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." It-; REPLY REFER TO United States Department of the Interior BUREAU OF LAND MANAGEMENT Colorado State Office 2850 Youngtield Street Lakewood. Colorado 80215-7093 www.co.blm.gov CO-932 7250 DEe 15 2J04 Mr. Dan Merriman Colorado Water Conservation Board 1313 Sherman Street, Room 721 Denver, Colorado 80203 Dear Mr. Merriman: The Bureau of Land Management (BLM) is writing this letter to formally communicate its instream flow recommendation for Minnie Gulch, located in Water Division 7. Location and Land Status - Minnie Gulch is tributary to the Animas River approximately six miles northeast of Silverton. The stream reach covered by the surveys conducted on BLM lands runs from the headwaters to the confluence with the Animas River. Of the 3.9 mile reach, approximately 84% is located on federal lands while the remaining 16% is privately owned. Biological Summary - Fishery surveys indicate that the creek supports a self-sustaining brook trout fishery. The stream environment is presently in good condition and provides suitable substrate, channel stability, water quality, and food supplies for salmonids. However, the stream is very steep and high velocity, so pools and other feeding/spawning locations are limited. Accordingly, it is important to provide stream flows that maintain the limited amount of physical habitat and that maintain water exchange in pools during low flow periods. R2Cross Analysis - BLM's data analysis, coordinated with the Division of Wildlife, indicates that the following flows are needed to protect the fishery and natural environment to a reasonable degree. A 0.7 cubic feet per second enlargement is recommended from May 1 to October 31. This recommendation was derived by averaging the results of three cross sections. The existing instream flow water right is 1.0 cubic feet per second year round, so the enlargement would increase the water right to 1.7 cubic feet per second from May 1 to October 31. This recommendation is driven by the average depth criteria. BLM was concerned that the existing 1.0 cfs instream now water right did not provide sufficient physical habitat during the warm weather months, and the R2Cross surveys verified this concern.