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Technical Description
XP Solutions
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Overview
GIS Integration - connect to OBDC compliant databases, import/export & display ESRI shape files and MapInfo
files. Directly input GIS data with the graphical interface. Display and color code attributes of any object.
CAD Integration - import .dxf and .dwg files and manage the display of layers. Convert the layers to model
nodes, links and catchments. LandXML files of networks and terrain can be imported/exported.
Scenario Manager - compare graphically and in tabular format model results for various scenarios. All model
data including 2D layers are available to the Scenario Manager.
xpviewer
- distribute your model to stakeholders in a read-only format. Model simulations, including all
scenarios may be viewed with downloadable free software.
2 Dimensional Hydrodynamic Modeling - model overland ows, street ooding and oodplains using either a
1D/2D integrated model or as a comprehensive 2D only model.
Animations - review and present model results through customizable animations including dynamic long
section, color coded dynamic plan view and the synchronized long and cross section view with hydrographs. 2D
plan animation includes vectors for ow and velocity and color coding of cells for many map types such as
depth, elevation and hazard. These animations oer an unparalleled visualization of model results and can be
directly saved to an AVI file.
Real Time Control Simulation -
xpswmm‘
s Real Time Control (RTC) module expands the control capabilities for
gates valves, ow regulators, moveable weirs and telemetry-controlled pumps. It extends RTC to a
comprehensive management and design tool. RTC sensors can be any combination of velocity, ow and water
level at nodes, conduits, pumps, weirs or orifices in the network.
Global Storms - simulate and compare model runs using a series of storms such as design storms with varying
return period or storm durations from the Global Database. The Global Database dramatically reduces data
redundancy and the associated problems of updating multiple locations when changes are made. Examples of
global data include rainfall, infiltration, pollutant description, cross sections, dry weather ows and pump curves.
Dual Drainage - simulate ow in conduits and in streets and situations where ow is limited by inlet capacity.
EPA SWMM 5.0 Compatibility -
xpswmm
can import from or export to SWMM5 model formats.
FEMA Approval - approved by US Federal Emergency Management Authority (FEMA) as meeting the minimum
requirements for using a computer model in oodplain mapping for the National Flood Insurance Program.
Approval is for Hydrology and 1 and 2 dimensional Hydraulics.
Hydromodification -
xpswmm
produces ow duration and exceedance curves for continuous simulations.
Coupled with the scenario manager and the monthly and annual changes to parameters you can evaluate the
impacts of development and mitigation scenarios.
CMOM -
xpswmm
has a suite of integrated tools that will assist utilities in compiling with the US EPA’s Capacity,
Management Operations and Maintenance regulations.
NPDES -
xpswmm
models the sewer collection network which can be used to assist National Pollutant Discharge
Elimination System permittees to obtain permits and comply with the conditions.
LID - Low Impact Development, also known as Water Sensitive Urban Design (WSUD) or Sustainable Drainage
Systems (SuDS) is a philosophy that focuses on specific sustainable water conservation goals. Its aim is to
minimize adverse impacts to the hydrologic cycle and water quality principles of low impact development
require that projects not increase peak ows.
Evacuation Planning -
xpswmm
2D models can include the analysis of evacuation planning routes and
graphically report time to inundation and duration of inundation. Additionally, user defined hazard mapping
can be generated using depth, velocity and debris factors.
Special
Applications
Key
Features
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Technical Description
XP Solutions
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xpswmm
simulates the complete hydrologic cycle in rural and urban watersheds. Beginning with single or multiple rainfall events and
dry weather ows, it models ows through collection, conveyance and treatment systems to the final outfalls. All hydrologic process-
es including snowmelt, evaporation infiltration, surface ponding and ground-surface water exchanges are included in the model.
Local hydrology can be further described by redirecting ows from impervious areas to pervious surfaces to allow infiltration.
Rainfall
Users may select either design storms or actual recorded rainfall events. Rainfall hyetographs may be linked to a
model using o line files or assigned from a global list to catchments. Continuous simulation can be used to
evaluate Hydromodification and model catchment response to long term rainfall records while including
multiple rainfall stations.
Design storms for any duration and return period may be created from a library of rainfall patterns that includes:
SCS Types: I, IA, II, Florida Modified, III, B
Hu Distributions
Chicago Storm
AR&R temporal patterns
UK Summer and Winter Storm Patterns
Storms from localized templates
User defined distributions
Each subcatchment can reference a separate hyetograph
enabling the modeling of radar rainfall data, localized storm
events or the timing of the hyetographs can be adjusted to
simulate movement of a storm across a watershed.
xpswmm
also models snowmelt using the Degree-Day method developed by the US National Weather Service.
Runo
There are numerous methods available for computing storm
runo hydrographs for event or continuous simulations. These
are:
Non-linear Runo Routing (US EPA Runo Method)
Laurenson’s Non Linear Runo Routing (RAFTS)
SCS Unit Hydrographs using a Curve Number with
curvilinear or triangular unit hydrographs.
