Software for Pressurized Distribution Systems

I do not know of any software specific to do Sand Mound calculations but you might be able to simulate the pressurized system using something like EPANET. You would just need to figure out the outlet pressure.

From the website:

Capabilities

EPANET provides a fully equipped, extended-period hydraulic analysis package that can:

• Handle systems of any size
• Compute friction head loss using the Hazen-Williams, the Darcy Weisbach, or the Chezy-Manning head loss formula
• Include minor head losses for bends, fittings, etc.
• Model constant or variable speed pumps
• Compute pumping energy and cost
• Model various types of valves, including shutoff, check, pressure regulating, and flow control
• Allow storage tanks to have any shape (i.e., surface area can vary with height)
• Consider multiple demand categories at nodes, each with its own pattern of time variation
• Model pressure-dependent flow issuing from emitters (sprinkler heads)
• Base system operation on simple tank level or timer controls as well as on complex rule-based controls

In addition, EPANET's water quality analyzer can:

• Model the movement of a non-reactive tracer material through the network over time
• Model the movement and fate of a reactive material as it grows (e.g., a disinfection by-product) or decays (e.g., chlorine residual) over time
• Model the age of water throughout a network
• Track the percent of flow from a given node reaching all other nodes over time
• Model reactions both in the bulk flow and at the pipe wall
• Allow growth or decay reactions to proceed up to a limiting concentration
• Employ global reaction rate coefficients that can be modified on a pipe-by-pipe basis
• Allow for time-varying concentration or mass inputs at any location in the network
• Model storage tanks as being complete mix, plug flow, or two-compartment reactors

EPANET's Windows user interface provides a visual network editor that simplifies the process of building piping network models and editing their properties. Various data reporting and visualization tools are used to assist in interpreting the results of a network analysis. These include graphical views (e.g., time series plots, profile plots, and contour plots), tabular views, and special reports (e.g., energy usage, reaction, and calibration).

Or you could go the groundwater model route and try MODFLOW or one of the many add-ons listed on this page at the USGS website. Also try FEFLOW. The groundwater models may be the better bet.

Good luck

Thanks for the information, it has helped.