SWMM-USERS Digest - 13 May 2008 to 14 May 2008 (#2008-88)

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May 15, 2008, 12:00:39 AM5/15/08

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There are 9 messages totalling 664 lines in this issue.

Topics of the day:

1. Sanitary Sewer (3)
2. Weir Height (5)
3. Armco, "Handbook of Water control"

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Date: Wed, 14 May 2008 11:01:48 +0500
From: saeedmahar <saeed...@ACES.NET.PK>
Subject: Sanitary Sewer

Q: I am inteested in using SWMM for design of an independent sanitary sewer system (not a combined system). I did not find any thing in the help menu. Can some one guide me on this issue, preferably with an input file?
Saeed Mahar

------------------------------

Date: Wed, 14 May 2008 11:29:07 -0400
From: Robert E Dickinson <Robert.E....@US.MWHGLOBAL.COM>
Subject: Re: Sanitary Sewer

Saeed,

I already send you an example of a stand alone sanitary system but your
question made me think:

How different is a sanitary model in SWMM 5 versus a combined sewer mode?

(1) A sanitary only model can have 10 of the major object types in SWMM 5.
It is only missing the objects exclusively connected to a subcatchment.

GAGE, // rain gage
SUBCATCH, // subcatchment
NODE, // conveyance system node
LINK, // conveyance system link
POLLUT, // pollutant
LANDUSE, // land use category
TIMEPATTERN, // dry weather flow time pattern
CURVE, // generic table of values
TSERIES, // generic time series of values
CONTROL, // conveyance system control rules
TRANSECT, // irregular channel cross-section
AQUIFER, // groundwater aquifer
UNITHYD, // RDII unit hydrograph
SNOWMELT, // snowmelt parameter set
SHAPE // custom conduit shape

So that is a 2/3 similarity based just on the major object types; however
all of the hydraulic objects of SWMM 5 can be in either a combined,
sanitary or stormwater only network.

Best and Kind Regards,
Robert Edgar Dickinson
MWH Soft Inc.

saeedmahar <saeed...@ACES.NET.PK>
Sent by: SWMM-USERS <SWMM-...@listserv.uoguelph.ca>
05/14/2008 02:01 AM
Please respond to
SWMM-USERS <SWMM-...@listserv.uoguelph.ca>

To
SWMM-...@listserv.uoguelph.ca
cc

Subject
[SWMM-USERS] Sanitary Sewer

Q: I am inteested in using SWMM for design of an independent sanitary
sewer system (not a combined system). I did not find any thing in the help
menu. Can some one guide me on this issue, preferably with an input file?
Saeed Mahar

------------------------------

Date: Wed, 14 May 2008 10:50:21 -0500
From: Muralikumar Katta-Muddanna <mka...@ENID.ORG>
Subject: Re: Sanitary Sewer

Robert,
If you don't mind can you send me the example of standalone sanitary system. I really appreciate it.
Thank you,
Murali.

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of Robert E Dickinson
Sent: Wednesday, May 14, 2008 10:29 AM
To: SWMM-...@listserv.uoguelph.ca
Subject: Re: [SWMM-USERS] Sanitary Sewer

Saeed,

I already send you an example of a stand alone sanitary system but your
question made me think:

How different is a sanitary model in SWMM 5 versus a combined sewer mode?

(1) A sanitary only model can have 10 of the major object types in SWMM 5.
It is only missing the objects exclusively connected to a subcatchment.

So that is a 2/3 similarity based just on the major object types; however
all of the hydraulic objects of SWMM 5 can be in either a combined,
sanitary or stormwater only network.

Best and Kind Regards,
Robert Edgar Dickinson
MWH Soft Inc.

saeedmahar <saeed...@ACES.NET.PK>
Sent by: SWMM-USERS <SWMM-...@listserv.uoguelph.ca>
05/14/2008 02:01 AM
Please respond to
SWMM-USERS <SWMM-...@listserv.uoguelph.ca>

To
SWMM-...@listserv.uoguelph.ca
cc

Subject
[SWMM-USERS] Sanitary Sewer

Q: I am inteested in using SWMM for design of an independent sanitary
sewer system (not a combined system). I did not find any thing in the help
menu. Can some one guide me on this issue, preferably with an input file?
Saeed Mahar

--
This message has been scanned for viruses and
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believed to be clean.

------------------------------

Date: Wed, 14 May 2008 09:34:28 -0700
From: Mark Boucher <mb...@PW.CCCOUNTY.US>
Subject: Weir Height

For a weir, what is the weir height for? Is it a vertical limit, like
the top of an opening, at which point the weir is treated like an
orifice? It appears to be a vertical distance above the weir crest and
not from the crest to the channel floor.

