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• protection as listed species. <br />H. Cultural Resources <br />The area was not inventoried for cultural resources because no disturbance is proposed, the <br />elevation of the area, the steep slopes and vegetative cover. <br />Water Resources <br />Surface Water <br />The entire permit area is within the North Fork of the Gunnison River (North Fork) drainage, which <br />is part of the Colorado River system. The North Fork watershed, above the lease area, is <br />approximately 531 square miles, having a mean basin elevation of 8,900 feet. About two thirds of <br />the watershed is forest land and one third rangeland. The flow of the North Fork varies seasonally <br />IFigure 1), with high flows occurring during spring from snowmelt. After snowmelt, flows begin to <br />recede, reaching their low during winter. The 100-year flood event produces a flow rate of about <br />7,920 cubic feet per second IFigure 21. <br />East Roatcap Creek, an intermittent creek, drains in a southerly direction from the proposed lease <br />area into the North Fork. It is dry by late summer because discharge from the alluvium is limited. <br />The drainage area of East Roatcap Creek is about 4 miles square and the headwaters is located on <br />the proposed lease tract. Flow results from spring snowmelt and high intensity rainfall events, <br />which commonly occur in late summer and water from Overland Ditch. It has been postulated that <br />tha drainage pattern coincides with joint systems in the underlying rock. These joint systems <br />possibly provide hydraulic connection between surface and subsurface flow systems associated <br />with the Mesa Verde formation. <br />Water quality data (inorganic constituents and suspended sediment concentrations) for the North <br />Fork indicates that generally, water quality is good. The water is an alkaline, soft, calcium- <br />bicarbonate-sulfate type with total dissolved solids concentration averaging around 100 mg/I. The <br />water is cold, with winter temperatures near freezing and summer temperatures in the 18-20 <br />degree C range. Suspended solids concentration averages near 50 mg/I with maximum <br />concentrations occurring during snowmelt, in the range of 200-250 mgA. Both dissolved metals <br />and nutrient concentrations are generally low throughout the year. <br />Ground Water <br />The Mesaverde Formation is the primary hydrogeologic unit within the proposed lease area. <br />Ground water may be transmitted down dip and northward within the Meaaverde Formation and <br />discharge somewhere north of the Grand Mesa, or it may discharge somewhere down the North <br />Fork Gunnison River valley. Any discharge would be small and likely subject to evapotranspiration. <br />Essentially all ground water in the Mesaverde Formation is associated with secondary porosity <br />(fracturing or natural bedding planed. which usually occurs in anon-continuous fashion. Possible <br />hydraulic connection to surface water also occurs along joint systems in the Mesaverde Formation <br />that coincide with the overlying ephemeral gulches. Recharge to the Mesaverde Formation from <br />these joints would be mainly during the snowmelt season. Generally, water yields of the <br />Mesaverde Formation are less than 10 gpm. In areas where secondary porosity is high, water <br />yields can be much greater. Water quality in the Mesaverde Formation is an alkaline sodium- <br />• bicarbonate type, with Total Dissolved Solids concentration ranging from several hundred to several <br />thousand mg/I. <br />Unconsolidated quaternary deposits can transmit a significant quantity of water. The more <br />Page 8 <br />