Office of Water
4305
United States
Environmental Protection
Agency
July 20, 2007
&EPA BASINS Technical Note 9
Web-based HSPF Toolkit to Support Low
Impact Development (LID) and Other
Urban Stormwater Modeling
Applications
1
-------
Technical Note 9
Web-based HSPF Toolkit to Support Low Impact Development (LID) and Other
Urban Stormwater Modeling Applications
By Yusuf Mohamoud, Kurt Wolfe, and Rajbir Parmar
July 20, 2007
The RCHRES module of the Hydrological Simulation Program - FORTRAN (HSPF) is
used to simulate various features including hydraulic behavior, sediments, general water
quality constituents, and biochemical constituents in free-flowing channel reaches and
well-mixed reservoirs. The toolkit described in this technical note is accessible at
http://www.epa.gov/athens/research/modeling/ftable/index.htm and uses the RCHRES
module to simulate how certain structural best management practices (BMPs) such as
detention basins (wet ponds, treatment wetlands, etc.) mitigate the impacts of stormwater
runoff. This technical note focuses on the use of RCHRES to simulate the impacts of
BMPs on flow only. Future notes will explore the simulation of pollutant retention as
well. In its current development stage, the tool represents open channels and flow control
devices (weirs and orifices). The open channel component has five shape choices; each
shape is represented by a depth-area-volume-flow relationship known as hydraulic
function table or FTABLE. The open channel's shapes are: circular, parabolic,
rectangular, triangular, trapezoidal, and natural. Simulated flow control devices consist of
V-notch, sharp-crested (Cipoletti), rectangular, broad-crested weirs, and under-drain and
riser pipe orifices. For each channel shape, users have the option of selecting an open
channel with or without a flow control device. In many applications, users may select an
open channel only, while in other applications, users may select an open channel with one
or more flow control devices. Note that HSPF allows a maximum of five flow exits in
one FTABLE.
This toolkit enables HSPF users to extend the model's application to urban watersheds
with sewer system networks and to areas with flow-modifying BMPs such as detention
basins. The toolkit was developed for low impact development (LID) modeling
applications. Specifically, the tool simulates BMPs that store stormwater runoff to
attenuate flooding and remove pollutants. Presently, the tool is not recommended for
simulating infiltration trenches, dry wells or other BMPs that function by enhancing
infiltration.
The tool requires some UCI file manipulations, but does not require HSPF code changes.
Detailed instructions on how to run the program are given in the tutorials.
Note: The applet was compiled using the Java 1.5. If you cannot see the applet when you
open the web page in the browser, go to http://java.sun.com and download the latest Java
Runtime Engine. The Java Runtime Engine, or (JRE), is under the Java SE category on
Sun's website. We recommend that users read the tutorial before using the tool.
1
-------
1. Web-tool Tutorials
A. Human-made open channels with and without flow control devices
The Web-tool generates FTABLES for five human-made channel shapes and six flow
control devices. Generating FTABLES for the human-made shapes and flow control
devices are straightforward if these steps are followed.
STEP 1. Select a channel shape (e.g., trapezoidal as shown in Figure 1).
CIRCULAR CHANNEL RECTANGULAR CHANNEL TRIANGULAR CHANNEL
TRAPEZOIDAL CHANNEL PARABOLIC CHANNEL NATURAL CHANNEL
(S
~
6.0
Figure 1. trapezoidal channel shape
STEP 2. After the desired channel shape is selected, users should enter channel geometry
data in the input grid (Figure 2). Note that changing one parameter value without
adjusting other parameters can change the channel shape and invalidate the FTABLE.
Always check the channel shape after it is redrawn following each program execution.
No output is generated if the channel shape changes. For example, changing the side
slope from 2 to 4 without changing other parameters alters the channel shape from
trapezoidal to triangular.
OPEN CHANNEL INPUT DATA
Maximum Channel Depth (ft):
6.0
Top Channel Width (ft):
36.0
Channel Side Slope (H:V):
2.0
Channel Length (ft):
4000.0
Channel Mannings Value:
0.05
Longitudinal Slope (ft.ft):
0.025
"igure 2. Input grid for a trapezoidal channel
STEP 3. After the desired input data is entered, users should hit "Calculate FTABLE" to
generate the FTABLE without a control device (Figure 3). Note that only four columns of
the output grid table are populated.
