Yes. Through Shapefiles and DXF files.

Yes. You can import Shapefiles into HYDRA. Purchase of HYDRA includes a new GIS Layer Transfer Wizard for import and export of GIS data - it's a separate utility that walks you step-by-step through transfer of files between HYDRA and ESRI's ArcInfo or ArcView. The drawing of the collection system and other graphical data is brought in from Shape Files (SHP) along with associated database (DBF) data.

Yes. You can use AutoCAD versions 12, 13, 14 - both DOS and Windows versions, or AutoCAD 2000, 2000i, 2002, 2004, 2005 and 2006. Purchase of HYDRA 6 includes our GIS Master module - an AutoCAD "add on" tool which facilitates creation of drawings for use in HYDRA. GIS Master adds an extra menu to the AutoCAD interface which provide specialized menu tools for digitizing HYDRA layers. Using PIZER's GIS Master module is advantageous because drawings will be significantly "cleaner" (fewer digitizing errors) than digital drawings created for purposes other than sewer modeling.

Yes. The GISMaster utility also works with AutoCAD Map. Or, if you have your own identification numbering system, you can use the GIS Layer Transfer Wizard utility to import the GIS data to HYDRA.

Sort of. HYDRA is NOT an AutoCAD add-on utility, it is a stand-alone program. It works WITH AutoCAD, but not INSIDE AutoCAD (as Eagle Point and others do.) This way we are able to provide in HYDRA very powerful features that simply would not be possible within the AutoCAD development environment. The benefit for the user is that they don't need to have a license of AutoCAD on the same computer that HYDRA is on. Also, it means you as a user can use the latest version of Hydra with any version of AutoCAD (12, 13, 14, 2000, 2000i, 2002, 2004, or 2005), AutoCAD Map and other variations. Purchase of the HYDRA package does include an AutoCAD add-on utility called GISMaster, which helps you create data for Hydra. (see more in GIS Integration section)

Yes. You can use Microstation to create Drawing Exchange Files (DXF) which can then be imported into HYDRA 6 with the new GIS Layer Import and Export Wizard utility. However, if other CAD or GIS programs are available, we highly recommend using those instead, as we have found Microstation files prone to problems.

You can import graphical data from any CAD or GIS software package that can output a Shape File or an AutoCAD version 14 DXF file. This might include AutoCAD LT, VisualCAD, IntelliCAD, etc. You can import tabular data from any database software that can output a Microsoft Access MDB, Paradox DB, or dBASE DBF file format.

Yes, but only for correcting minor digitizing errors. You can "snap" together unconnected pipes, and eliminate some types of entities that have been accidentally digitized twice. To add, delete, or move pipes, you simply go back out to your CAD or GIS software, make the changes, and refresh the HYDRA files. GISMaster and Layer Transfer Wizard utilities help maintain the proper identification numbering.

Yes. HYDRA uses a standard DBF file format for storage of input data. If you have input data for your collection system (such as pipe diameter, pipe length, slope, etc.) or population data for land use areas or other such tabular data, you can pull the data into your modeling project by manipulating the data outside of HYDRA using a database program, such as Microsoft Access or dBASE. You can also link data from Microsoft Access MDB, Paradox DB, or dBASE DBF files to a layer drawing file using PIZER's new GIS Layer Import and Export Wizard utility.

Yes, you can. You will need to be careful to save the data as a dBASE DBF file without changing field type or field widths. You will need to carefully review the documentation of your spreadsheet program to prevent corruption of the DBF files.

Yes. Any associated data can be annotated in the drawing as text.

Yes. HYDRA can model structures which split flows into two components - one that continues downstream, and one that is diverted to another lateral or onto the ground. Data input uses a performance curve of how much flow is diverted at different flow levels.

Yes. HYDRA can model up to 3 pumps and one wet well at a pump station (or lift station). For data input you need to define the volume of the wet well and the performance characteristics of each pump - constant or variable discharge type, on and off volume switches, maximum discharge, and where excess overflow is directed.

Yes. It is limited to a single pipe. If there are multiple pipes in the siphon you simply use an equivalent size pipe diameter.

You have the option of using 3 different stormwater runoff analysis methods used by HYDRA: Rational, SCS, and Hydrologic Simulation.

