Frequently asked questions
King County Runoff Time Series (KCRTS) model

Q How do I determine what version of KCRTS I am using?

The program version number is displayed on the program header. The header appears on the output screen after starting the program.

In the DOS version, you can press the F10 key from the main menu screen, or you can select the output window to view the program header.

Q What versions are available?

The current version is 6.0.

The version on the golden CD-ROM is 6.0.

The CD-ROM version can be updated by going to the KCRTS Page.
The web page includes a "Bug Report" which describes the bugs which have been reported and fixed since the CD-ROM was distributed.

Versions earlier than 4.40g are obsolete and should be replaced with the version on the CD-ROM or a later version. We recommend that you run CLEANUP.BAT (on the CD-ROM) prior to installing a newer version.

Note: DDES requires Version 4.40g or later on submittals.

Q Can the KCRTS program be installed on a drive other than the C Drive?

Yes, but...

There is one file in the program that HAS to be located on the C drive. - "kcrts.dat".

If you locate kcrts.dat in Explorer and then look at it in notepad it says this.... C:\KC_SWDM\KC_DATA\ King County, WA .... Change the "C" to whatever drive you are going to install the program on but MAKE SURE the "kcrts.dat" file is on the C drive!!!! This will ensure the program will work.

Also, in whichever ICON you are working in, MAKE SURE you change the drive letter in the COMMAND line. You find that in the same place we changed the working directory. Right click the icon, go to properties, click on the PROGRAM file tab and there you are.

Q Why do I get an error message that says the program cannot open files?
(such as KCRTS.DAT, ST_LU.DAT, *.RNF, *.HLP)

This problem should only occur after a new installation or a change in your computers operating system. The problem has occurred on a relatively small number of computers and it is related to the file properties. The program files are installed as "Read-Only" and "Archive". On some machines, this makes the files unavailable to the KCRTS Program.

The easiest way to fix this problem is to change the file properties using Windows Explorer.

1. Select the folder containing the KCRTS files. The default installation location is C:\KC_SWDM.
2. Select all the files in the folder. They should appear highlighted.
3. Right-click the group of files and select Properties.
4. Clear the Archive check box and the Read-Only check box if they have checks in them.
5. Repeat this same procedure for the files in the KC_bluehead folder (default location of C:\KC_SWDM\KC_bluehead )

Q Why do I get an error message that says "The working folder does not exist" when I start KCRTS?

The working directory must exist prior to running either the DOS or the Windows version of KCRTS. If the program is having trouble finding files, or if you get error message at startup, it is likely that the working directory is not set up correctly.

Use Windows Explorer to create a working directory.

1. Select the drive (and folder) that you want to make your working directory (the location where your bluehead will be stored)
2. Select File - New - Folder from the pull down menu.
3. Give the New Folder a name and press Enter or click somewhere so that the new name is registered.

Now set the Working Directory in/for KCRTS

If you are running the DOS version of KCRTS, set the working directory via the shortcut icon.

1. Before running KCRTS, right-click on the shortcut to the program and select Properties. If you already started KCRTS, close it and start this step over.
2. Under the Program tab, you should see "Working directory" or "Start in" or something similar. (Different operating systems use different terminology).
3. Type in the name of the working directory you created earlier.

If you are running the Windows version of KCRTS (wKCRTS), the working directory is set in the first window of the program. You will be prompted for the working directory each time you start the program.

Q Why do I get a "File does not exist" error message when I try to view the plot of my Level 2 analysis duration curve?

This is a common error!

The user needs to make sure they have set up a project specific working directory, as discussed in Chapter 1 of the software manual. Then it is CRITICAL that the user uses the same project file name as they used when setting up their working directory. See page 1-7 under [O!]. In O!record.txt replace "record" with the project file name and leave the .txt ending as is. This way the model can find the output data file for the required output tables, plots, etc. Chapter 1 of the KCRTS Manual summarizes the program execution and startup parameters.