Kinematic Wave
Clark Unit Hydrograph
Snyder Unit Hydrograph
Alameda County Snyder and Rational methods
Nash Unit Hydrograph
Santa Barbara Urban Hydrograph
Time Area
Rational Method
LA County Modified Rational Method
Sacramento County Nolte and Hydrograph Methods
Colorado Urban Hydrograph Procedure (CUHP)
EPA RTK Unit Hydrograph for RDII
5 UK Methods: Variable PR, Wallingford, ReFH, FEH, and FSR
Direct Rainfall on 2D Grid with IC or Green-Ampt infiltration
Hydrology
xpswmm
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Technical Description
XP Solutions
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Non-Linear
Runo
Routing
The primary runo hydrograph generation method is the EPA
SWMM non-linear runo method. Overland ow hydrographs are
generated by a routing procedure using Manning’s equation and a
lumped continuity equation. Surface roughness and depression
storage for pervious and impervious area parameters further
describe the catchment. The subcatchment width parameter is
related to the collection length of overland ow and is easily
calculated based on watershed characteristics. Urban, suburban,
and rural areas of any size may be simulated using non-linear
reservoir routing.
The unit hydrograph methods such as SCS, SBUH, LA County Modified Rational, etc. are primarily used for single
event simulations. The SWMM runo method is a deterministic hydrologic method suitable for comprehensive
analysis and design including the simulation of LID (WSUD) using catchment surface redirection capabilities.
Additional seasonal and annual adjustments can also be made the hydrologic parameters to capture the eects
of a changing watershed over time. For example, frozen ground during winter months can be simulated by
adjusting infiltration with monthly factors and development can be modeled by increased impervious
percentage over several years.
Groundwater
Interactions
Subcatchment infiltration can be coupled to groundwater and is computed using a selection of these methods:
If groundwater is simulated then the unsaturated zone interacts with the infiltration from the watershed surface.
Decreased infiltration increases surface runo. For example, the water table can rise to the ground level from
excessive infiltration and cut o the infiltration.
The recovery of depression storage between storms is achieved by means of evaporation as well as recovery of
infiltration capacity. Sub-surface ow is routed through saturated and unsaturated zones using the method of
lumped storages. Sub-surface outow is computed using a power equation. Seasonal variation in groundwater
levels can drive base ows in streams and infiltration in sewers.
Horton (including cumulative depth cuto)
Green-Ampt
SCS method with optional sub-surface routing
Initial and Continuing loss
Proportional loss
Initial and Proportional
Hydrology
xpswmm
Seasonal
Parameter
Changes
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Technical Description
XP Solutions
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The versatility of
xpswmm
allows modelers to load and simulate hydraulics in both separate sanitary and combined sewers. Temporal
variation of both sanitary ow and groundwater infiltration are fully accommodated.
Dry
Weather
Flows
Sanitary ows may be loaded globally using the EPA SWMM Method.
Sanitary ows may also be locally loaded using hourly and daily variation factors and peaking factors to produce
unique loads to each node using these methods:
Direct ow
Unit ow rate
Census based
In all cases base ows may be multiplied by hourly
and daily temporal variation factors to produce
sanitary loads to each node. Multiple computations
of Dry Weather Flow can be stored in the global
database and applied to a hydraulics node.
Wet Weather
Wet weather ows in sanitary and combined sewers, sometimes referred to as rainfall derived inow and
infiltration (RDII), can be incorporated into an
xpswmm
model with a variety of techniques:
Infiltration based on the EPA SWMM Transport infiltration algorithm
Specifying infiltration as constant ows or user defined hydrographs to manholes
Regression based RDII input as user defined hydrographs
Simulating groundwater mounding to generate RDII
RDII hydrographs based on simulated rainfall and unit hydrograph methods for sewershed data
RTK Unit Hydrograph Method
Sanitary Flows
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Technical Description
XP Solutions
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xpswmm
solves the complete St. Venant (Dynamic Flow) equations for gradually varied, one dimensional, unsteady ow throughout
the drainage network. The calculation accurately models backwater eects, ow reversal, surcharging, pressure ow, tidal outfalls
and interconnected ponds. The model allows for looped networks, multiple outfalls and accounts for storage in conduits. Flow can
also be routed using kinematic or diusive wave methods. Additionally, models can be solved using the SWMM5 engine.
Inlet Capacity
and
Dual Drainage
xpswmm
determines the captured ow for a range of inlet types including slot, grate and curb inlets. Options for
calculating the inlet capacity are:
Maximum capacity
Rated by approach depth or ow
Flow not captured by the inlet is stored on the surface or lost from the system or diverted automatically to
overland ow conduits. Additionally, with the included
xp2D
module, surface ows can be routed on a 2D grid.