• The Rational Method. HYDRA's rational method is a modified version of the traditional method. HYDRA's method is unique in that the peak runoff is dictated by the traditional Rational Method, but still generates a realistic runoff hydrograph that is routed through the collections system. This allows you to use the Rational Method and still account for storage.
• The SCS Method. HYDRA uses the Santa Barbara SCS method - a method originally developed by the US Soil Conservation Service and later modified by Santa Barbara County, California to be more sensitive to small urban runoff basins.
• Hydrologic Simulation. HYDRA uses a highly sophisticated technique patterned after the Stanford Watershed Model developed by Crawford and Lindsey at Stanford University, credited as the fathers of modern hydrology. This method accounts for all the water that falls on a land segment mathematically and has the advantage that the model can closely match flows generated from actual storms.

In addition, HYDRA gives you 3 different approaches to modeling rainfall over the basin:

• The traditional method of simply defining the rainfall over the entire basin as a single storm cell. This method works very well for basins 2 or 3 square miles in size.

Larger municipalities, that may cover 25 to 100 square miles of area, should consider methods 2 or 3.

• Routing a storm cell across a basin. The ability of defining the diameter, taper zone, and track of the storm over the basin.
• Entering information on multiple rain gauges at specific locations around the basin. This method allows Radar data to be utilized, in effect placing thousands of "virtual" rain gauges uniformly over a basin.

Yes. You can perform a Peaking Factor analysis with HYDRA. HYDRA's optional Peaking Factor Method uses diurnal curves to generate and route realistic sanitary hydrographs through the system (including pumps and diversions) and then link by link adjusts these hydrographs to comply with the Peaking Factor curve that you define.

This approach is unique to HYDRA and combines the best of both worlds into a single, easy to use method that can be turned on and off on a pipe by pipe basis and can use a single system wide Peaking Factor or one that is dependant on the instantaneous flow at a location. This approach allows you to account for "in line" storage in pipes and wet wells which cannot be done in the traditional approach to using Peaking Factors. This results in far more accurate answers and still allows you to use the method that you are comfortable with.

The basic equations used for routing is the Manning's equation for open channel flow, and the Hazen Williams formula for pressure discharge lines. The routing of the flows through the system is done on a time-routing basis using the Holz Attuation Algorthium with time steps automatically adjusted to reflect the specific requirements for each entity (pipe, pump, channel, manhole, etc.).

HYDRA is not a "static" model -- it is "dynamic". HYDRA is dynamic because it uses hydrograph-based analysis (flow over time), including factoring flow attenuation and iterative backwater. Many people in the industry say that HYDRA is "not fully dynamic", because what they really mean by "dynamic" is the use of the St. Venant's equation. (see more explaination below)

A static model routes only a single flow value (the peak flow) through a collection system and uses this single flow value to calculate such things as velocity and depth of flow for every pipe in the system. Static models are very simplistic. 20 years ago, HYDRA was a static model, and even now many people mistakenly describe HYDRA as a static model. However, it is not true.

Although HYDRA normally reports a single value as the maximum flow and hydraulic grade line (HGL) for a pipe or channel, this value is only the final result of a dynamic, often minute-by-minute, 24-hour analysis of the flows. HYDRA's normal output is a selection of the-worst case situation over the time period, because the peak flow is the most important value for design and capacity analysis. The 24-hour HGL (the peak flows for every time step during the analysis period) is available for viewing in a spreadsheet.

Yes. HYDRA calculates both "bend" and "drop" losses.

HYDRA calculates bend and drop losses on a minute by minute basis taking into account the direction, velocity and elevation of incoming flow as well as the diameter of the manhole and the type of benching or channalization in the manhole base. This is done by using a special database that we have developed over the years of actual measured Hydraulic Grade Line losses (or gains) through manholes from numerous studies and then adjustments made as users report what they are observing from metered data. Project results indicate high level of accuracy.

There is probably no other program that is as sensitive to manhole losses as HYDRA. None of the approaches we found being used by other models are sensitive to the chaotic conditions in manholes. In fact many other models simply adjust the friction factor of the downstream pipe to approximate the head losses in the upstream manhole. Since the head losses in the manhole change very dynamically, minute by minute, depending on many conditions, such an approach can yield some very distorted results, regardless of the sophistication of the algorithms being used.

Yes. HYDRA calculates a hydraulic grade line (HGL), and accounts for overflows. For each entity in the collection system, HYDRA displays the HGL for the worst-case scenario - peak flow.