Mark Boucher, PE
Senior Hydrologist
Contra Costa County Flood Control and Water Conservation District
Martinez, California

------------------------------

Date: Wed, 14 May 2008 12:35:09 -0400
From: Rob James <r...@COMPUTATIONALHYDRAULICS.COM>
Subject: Re: Weir Height

Mark,

You're correct. The Inlet Offset attribute defines the crest height above
the inlet node invert elevation.

Sincerely,

Rob James
Computational Hydraulics Int.
www.computationalhydraulics.com
Tel. 519-767-0197

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of Mark
Boucher
Sent: Wednesday, May 14, 2008 12:34 PM
To: SWMM-...@listserv.uoguelph.ca
Subject: [SWMM-USERS] Weir Height

Mark Boucher, PE
Senior Hydrologist
Contra Costa County Flood Control and Water Conservation District
Martinez, California

------------------------------

Date: Wed, 14 May 2008 13:12:20 -0400
From: Robert E Dickinson <Robert.E....@US.MWHGLOBAL.COM>
Subject: Re: Weir Height

Hi Mark and Rob,

I think some of the confusion regarding weir height in SWMM models is due
to multitasking attributes of SWMM. Weirs were originally added to SWMM
to better simulate diversions in sanitary/combined networks. The
diversion was a hole in the side of the chamber with a crest elevation or
depth, a weir length and a weir top or weight height - in other words it
was a large rectangular hole in the concrete used to divert large flows to
outfalls. The weir data defines the shape and crest elevation of that
hole.

SWMM evolved over time and weirs started to be applied to stormwater
networks. The weir crest and weir length still made sense in this context
but the weir height became less defined and became the defining depth or
elevation in which the flow over the weir became more like open channel
flow. In many models that I have seen the user will set the weir height
to a large value so that it never becomes an orifice in a stormwater
network.

Best and Kind Regards,
Robert Edgar Dickinson
MWH Soft Inc.

Rob James <r...@COMPUTATIONALHYDRAULICS.COM>
Sent by: SWMM-USERS <SWMM-...@listserv.uoguelph.ca>
05/14/2008 12:35 PM
Please respond to
r...@COMPUTATIONALHYDRAULICS.COM

To
SWMM-...@listserv.uoguelph.ca
cc

Subject
Re: [SWMM-USERS] Weir Height

Mark,

You're correct. The Inlet Offset attribute defines the crest height above
the inlet node invert elevation.

Sincerely,

Rob James
Computational Hydraulics Int.
www.computationalhydraulics.com
Tel. 519-767-0197

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of
Mark
Boucher
Sent: Wednesday, May 14, 2008 12:34 PM
To: SWMM-...@listserv.uoguelph.ca
Subject: [SWMM-USERS] Weir Height

Mark Boucher, PE
Senior Hydrologist
Contra Costa County Flood Control and Water Conservation District
Martinez, California

------------------------------

Date: Wed, 14 May 2008 10:35:49 -0700
From: Mark Boucher <mb...@PW.CCCOUNTY.US>
Subject: Re: Weir Height

Robert. Your background on this model is invaluable. Thanks for taking
the time to explain this.

Mark Boucher

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of
Robert E Dickinson
Sent: Wednesday, May 14, 2008 10:12 AM
To: SWMM-...@listserv.uoguelph.ca
Subject: Re: [SWMM-USERS] Weir Height

Hi Mark and Rob,

I think some of the confusion regarding weir height in SWMM models is
due
to multitasking attributes of SWMM. Weirs were originally added to SWMM
to better simulate diversions in sanitary/combined networks. The
diversion was a hole in the side of the chamber with a crest elevation
or
depth, a weir length and a weir top or weight height - in other words
it
was a large rectangular hole in the concrete used to divert large flows
to
outfalls. The weir data defines the shape and crest elevation of that
hole.

SWMM evolved over time and weirs started to be applied to stormwater
networks. The weir crest and weir length still made sense in this
context
but the weir height became less defined and became the defining depth or
elevation in which the flow over the weir became more like open channel
flow. In many models that I have seen the user will set the weir height
to a large value so that it never becomes an orifice in a stormwater
network.

Best and Kind Regards,
Robert Edgar Dickinson
MWH Soft Inc.

------------------------------

Date: Wed, 14 May 2008 14:34:55 -0400
From: Rob James <r...@COMPUTATIONALHYDRAULICS.COM>
Subject: Re: Weir Height

In case my answer is confusing, I meant you are correct... in your
assumption that the weir Height attribute is the vertical distance from the
weir crest to the top of the opening (as would be applicable for underground
weir structures with ceilings).

