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1993 Annual Hydrology Report September 2, 1994 Page 2 acres. Because this area was not mined, your statement is probably correct. However, a flow measurement should be taken in addition to pH and conductivity at the Lower Hubbard Creek sampling point so that an assessment can made of the quality. Quality measurements without quantity measurements are meaningless. 3. Units for conductivity have been included for upper and lower Hubbard Creek. 4. The graph for piezometer P-2 was included in the 1993 AHR. 5. The method used to convert the quantity of flow from the bench underdrains from gallons per minute (gpm) to acre feet appears to be appropriate. The Division was able to obtain the same value by taking the average flow from the 4th, 1st, 2nd, and 3rd quarter and converting to acre-feet. Section II• Recommendations: 1. Please include the total depth for each piezometer in subsequent AHRs. Observations: 1. Pond ~5 discharged approximately 0.22 acre-feet during March 1993. The discharge was within effluent limitations. This small volume of water most likely did not impact Hubbard Creek or the North Fork of the Gunnison River. The discharge consisted of surface run-off and discharge from the underdrains. Although the conductivity "Yncreased from upstream to downstream, the increase is probably due to other factors, in addition to the mine. The flow recorded for Hubbard Creek during water year 1993 is 3, l0, 3, and 2 gallons per minute (gpm) for first, second, third, and fourth quarter, respectively. Hubbard Creek, even during the winter, flows at a pretty good velocity; therefore, 2-10 gpm appears to be too low. Please recheck your measurements. The Division recommends that a flow meter be utilized to collect more accurate flow measurements in Hubbard Creek. 2. The middle drain discharged. It has not discharged since