1995-08-28_PERMIT FILE - M1995035 (4)

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3034526611 TU~LE RPPLEGRTE INC 172 P04 RUG 28 '95 12:51 • Mr. Gregg Squire Division of Minerals and Geology August 25, 1995 Page 3 4. C. Rater Information The culvert under County Road #36 is.24 inches in diametrr. The following is a summary of the expected maximum flows through this culvert. 1) Connell expects to pump at a+++AYi~*+um rate 600 gpm, when the *r+'++' ~ first intercepu the groundwater table. They expect an avetape pumping rate of 250 gpm. 2) The water pumped from Western Mobile's operation flows down the irrigation ditch on the east side of the Wellington Downs property. The 'irrigation ditch Ts in an east- wes[ direction on the south end of the property. The eastbound irrigation ditch drains into a 24 inch culvert under I-25. The westbound irrigation ditch connects with the culvert under County Road 36. Since Western Mobile has been dewateting at their mining operation for some time, we will assume they are pumping the same avera¢e sate as Connell (250 gpm). In addition, we will assume there is no loss due to infiltration, but half of the flow is diverted to the east irrigation ditch. Thus, these would be an additional 125 gpm of flow into the County Road 36 culvert. 3) At the most there will be around 80 acres of land available for irrigation. The amount of available farming land will shrink as mining progresses. Assuming the following: a) total depth of irrigation for the season (150 growing days) is three feet, half (1.5 fcet) of this will be lost due to plant consumption and one foot of water would be lost to infiltration. So, one half foot of irrigation water would drain from the 80 acre irrigation site over the period of the 150 day growing season. Converting this into gpm yields 60 gpm. SUMMARY OF MAXIMUM FLOW IN CULVERT Culvert Flow Contributions Gallons Per Minute (GPM) 1) Wellington Downs Pit 600 2) Western Mobile Pit 125 3) Irrigation 60 TOTAL: 785