WWHM 1

[civilguy98418]

Can I stamp calculations using this model? I have no clue what is going on in this black box model, and therefore am refusing to put my seal to the output of them.

In fact, I would contend that any registered engineer who does not know what is going on in the black box is putting his license on the line by sealing the output.

I am wondering if anybody else feels the same.

 

[RWF7437]

Woththell is WWHM ?

 

[cvg]

you can stamp anything you want, you are the engineer. Just hope you have confidence in the results of your analysis. If you have not supervised the work you are stamping and by that it is implied that you have reviewed and understand it, then you should not be stamping it. Only you can be the judge of whether the black box is doing what it should.

 

[civilperson]

If my back of envelope calculations come within 10% of results out of black box, I do not need to understand every detail of the programming and model assumptions. I still run some standard presolved problems to prove the software gets same results as theoretical answer.

 

[Cruzer84]

When you figure out how WWHM works, you will put your stamp on it.

 

[hydrae]

WWHM is the Western Washinton Hydraulic Model, a Program commsioned by the State of Washinton to model storm water flows and treatment pre and post development in counties west of the Cascade Mountains. Some regulators require its use to calculate detention volumes, pipe sizes, slopes, and treatment structures.
As for stamping its output, I would, but as a report on the output, not a calculation.
Hydrae

 

[RWF7437]

Thanks for clarifying what WWHM means.

I work in Oregon and have never used WWHM. What little I've seen of it seems pretty obscure, however. If I were "required" to use it I would, as Civilperson suggests,check the results by some other method to be certain they are reasonable. If they seem to be, then I'd have no problem stamping the design. Remember, you are certifying the design, you are not, and as far as I know,not required to certify that every calculation done to arrive at the final design is correct in every detail.

If you were required to certify every detail you would have to do all calculations by "hand" since you don't even know exactly what goes in inside your electronic calculator,or a spreadsheet,or any other computer program you didn't personally write.

good luck

 

[schurman]

As Hydrae mentioned it is a model for Western Washington. It was developed for the Department of Ecology is currently maintained by Clear Creek Solutions. It is a GUI for HSPF with precalibrated variables based on project location. If you developed a HSPF model with the same calibration data and rainfall input you should get the same results. However, I'm not sure if Clear Creek Solutions has added or modified any of the equations in the HSPF engine for WWHM.

At times the program can be buggy, but overall it isn't a bad program. I wouldn't hesitate to stamp a report with the output, but I would definitely make sure my input was correct.

I have used this program for 6+ years so if you have any additional questions please don't hesitate to ask.

Schurman