31	0.57	1.94	0.82	0.64	2.35	0.07	0.47	0.64	0.14	0.41	8.45
Site Type: Alfalfa	Total Alfalfa ETr "	2.78	2.64	7.38	7.38	9.67	13.35	12.14	10.44	7.83	4.49	3.03	2.06	83.19
Total Growing Degee Days from March 1		0	0	288	272	429	664	742	639	474	240	174	40	3962
Gross Pond Evap	Total "	2.34	2.22	6.2	6.2	8.12	11.21	10.2	8.77	6.58	3.77	2.55	1.73	69.89
Net Pond Evap	Total "	2.27	2	5.8	4.84	7.55	10.77	8.55	8.72	6.25	3.32	2.45	1.44	63.96
Crook	Avg. Temp ° F	29.91	29.36	46.95	53.14	59.5	74.56	77.58	72.22	63.03	46.29	38.06	26.69	51.44
Ref date as of 12/31/2012	Total Precip "	0.13	0.55	0.51	1.71	1.09	0.37	3.12	0.92	0.79	0.8	0.16	0.41	10.56
Site Type: Alfalfa	Total Alfalfa ETr "	2.74	2.72	7.15	7.12	8.74	11.98	10.23	8.86	6.8	4.17	2.92	1.98	75.41
Total Growing Degee Days from March 1		0	0	272	258	392	617	690	587	453	232	164	40	3705
Gross Pond Evap	Inch	2.3	2.28	6.01	5.98	7.34	10.06	8.59	7.44	5.71	3.5	2.45	1.66	63.32
Net Pond Evap	Inch	2.21	1.9	5.65	4.78	6.58	9.8	6.41	6.8	5.16	2.94	2.34	1.38	55.95
Sterling	Avg. Temp ° F	30.82	28.58	47.61	54.76	60.72	75.72	78.64	74.01	64.04	46.89	38.76	27.35	52.33
Ref date as of 12/31/2012	Total Precip "	0.1	0.66	0.23	1.34	0.99	0.47	2.96	0.02	0.6	1.09	0.15	0.38	8.99
Site Type: Alfalfa	Total Alfalfa ETr "	2.62	2.57	6.86	7.39	8.33	12.2	11.29	9.83	6.95	4.18	2.73	1.91	76.86
Total Growing Degee Days from March 1		0	0	279	284	405	640	728	631	458	242	172	46	3885
Gross Pond Evap	Inch	2.2	2.16	5.76	6.21	7	10.25	9.48	8.26	5.84	3.51	2.29	1.6	64.56
Net Pond Evap	Inch	2.13	1.7	5.6	5.27	6.3	9.92	7.41	8.24	5.42	2.75	2.19	1.34	58.27
Brush	Avg. Temp ° F	31.78	28.54	47.69	53.93	60.01	73.61	75.71	71.79	63.08	45.75	36.93	26.06	51.24
Ref date as of 12/31/2012	Total Precip "	0.08	0.79	0.03	1.52	1.04	1.03	2.49	0.26	0.84	0.87	0.26	0.29	9.5
Site Type: Alfalfa	Total Alfalfa ETr "	2.68	2.29	6.91	7.39	8.46	11.4	9.94	9.19	6.86	4.09	2.32	1.88	73.41
Total Growing Degee Days from March 1		0	0	282	294	401	593	695	600	456	233	137	37	3728
Gross Pond Evap	Inch	2.25	1.92	5.8	6.21	7.11	9.58	8.35	7.72	5.76	3.44	1.95	1.58	61.67
Net Pond Evap	Inch	2.2	1.37	5.78	5.14	6.38	8.86	6.61	7.54	5.17	2.83	1.77	1.38	55.03
Fort Morgan	Avg. Temp ° F	30.18	27.95	46.31	55.15	61.29	75.1	77.91	73.93	64.57	47.08	37.79	27.15	52.03
Ref date as of 12/31/2012	Total Precip "	0.03	0.85	0.03	2.1	1.42	1.96	1.86	0.5	1.18	1.13	0.59	0.28	11.93
Site Type: Turf	Total Alfalfa ETr "	2.12	2.1	5.49	6.94	7.9	10.53	9.72	8.85	6.21	3.69	2.08	1.58	67.21