Q How do I incorporate the results of a backwater analysis into KCRTS to see how it impacts the sizing of a flow control facility?

• In the "Size Facility" screen, go to [P] Point of Compliance set-up.
• Find where it says "HW/TW file for control structure outlet pipe (file generated by backwater program)"
• Specify the file name of your backwater file.

When you route your developed flows through the pond, it will take the backwater into account.

Known Problems with the DOS Version of KCRTS

Q Cannot view "Analysis Tools" summary tables in KCRTS.

This error has been reported on some NT machines. The routine is executed and all output files are generated. The displayed summary screen is blank.
A code fix to this problem has not been identified, and it appears most NT machines do not experience this problem.

One solution is to upgrade KCRTS/wKCRTS to version 6.0 from the KCRTS web page. This should allow the user to run the Windows version (wKCRTS) on an NT operating system.

Even though the summary table is blank, the output files are created. The user can go to the working directory and open the output files to view the results.

Q Printing graphs from the DOS version.

When you press the PrtScn Key, Windows copies the image to the clipboard. It does not send it to the printer. The image can be pasted from the clipboard into other applications for printing.

For direct printing, there are many Print Screen Utilities available. Some of these are freeware or shareware. A shareware version of Printscreen95 is included on the Blue CD-ROM under related files. Read the readme.txt file for more information and recommended settings.

Known Problems with the Windows Version of KCRTS (wKCRTS)

Q The output screens appear blank.

The wKCRTS output windows include 200 lines of bluehead . wKCRTS writes to the bottom of these output windows and earlier output is pushed up. This allows the user to scroll-up in the window to view earlier output. On some machines, when wKCRTS is first started, the output window scrolls to the top. To view the results, the user may need to scroll up or down in the output window.

Q Printing graphs from the Windows version.

When a graph window is open, the user can click on the green symbol in the upper left corner of the window to get a pull-down menu., which will include access to the windows printer dialog box. We recommend printing graphs using the landscape orientation on 8.5"x11" paper.

Q Unexpected pause when sizing a facility using "Iterate and Save"

In wKCRTS, the routine will sometimes pause prior to displaying the "Iteration Complete" screen. Pressing the space bar (usually once) will get the program past this inadvertent pause.

Q Why will wKCRTS not allow me to enter a range of dates properly, so that I can calculate the runoff volume of a time series? I am running version 4.41 on Windows 2000.

This problem has been reported a few times. It appears to only be a problem in the Windows version of KCRTS. The problem is related to the number of digits (2) that are allowed for the month, day and year values in the date. The simplest solution is to press the insert key, which toggles the computer from insert to overwrite mode. In overwrite mode wKCRTS should allow you to enter both digits.

We hope to resolve this in a future version of the program, as the source appears to be related to settings in libraries obtained from Microsoft.

A alternative solution is to run the DOS version of the program (KCRTS.EXE). Once you get your working directory set (right-click shortcut icon and select properties, and then select program tab), you will be able to work with the files you have already created. All KCRTS files are interchangeable between the DOS and Windows versions.

Q WKCRTS.EXE Fatal Error at Startup

Prior to version 4.40g, the Windows Version of KCRTS (wKCRTS.EXE) did not run on Windows NT/ME/2000 operating systems.

Users should use DOS version (KCRTS.EXE), or upgrade to latest version from webpage.

Note: The Windows Version of the Backwater program (wKCBW.EXE) still experiences errors in the NT/ME/2000 Operating Systems. Users with these Operating Systems should instead use the DOS Version of the Backwater Program (KCBW.EXE).

Facility Sizing Questions and Examples

Q Infiltration Facilities

A common problem designers encounter with infiltration facilities is KCRTS's need for consistency between the Number of Orifices and the Target Discharge for the Primary Design Hydrograph (PDH). If infiltrating all events up to the PDH, the PDH target discharge should be 0.0 and the number of orifices should also be zero. This input directs KCRTS to size the reservoir such that the permeable area provides the only discharge path for storm events up to the PDH level.

