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• EDNA MINE--1992 EROSION INVENTORY REPORT Stakes were driven on each end of the cross-sections and a stadia rod placed on top of them to take depth measurements at 1-foot intervals horizontally along the rod. Depths were measured to the nearest 0.5 inches. The cross-sectional areas and profiles of the feature at the 5 permanent locations are depicted in Figure 1. Descriptions of the concentrated flow channel at each location are as follows: Cross-section 1-In the immediate vicinity of this cross-section vegetation is establishing on both of the sides and in the bottom of the channel. The average size of rock cobble in the bottom of the channel is approximately 1 by 2 inches; the channel appears to be adequately armored. The banks of the channel slope away from the bottom between lv:l.lh and 1v:1.8h. The channel appears to be adequately stable, with no visible signs of excessive ongoing erosion. The potential for excessive future erosion also appears minimal. Cross-section 2-In the immediate vicinity of this cross-section vegetation is establishing on both of the sides and in the bottom of the channel. The average size of rock cobble in the bottom of the channel is approximately 1 by 1 inches; the channel appears to be adequately armored. The banks of the channel slope away from the bottom between 1v:2.4h and 1v:6.Oh. The channel appears to be adequately stable, with no visible signs of excessive ongoing erosion. The potential for excessive future erosion also appears minimal. • Cross-section 3-In the immediate vicinity of this cross-section vegetation is establishing on both sides of the channel; vegetation is absent in the bottom of the channel. The average size of rock cobble in the bottom of the channel is approximately 2 by 3 inches; the channel appears to be adequately armored. The banks of the channel slope away from the bottom between 1v:2.7h and 1v:8.Oh. The channel appears to be adequately stable, with no visible signs of excessive ongoing erosion. The potential for excessive future erosion also appears minimal. A short distance below this cross-section the banks of the channel become noticeably steeper. The increased gradient existing between Cross-sections 3 and 4 has resulted in higher flow velocities through this section, which appears to have contributed to the formation of a narrower, deeper, steep-sided channel armored with the larger sized rock. Cross-section 4-This cross-section is at the edge of the bonded area and is located immediately above the point where the runoff through this feature drops off into the closed basin formed by the previous slide. Two discrete channels exist at this location which appear to conduct concentrated flow. A third channel is located to the southwest which no longer appears to conduct runoff. These channels are relatively discrete and are not significantly braided. In the immediate vicinity of this cross-section vegetation is establishing in the bottom of the channel; the sides are not vegetated. The average size of rock WRE May 28, 1992