Constant Q Pond Outlet

The Lane Constant Q Pond Outlet (CQ) is a unique and extremely cost effective storm water BMP which significantly improves the quality of the water being discharged from ponds. The CQ is a constant discharge device that draws water from the highest level of a pond, insuring that only the cleanest water is discharged.

web constant QThe Lane Constant Q Pond Outlet is the fixed depth orifice cousin of the variable depth Reverse Q. Whereas the Reverse Q orifice depth changes inverse to the depth of the pond, the Constant Q depth remains the same regardless of pond depth or volume. This fixed orifice depth feature allows for a much shallower float body, allowing the Constant Q to be utilized in even the shallowest of ponds. The Lane CQ is designed to be utilized in even the shallowest ponds. The smallest CQ, the 1.5” model requires only 3.5” of draft, meaning that it will function in only 3.5” of water above the bottom of the CQ float body.

General Notes

  • The Lane Constant Q Pond Outlet is designed to be used with either a straight pipe through the berm of the pond, or attached to a riser structure. In either case, the CQ is supplied with the necessary flexible coupling that will allow for the connection to and smoothwall pipe outlet.
  • The CQ is available in three sizes: 1.5”, 2.0” and 2.5”.
  • The CQ is constructed from dual wall corrugated polyethylene pile and 0.5” thick HDPE sheet. The dual wall pipe conforms to AASHTO M-252, type S. The pipe floats are filled with a closed cell expanding urethane foam (U.S. Coast Guard Marine Foam). The outlet lever arm is constructed from Schedule 40 PVC pipe conforming to ASTM D2566.
  • Lane Constant Q is supplied with three orifice plates. The two extra orifice plates can be drilled to the appropriate diameter for additional projects.