H2OMAP and InfoSWMM Sediment Transport Modeling

H2OMAP SWMM and InfoSWMM Sediment Transport Modeling

Sanitary and combined sewer systems can carry substantial loads of suspended solids (waste solids) which can accumulate and cause blockages thereby impairing the hydraulic capacity of the sewer pipes (by restricting their flow area and increasing the bed friction resistance). H2OMAP SWMM and InfoSWMM can simulate the transport and gravitational settling of (total suspended solids including grit) over time throughout the sewer collection system under varying hydraulic conditions. As long as flow velocity exceeds the critical/terminal velocity, H2OMAP SWMM and InfoSWMM assumes that the sewage flow has the capacity to transport all incoming . Deposited  particles are also assumed to be scoured and transported downstream when velocity of the sewage flow exceeds the terminal velocity. Settling starts when flow velocity falls below the critical velocity. In the model, transport of thet particles is governed by advection implying that the particles are transported at local flow velocity. 

The sediment transport modeling using H2OMAP SWMM and InfoSWMM  requires only few inputs, namely limiting flow velocity, particle settling velocity, and source node(s) and initial concentrations (in mg/l) at the source nodes. 

In order to specify the first two inputs (i.e., limiting flow velocity and particle settling velocity), the user should first select from the quality tab which in turn activates the editing tabs for particle settling velocity and limiting flow velocity. Specification of source node(s) and its/their initial concentration is similar to the method described above in relation to pollutant transport. The default values used by the model for limiting flow velocity and particle settling velocity are 2 ft/s and 0.1 ft/s, respectively.  User specified values over rid these default figures .

H2OMAP SWMM and InfoSWMM  deposition (in kg)  in pipes and  concentration (in mg/l) at manholes,  wet wells, and outlets are the outputs reported following successful simulation of  transport for a collection system.

Modified Basket Handle Cross Section Warnings

There is a rule in SWMM 5 that the depth cannot be less than half the bottom width for a modified basket handle(see below).  You always have to have a maximum depth less than 50 percent or 1/1 of the bottom width,  If you do not meet this criterion then the program will generate an invalid number warning.  This is the code from xsect.c that checks the validity of the cross section data:

    case MOD_BASKET:

        if ( p[1] <= 0.0 || p[0] <>

        xsect->yFull = p[0]/ucf;

        xsect->wMax  = p[1]/ucf;

Wave Of Sewage Flows Toward Tampa Bay

TBO > News

Wave Of Sewage Flows Toward Bay

Tribune photo by CANDACE C. MUNDY

Workers with Spectrum Underground Inc. work to repair a 20-inch sewage pipeline which broke in Town 'N Country this afternoon.

The Tampa Tribune

Published: September 13, 2008

TOWN 'N COUNTRY - Approximately 200,000 gallons of untreated sewage spilled into Sweetwater Creek on Friday afternoon, prompting a warning to residents along the creek to avoid the water, Hillsborough County officials said.

The spill occurred along Comanche Avenue just east of Hanley Road when a 20-inch sewage pipeline ruptured. The break was at a connection point to a section that had been replaced about eight weeks ago, officials said.

Because the work had been done so recently, it was under warranty, and the original contractor returned to fix the break, said Bill Bozeman, project manager for the county's water resource services. Bozeman did not know what caused it.

The fracture, reported by a passer-by at about 12:45 p.m., caused sewage to spill onto Hanley Road and ooze down Comanche toward the creek. The flow was contained two hours later. After five hours, a cloud of sewage still fogged the water along one of the creek's banks.

The section of Comanche where the spill occurred is home to a couple of businesses and a small strip of offices under construction. A narrow bridge over Sweetwater Creek leads to a neighborhood and to Sweetwater Organic Community Farm.

The farm does not rely on the creek for irrigation and the creek in that section is too shallow and choked with overgrowth in places for kayaking or swimming. County workers posted signs in English and Spanish notifying visitors of high bacterial levels and a health risk, telling them not to swim, wade or fish in the water.

Residents along the creek, which flows south to the Courtney Campbell Parkway area, are urged not to have any contact with the water for the next several days in the creek or the area where it flows into Tampa Bay.

While the contractor worked to repair the pipe, the county diverted the flow from nearby lift stations that serve the areas into tanker trucks.

The spill did not affect home use of water, Bozeman said.

The Water Resource Services staff will notify local and state environmental agencies, take samples and monitor the area where the spill occurred.