For calculation of hydraulic grade line, HYDRA uses a proprietary self-adjusting situation-dependant methodology. In areas of partial or full flow pressurization or submerged conditions, HYDRA uses a semi-iterative calculation method to appropriately apply Manning's equation, Hazen-Williams equation, and an empirical approach based on American Society of Civil Engineers field research for drop and bend losses. This unique backwater analysis methodology for results in highly accurate hydraulic grade lines without the excessive numerical calculation iterations of wave-based models.

HYDRA does a two-pass analysis. The first pass routes the system hydrographs from the top of the system to the bottom. In making this analysis, HYDRA watches for possible backwater situations. If it finds that backwater is probable anywhere in the system, it restarts the analysis at the outfall(s), and calculates the HGL while moving upstream through the collection system.

Although the reported results for this analysis defaults to a single worst case HGL, you may request that HYDRA do a backwater analysis on a step basis over a 24 hour period, allowing you to watch the rise and fall of the HGL over a 1, 2 or 3 day period. This gives the appearance of a "wave" moving up and down the system.

While in most cases, knowing the worst case HGL is all the engineer needs, there are occasions where it is desirable to know what the HGL looks like at 10:15 AM. This is available, but must be requested in advance of the analysis as the storage of this data over the entire system is significant but it is useful if you need to know where and how much fluid leaves the collection system via a manhole or by over topping a channel.

No and Yes.

No: For calculation of hydraulic grade line, instead of the St. Venant's equation, HYDRA uses a proprietary self-adjusting (you might even say "dynamic") situation-dependant methodology. In areas of partial or full flow pressurization or submerged conditions, HYDRA uses a semi-iterative calculation method to appropriately apply Manning's equation, Hazen-Williams equation, and an empirical approach based on American Society of Civil Engineers field research for drop and bend losses. This unique backwater analysis methodology results in highly accurate hydraulic grade lines without the excessive numerical calculation iterations of wave-based models. HYDRA's proprietary dynamic modeling method is much faster, much more stable, can handle much larger collection systems, and results in comparable calculations in the majority of cases.

Yes: With the new SWMM Module for Hydra 6.2, you can export all or part of your Hydra model to a .DAT file for use with EPA SWMM Extran, or other sewer modeling programs that use the St. Vennant's equation (XP-SWMM, PC-SWMM, MIKE-SWMM, etc.).

Most modeling experts would agree that the St. Venant's equation is not necessary (even "overkill") for 90% of all municipal modeling projects. In fact, for most collection system modeling projects, the St. Vennant's Equation actually gets in the way of the practical analysis because of system size limitations, slow analysis speed, and model stability problems.

The St. Venant's equation was designed for the calculation of the downstream attenuation of the wave resulting from a massive single injection, such as a dam breaking. It results in a marginally better solution for a system impacted by tidal waters on very flat slow moving systems.

The real problem with the St. Venant's equation is that it is compute intensive - often resulting in an analysis of a 500-pipe system taking nearly an hour. HYDRA's routing approach on the other hand has clocked in at under 45 seconds for the complete analysis of a 12,000 entity system - including the generation of all injection hydrographs, downstream routing and full backwater analysis. The results have proved to be very close to actual metered data and often better than that from SWMM probably because size limitations in SWMM limited the number of injections and pipes in the system. This is not to say that the St. Vennant's equation is not useful, but the engineer must carefully analize if his system will gain for its use over the methods used by HYDRA.

In fact the St. Venant's equations have been so troublesome in other programs that all of these programs have been forced to modify the pure St. Venant's solution by decreasing the step length at the expense of compute time, falsifying pipe length data to prevent mathematical instability, using such tools at the Preissmann slot (which changes a pipe into a channel), switching to traditional methods to solve pressurized portions of the system, and closing on the solution using the Newton-Raphson Method.

SWMM must often run in time steps that approach 2 or 3 seconds in length resulting in 43,200 complete analysis of the collection system for a 24-hour period. The massive hydrographs that result for such an analysis require that the user only select a few of the entities to store the results on and often the user isn't sure where the problems will occur - making a real challenge for the engineer.

With the new SWMM Module for Hydra, you can use the best of both worlds in your next project! You can quickly and easily run a comparative hydraulic analysis, and see for yourself!