Laserfiche WebLink
Cross Gold Mine <br />December 2024 G-1 <br /> <br /> <br />Exhibit G Water Information <br />1. Surface Water Resources <br />Coon Track Creek bisects the proposed permit area. Associated with the drainage are some wetlands <br />on either side of Coon Track Creek. No site-specific stream flow data are available for Coon Track <br />Creek. <br />Wetlands on the Cross Mine property are primarily associated with Coon Track Creek, which is a <br />narrow and well-defined channel that flows through the length of the property and drains the entire <br />Cross Mine area watershed. Coon Track Creek is a tributary of Beaver Creek, which flows into Middle <br />Boulder Creek above Barker Reservoir. Coon Track Creek below the mine site due to both the <br />seasonal flows from up-stream basin drainage and from discharges the Cross and Caribou mines. <br />Flows in the creek are elevated in the spring and early summer during snowmelt runoff. The path of <br />Coon Track Creek can be seen on the Exhibit C maps. <br />Waters of the U.S., including associated wetlands, were surveyed within the proposed site boundary, <br />and plotted by a Professional Wetland Scientist for Walsh Environmental using a Trimble XT (hand-held <br />GPS unit with ESRI ARC Pad mobile mapping software) and total 1.94- acres (84,506 sq. ft.). This <br />wetland survey is shown on Exhibit C maps. A Jurisdictional Determination was approved by US Army <br />Corps of Engineer (US ACE) on February 7, 2008, and the approval letter is provided in Appendix M-1. <br />No wetlands will be disturbed by the proposed activities until appropriate approvals are obtained from <br />the US ACE. <br />Coon Track Creek is characterized by steep side slopes and a rocky channel bottom. In the upper and <br />mid-reaches of the creek, the presence of wetland habitat is nominal and only extends beyond the <br />banks in a few isolated, low-lying areas. Two manufactured, plastic lined ponds flank the north and <br />west sides of the mining complex. The pond fringes are devoid of vegetation but have been determined <br />to be jurisdictional by the U.S. Army Corps of Engineers as they are hydrologically connected to the <br />creek downstream through a series of PVC pipes. Below the mine structures, the creek meanders <br />along a narrow ravine before exiting the property through a Boulder County maintained culvert under <br />the Cross Mine access road. The wetland habitat associated with the downstream reaches is limited to <br />the riparian corridor and to a wet meadow area on the north bank that is situated just east of Pond 2 <br />and extends into the adjacent aspen woodland (Map C-1). <br />The primary source of hydrology for wetlands is provided by up-slope runoff and flows from the creek. <br />Flows from the Idaho Tunnel are directed into the water treatment system and then contribute to <br />wetland hydrology via eventual discharge in the lower half of the property. Secondary sources are <br />provided by naturally occurring side slope seeps, snowmelt and precipitation events. Surface water <br />flows in these lower wetlands will be maintained by the water treatment discharge during and after <br />mining.