supported by HydroCAD
HydroCAD-10 provides direct support for the
PaveDrain system of permeable articulating concrete block mats.
This allows the storage and infiltration capabilities of PaveDrain
installations to be easily modeled with HydroCAD.
The PaveDrain can be modeled with HydroCAD-10, which provides an interactive
chamber wizard for easy layout, pricing, and modeling of modular storage
systems. Earlier versions will require a program
update in order to model PaveDrain systems.
If you're already
using HydroCAD-10, make sure you have "build 3" or later
in order to get PaveDrain support. Details here.
How chambers are modeled
In a HydroCAD model, stormwater storage, such as the internal PaveDrain
tunnel, typically appears as part of the storage definition for a "pond".
In the simplest case, HydroCAD calculates the total storage for use with other calculations.
But more often, HydroCAD is used to generate a complete inflow or runoff hydrograph and
route it through the pond. The resulting analysis indicates the water
levels attained throughout the rainfall event, as well as any discharge
that may occur through outlet devices or infiltration into the surrounding
Flexible storage options
Each pond can include an unlimited number of storage definitions as required
to describe its overall storage characteristics. This makes it
easy to model complex storage arrangements, such as a combination of multiple
chambers, pipe storage, catch basins, or other contributing volumes.
In the case of a PaveDrain block, HydroCAD calculates the internal storage of
the PaveDrain arch, plus the underlying stone bed. This determines the
total storage available in the "pond", as well as the area available for
The HydroCAD model can also include auxiliary storage provided by adjacent
pipes and catch basins, plus above-grade areas (e.g. parking lot)
that may provide overflow storage for certain events.
Modeling PaveDrain systems
Setting up a "pond" with PaveDrain storage is a simple process:
Just select the Chamber Wizard,
pick PaveDrain from the drop-down list, and set the number of rows and the row
length. Check the "Default" box to set the minimum 6" stone bed, or set a
custom depth as required.
Based on this information, the chamber wizard calculates the dimensions of the
underlying stone bed and the total volume of stone. Storage is then
calculated based on the stone voids (porosity) plus the internal PaveDrain
storage, and the storage in the 1/4" gap between blocks. The wizard can also be used to estimate the total installed cost,
including the PaveDrain blocks, stone base, and other elements.
Note: In addition to the stone base, HydroCAD models stone
fill in the 1" waists of all the perimeter blocks, as well as the half-block
area at the end of each row. In practice, a solid half block will
normally be inserted in this space, resulting in slightly less storage than
predicted by HydroCAD.
In addition to calculating the total storage in the PaveDrain system,
HydroCAD can perform runoff and routing calculations to verify the behavior of
the PaveDrain system under any desired rainfall conditions.
Detailed chamber information
For detailed PaveDrain specifications and design information, please visit the
PaveDrain web site.
For more information about HydroCAD
Please see the following pages for further HydroCAD information:
Pond storage calculations
Storage chamber modeling
General support page
HydroCAD features and capabilities
Free evaluation program
Pricing and ordering
HydroCAD® is a registered trademark of HydroCAD
Software Solutions LLC.
PaveDrain® is a registered trademark of PaveDrain.