Total Growing Degee Days from March 1		0	0	261	318	427	622	718	642	479	241	133	45	3886
Gross Pond Evap	Inch	1.78	1.76	4.61	5.83	6.64	8.85	8.16	7.43	5.22	3.1	1.75	1.33	56.46
Net Pond Evap	Inch	1.76	1.17	4.59	4.36	5.64	7.47	6.86	7.08	4.39	2.31	1.33	1.13	48.09
Wiggins	Avg. Temp ° F	30.56	28.11	46.15	52.64	58.77	72.89	75.6	72.06	62.56	44.82	34.99	24.93	50.34
Ref date as of 12/31/2012	Total Precip "	0.01	0.54	0.09	1.57	1.36	0.25	1.96	0.23	0.9	1.04	0.43	0.1	8.48
Site Type: Alfalfa	Total Alfalfa ETr "	2.52	2.43	6.65	7.28	8.16	11.73	10.4	9.73	6.64	3.8	2.04	1.77	73.15
Total Growing Degee Days from March 1		0	0	263	281	389	577	681	606	449	212	108	33	3599
Gross Pond Evap	Inch	2.12	2.04	5.59	6.12	6.85	9.85	8.74	8.17	5.58	3.19	1.71	1.49	61.45
Net Pond Evap	Inch	2.11	1.66	5.52	5.02	5.9	9.68	7.36	8.01	4.95	2.46	1.41	1.42	55.5
Fort Collins East	Avg. Temp ° F	33.76	29.71	47.29	52.59	58.38	71.53	73.82	69.61	61.45	45.92	37.74	26.72	50.71
Ref date as of 12/31/2012	Total Precip "	0.07	0.3	0.05	0.33	1.91	0.64	2.17	0.19	1.38	0.59	0.21	0.21	8.05
Site Type: Alfalfa	Total Alfalfa ETr "	2.98	2.82	7.12	7.39	7.77	10.42	9.29	8.22	6.57	3.98	2.52	1.94	71.02
Total Growing Degee Days from March 1		0	0	269	280	362	558	659	569	437	210	117	35	3496
Gross Pond Evap	Inch	2.5	2.37	5.98	6.21	6.53	8.75	7.8	6.9	5.52	3.34	2.12	1.63	59.65
Net Pond Evap	Inch	2.45	2.16	5.95	5.98	5.19	8.3	6.28	6.77	4.55	2.93	1.97	1.48	54.01
Eaton	Avg. Temp ° F	32.38	29.85	46.87	52.55	58.68	72.38	73.79	69.52	61.93	45.83	37.22	26.56	50.63
Ref date as of 12/31/2012	Total Precip "	0.06	0.32	0.08	0.73	1.5	1.18	2.19	0.06	1.31	0.85	0.22	0.17	8.67
Site Type: Alfalfa	Total Alfalfa ETr "	2.86	2.76	6.98	7.49	8.34	11.16	9.25	8	6.28	3.82	2.23	1.81	70.98
Total Growing Degee Days from March 1		0	0	273	284	377	570	669	571	440	207	106	34	3531
Gross Pond Evap	Inch	2.4	2.32	5.86	6.29	7.01	9.37	7.77	6.72	5.28	3.21	1.87	1.52	59.62
Net Pond Evap	Inch	2.36	2.09	5.81	5.78	5.96	8.55	6.24	6.68	4.36	2.61	1.72	1.4	53.56
Johnsons Corner	Avg. Temp ° F	34.89	29.44	48.67	53.44	59.35	74.29	75.36	72.37	64.45	47.58	39.31	28.88	52.34
Ref date as of 12/31/2012	Total Precip "	0.31	0.77	0.15	0.68	1.39	0.32	2.61	0.13	1.19	0.82	0.44	0.38	9.19
Site Type: Alfalfa	Total Alfalfa ETr "	2.65	2.48	6.69	7.02	8.15	11.63	9.75	9.05	6.81	4.08	2.32	1.9	72.53
Total Growing Degee Days from March 1		0	0	266	286	379	593	700	624	461	219	104	38	3670
Gross Pond Evap	Inch	2.23	2.08	5.62	5.9	6.85	9.77	8.19	7.6	5.72	3.43	1.95	1.6	60.94