Manual de SWMM 5 en espanol

Manual de SWMM 5 en espanol

http://www.instagua.upv.es/swmm/descargas/Manual_SWMM5vE.pdf

SWMM 5 View Variables

SWMM 5 View Variables

There are four types of graphical variables in SWMM 5: (1) Subcatchements, (2) System, (3) Nodes and (4) Links.  The SWMM 5 Hydrology binary graphics file consists of 21 view variables for each subcatcment simulation in SWMM 5.  The variables are:
    

Subcatchment Variables	Description
SUBCATCH_RAINFALL	rainfall intensity
SUBCATCH_SNOWFALL	snowfall intensity
SUBCATCH_RUNOFF	total runoff flow rate
SUBCATCH_RUNOFF_IMPZero	runoff flow rate from zero imp area feb 2007
SUBCATCH_RUNOFF_IMP	runoff flow rate from imp area feb 2007
SUBCATCH_RUNOFF_Pervious	runoff flow rate from pervious area feb 2007
SUBCATCH_LOSSES	total losses (infil)
SUBCATCH_EVAP	watershed evaporation loss
SUBCATCH_DEPTH	watershed depth
SUBCATCH_GW_FLOW	groundwater flow rate to node
SUBCATCH_GW_FLOW_A1	groundwater flow rate to node
SUBCATCH_GW_FLOW_A2	groundwater flow rate to node
SUBCATCH_GW_FLOW_A3	groundwater flow rate to node
SUBCATCH_GW_ELEV	elevation of saturated gw table
SUBCATCH_GW_THETA	soil moisture
SUBCATCH_GW_PERCOLATION	aquifer deep percolation
SUBCATCH_SNOWMELT	watershed snow melt
SUBCATCH_SNOWDEPTH	watershed snow depth
SUBCATCH_FREEWATER	watershed snow depth
SUBCATCH_COLD	watershed cold content
SUBCATCH_SNOWAREA	watershed snow coverage
SUBCATCH_UL	soil thickness
SUBCATCH_FTOT	infiltration during an event
SUBCATCH_FU	current value of F
SUBCATCH_FUMAX	maximum value of F
SUBCATCH_MOISTURE	current soil mositure (less than porosity)
SUBCATCH_IMD	current IMD (Porisity - Moisture)
SUBCATCH_IMDbyEvent	IMD at the beginning of an event
SUBCATCH_SAT	Flag for saturation (1 is saturated)
SUBCATCH_INFIL_TIME	GA infiltration time
SUBCATCH_WLMAX	current infiltration RATE
SUBCATCH_NETPRECIP	rainfall intensity
SUBCATCH_BUILDUP	pollutant buildup concentration
SUBCATCH_WASHOFF	pollutant washoff concentration

The SWMM 5 system binary graphics file consists of 25 variables on one line for each system variable simulated in SWMM 5.  The variables are:

System Variables	Description
SYS_TEMPERATURE	air temperature
SYS_WINDSPEED	wind speed
SYS_RAINFALL	rainfall intensity
SYS_SNOWFALL	snow depth
SYS_RUNOFF	runoff flow
SYS_LOSSES	evap + infil
SYS_EVAP	evap
SYS_DWFLOW	dry weather inflow
SYS_GWFLOW	ground water inflow
SYS_IIFLOW	RDII inflow
SYS_EXFLOW	external inflow
SYS_INFLOW	total lateral inflow
SYS_FLOODING	flooding outflow
SYS_OUTFLOW	outfall outflow
SYS_STORAGE	storage volume
SYS_CE	continuity error for the basin
SYS_ITERATIONS	average iterations over the basin
SYS_SNOWDEPTH	snow depth
SYS_COLD	cold storage for the basin
SYS_SNOWMELT	snowmelt for the basin
SYS_RAINMELT	rainmelt for the basin
SYS_TS	time steps during the simulation
SYS_DWFLoad	total K3 line DWF load
SYS_WWFLoad	total K3 line WWF load
SYS_WWFLoadExtra	agency extra WWF Load

The SWMM 5 Node graphics binary file consists of 20 variables on one line for each junction/storage/outfall/divider  simulated in SWMM 5.  The variables are:

Node Variables	Description
NODE_DEPTH	water depth above invert
NODE_HEAD	hydraulic head
NODE_VOLUME	volume stored & ponded
NODE_LATFLOW	lateral inflow rate
NODE_IIFLOW	total rdii inflow rate
NODE_UH1	total rdii inflow rate from UH 1
NODE_UH2	total rdii inflow rate from UH 2
NODE_UH3	total rdii inflow rate from UH 3
NODE_DWFFLOW	total DWF inflow rate
NODE_INFLOW	total inflow rate
NODE_OUTFLOW	total outflow rate
NODE_OVERFLOW	overflow rate
NODE_CE	node ce
NODE_AREA	node surface area
NODE_DQDH	node surcharge dqdh
NODE_DENOM	node surcharge dqdh
NODE_ITERATIONS	node iterations to this time step
NODE_TIMESTEP	node iterations to this time step
NODE_CONVERGENCE	node iterations to this time step
NODE_QUAL	concentration of each pollutant

Link Variables