TR20 basflo command

[mzaprzalka]

Hi,

Anyone have any hints for running a BASFLO command in TR20 (procedure 1)? I'm modeling a basic detention pond with a hydrograph entered as a runoff (using Area, CN and Tc). All i'm looking to do is add 5 cfs into the pond as a constant flow. According to the manual, i need a COMPUT command after the BASFLO command and a constant rate of baseflow can be added to hydrographs only in a reach routing.

Following are my commands without using BASFLO (not sure if it will come up looking ok or all jumbled). The question is where does it get entered and how? I think i tried everything and hand are almost up in the air (but i can't give up). TIA!

3 STRUCT 01 POND 1
8 768.50 0.000 0.000
8 769.00 0.639 0.013
8 770.00 0.964 0.053
8 771.00 1.204 0.116
9 ENDTBL
6 RUNOFF 1 050 1 .00214 96.00 0.39 1
6 RESVOR 2 01 1 2 768.50 1 1
ENDATA
7 INCREM 6 0.10
7 COMPUT 7 050 01 7.58 24.0 3 2 1 99 100YR
ENDCMP 1
ENDJOB 2

 

[psmart]

Since a constant base flow is only added to a reach routing, I believe you would need to include a "dummy" reach in the model in order to utilize this feature.


Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[mzaprzalka]

i tried a dummy RUNOFF to get COMPUT to work, i even tried a dummy REACH (which is flow through a channel) and can't get it to work. any other ideas? here is my reach data that didn't work:

3 STRUCT 03 POND 3
8 885.66 0.00 0.00
8 886.00 0.61 0.19
8 887.00 1.67 0.79
8 888.00 4.68 1.48
8 889.00 6.27 2.26
8 890.00 7.51 3.14
9 ENDTBL
6 RUNOFF 1 050 2 0.00001 61.00 0.26 1
ENDDATA
7 INCREM 6 0.13
7 BASFLO 5 5.12
7 COMPUT 7 050 050
ENDCMP 1
6 REACH 3 1 2 7 667 1
6 RUNOFF 1 053 5 .01763 70.00 0.26 1
6 RESVOR 2 03 5 6 885.66 1 1 1 1
ENDATA
7 INCREM 6 0.13
7 COMPUT 7 053 03 0.0 3.04 24.0 3 2 02 24
ENDCMP 1
7 COMPUT 7 053 03 0.0 7.58 24.0 3 2 99 24
ENDCMP 1
ENDJOB 2

 

[psmart]

I think your got some extraneous lines.

According to the TR-20 manual, the BASEFLO is only in effect up to the next BASEFLO or ENDCMP statement. So you need to eliminate the first COMPUT/ENDCMP pair before the REACH statement.

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[mzaprzalka]

that's what i was thinking but it says that the BASFLO needs to preceed a COMPUT command. i do think there are some extra lines (i set up a dummy runoff in order to get the comput to run). i'll play around some more, i think i tried most every combination (with COMPUT, without, etc.). any other ideas would be great! tgif, i'll probably be dreaming tr20

 

[psmart]

...but you also have place the reach statement before compute.

I think you can use just the one compute statement at the end. It doesn't have to be immediately after the baseflow.

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[mzaprzalka]

btt

tried some more variations but still can't get it to work. does anyone have an example of a BASFLO they can post? tia!

 

[psmart]

Have a look at the examples in the TR-20 manual for the required command sequence...

Peter Smart
HydroCAD Software

http://www.hydrocad.net