2017-03-23_HYDROLOGY - M2008080 - Laserfiche WebLink

Home Browse Search

Journey Ventures Pit SWSP Page 3 of 6 March 21, 2017 Dewatering Dewatering began in October 2015 and is expected to continue up to the completion of the repair of the slurry wall, estimated to be March 2017. Dewatering water that is pumped to the silt pond and the recharge pond will be assumed to return to the stream in the same timing as the dewatering depletions. Dewatering is projected to occur at a rate of 1,000 gpm (135 acre -feet per month), with a total capacity of 4,000 gpm (540 acre-feet) from the dewatering sump to the silt pond and recharge pond. The configuration of the recharge pond within the pit is shown in attached Map 3. Dewatering operations must be measured by totalizing flow meters that can accurately show the monthly volume of water dewatered into the silt pond and the recharge. Any dewatering water placed into silt pond and recharge pond cannot be used for any purpose by the operator, and must be allowed to accrete to the stream. Should it be determined by the water commissioner or division engineer that water within the silt pond and the recharge pond is being diverted for any purpose by the operator and accounting is not adequate to show the recharge of dewatering is occurring the Applicant will need to account for any lagged dewatering depletions at the site once dewatering stopped. Replacements The operator proposes to provide replacement for this pit using fully consumable water leased from the City of Greeley (“Greeley”). A copy of the lease agreement with Greeley for 39.74 acre-feet for the period of April 1, 2017 through March 31, 2018 of fully consumable effluent from Greeley’s wastewater treatment plant was provided to this office with the SWSP request and is attached to this letter. The leased water includes additional water to cover transit looses. Transit losses were estimated at 0.25 percent per mile for six miles from the Greeley’s WWTP to the Journey Venture Pit. Ideally the transit loss should be based on 0.25 percent per mile for five miles from the Greeley’s WWTP to the confluence of the South Platte and Cache La Poudre rivers and 0.25 percent per mile during the non-irrigation season and 0.50 percent per mile during the irrigation season along the South Platte for 1 mile from the confluence to the Journey Venture Pit. Due to the small variation in the transit loss numbers for the irrigation and non-irrigation season, the estimated transit loss of 0.59 acre-feet is accepted in this SWSP. The point of delivery for the Greeley lease replacement water is the Greeley Wastewater Treatment Plant (“WWTP”) outfall. However the point of delivery for the Greeley lease water may also be one or more of the following locations:  Cache La Poudre River immediately below Greeley’s existing WWTP, at the outlet of the Flatiron Reservoir Nos. 1-5 (aka Poudre Ponds at Greeley), or at delivery stations from the Greeley Canal No. 3  In Lonetree Creek, a tributary to the South Plate River, immediately below the Swift WWTP outfall  In the Big Thompson River at delivery stations or release structures from Greeley Loveland Canal and related structures  Other points to the Cache La Poudre or Big Thompson River at delivery stations or release structures owned and operated by Greeley or available for Greeley’s use where Greeley had augmentation water legally and physically available. Greeley must notify the District 3 Water Commissioner when releases are made at locations other than the WWTP. The Ogilvy Ditch headgate on the Cache La Poudre River is a potential