Net Pond Evap	Inch	2.01	1.54	5.51	5.42	5.87	9.55	6.36	7.51	4.89	2.85	1.64	1.33	54.48
Gilcrest	Avg. Temp ° F	33.34	28.49	47.6	53.46	59.35	74.76	76.52	72.63	64.03	47.49	37.74	27.82	51.94
Ref date as of 12/31/2012	Total Precip "	0.04	0.43	0.04	1.01	1.31	0.66	2.12	1.52	2.24	1.23	0.43	0.23	11.26
Site Type: Alfalfa	Total Alfalfa ETr "	2.27	2.34	6.61	6.91	7.61	11.08	9.54	8.37	5.73	3.65	1.99	1.77	67.87
Total Growing Degee Days from March 1		0	0	278	301	389	597	714	628	474	240	112	43	3776
Gross Pond Evap	Inch	1.91	1.97	5.55	5.8	6.39	9.31	8.01	7.03	4.81	3.07	1.67	1.49	57.01
Net Pond Evap	Inch	1.88	1.66	5.52	5.1	5.48	8.85	6.53	5.97	3.25	2.21	1.37	1.33	49.15
Longmont South	Avg. Temp ° F	37.54	29.56	50.16	54.5	60.35	74.63	75.88	73.1	65.15	48.92	41.73	31.11	53.55
Ref date as of 12/31/2012	Total Precip "	0.27	0.76	0.05	1.02	1.62	0.31	1.6	0.15	1.19	1.04	0.38	0.24	8.63
Site Type: Alfalfa	Total Alfalfa ETr "	3.51	2.61	7.23	7.54	8.08	11.24	9.62	8.89	6.63	4.21	2.82	2.39	74.77
Total Growing Degee Days from March 1		0	0	272	299	388	611	706	640	462	240	144	54	3816
Gross Pond Evap	Inch	2.95	2.19	6.07	6.33	6.79	9.44	8.08	7.47	5.57	3.54	2.37	2.01	62.81
Net Pond Evap	Inch	2.76	1.66	6.04	5.62	5.65	9.22	6.96	7.36	4.74	2.81	2.1	1.84	56.76
Fort Collins NW	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 12/31/2010	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
Fort Collins Central	Avg. Temp ° F	35.04	30.24	48.51	53.29	58.58	72.34	74.17	70.45	62.17	46.42	38.69	28.15	51.5
Ref date as of 12/31/2012	Total Precip "	0.07	0.92	0.02	0.32	1.62	0.25	3.41	0.02	1.79	0.55	0.1	0.08	9.15
Site Type: Turf	Total Alfalfa ETr "	2.39	2.48	6.12	6.25	7.15	8.97	7.67	6.82	5.29	3.12	2.07	1.49	59.82
Total Growing Degee Days from March 1		0	0	265	277	368	564	674	585	444	223	135	37	3572
Gross Pond Evap	Inch	2.01	2.08	5.14	5.25	6.01	7.53	6.44	5.73	4.44	2.62	1.74	1.25	50.24
Net Pond Evap	Inch	1.96	1.44	5.13	5.03	4.87	7.36	4.06	5.71	3.19	2.24	1.67	1.2	43.86
Windsor	Avg. Temp ° F	34.73	30.75	49.32	54.56	60.53	75.1	80.1	#N/A	#N/A	#N/A	#N/A	#N/A	55.01
Ref date as of 7/1/2012	Total Precip "	0.02	0.47	0.03	1.07	1.6	0.05	0	#N/A	#N/A	#N/A	#N/A	#N/A	3.24
Site Type: Dryland Pasture	Total Alfalfa ETr "	2.56	2.44	6.69	6.86	6.23	6.65	0	#N/A	#N/A	#N/A	#N/A	#N/A	31.43
Total Growing Degee Days from March 1		0	0	285	312	399	622	22	#N/A	#N/A	#N/A	#N/A	#N/A	1640
Gross Pond Evap	Inch	2.15	2.05	5.62	5.76	5.23	5.59	0	#N/A	#N/A	#N/A	#N/A	#N/A	26.4
