2015-05-12_HYDROLOGY - M2003091 - Laserfiche WebLink

Home Browse Search

Mr. David Heintz Page 4 of 10 Duckworth SWSP May 6, 2015 based on the pro -rata delivery of MMM's two shares of the Rural Ditch water and/or, excess augmentation credits available from MMM's South Platte Combined SWSP. Rural Ditch (WDID 0600551) Shares MMM owns two shares in the Rural Ditch that were historically used on the Heaton property for irrigation. The Heaton property is north of the Duckworth pit and is the current site of Heaton Reservoir (WDID 0504089). These shares were previously apart of Case No. 2001CW194 to be changed from irrigation to augmentation and other uses associated with Lafarge's (MMM's predecessor) sand and gravel operations. This case was dismissed without prejudice on April 5, 2011 before going to trial at the request of Lafarge because the credit sought would not adequately meet the needs of Lafarge's operation and new mining properties along the lower St. Vrain or the South Platte River, which could use the consumptive use credit, had not been identified. An engineering report was completed for Case no. 2001CW194 and presents the historical consumptive use analysis for these two shares. This report is the basis for the historical consumptive use ("HCU") analysis for this SWSP. As requested by the previous SWSP the Applicant provided information on the assumptions used the HCU analysis, as described below. The Applicant owns 2 shares of 50 shares of the Rural Ditch, or four percent. The Rural Ditch water right was decreed in CAI 336 for the following appropriations: • May 10, 1862, 22.75 cfs • March 10, 1863, 175.54 cfs" "115.29 cfs of the 175.54 cfs was abandoned by decree in case no. 84CW412. The applicant's shares equate to an ownership interest of 0.91 cfs in the senior priority and 2.41 cfs in the junior priority. The Heaton propertx is located in the N1 /2 of the NEI /4 of Section 9, Township 2 North, Range 68 West of the 6` P.M. According to the engineering report, the HCU analysis was performed using the modified Blaney-Criddle method. The HCU analysis was conducted for the period 1911-1998. The Longmont 2ESE climate station was used in the analysis. The Applicant noted that irrigation continued through 1999, when the mining operation took the land out of agricultural production. The two Rural Ditch shares were continued to be used at the Heaton property Batch Plant (Del Camino Batch Plan) under approved SWSP's from approximately 2003 through 2008 and in this SWSP thereafter. Rural Ditch diversion records were obtained from the State Engineer's Office ("SEtO") for the period of 1911 through 1949 and from the Colorado Decision Support System ("CDSS") database for the period of 1950 through 1998. Records for the years 1934-1936 were not available, so the monthly averages for the remaining study period were used in the HCU analysis in these three years. According to the engineering report the average annual ditch diversions attributable to MMM's two shares is 204.2 acre-feet per year. An assumed 20% ditch loss assessed on the diversions provides an average annual farm headgate delivery of 163.4 acre-feet per year. Aerial photography taken in 1953, 1975, 1980 and 1998 were reviewed to confirm the historic use on the property. Based on the review of the above aerial photography the following irrigated acreages were used in the HCU analysis: 68.9 acres from 1911 to 1961, 52 acres from 1962 to 1969 and 47 acres from 1970 to 1998. Based on conversation with Mr. Adams the ditch company president, the crop distribution was assumed to be 50 percent silage corn and 50 percent alfalfa and that the ditch diversions have been used to flood irrigate the property. A maximum irrigation efficiency of 65 percent was estimated in the HCU analysis. According to