SW Products LLC
undefinedMarsh Properties received a notice from the City of Charlotte, N.C., that an inspection was scheduled for an existing detention pond at the Providence Park Apartments in Charlotte. Prior to this notice, the facility had not been regularly maintained, and it required substantial work to become compliant. This included removal of excess vegetation, removal of sediment buildup and installation of a riprap ring around the primary outlet – a 6-in. orifice.
After the work was completed, the pond continued to experience challenges due to the outlet structure clogging. The detention basin is located in a natural area. The primary 6-in. orifice of the outlet structure is located in a depressed area and would often clog with leaves, branches, trash and other debris.
Solution
Marsh Properties requested that SW Products look for ways to reduce the ongoing maintenance issues. When the outlet would clog, the pond would often be too deep to reach the outlet, and extensive work would be required to remove the clog. SW Products suggested that the outlet structure be modified to include a riser structure and a Marlee Float skimmer. The Marlee Float skimmer design would handle the base flow and smaller storm events while reducing clogging due to its shielded orifice. Because it is made of high-density polyethylene, it is suitable for permanent use.
The modified design was submitted to the City of Charlotte for review and approval prior to installation. The new design resulted in lower flow rates during the two- and ten-year storms, as well as extended detention of the water quality storm event. Therefore, it met many of the requirements of the City of Charlotte Stormwater Fee Credit Policy that resulted in a storm water fee credit of 95%, which resulted in a savings of over $20,000 per year for the property. This savings easily offset the cost of installation of the new riser structure and outlet system.
Results
The system has been in place for several years. During this time, it has been monitored and has required minimal maintenance and only minor adjustments to the skimmer. It has been effective in reducing the maintenance issues previously experienced on the property and rarely experienced clogging. When there have been clogs, it has been much easier to remove the debris and return to normal flow.
The creative use of the Marlee Float skimmer for this permanent application resulted in reduced maintenance and substantial savings in storm water utilities fees for Marsh Properties.