Conversely, if PDH Target Discharge is set greater than 0.0, then there must be at least one orifice to discharge that flowrate.

Q Bypass Areas

If designing a facility to compensate for bypass area, it is worthwhile plotting the flow frequency of the predev and bypass area timeseries (Level 1), and the flow duration curves (Level 2/3) to make sure that the bypass curves are below the predev curves. If not, flow control performance cannot be met with any size facility.

Q Calculating Facility Size

The tables below give the factors used to estimate a facility size based on the acreage, location, and type of landcover being converted, and the the flow control standards. To use the tables:

1. Consult the map to determine which Rainfall Region the project is located in (Sea-Tac or Landsburg).
2. Identify the Level of Flow Control required (Level 1, 2, or 3).
3. Determine the number of acres for each converted landcover type.
4. Get the factor from the tables for each conversion.
5. Multiply the number of acres by the inches shown in the table for each conversion.
6. Add the products of each landcover conversion.
7. Multiply the sum of the products by 1/12 to convert the units from acre-inches to acre-feet.

See the example following the tables.

Converting Till Forest (to Impervious or Grass)
Units are inches of storage per converted acre

Converting Till Pasture (to Impervious or Grass)
Units are inches of storage per converted acre

Example Conditions:

• Level 2 Flow Control required
• Sea-Tac Rainfall Region
• 3 acres of Till Forest being converted to Grass
• 1 acre of Till Forest being converted to Impervious
• 2 acres of Till Pasture being converted to Grass, and
• 0.5 acres of Till Pasture being converted to Impervious.

Estimate of Design Storage:

• 3 acres x 1.4 = 4.2
• 1 acre x 4.87 = 4.87
• 2 acres x 0.81 = 1.62
• 0.5 acres x 3.93 = 1.965
• Total = 12.655
• x 1/12 (to convert acre-inches to acre-feet)
• = 1.05 acre-feet

Q Why don't the peak inflows into a pond correspond to the peak outflows?

An intense, short storm might produce a large peak flow, but not a large runoff volume. A brief thunderstorm might be effectively detained by an RD system, but several days of medium-intensity, continuous rainfall would fill up a pond and eventually produce larger outflow peaks.

Q In a Level 2 Flow Control facility with 3 orifices, how do the height and size of the orifices affect the duration curve? What is the benefit of the 3rd orifice? How do I size the 3rd orifice?

Often times, on deeper ponds, you will see that the target duration curve and the outflow duration curve diverge, and, at higher discharge rates, the outflow curve will be much lower than the target. The outflow curve "flattens out" as the flow out the second orifice nears its maximum.

A third orifice will let water out of the pond more efficiently, will help to prevent overflows, and in some cases will allow the designer to make reductions in storage volumes (decrease the size of the pond). If done correctly, the third orifice will cause the outflow curve to rise and tighten up against the target curve. The third orifice should "kick in" at the point where the curves start to diverge.

A good rule of thumb is to initially make the third orifice the same size as the second orifice (Use Manual Sizing Mode). You should begin by putting the 3rd orifice at a height equal to 90% of the effective storage depth. Try lowering the height so that the 3rd orifice/arc kicks in where the curves are diverging. Adjust the orifice diameter to raise and lower the 3rd discharge arc, in same manner as described for the 1st and 2nd orifices. If 3rd arc is below target, increase diameter to let more water out, and visa versa. If it appears that the 3rd orifice needs to kick in earlier, lower it a bit. If the pond is no longer filling completely, reduce the pond bottom area. Note: as bottom area is reduced, storage volume is reduced, and the pond will stage higher which will tend to cause the discharge curve to rise. As needed to stay in compliance, reduce orifice sizes to compensate for the effect of higher stages/discharges.

Q Error message when plotting a flow duration curve - Less than 3 points. There are less than three flowrate cutoffs with greater than 0% time exceeded.

