Orange County NC Website
Browse       Search
7 <br /> Wet Detention Basin <br /> Location: PIN 9864-39-4358 <br /> The wet detention basin system is defined as the wet detention basin,pre-treatment including forebays and the vegetated filter if one is <br /> provided. <br /> These systems do not incorporate vegetated filters at the outlets. <br /> These systems do not incorporate pre-treatment other than a forebays. <br /> Important maintenance procedures: <br /> • Immediately after the wet detention basin is established,the plants on the vegetated shelf and perimeter of the basin shall be <br /> watered twice weekly if needed,until the plants become established(commonly 6 weeks). <br /> • No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the <br /> plants on the vegetated shelf. <br /> • Stable groundcover shall be maintained in the drainage area to reduce the sediment load to the wet detention basin. <br /> • If the basin must be drained for an emergency or to perform maintenance,the flushing of sediment through the emergency <br /> drain shall be minimized to the maximum extent practical. <br /> • Once a year,a dam safety expert shall inspect the embankment. <br /> After the wet detention pond is established,it shall be inspected once a month and within 24 hours after every storm event greater <br /> than 1.0 inches.Records of operation and maintenance shall be kept in a known set location on the project site and shall be made <br /> available upon request. <br /> Inspection activities shall be performed as follows.Any problems that are found shall be repaired immediately. <br /> SCM Element: Potential Problem: How Property Owner Will Remediate the <br /> Problem: <br /> The Entire SCM Trash/Debris is present. Remove the trash/debris <br /> The Perimeter of the Wet Areas of bare soil and/or erosive gullies Re-grade the soil if necessary to remove the <br /> Detention Basin have formed. gully,and then plant a ground cover and water <br /> until it is established.Provide lime and a one- <br /> time fertilizer application. <br /> Vegetation is too short or too long. Maintain vegetation at a height of <br /> approximately 6 inches. <br /> The Inlet Device: Pipe or Swale The pipe is clogged. Unclog the pipe.Dispose of the sediment off- <br /> site. <br /> The pipe is cracked or otherwise Replace the pipe. <br /> damaged. <br /> Erosion is occurring in the swale. Re-grade the swale if necessary to smooth it <br /> over and provide erosion control devices such <br /> as reinforced turf matting or riprap to avoid <br /> future problems with erosion. <br /> The Forebay Sediment has accumulated to a depth Search for the source of the sediment and <br /> greater than the original design depth for remedy the problem if possible.Remove the <br /> sediment storage(see diagrams below). sediment and dispose of it in a location where it <br /> will not cause impacts to streams or the SCM. <br /> Erosion has occurred. Provide additional erosion protection such as <br /> reinforced turf matting or riprap if needed to <br /> revent future erosion problems. <br /> Weeds are present. Remove the weeds,preferably by hand.If <br /> cattails or other weeds become invasive and <br /> pesticide application is necessary,have a <br /> licensed aquatic pesticide applicator treat the <br /> weeds by wiping aquatic glyphosate on the <br /> leaves rather than spraying. <br /> Page 2 of 4 <br />