Net Pond Evap	Inch	2.14	1.72	5.6	5.01	4.11	5.55	0	#N/A	#N/A	#N/A	#N/A	#N/A	24.13
Greeley West	Avg. Temp ° F	32.49	29.05	47.45	53.31	59.35	73.87	75.65	71.91	63.46	46.07	36.91	26.93	51.37
Ref date as of 12/31/2012	Total Precip "	0.1	0.45	0.06	0.67	1.3	0.46	1.32	0.15	2.2	1.11	0.44	0.33	8.59
Site Type: Turf	Total Alfalfa ETr "	2.17	2.38	5.96	6.65	7.59	9.98	9.08	7.81	5.68	3.34	1.78	1.5	63.92
Total Growing Degee Days from March 1		0	0	273	296	387	605	705	621	456	208	93	29	3673
Gross Pond Evap	Inch	1.82	2	5.01	5.59	6.38	8.38	7.63	6.56	4.77	2.81	1.5	1.26	53.71
Net Pond Evap	Inch	1.75	1.68	4.96	5.12	5.47	8.06	6.7	6.46	3.23	2.03	1.19	1.03	47.68
Loveland	Avg. Temp ° F	35	29.68	48.99	54.2	59.72	73.75	75.8	72.24	64.46	47.22	39.67	29.01	52.48
Ref date as of 12/31/2012	Total Precip "	0.17	0.14	0	0.38	1.64	0.07	2.09	0.09	1.16	0.67	0.32	0.04	6.77
Site Type: Turf	Total Alfalfa ETr "	2.29	2.26	5.67	6.22	7.12	9.09	8.13	7.25	5.4	3.23	1.91	1.58	60.15
Total Growing Degee Days from March 1		0	0	289	317	393	616	722	643	482	230	126	42	3860
Gross Pond Evap	Inch	1.92	1.9	4.76	5.22	5.98	7.64	6.83	6.09	4.54	2.71	1.6	1.33	50.52
Net Pond Evap	Inch	1.8	1.8	4.76	4.96	4.83	7.59	5.37	6.03	3.72	2.24	1.38	1.3	45.78
Berthoud	Avg. Temp ° F	34.92	29.16	49.03	53.66	59.43	73.87	75.01	72.04	63.88	46.95	39.31	28.73	52.17
Ref date as of 12/31/2012	Total Precip "	0.2	0.63	0.04	0.59	1.42	0.18	2.95	0.18	1.16	0.84	0.34	0.15	8.68
Site Type: Turf	Total Alfalfa ETr "	2.35	2.36	6	6.5	7.58	10	8.86	8.22	5.88	3.44	2	1.75	64.94
Total Growing Degee Days from March 1		0	0	259	286	365	608	717	637	444	199	94	33	3642
Gross Pond Evap	Inch	1.97	1.98	5.04	5.46	6.37	8.4	7.44	6.9	4.94	2.89	1.68	1.47	54.54
Net Pond Evap	Inch	1.83	1.54	5.01	5.05	5.37	8.27	5.38	6.78	4.13	2.3	1.44	1.37	48.47
Longmont West	Avg. Temp ° F	37.89	31.44	51.42	55.95	61.44	75.83	77.23	73.09	64.16	47.73	40.38	30.32	53.91
Ref date as of 12/31/2012	Total Precip "	0.13	0.39	0	0.65	1.44	0.11	1.63	0.15	1.32	0.73	0.33	0.13	7.01
Site Type: Turf	Total Alfalfa ETr "	2.41	2.27	5.58	6.33	6.86	8.84	8.07	7.16	5.15	3.08	1.94	1.7	59.39
Total Growing Degee Days from March 1		0	0	276	308	395	645	751	652	447	215	122	41	3852
Gross Pond Evap	Inch	2.02	1.91	4.69	5.32	5.76	7.43	6.78	6.01	4.33	2.59	1.63	1.43	49.9
Net Pond Evap	Inch	1.93	1.63	4.69	4.86	4.75	7.35	5.64	5.91	3.4	2.08	1.4	1.34	44.98
Fort Lupton	Avg. Temp ° F	37.02	30.6	51.04	55.43	61.44	75.64	76.5	73.1	64.87	47.86	40.27	29.98	53.65
