3214 BROADWAY BROADWAY KINECT APARTMENTS 2021-08-11

• • • CITY OF EVERETT STORMWATER MANAGEMENT MANUAL • • 5. Stone for riprap shall consist of field stone or quarry stone of approximately rectangular shape. The stone shall be hard and angular and of such quality that it will not disintegrate on exposure to • water or weathering and it shall be suitable in all respects for the purpose intended. • 6. Rubble concrete may be used provided it has a density of at least 150 pounds per cubic foot,and • otherwise meets the requirement of this standard and specification. • 7. A lining of engineering filter fabric(geotextile) shall be placed between the riprap and the • underlying soil surface to prevent soil movement into or through the riprap. The geotextile should be keyed in at the top of the bank. • 8. Filter fabric shall not be used on slopes greater than 1.5:1 as slippage may occur. It should be • used in conjunction with a layer of coarse aggregate (granular filter blanket)when the riprap to be • placed is 12 inches and larger. • 3.3.4 BMP C203: Water Bars • Purpose • A small ditch or ridge of material is constructed diagonally across a road or right-of-way to divert • stormwater runoff from the road surface,wheel tracks,or a shallow road ditch. • Conditions of Use • Clearing right-of-way and construction of access for power lines,pipelines, and other similar installations • often require long narrow right-of-ways over sloping terrain. Disturbance and compaction promotes gully • formation in these cleared strips by increasing the volume and velocity of runoff. Gully formation may be especially severe in tire tracks and ruts. To prevent gullying, runoff can often be diverted across the • width of the right-of-way to undisturbed areas by using small predesigned diversions. • Special consideration shall be given to each individual outlet area,as well as to the cumulative effect of • added diversions. Use gravel to stabilize the diversion where significant vehicular traffic is anticipated. • Design and Installation Specifications • 1. Height: 8-inch minimum measured from the channel bottom to the ridge top. • 2. Side slope of channel: 2:1 maximum; 3:1 or flatter when vehicles will cross. • 3. Base width of ridge: 6-inch minimum. • 4. Locate them to use natural drainage systems and to discharge into well vegetated stable areas. • 5. Grade of water bar and angle: Select angle that results in ditch slope less than 2 percent. • 6. Install as soon as the clearing and grading is complete. Reconstruct when construction is • complete on a section when utilities are being installed. • 7. Compact the ridge when installed. Stabilize, seed and mulch the portions that are not subject to • traffic. Gravel the areas crossed by vehicles. • • • • • • • • Volume ll— Construction Stormwater Pollution Prevention 3-40 • •