Conduit
Shapes
There are more than 30 dierent pre-defined hydraulic elements available for hydraulic routing and user-
defined open and closed conduits making the number of available shapes virtually limitless:
Circular
Rectangular
Horseshoe
Trapezoidal Channel
Rectangular Triangular Bottom
Basket-handle
Modified Basket-handle
Egg-shaped
Power Function Channel
Semi-Elliptic
Catenary
Gothic
Semi-Circular
Rectangular Round Bottom
Arch
Vertical and Horizontal Ellipse
User-Defined (HEC-2) Open Channel
Rating Curve
Regulator
Reaction Link
User-Defined Closed Section
xpswmm
can also accommodate channels and conduits having roughness changes as a function of depth and
can simulate sediment deposition and transport in all conduit shapes.
Hydraulics
Node Data
Dialogs
Data is easily entered and reviewed in graphically enhanced
dialogs. Check boxes indicate which options are invoked. Radio
buttons are used for selecting a single option from a group.
Copy and paste tools are used to replicate data between
multiple objects. Tooltips are available indicating field name,
parameter description and units when the cursor hovers over a
field.
HEC 22 methods
Local and Global 2D Inow Capture equations
xpswmm
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Technical Description
XP Solutions
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Pumps
Pumping of stormwater or wastewater is easily modeled in
xpswmm
. A pump station may be represented as
either an in-line lift station, or an o-line node representing a wet-well, from which the contents are pumped to
another node or outfall. Using a multilink up to seven pumps may be assigned to a single pump station
representing seven individually controlled pumps or seven settings for a variable speed pump.
Pumps may be one of six types:
Rated by Well Volume An in-line or o-line pump station with a wet well; the rate of pumping depends
upon the volume (level) of water in the wet well.
Rated by Depth in Node An in-line or o-line lift station that pumps according to the level of the water
surface at the junction being pumped.
Rated By Dynamic Head An in-line or o-line pump that pumps according to the depth (head)
dierence over the pump using a multi point pump curve and starting and stopping elevations.
Rated By Static Head An in-line or o-line pump that pumps according to the head at the upstream
node using a multi point pump curve and starting and stopping elevations.
Special Dynamic Head These pumps use a rule curve to modify the ow of the dynamic head pump
based on the depth at either an adjacent or non-adjacent node.
Variable Speed These pumps are defined by pump curves that are based on wet well depth or other user
defined parameters.
Control
Structures
and
Diversions
In gravity conveyance systems, a variety of structures are used to measure, control and divert ows. In
xpswmm
all diversions occur from nodes and the complex hydraulics of ow regulation devices are modeled in links. User
defined diversion rules that can direct ow to the appropriate node as Control devices in
xpswmm
include:
Weirs:
Transverse
Side ow
Inatable
Bendable
User-defined geometry
Orifices:
Circular bottom
Circular side
Rectangular bottom
Rectangular side
Orifices may have time dependent area and discharge
coecients.
Hydraulics
xpswmm
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Technical Description
XP Solutions
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Real Time
Control
xpswmm
’s Real Time Control (RTC) add-on module expands existing depth based control capabilities for gates,
valves, ow regulators, moveable weirs and telemetry-controlled pumps. It extends RTC to a comprehensive
simulation tool. The sensors can be any combination of time and date variables, conduit velocity and ow, node
depth and elevation, and ows in pumps, weirs or orifices. The comprehensive real time control option provides
the ability to control any conduit, pump, weir, orifice or rating curve from an unlimited number of sensors.
The types of elements subject to RTC and the Parameters capable of being controlled are:
Other control parameters include a variety of time and date options, ramp times and target values. Operators
can be concatenated with Boolean operators and parameters can be compared with other sensors or with
absolute values. Real time control can be activated only during a certain time period (schedule) and the control
can ramp on and/or o over a user-defined time period.
Detention
Storage
In addition to conduits, channels and other ow elements, ow may also be routed through a variety of dierent
storage shapes. The shape of the storage may be defined as:
Constant surface area (tank)
A power function
Also, a stepwise linear relationship may be defined as:
Stage vs. surface area
Elevation vs. surface area
Stage vs. volume
Elevation vs. volume
The routing of ows through detention storage units is performed by:
Modified Puls method in the kinematic wave of the Sanitary layer
Dynamic ow equations (St. Venant) in the Hydraulics layer
Interconnected ponds and detention basins can be modeled in either parallel or series. Storage can be assigned
from the invert of a node to represent typical detention ponds or from the ground surface to represent surface
storage such as trap-lows, sag inlets or ooded inlets and intersections.
Element
Parameter
Conduit
Flow, Roughness, Diameter (or Depth)
Node
Depth, Elevation
Pump
On Elevation, O Elevation, Speed Factor, Pump Flow Rate, Well Volume
Weir
Flow, Crest Elevation, Surface Elevation, Length, Discharge Coecient
Orifice
Area, Discharge Coecient
Rating Curve
Flow
Hydraulics
xpswmm
Documents you may be interested
Documents you may be interested
