Drainage Design Manual - the City of San Luis Obispo

10.3.1 Gravel Construction Entrance• A gravel construction entrance is required (Figure 10-1). If there is more than onevehicle access point, a gravel construction entrance shall be required at each entrance.The responsibility for design and performance of the driveway remains with thepermittee.• Vehicles or equipment shall not enter a property adjacent to a stream, watercourse, orstorm and surface water facility, or wetlands unless adequate measures are installed toprevent physical erosion into the water or wetland.10.3.2 Catch Basin Protection• A filter system shall be used (Figure 10-2) on catch basins (drop inlets) in publicstreets as a means of sediment control. The installation shall conform to the standarddetails in the cited references.10.3.3 Sediment Filters/Barriers• For projects constructed during the period of October 15 through April 15, a silt fenceor straw wattle dike shall be installed along the downslope edge of the disturbed area,prior to the commencement of grading. The sediment retention structure will belocated so that all runoff from the construction site is contained. Sediment retentionstructures are to be inspected regularly and sediment removed when the depth ofsediment is one half the height of the structure. Silt fences and straw wattles shall beinstalled according to the standard references cited.• Straw wattles (Figure 10-3) can be used as dikes to stabilize temporary channelflowlines or as a perimeter filter barrier. Straw wattles must be installed in a trench,staked and backfilled if they are to be effective in reducing flow velocity and filteringsediment from runoff. Straw wattles can also be placed around stormdrain drop inletsand at back of curb to trap sediment.• Straw wattles should not remain in place more than 12 months after installationunless it can be determining significant deterioration has not occurred. When used asa perimeter filter, sediment should be removed when material is within 76 mm (3 in)of the top of any wattle.2. Note: The Standard Erosion Control Drawings were provided by and used with the permission by Salix Applied Earthcare, aNatural Resource Consulting firm in Redding, California. The drawings are available in CAD format in “Erosion Draw”.Neither the City of County of San Luis Obispo specifically requires use of, or endorses Erosion Draw, and authors of ErosionControl Plans may use other, similar drawings and platforms that achieve the same results.SLO Creek Drainage Design Manual 113 February 2003