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ME <br />Streamflow records from a gage on the Lake Fork below Mill Gulch indicate peak <br />flows reached 1, 380 cfs and 1, 530 cfs for the 1984 and 1985 water year, <br />respectively- Unfortunately, the period of record for the gage station <br />extends only from 1981 and was discontinued September 1986. The predicted <br />100 -year flood far exceeds any recorded maximum flow on the Lake Fork. <br />A P: M ti ft <br />It is apparent that natural floods in excess of 45% of the predicted 100 -year <br />flood would substantially exceed the capacity of the existing outflow <br />channel. Furthermore, large velocities which accompany these flows would <br />cause erosion and scour along the banks and bottom of the outflow channel in <br />its current condition. <br />various alternatives are envisioned that would gaurd against channel <br />degradation for the same level of flood protection the existing outflow <br />channel currently provides. Alternatives could range from a regular <br />maintenance program of replacing riprap to construction of a concrete cutoff <br />with wing walls. Placement of additional riprap on the abutments at the <br />entrance, channel banks, and the bottom extending downstream past the bridge <br />may be the least expensive alternative. A concrete cutoff to replace the <br />existing timber and rock erosion bar would be more costly, but accordingly <br />would require less maintenance. <br />Whichever alternative is selected, the hydraulic capacity of the existing <br />channel should not be reduced. In addition, every effort should be made to <br />improve the hydraulics of the entrance to the channel from the lake. <br />