TrueNorth Steel has manufactured and supplied underground stormwater management systems since the 1980’s and we continue to assist stormwater regulators, engineers, and contractors with the design and installation of these complex systems. We’ve created this stormwater design tool to provide engineers with the information and resources necessary to begin the design process for a successful Corrugated Metal Pipe (CMP) stormwater management system.
This tool has been developed to assist with the layout of an underground stormwater system. Whether the stormwater system is being utilized for detention or retention purposes, this program will quickly and effectively translate a few key inputs into a functional design complete with storage volumes (in the pipe and potentially in the void spaces of the backfill around or beneath the pipe), corrugation profile, material thickness, footprint area, and required system length.
Users of this tool can create three types of systems:
1. Detention System – Stormwater is captured within the pipe(s) and then released through an outlet orifice. These systems typically utilize solid-walled CMP.
2. Infiltration System – Stormwater is captured within perforated pipe and void spaces within stone backfill. Properly designed backfill can provide up to 40% void spaces. These systems release stored stormwater through an outlet orifice while also allowing any stored water below the invert of the outlet to infiltrate down into the underlying soils.
3. Filtration System – Stormwater is captured within perforated pipe and released down through the perforations into an underlying sand layer that provides filtration much like a conventional sand filter. This system configuration achieves both stormwater volume management as well as stormwater water quality treatment.
After the system type is selected, key user inputs of required storage volume, minimum finished grade elevation, minimum CMP system invert elevation, pavement type and thickness, and # of barrels must be entered. The program output includes a system plan view drawing and end cross-section view showing the pipe in relation to finished grade along with related notes. This program is capable of creating system layouts featuring pipe barrels of equal length with collector or equalizer manifolds on both or only one end.
TrueNorth Steel is available to assist with layouts and drawings featuring pipe barrels of differing lengths. Once the user finalizes the system design your local TrueNorth Steel Representative who is trained to assist you with your project can further assist with complete system drawings featuring inlets, outlets, manholes, ladders, and other required design considerations that this program does not currently have the capability to output.
TrueNorth Steel has utilized guidance provided by AASHTO for pipe designs considering HL-93 load conditions. Further guidance is sourced from the National Corrugated Steel Pipe Association. System specifications, standard details and other design resources may be downloaded from https://truenorthsteel.com/stormwater-management/.
The design of CMP underground stormwater systems requires extensive knowledge of local stormwater management practices, stormwater management systems, and the proposed site. Users of this program are ultimately responsible for ensuring proper usage of the program and application of the output. Users are encouraged to contact their TrueNorth Steel Representative for support and guidance or in the event that other concerns, errors, suggestions, and subsequent questions arise.