I've seen a wide range of HydoCAD applications from simple detention pond designs, to underground detention and exfiltration, and even mine drainage systems! It would be interesting to know how others are using HydroCAD.
We have been considering HydroCAD for hydraulic analysis, tank placement, and flow diagraming. We are changing base maps so I have been doing overlays, but I have had some of our engineers check out the product, and they seem impressed.
We have been using HydroCAD for several years for storage and treatment system design and have found it to be a very powerful combination of routines for a variety of tasks. Definitely a bargain for the price!
Been working with the demo for a month or so now. Am going to purchase the program as soon as I get positive feedback from the jurisdictions indicating that the output of this program is acceptable.
I like the way the program works, definitly less painfull than PONDS in MANY ways (price, ease of use, etc.).
So far I have modeled a retention pond and am working on resolving a flooding problem in a subidvision.
I have been looking at the demo. I'm not sure it does what I need. I believe my needs are probably similar to mike's above. He must be from Florida. Here, we are tasked to evaluate the 1, 2, 4, 8 and 24 hour duration, 25 year events for the critical duration storm. The intesity of the storm should vary with the duration for both the pre and post developed storm. The critcal duration storm would be the one generating the largest pond volume while keeping postdevelopment flow to predevelopment rates for all the storm durations. With HydroCad it appears I would have to model each individual storm, pre and post conditions, and from reading other posts on this site, it appears the software may set a zero percolation at the pond bottom. Regulatory agencies here require a 24" minimum distance from bottom of pond to groundwater, so percoalation rate at the pond bottom would never be zero. I am still looking into this software as I have not been able to find anything yet that does what I need. We bought PondPak awhile back and it incorrectly models the percolation rate to zero at the pond bottom.
Still searching.
Florida often requires multiple rainfall distributions, which makes these studies more complex than in most areas, which employ only a single distribution. But HydroCAD will still do what you need.
When using the SCS runoff method for Florida, HydroCAD includes the FDOT rainfalls for 1,2,4,8 and 24 hours, plus the 3,7, and 10 day rainfalls. (The complete rainfall library covers the entire country with over 50 distributions.)
You will generally have two "projects". One for the existing conditions and one for proposed. For each project, just pick each distribution and print the report. (The calculations are done automatically for each event.) You can then compare the results to identfy the critical event.
As for percolation, HydroCAD will do this any way you wish. There are a number of options that let you include or exclude percolation through the bottom of the pond. This is configured when you set up the "exfiltration outlet" on the pond.
You can test all this with the free HydroCAD sampler at
Where I work we used Hydraflow and I am thinking of buying a program for my home office. I would appreciate any opinions on one program versus the other or other programs that may be better, but still reasonably priced.
Are you talking about Hydraflow from Intellisolve? or HydroCAD from AMS?
I have used Hydraflow stormsewers.... I now see they have a product called Hydraflow Hydrographs which looks like it is along the lines of Hydrocad. Is that the product you are referring to?
I would highly recommend you get a demo of HydroCAd for comparison.
I plan to demonstrate its effectiveness by simulating a runoff event fron a 1,100 acre drainage area. The basin outlet consists of a detention basin with two 6x8 ft box concrete culverts and the top of the road serving as a weir.
The results will be compared to a HEC-1 generated inflow peak, outflow peak and the peak flow generated from the use of the Rational Method.
queque, for your demonstration project, will you use a guaged basin to compare modeled estimates to recorded events?
I too have used both HydroCAD and HEC-HMS to see how the results compared. They were quite different in peak flows perhaps due to an apparent different treatment of the initial abstraction. Unfortunately, that study is for an ungaged site, so no calibration possible. I would be interested to see your results.
For a different project, HydroCAD was a breeze in designing a flow-control and detention structure for a commercial site using off the shelf manholes & pipes with a simple orifice & weir modification. Trial and error goes so fast, it was easy to hit two target flows (10-year and 100-year). I can't wait for the ability to input sloped pipes as "horizontal cylinder" storage however!
I do not have a gauged basin. The problem is made worse because "someone" used the Rational Equation to develop the peak. Then they took the peak flow and developed height of water at selected downstream cross sections using Manning's equation.
No routing through the outlets at the detention basin was made, nor overtopping flow considered with a wier outlet.
Hydrocad takes the HEC 1 results and by matching the peak and volumes, this comparison problem is evaluated it in minutes. Secondly, it provides the basis for increasing the detention volume through further excavation.
As I was explainimng the unzipping of the Sampler to a City of Tucson staff member, he made a first run in minutes after unzipping it. He is still stunned.