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NOTE: THIS IS A REPRODUCTION OF TABLE 2 -1 OF METCALFE & EDDY, <br />AND ALSO THE HANDBOOK OF HYDRAULICS, PAGE 7 -22. <br />Surface <br />Best <br />Good <br />Fair <br />Bad <br />Uncoated cast -iron pipe <br />0.012 <br />0.013 <br />0.014 <br />0.015 <br />Coated cast -iron pipe <br />0.011 <br />0.012" <br />0.013' <br />Commercial wrought -iron pipe, black <br />0.012 <br />0.013 <br />0.014 <br />0.015 <br />Commercial wrought -iron pipe, galvanized <br />0.013 <br />0.014 <br />0.015 <br />0.017 <br />Smooth brass and glass pipe <br />0.009 <br />0.010 <br />0.011 <br />0.013 <br />Smooth lockbar and welded "OD" pipe <br />0.010 <br />0.011" <br />0.013" <br />Riveted and spiral steel pipe <br />0.013 <br />0.015" <br />0.017" <br />Vitrified sewer pipe <br />S 0.0101 <br />1 0.011 S <br />0.013" <br />0.015 <br />0.017 <br />Common clay drainage the <br />0.011 <br />0.012" <br />0.014' <br />0.017 <br />Glazed brickwork <br />0.011 <br />0.012 <br />0.013" <br />0.015 <br />Brick in cement mortar: brick sewers <br />0.012 <br />0.013 <br />0.015" <br />0.017 <br />Neat cement surfaces <br />0.010 <br />0.011 <br />0.012 <br />0.013 <br />Cement mortar surfaces <br />0.011 <br />0.012 <br />0.013" <br />0.015 <br />Concrete pipe <br />0.012 <br />0.013 <br />0.015" <br />0.016 <br />Wood stave pipe <br />0.010 <br />0.011 <br />0.012 <br />0.013 <br />Plank flumes <br />Planed <br />0.010 <br />0.012" <br />0.013 <br />0.014 <br />Unplaned <br />0.011, <br />0.013' <br />0.014 <br />0.015 <br />With battens <br />0.012 <br />0.015" <br />0.016 <br />Concrete -lined channels <br />0.012 <br />0.014" <br />0.016' <br />0.018 <br />Cement - rubble surface <br />0.017 <br />0.020 <br />0.025 <br />0.030 <br />Drv- rubble surface <br />0.025 <br />0.030 <br />0.033 <br />0.035 <br />Dressed-ashlar surface <br />0.013 <br />0.014 <br />0.015 <br />0.017 <br />Semicircular metal flumes, smooth <br />0.011 <br />0.012 <br />0.013 <br />0.015 <br />Semicircular metal flumes, corrugated <br />0.0225 <br />0.025 <br />0.0275 <br />0.030 <br />Canals and ditches <br />Earth, straight and uniform <br />0.017 <br />0.020 <br />0.0225' <br />0.025 <br />Rock cuts. smooth and uniform <br />0.025 <br />0.030 <br />0.033' <br />0.035 <br />Rock cuts, jagged and irregular <br />0.035 <br />0.040 <br />0.045 <br />Winding sluggish canals <br />0.0225 <br />0.025" <br />0.0275 <br />0.030 <br />Dredged -earth channels <br />0.025 <br />0.0275" <br />0.030 <br />0.033 <br />Canals with rough stony beds, weeds on <br />earth banks <br />0.025 <br />0.030 <br />0.035' <br />0.040 <br />Earth bottom. rubble sides <br />0.028 <br />0.030' <br />0.033" <br />0.035 <br />Natural - stream channels <br />1. Clean, straight bank, full stage, no rifts or <br />deep pools <br />0.025 <br />0.0275 <br />0.030 <br />0.033 <br />'_. Same as (1). but some weeds and stones <br />0.030 <br />0.033 <br />0.035 <br />0.040 <br />3. Winding, some pools and shoals, clean <br />0.033 <br />0.035 <br />0.040 <br />0.045 <br />4. Same as (3). lower stages, more ineffective <br />slope and sections <br />0.040 <br />0.045 <br />0.050 <br />0.055 <br />5. Same as 131, some weeds and stones <br />0.035 <br />0.040 <br />0.045 <br />0.050 <br />6. Same as (4). stony sections <br />0.045 <br />0.050 <br />___ <br />0.060 <br />7. Sluggish river reaches, rather weedy or <br />with very deep pools <br />0.050 <br />0.060 <br />0.070 <br />0.090 <br />8. Very weedy reaches <br />0.075 <br />0.100 <br />0.125 <br />0.150 <br />"Values commonly used in designing. <br />TYPICAL MANNING BASE "n" VALUES <br />TABLE 7- W <br />DEC 1994 <br />F -5 <br />