You are also correct in that an equivalent orifice equation is used to
compute flow when the weir is submerged (head is above the top of the weir
opening crown elevation, where the weir opening crown elevation = inlet node
invert + weir inlet offset + weir height). For submerged weirs (tail water
higher than the crest of the weir), a flow correction is applied with the
Villemonte eqn., otherwise flow is simply defined by the appropriate
sharp-crested weir eqn. (depending on the weir type selected). The same set
of equations apply no matter which direction the flow is in (i.e. weirs
handle reverse flow in the same way), with the exception of side flow weirs,
which behave as transverse weirs under reverse flow, and of course baring
the use of the flap gate option which prevents any reverse flow. For flap
gates in weirs and orifices (SWMM5.0.013) there is also a small
velocity-dependent head loss calculated from an equation derived by Floyd
Nagler (State U of Iowa) and referenced in some ARMCO reports.
Interestingly, this head loss isn't calculated for flap gates in conduits,
in favor of static user-defined head loss coefficients. I still haven't
figured out how to embed graphics such that they are archived in the Q&A -
however the equations are in the link.c source code file (Weir Methods
section) and relatively easy to decipher. They are also in our Urban
Drainage Modeling Work Book and will be included in the upcoming US EPA
manual (no release date yet that I know of).

Thanks Bob for the historical context.

Sincerely,

Rob James
Computational Hydraulics Int.

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of Rob
James
Sent: Wednesday, May 14, 2008 12:35 PM
To: SWMM-...@listserv.uoguelph.ca
Subject: Re: [SWMM-USERS] Weir Height

Mark,

You're correct. The Inlet Offset attribute defines the crest height above
the inlet node invert elevation.

Sincerely,

Rob James
Computational Hydraulics Int.
www.computationalhydraulics.com
Tel. 519-767-0197

Mark Boucher, PE
Senior Hydrologist
Contra Costa County Flood Control and Water Conservation District
Martinez, California

------------------------------

Date: Wed, 14 May 2008 14:58:13 -0400
From: Robert E Dickinson <Robert.E....@US.MWHGLOBAL.COM>
Subject: Armco, "Handbook of Water control"

Hi,

If I can add one more historical note here. The ARMCO citation is not
completely correct in the
SWMM 3 and SWMM 4 manuals. The actual pages are:
Armco, "Handbook of Water control," Lederer, Street, and Zeus Co.,
Inc., Berkeley, California, 1946 pp. 383-512.
This has been digitized and can be obtained by searching in Google Books.
ARMCO was based in Middleton, Ohio which explains the SWMM 3/SWMM 4
citation.

Best and Kind Regards,
Robert Edgar Dickinson
MWH Soft Inc.

Rob James <r...@computationalhydraulics.com>
Sent by: SWMM-USERS <SWMM-...@listserv.uoguelph.ca>
05/14/2008 02:34 PM
Please respond to
r...@computationalhydraulics.com

To
SWMM-...@listserv.uoguelph.ca
cc

Subject
Re: [SWMM-USERS] Weir Height

In case my answer is confusing, I meant you are correct... in your
assumption that the weir Height attribute is the vertical distance from
the
weir crest to the top of the opening (as would be applicable for
underground
weir structures with ceilings).

You are also correct in that an equivalent orifice equation is used to
compute flow when the weir is submerged (head is above the top of the weir
opening crown elevation, where the weir opening crown elevation = inlet
node
invert + weir inlet offset + weir height). For submerged weirs (tail water
higher than the crest of the weir), a flow correction is applied with the
Villemonte eqn., otherwise flow is simply defined by the appropriate
sharp-crested weir eqn. (depending on the weir type selected). The same
set
of equations apply no matter which direction the flow is in (i.e. weirs
handle reverse flow in the same way), with the exception of side flow
weirs,
which behave as transverse weirs under reverse flow, and of course baring
the use of the flap gate option which prevents any reverse flow. For flap
gates in weirs and orifices (SWMM5.0.013) there is also a small
velocity-dependent head loss calculated from an equation derived by Floyd
Nagler (State U of Iowa) and referenced in some ARMCO reports.
Interestingly, this head loss isn't calculated for flap gates in conduits,
in favor of static user-defined head loss coefficients. I still haven't
figured out how to embed graphics such that they are archived in the Q&A -
however the equations are in the link.c source code file (Weir Methods
section) and relatively easy to decipher. They are also in our Urban
Drainage Modeling Work Book and will be included in the upcoming US EPA
manual (no release date yet that I know of).

Thanks Bob for the historical context.

Sincerely,

Rob James
Computational Hydraulics Int.

Mark,

You're correct. The Inlet Offset attribute defines the crest height above
the inlet node invert elevation.

Sincerely,

Rob James
Computational Hydraulics Int.
www.computationalhydraulics.com
Tel. 519-767-0197

-----Original Message-----
From: SWMM-USERS [mailto:SWMM-...@listserv.uoguelph.ca] On Behalf Of
Mark
Boucher
Sent: Wednesday, May 14, 2008 12:34 PM
To: SWMM-...@listserv.uoguelph.ca
Subject: [SWMM-USERS] Weir Height

Mark Boucher, PE
Senior Hydrologist
Contra Costa County Flood Control and Water Conservation District
Martinez, California

------------------------------

End of SWMM-USERS Digest - 13 May 2008 to 14 May 2008 (#2008-88)
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