2
-------
~
Calculate FTable
Results | Copy Results |
Right click the grid for more options.
depth (ft)
area(acres)
volurne(ac-ft)
outflowl (cfs)
0.00
1.10
0.00
0.00
*
0.10
1.14
0.11
1.24
=
0.20
1.18
0.23
3.92
0.30
1.21
0.35
7.71
0.40
1.25
0.47
12.48
0.50
1.29
0.60
18.17
0.60
1.32
0.73
24.73
0.70
1.36
0.86
32.13
—
Figure 3. Generated FTABLE for a trapezoidal channel
STEP 4. Generation of an FTABLE with a control device requires the selection of one or
more flow control devices by checking the box next to the desired device. In this
example, a riser orifice was selected (Figure 4).
CONTROL STRUCTURES (optional)
~ Vnotch Weir
Vertex Angle (deg):
30
Weir Invert (ft):
5 I
~ Sharp Crested Weir (Cipoletti)
Weir Crest Width (ft):
30
Weir Invert (ft):
5
~ Broad Crested Weir
Weir Crest Width (ft):
30
Weir Invert (ft):
5
~ Rectangular Weir
Weir Crest Width (ft):
30
Weir Invert (ft):
5
~ Underdrain Orifice
Orifice Diameter (ft):
5
Orifice Heiyht (ft):
2
0 Riser Orifice
Orifice Diameter (ft):
5
Weir Invert (ft):
2 I
:igure 4. Input grid for flow control devices
STEP 5. After selecting the riser orifice, a new FTABLE with an additional flow column
for the flow control device (riserorf) is generated by clicking on "Calculate FTABLE"
(Figure 5).
3
-------
Calculate FTable
f Results Copy Results
Right click the grid for more options.
depth (ft)
area(acres)
volume(ac-ft)
riserorffcfs)
-
0.40
1.25
0.47
0.0
0.50
1.29
0.60
0.0
0.60
1.32
0.73
0.0
0.70
1.36
0.86
0.0
0.80
1.40
1.00
0.0
0.90
1.43
1.14
0.0
1.00
1.47
1.29
0.0
1.10
1.51
1.44
0.0
Figure 5. FTABLE generated for a trapezoidal channel
STEP 6. Now that the program has generated an FTABLE with the desired channel and
flow control combinations, the next step is to transfer the FTABLE to the HSPF UCI file
and to ensure that its format is compatible with that of the UCI file. To transfer the
FTABLE to a UCI file, point the mouse any where of the output grid, right click and then
select "Copy to UCI file" (see Figure 6).
Calculate FTable
[ Results Copy Results |
Right click the grid for more options.
depth (ft)
area(acres)
volume(ac-ft)
riserorffcfs)
-A.
0.40
1.25
0.47
0.0
0.50
1.29
0.0
~
0.60
1.32
copy i o spreaasneet
0.0
0.70
1.36
Copy To UCI File
0.0
0.80
1.40
0.0
0.90
1.43
Java Applet Window
0.0
1.00
1.47
1.29
0.0
1.10
1.51
1.44
0.0
Figure 6. FTABLE transfer to HSPF UCI file
STEP 7. After clicking on "Copy to UCI FILE," the program generates an FTABLE that
is compatible with the UCI format (Figure 7). To copy the FTABLE to a UCI file, select
the entire FTABLE, then press CTRL+C to export the file to a UCI file. For UCI file
related guidance, refer to the section on UCI File Manipulations (Step 12).
Calculate FTable
Results | Copy Results
Select the contents of the text area below and press Ctrl+C to copy.
I KrtrtZUIUrtL
FTABLE JD***
rows cols ***
61 4
depth area volume riserorf***
0.00 1.1 0.00 0.00
0.1 1.14 0.11 0.00
0.2 1.18 0.23 0.00
0.3 1.21 0.35 0.00
0.4 1.25 0.47 O.OOl
Figure 7. Exporting FTABLE to HSPF UCI file.
