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9' <br /> Page IX-A8-3: fourth paragraph, last sentence, change <br /> "Conservations" to "Conservation" . <br /> Page IX-A8-4: second paragraph, delete "the" . <br /> Page IX-A8-7: lines 3 and 4, change "Velocity of" to "Peak rate of <br /> runoff for" . <br /> Page IX-A8-8: Substitute the following italicized paragraphs for <br /> the first two steps under "PROCEDURE. " <br /> Sten I: Estimate Velocity at the Outlet and Q10/Qfull' <br /> Using Figure 1, enter the slope of the pipe at the bottom and <br /> follow that slope up until it intersects the line for the <br /> diameter (D) of that pipe. From that intersection, read <br /> horizontally to the left scale and find the potential Qfull <br /> for that pipe on that slope. From the first intersection, <br /> find the Vfull for the pipe from the scale at a right angle <br /> to the line for the pipe size; read Vfull from the scale at <br /> the bottom of the slanted lines. <br /> Compute Q10/Qiull, proportion of value for full flow. Use the <br /> calculation of Q10 (the peak rate after development) and <br /> divide by the value of Qfull determined from Figure 1: Flow <br /> for circular pipe flowing full. <br /> Step 2: Estimate Depth of Flow, V10/Vfull, <br /> and Tailwater <br /> Conditions. <br /> Use the value of Q10/Qfull; enter it on the scale "Proportion <br /> of Value for Full Flow" of Figure 2, and go vertically to the solid <br /> line marked "FLOW. " From this intersection, move horizontally to <br /> the left to determine the value of d/D from the depth of flow <br /> scale. From the first intersection with the line "FLOW", move to <br /> the right until intersecting the solid line marked "VELOCITY, " and <br /> move down to the bottom scale to find the value of V10/Vfull. <br /> Calculate the actual depth of discharge, d. Using the value <br /> of d/D determined from Figure 2, enter D, the known diameter <br /> of the pipe, and calculate the actual depth of flow, d, for <br /> the Q10 in the pipe. <br /> Calculate the velocity of discharge for the 10-year storm, <br /> V10. Using the value of V10/Vfull determined from Figure 2, <br /> enter Vfull from Step 1, and calculate V10. If V10 exceeds <br /> the permissible velocity for the receiving channel (determined from <br /> Figure 9), outlet protection or other measures are needed to <br /> prevent erosion. Proceed with apron design or take steps to reduce <br /> V10, such as reducing the me slope or implementing stormwater <br /> management techniques. <br /> Determine tailwater conditions. If the depth of discharge <br />