2018-09-05_HYDROLOGY - M1996049 - Laserfiche WebLink

Home Browse Search

1.0 INTRODUCTION On behalf of Everist Materials, LLC (Everist), Resource Engineering, Inc. (RESOURCE) hereby submits this renewal request for the Substitute Water Supply Plan (SWSP) associated with Everist's aggregate operation in Maryland Creek Ranch (MCR), Summit County, Colorado. Everist's SWSP for MCR was originally approved by the Office of the State Engineer on April 3, 1997; the most recent renewal to the Plan was approved on June 24, 2015. This letter report was prepared to support the renewal request, following the General Guidelines for Substitute Water Supply Plans for Sand and Gravel Pits (Guidelines).' 2.0 PROJECT DESCRIPTION 2.1 PROJECT SITE The Colorado Division of Reclamation, Mining and Safety (DRMS) issued Permit No. M-1996-049 for the operation of Everist's gravel pits within MCR. Operations in MCR include aggregate mining, a crusher and wash plant,an asphalt plant, and a concrete batch plant.Aggregate mining in MCR began in the late 1990s; it is estimated that production of aggregate, concrete and asphalt will continue for an additional 10 to 15 years. MCR is located in Summit County, Colorado, on the west bank of the Blue River, approximately 6 miles downstream of Dillon Reservoir and 20 miles upstream of Green Mountain Reservoir. Aggregate mining operations in MCR take place at an elevation of approximately 8,550 feet, within a distance of 2,000 feet of the Blue River, in Sections 15 and 22, all in Township 4 South, Range 78 West of the 6th P.M. Figure A- 1, included in Attachment A, shows a location map of MCR. Climatic data for MCR was obtained from the Dillon 1 E and Green Mountain Dam weather stations records, available through the Western Regional Climate Center's web-site2. Annual average precipitation for MCR was estimated based upon isohyetal lines downloaded from the Colorado's Decision Support Systems web- site3. The isohyetal annual precipitation corresponding to MCR was then apportioned based on the distribution of monthly average precipitation at the Dillon 1 E station.As shown in Figure A-2, the isohyetal lines indicate that, on average, both MCR and the Dillon 1 E station would experience the same annual precipitation (16 inches). This is not surprising, since just 6 miles separate the 2 sites with an elevation difference of about 550 feet. Average monthly temperature data was obtained from Dillon 1 E records adjusted by difference in elevation between the station and MCR using monthly temperature lapse rates derived from the Dillon 1E and Green Mountain Dam weather stations data. Table 1, below, displays the ' General Guidelines for Substitute Water Supply Plans for Sand and Gravel Pits. State of Colorado, Office of the State Engineer. April 1, 2011. 2 http://www.wrcc.dri.edu/summary/Climsmco.htmi accessed 12/01/2016. 3 http://cdss.state.co.us/GIS/Pages/Division5Colorado.aspx accessed 12/01/2016. 1 iRESOURCE