4
-------
B. Natural channels with and without flow control devices
Presently, BASINS/WinHSPF may use either of two automated methods to generate
FTABLEs for a reach cross-section. These are the default and the Alternate FTABLE
methods. These automated FTABLE generation methods are intended for use in areas
with no surveyed channel cross-section data (x, y). In reaches where surveyed channel
cross-section data is available, users can select the natural channel option to generate
FTABLEs from surveyed data.
The natural channel option produces channel profiles similar to those obtained with the
U.S. Army Corps of Engineers' HECRAS model. Just like the HECRAS program, when
entering (x, y) data, the x values must always increase from the left over-bank to the right
over-bank (Figure 8). Although the natural channel program is capable of generating
FTABLEs for many irregular channel shapes, it may not work for some channel cross-
sections. For example, the natural channel program does not work for divided channels or
for channels with fewer than six data points. In such cases, users may increase the
number of data points for example by interpolation, or choose one of the human-made
channel shapes to approximate the natural channel.
CIRCULAR CHANNEL
RECTANGULAR CHANNEL
TRIANGULAR CHANNEL
TRAPEZOIDAL CHANNEL
PARABOLIC CHANNEL
NATURAL CHANNEL
xl.yl
M
j4v4
x2,y2
x5,y5
:igure 8. Schematic diagram of a natural channel cross-section
Step 8. To use the natural channel FTABLE option, prepare cross-sectional profile (x, y)
data in comma-delimited text format by using a text editor such as Notepad. The user
must first populate the left-hand side of the input grid with channel length, Manning's
roughness coefficient, longitudinal slope, and height or depth increment. To import (x, y)
data for the right hand side of the grid table, point the mouse at the input grid table and
then right click to get "Import from CSV file" ( Figure 9).
5
-------
OPEN CHANNEL INPUT DATA
Channel Length (ft):
Mannings Value:
Longitudinal Slope (ft/ft):
Height Increment (ft):
0.05
0.025
Distance from Bank (ft):
Depth (ft):
Import from Spreadsheet
Import from CSV File
Clear Table
igure 9. Natural input grid table
STEP 9. Right click on "Import from CSV file" shown in Figure 9 to open an empty Java
Applet Window (Figure 10). Go to the input data file containing the (x, y) data (just a
notepad not shown here), then select all the (x, y) data then copy it.
= Import Data From CSV File
Open your CSV file. It should have a range of two numbers separated by commas.
Copy the range of numbers and paste (Ctrl+V) it into the text area below.
Click 'Import Data" to place the data into the grid.
Import Data
Java Applet Window
Figure 10. Data import screen
Step 10. The data in the notepad must have the format shown in Figure 11. Go back to the
empty Java Applet Window and hit CTRL+V to paste the data into the Applet Window
(Figure 11).
6
-------
Import Data From CSV File (^]
Open your CSV file. It should have a range of two numbers separated by commas.
Copy the range of numbers and paste (Ctrl+V) it into the text area below.
Click 'Import Data" to place the data into the grid.
0,6
3,5
6,4
9,3
12,2
15,1
18.0
21.1
24.2
27.3
30.4
33.5
36.6
Import Data
Java Applet Window
Figure 11. A Java Applet Window data import showing imported (x, y) data.
STEP 11. To transfer the pasted data into the natural channel grid, hit "Import Data" (see
the lower side of Figure 11). Make sure that the data is entered into the grid (Figure 12).
1
OPEN CHANNEL INPUT DATA
Distance from Bank (ft):
Depth (ft):
A
Channel Length (ft):
4000
0
6
A
3
5
~
Mannings Value:
0.05
6
4
Longitudinal Slope (ft/ft):
Height Increment (ft):
0.025
9
3
12
2
1.0
15
1
~
Figure 12. A natural channel showing imported data points
Calculate FTable
STEP 12. Generate an FTABLE by clicking on - - - . The default height
increment is one foot for the natural channel. To refine the resolution of the FTABLE, set
the height increment to any number from 0 to 1. The generated FTABLE can be
exported to a UCI following the instructions given in Step 7.
