Laserfiche WebLink
Providinq access to the bottom of the open water cell would <br /> be problematic, due to the retaininq walls associated with <br /> tha wetpond. To eliminate the access road, a portion of the <br /> open water cell volume (enouqh volume for effectiva sadiment <br /> removal) can be provided in a wetvault upstream of the pond. <br /> The minimum volume that must be provided to eliminate the <br /> / need for access to the bottom of the open water cell is a <br /> � volume equivalent to a 15 minute detention time for the peak <br /> rate of developed flaw from the design storm. Vafiicle <br /> access can be provided to the top of the weLvault instead of <br /> to the bottom of the pond, and a 72 inch manhole is not <br /> required upstream of the pond for qrit removal. The dead <br /> storage depth in the wetvault must be betwean 3 and 6 feet, <br /> the lenqth to width ratio should be at least 2:1, and the <br /> inlet and outlet should ba provlded at opposite ends of the <br /> vault. <br /> / The inlet and outlet structures to the wetpond need to be <br /> ✓ desiqned so that all stormflow is forced to travel the full <br /> length of the watpond. <br /> i A trashrack is needed on the outlet of the wetpond to <br /> / prevent floatable materials from enterinq the reatrictor <br /> V manhole. <br /> l�noinas <br /> City standards require all surface ponds or basins with a <br /> / maximum depth qreater than three feet to be fenced with a <br /> ��� six foot high perimeter fence unless one of the following <br /> conditions is met: <br /> i) a 10 foot wida safety bench for every three feet of <br /> desiqn water depth and the side slopes of the pond are <br /> no qreater than 3: 1 (H:V) ; or <br /> 2) the maximum water depth of the facility does not exceed <br /> three feet during a two year storm, nor exceed three <br /> feet for more than four hours for a 25 year storm; the <br /> side slopes are a maximum of 3 : 1 (H:V) ; and the <br /> facility is a dual use facility; or <br /> 3) specific City Council approval is granted for an <br /> exemption per the criteria in the City's Desiqn and <br /> Construction Standards and Specificationa. <br /> � it appears that, at a minimum, the open water cell of the <br /> wetpond will need to be fenced. Fencinq of the wetland <br /> treatment cell is optional. <br /> 3�5 <br />