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-33- more significant effect on water quality in the Foidel Creek stream/alluvial aquifer system. The discharge of water from the spoils aquifer to the surface water system could be avoided. Other sources of ground water are available, or following its use, the spoil water could be returned to the spoils aquifer. Therefore, the following stipulation is required to minimize water quality degradation in the receiving stream system: Stipulation No. 2 WITHIN 30 DAYS OF THE PERMIT ISSUANCE, THE APPLICANT SHALL SUBMIT TO THE DIVISION FOR REVIEW A PLAN TO DISCONTINUE THE DISCHARGE OF ANY WATER FROM THE SPOILS AQUIFER TO THE SURFACE WATER/ALLUVIAL AQUIFER SYSTEM. THE PLAN SHALL BE PUT INTO EFFECT WITHIN 45 DAYS OF APPROVAL BY THE DIVISION. Streamflow data indicate that Foidel Creek is an intermittent stream which flows in response to snowmelt and heavy rainfall, with the water table below the streambed for most parts of the year. By discharging effluent at times when the stream is normally dry, the regime will revert to perennial flow, with a base flow rate dependent on the rate of pumpage from the underground mine. In the fifth year of mining, discharge from the underground mine is estimated to be 650 gallons per minute (1.5 cfs). Changing an intermittent stream into a perennial stream could potentially alter the geomorphic equilibrium of the receiving stream and cause the stream to downcut. The applicant reports that the headwaters and upper reaches of Foidel Creek in Eckman Park display an armored streambed. In the middle reaches, stream gradients are reduced, and three narrow floodplains have developed. The uppermost area is shown on Map 9a, Foidel Creek Mine Baseline Hydrology. (Mine water and water from the wash-bay spoils well would be discharged to this area.) The floodplain of this upper area is truncated by bedrock outcrops as Foidel Creek passes through a watergap in TSN, R86W, Section 28. These bedrock outcrops probably control the local base level of the stream. Downstream from the watergap, a second floodplain has developed (shown on Map 17b, Foidel Creek Mine- Foidel Creek Floodplain (Second Area)). The stream then flows through a shallow canyon, where resistant sandstone outcrops have prevented lateral migration of the stream. A third floodplain area is found on Foidel Creek just upstream of the confluence with Middle Creek. The applicant has indicated that the stream channel in the floodplain areas is already naturally incised as a result of recent downcutting. In addition, the amount of water expected to be discharged on a continuous basis to the channel would be relatively small. At amine discharge rate of 650 gpm and awash-bay, spoils well discharge of 100 gpm, the base flow in the stream would only be 750 gpm (1.67 cfs). In fact, this discharge would be further reduced by infiltration through the streambed into the alluvial aquifer system. Therefore, because of the relatively low discharges involved and the periodic bedrock control of the stream, mine water discharge is not expected to cause significant downcutting along Foidel Creek.