7
-------
Results Copy Results
depth (ft)
area(acres)
volurne(ac-ft)
outflowl (cfs)
0.00
0.00
0.000
0.00
1.00
0.55
0.275
8.57
2.00
1.10
1.102
54.44
3.00
1.65
2.479
160.52
4.00
2.20
4.408
345.70
5.00
2.75
6.887
626.79
6.00
3.31
9.917
1019.23
Figure 13. FTABLE generated for a natural channel
C. HSPF UCI FILE MANIPULATIONS
STEP 13. To place the generated FTABLE in a UCI file, users must have an HSPF
project that has existing FTABLES. It is wise to save a backup copy of the UCI file
before making any modifications. Select the UCI file to change in the HSPF project, open
it with a text editor, identify the FTABLE to change, and then paste the calculated
FTABLE (copied from the Web-tool) above or below the existing FTABLE. Give the
new FTABLE the same ID as the FTABLE to be replaced. Make sure to delete or
comment out the existing FTABLE.
*** TRAPEZOIDAL ***
FTABLE
rows cols
***
61 5
depth
area
volume
outflowl
riserorf ***
0.00
1.1
0.00
0.00
0.00
0.1
1.14
0.11
1.24
0.00
0.2
1.18
0.23
3.92
0.00
0.3
1.21
0.35
7.71
0.00
0.4
1.25
0.47
12.48
0.00
0.5
1.29
0.6
18.17
0.00
0.6
1.32
0.73
24.73
0.00
0.7
1.36
0.86
32.13
0.00
0.8
1.4
1
40.33
0.00
0.9
1.43
1.14
49.34
0.00
1
1.47
1.29
59.13
0.00
Figure 14. An FTABLE generated for a trapezoidal channel
STEP 14. Set the appropriate number of exits in the GEN-INFO block of the RCHRES
section of the RCHRES module (Figure 15). Note that only reach 8 has multiple exits.
8
-------
Also, set the Print Flags (not shown here) to 2.0 for the RCHRES section to allow the
model to generate an output for each time step. This is important for testing and
evaluation.
GEN-INFO
* Name Nexits Unit Systems Printer
*** RCHRES t-series Engl Metr LKFG
***
- X
in out
3
CIRCULAR PIPE
1 1
1 1
0
0
0
0
4
CIRCULAR PIPE
1 1
1 1
0
0
0
0
5
CIRCULAR PIPE
1 1
1 1
0
0
0
0
6
CIRCULAR PIPE
1 1
1 1
0
0
0
0
7
CIRCULAR PIPE
1 1
1 1
0
0
0
0
8
NATURAL
5 1
1 1
0
1
0
0
9
CIRCULAR PIPE
1 1
1 1
0
0
0
0
Figure 15. HSPF input table with bolded multiple exit reach
STEP 15. Select the exits that have control devices in HYDR-PARM1 and type those
whose exit numbers are to be routed downstream. Users can select specific flow control
exits by placing the exit numbers (4, 5, 6, 7, and 8) in the UCI file (Figure 15). Placing
zero in a HYDR-PARM1 column allows HSPF to ignore the flow from that particular
exit of the FTABLE.
HYDR-PARM1
* * * Flags for HYDR section
***RC HRES VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT
for each
*** x - X
FGFGFGFG possible
exit ***
possible
exit
possible exit
3
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
4
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
5
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
6
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
7
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
8
Oil
1 4 5 6
7 8
0 0 0 0
0
3 3 3 3 3
9
0 1 1
1 4 0 0
0 0
0 0 0 0
0
3 3 3 3 3
END HYDR-PARM1
Figure 16. HSPF input table with bolded multiple exit reach
9
-------
STEP 16. If more than one control device is used, one must modify the MASS-LINK
block to allow that volume-dependent outflows from multiple exits are routed
downstream (see bolded row of Figure 17).
MASS-LINK 5
<-Volume-> <-Grp> <-Member-><~Mult~> <-Target vols> <-Grp> <-Member-> ***
x x<-factor-> x x * * *
* * *Reach Transfer of FLOW * * *
RCHRES ROFLOW RCHRES INFLOW
RCHRES 8 0FL0W RCHRES INFLOW (multiple exit reach)
END MASS-LINK 5
Figure 17. A MASS-LINK Block with bolded multiple exit reach
STEP 17. Convert generated FTABLE channel length to miles and place it in the "LEN"
Column 1 of HYDR-PARM2. To convert feet to miles multiply feet by 0.000189394 and
substitute that number to the one for the existing FTABLE. Make sure to choose the
correct FTABLE ID Number.