Because KCRTS plots duration curves on a log time scale, it cannot plot points where the % time exceeded = 0.0.

Almost always, the cause of this problems is that the user manually specifies the 1st interval and interval size (e.g., Target Duration Curve), and does it incorrectly. The first interval must be less than the largest flowrate (e.g., 50% of the predev 2-year). The interval size must be small enough that when consecutively added to the first interval there will be at least 2 additional flow cutoffs less than the largest time step.

You should recalculate the 1st interval and interval size, and then re-create the duration file (i.e., Compute Flow Durations and Exceedence). The duration file is most likely the file that was generating the error. You can confirm this by looking at the error message.

Q How do I create a target duration curve for a Level 2 facility?

There a number of ways to do this. Three of them are noted below. All should get you a workable curve that extends all the way to the left.

Note: PREB2.TSF is analogous to PREDEV.TSF, the predeveloped site runoff time series:

1. To create a duration output file for the full range of flows you might do the following inputs in Compute Durations. By leaving the Interval Size and First Interval starred out, KCRTS will calculate these based on the range of flows encountered in the time series file (1st 7 years if using reduced runoff files). By setting the number of intervals to 36, you will get the maximum number of points on the curve (best resolution).

2. To create a target duration curve you first must perform flow frequency analysis. The results of the flow frequency analysis are:

3. Following the equations in the KCRTS users guide to create a target duration curve:


# of intervals = 36
1st interval = 2-year * 0.5 = 0.126 cfs.
Interval size = (50yr - 1st interval ) /(# cutoffs - 1) = (0.603 - 0.126 ) /35 = 0.01363
Note the extra decimal points. I prefer to use a few extra to minimize rounding issues.

Doing this results in the following plot:

4. Since reduced record does not contain a 50-year event, it would be acceptable to replace the 50-year peak with the largest timestep of the 1st seven years (typically 25-year, see flow frequency in Step 2). Following the same equations:

# of intervals = 36
1st interval = 2-year * 0.5 = 0.126 cfs.
Interval size = (25yr - 1st interval ) /(# cutoffs - 1) = (0.536 - 0.126 ) /35 = 0.01171
Note the extra decimal points. I prefer to use a few extra to minimize rounding issues.

Doing this results in the following plot:

5. A trick I figured out, which works well with the reduced 8-year record (since no flows greater than 50-year) is to do the following.

# of intervals = 36
1st interval = 2-year * 0.5 = 0.126 cfs.
Leave the Interval Size starred out. KCRTS will calculate value to give you full range of flows. Note: this doesn't work well with full historical runoff files since there are flows that exceed the 50-year level.

Doing this results in the following plot:

Q For a Level 2 flow control facility, what is the difference between the interval sizing alternatives described at the bottom of page VI-2 of the KCRTS manual?

The first interval sizing method (50 yr - .5 * 2yr) / (#cutoffs-1) is so your duration curves don't extend beyond the 50 yr event if you're using the full historical record.

The alternative method gives a slightly better curve, with a few more points. KCRTS uses the first 7 years of data to calculate the duration curves. A plot of the duration curves using both methods shows that the curves are very similar, and would not change the facility size. Another alternative is to leave the interval sizing entry blank (******) (at the compute flow duration and exceedance screen). KCRTS will then calculate the interval size by finding the largest time step in the record.

Runtime Problems

Q WKCRTS.EXE Fatal Error at Startup

Prior to version 4.40g, the Windows Version of KCRTS (wKCRTS.EXE) did not run on Windows NT/ME/2000 operating systems.

Users should use DOS version (KCRTS.EXE), or upgrade to latest version from webpage.

Note: The Windows Version of the Backwater program (wKCBW.EXE) still experiences errors in the NT/ME/2000 Operating Systems. Users with these Operating Systems should instead use the DOS Version of the Backwater Program (KCBW.EXE).

For questions about KCRTS and the Stormwater Web Site, please contact Dale Nelson,Engineer II, King County Stormwater Services Section.