Ref date as of 12/31/2012	Total Precip "	0.22	0.62	0.18	0.93	1.27	0.41	1.15	0.19	1.58	1.36	0.62	0.23	8.76
Site Type: Turf	Total Alfalfa ETr "	2.91	2.58	6.86	7.39	8.64	11.6	10.22	9.16	6.33	3.84	2.47	2.06	74.06
Total Growing Degee Days from March 1		0	0	295	329	412	637	732	651	471	231	125	50	3933
Gross Pond Evap	Inch	2.44	2.17	5.76	6.21	7.26	9.74	8.58	7.69	5.32	3.23	2.07	1.73	62.2
Net Pond Evap	Inch	2.29	1.73	5.64	5.56	6.37	9.46	7.78	7.56	4.21	2.27	1.64	1.57	56.08
Boulder NW	Avg. Temp ° F	37.65	29.64	50.39	53.79	60.03	74.83	75.52	73.33	64.89	49.14	44.06	32.86	53.84
Ref date as of 12/31/2012	Total Precip "	0.17	0.9	0.01	1.2	1.64	0.63	3.28	0.24	2.33	1.02	0.24	0.26	11.92
Site Type: Turf	Total Alfalfa ETr "	3.02	2.28	5.99	6.28	7.09	8.53	8	7.62	5.53	3.55	2.65	2.06	62.6
Total Growing Degee Days from March 1		0	0	273	293	393	633	718	655	468	224	146	51	3854
Gross Pond Evap	Inch	2.54	1.92	5.03	5.28	5.96	7.17	6.72	6.4	4.65	2.98	2.23	1.73	52.61
Net Pond Evap	Inch	2.42	1.29	5.02	4.44	4.81	6.72	4.42	6.23	3.01	2.27	2.06	1.55	44.24
Boulder East	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 5/2/2010	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 Flatiron	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 5/2/2010	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 SW	Avg. Temp ° F	40.24	31.02	51.87	54.59	59.64	74.08	74.75	72.96	65.1	49.83	46.06	34.28	54.54
Ref date as of 12/31/2012	Total Precip "	0.15	0.79	0	1.31	1.63	0.42	3.96	0.27	2.24	1.13	0.1	0.18	12.18
Site Type: Turf	Total Alfalfa ETr "	3.62	2.47	6.34	6.71	7.29	9.64	8.4	7.83	5.83	3.74	3.02	2.29	67.18
Total Growing Degee Days from March 1		0	0	238	266	348	565	700	622	435	203	133	44	3554
Gross Pond Evap	Inch	3.04	2.07	5.33	5.64	6.12	8.1	7.06	6.58	4.9	3.14	2.54	1.92	56.44
Net Pond Evap	Inch	2.94	1.52	5.33	4.72	4.98	7.8	4.28	6.39	3.33	2.35	2.47	1.8	47.91
Greeley04	Avg. Temp ° F	30.55	29.19	46.43	53.33	59.38	73.17	74.55	70.43	62.28	45.79	35.94	25.94	50.58
Ref date as of 12/31/2012	Total Precip "	0.01	0.42	0.02	0.91	1.11	0.76	1.64	0.29	1.03	1	0.18	0.06	7.43
Site Type: Fully irrigated	Total Alfalfa ETr "	2.98	2.92	7.24	8.07	9.1	11.52	9.74	8.3	6.23	4.2	2.27	2.33	74.9
Total Growing Degee Days from March 1		0	0	282	300	391	592	687	597	456	221	97	31	3654
Gross Pond Evap	Inch	2.5	2.45	6.08	6.78	7.64	9.68	8.18	6.97	5.23	3.53	1.91	1.96	62.91
Net Pond Evap	Inch	2.5	2.16	6.07	6.14	6.87	9.14	7.03	6.77	4.51	2.83	1.78	1.92	57.72