HYDR-PARM2
*** RCHRES FTBW FTBU
LEN
DELTH
STCOR
KS
DB50
*** x - X
(miles)
(ft)
(ft)
(in)
1 0. 1.
2.8
22.
3.2
0.5
0.01
END HYDR-PARM2
Figure 18. HSPF input table showing reach length parameter in bold.
STEP 18. Save the UCI file and run the project with HSPFLite. If no errors are generated,
users can import the project into WinHSPF.
10
-------
D. Routing an Inflow Hydrograph through a Detention Basin (An example)
This example demonstrates how the HSPF model is used as a stormwater management
model. The model was applied to a small watershed for a single storm event to generate
an inflow hydrograph. The hydrograph was routed through a network of channels one of
which is a detention basin that has several flow control devices (Figure 19).
Figure 19. Schematic diagram of the channel network
11
-------
Note that flow in Reach 3 in the WDM file (EXAMPLE 1 .WDM) represents the inflow
hydrograph while flow in Reach 9 is the outflow hydrograph after the inflow hydrograph
was routed through the detention basin represented by Reach 8. The size and geometry of
the detention basin is determined through an iterative process that starts with the selection
of a basin geometry and size using the web-tool. This is followed by running the HSPF
model to route the inflow hydrograph until the desired outflow hydrograph is obtained.
The process is repeated until the desired size and geometry are achieved. In this example,
we used a 1-foot diameter underdrain orifice. For LID or other urban stormwater
modeling applications, consider the inflow hydrograph to represent post-development
runoff without mitigation, and the outflow hydrograph to represent post-development
runoff with BMPs in place. A goal may be to ensure that the post-development
hydrograph with BMPs in place is similar to the pre-development hydrograph
(Figure 20).
£
T
o
4
3
2
1
REACH 3
J
— REACH 9
I
12/31/197 1/1/1976 1/1/1976 1/1/1976 1/1/1976 1/1/1976 1/2/1976 1/2/1976 1/2/1976 1/2/1976
5 19:12 0:00 448 9:36 14:24 19:12 0:00 4:48 9:36 14:24
Time (minutes)
Figure 20. Inflow and outflow hydrographs simulated by the HSPF model
Users can download EXAMPLE1.UCI and EXAMPLE1.WDM files from this website
( http://www.epa.qov/athens/research/modelinq/ftable/index.htm ) and generate FTABLES
with and without control devices to replace those in the EXAMPLE1.UCI file. This
assumes that users have a good understanding of the HSPF model and can make changes
in the UCI using a text editor, run HSPF, and correct errors using the HSPFLite engine.
This web-tool extends HSPF applications to urban watersheds with limited sewer system
networks. The modeling results are comparable to those achieved with the USEPA
Stormwater Water Management Model's (SWMM5) under the Kinematic Wave option or
the TRANSPORT option in SWMM4. HSPF does not account for backwater effects,
entrance/exit losses, flow reversals, or pressurized flow. Under most circumstances, this
is not expected to measurably impact the accuracy of model predictions. However, the
12
-------
BMP simulation results are not strictly comparable to those achieved by using the
SWMM5 model's dynamic wave option. As such, we do not recommend the tool for the
design of complex sewer systems.
CONTACT US
If you have questions or would like to report bugs or make suggestions regarding the
web-tool, please contact the Center for Exposure Assessment Modeling (CEAM) at
CEAM-USERS@lists.epa.gov. Users may also contact the authors through the
basins@epa.gov , making sure that the subject line is "HSPF Web-tools".
DISCLAIMER
Although this Web-tool has been reviewed by its developers, no warranty, expressed or
implied, is made to the accuracy and functioning of the tools and related program
material nor shall the fact of its distribution constitute any such warranty and no
responsibility is assumed by the USEPA in connection therewith.
13
------- |