Laserfiche WebLink
Maintenance Standards <br />Replace riprap as needed. <br />BMP C203: Water Bars <br />Purpose <br />A water bar is a small ditch or ridge of material that is constructed diagonally across a road or right- <br />of-way to divert stormwater runoff from the road surface, wheel tracks, or a shallow road ditch. See <br />Fiaure II-3.12: Water Bar. <br />Conditions of Use <br />Clearing right-of-way and construction of access for power lines, pipelines, and other similar install- <br />ations often require long narrow right-of-ways over sloping terrain. Disturbance and compaction pro- <br />motes gully formation in these cleared strips by increasing the volume and velocity of runoff. Gully <br />formation may be especially severe in tire tracks and ruts. To prevent gullying, runoff can often be <br />diverted across the width of the right-of-way to undisturbed areas by using small predesigned diver- <br />sions. <br />Give special consideration to each individual outlet area, as well as to the cumulative effect of added <br />diversions. Use gravel to stabilize the diversion where significant vehicular traffic is anticipated. <br />Design and Installation Specifications <br />. Height: 8-inch minimum, measured from the channel bottom to the ridge top. <br />. Side slope of channel: 2H A V maximum; 3H A V or flatter when vehicles will cross. <br />. Top width of ridge: 6-inch minimum. <br />Locate water bars to use natural drainage systems and to discharge into well vegetated stable <br />areas. <br />- See Table II-3.9: Water Bar Spacinq Guidelines: <br />Table II-3.9: Water Bar Spacing <br />Guidelines <br />Slope Along Road (%) <br />Spacing (ft) <br />< 5 <br />125 <br />5-10 <br />100 <br />10 - 20 <br />75 <br />20 - 35 <br />50 <br />> 35 <br />Use rock lined ditch <br />2019 Stormwater Management Manual for Western Washington <br />Volume 11 - Chapter 3 - Page 338 <br />