Wastewater Networks Modeling Using InfoWorks CS

Omar Habouch & Nicholas BroadbentOctober 2009

Introduction

• Analytical tool to manage and maintain network models over a long time period.

• Share model data among a workgroup of users.

• Import model data from other systems. (Format restricted)

• View a geographical representation of the network on screen, with the network

displayed over the top of a detailed local map. (GIS)

• Enter rainfall and other time-series or event data (either recorded or synthetic).

• Perform hydraulic simulations to model the effects of a particular series of events.

• Produce reports and graphs, demonstrating the results of the simulations.

• Assess different scenarios/alternatives.

InfoWorks CS is a comprehensive software application for the management of urban drainage network models. The software provides a master database for storing network and hydraulic data and includes the routines necessary to import, create and edit that data.

Why use InfoWorks CS?

• The system provides fast, accurate and stable hydraulic modelling of

the key elements of wastewater systems.

• The software incorporates full solution modelling of backwater effects

and reverse flow, trunk sewers, complex pipe connections and complex

ancillary structures.

• Interactive views (plan views, long sections, spreadsheet-style grids,

time-varying graphs, three-dimensional junction view and access to the

underlying data is available from any graphical or geographical view.

• All views can be animated to show, analyze, and report results.

• It contains comprehensive diagnostic error checking and warning

routines.

Wastewater modeling

• The data out is only as good as the data in..! Verify..!

Why use InfoWorks CS?

• Large scale surface water and sewerage master planning

• Implementation of SUDS using the water cycle, infiltration and inflow

methods

• Real Time Control for Urban Drainage systems

• Undertake hydraulic analysis of wastewater treatment works

• Combined / wastewater interceptor system design and analysis

• Flooding and pollution prediction

• Enables identification and justification of cost effective infrastructure

improvements

• Secondary drainage and urban storm water system assessment and

management (3rd Party Reviews)

• Asset management tool in conjunction with InfoNET

Example applications

Why use InfoWorks CS?

Plan View

Trunk Sewer

Pump Sump

Pump

Rising Main

Sub-catchment

Why use InfoWorks CS?

Long Section

Trunk Sewer

Pump Sump

Rising Main

Head

Manhole

Ground Level

Why use InfoWorks CS?

• Ability to work with three types of databases (JET, Oracle, and SQL)

• Current and historical model network versions can be viewed.

• Data Flags are assigned to each asset attribute to identify its source. (Audit trail)

• Produce detailed report about changes between two model versions.

• Storing data in a centralised and controlled database to maintain the model data security in terms of data deletion and recovery.

• A group management approach can be achieved by several users on the same project or multiple projects.

Database management system and audit trail

Recommended Modeling Flow Diagram*

Geographic/Demographic Data Collection

Analysis:

Building the Model

Does the Model Exist?

No

Data Import

Extent and Level of Details Identification

Data Import and adaptation to suit InfoWork CS Modelling Environment

(if Required)

Model Simulation & AnalysisModel Verification & Re-verification

Reporting & Documentation

* Flow Chart adapted from Wessex Design Standard DS 520 (2008) and WaPUG Code of Practice for the Hydraulic Modelling Of Sewer Systems

Yes

• Manholes Naming• Connectivity• Outfalls• Long Sections• Ancillaries• etc…

• Model Naming• Dry Weather Flow Peaking Factors• Model Testing• Update to Design Horizon• Model analysis• Model Results

• Existing Flow Survey

• New Flow Survey

Data Import/Export

• All networks events and data from WASSP, WALLRUS and HydroWorks.

• Data from MapInfo (e.g. contributing areas, road/roof polygon area, and population data).

• AutoCAD DXF and DWG files, ESRI Shape files, data in delimited ASCII, dBase DBF, Microsoft Access file formats and CSV files.

Data import

• All networks data and events required for simulation in HydroWorks.

• Network data and results to MapInfo and eventually to AutoCAD DXF and DWG files, ESRI Shape and Intergraph/MicroStation Design

• To CSV files and subsequently to MS Excel or Access

Data export

Wastewater Diurnal Profile

• Flow fractions have to sum up to 24 when DP is taken for 24hrs readings.

Sample Simulation

Sample Simulation

Analysis & Alternatives Comparison

Model Element Analysis/Comparison Aspect

Manhole Flood Depth, Flood Volume, Infiltration Loss, Inflow, Level, Volume Lost, etc.

Pipe Flow, Froude Number, Hydraulic Gradient, Infiltration Loss, Lateral Inflow, Surcharge State, Velocity, etc.

Pump Flow, Pump State, etc.

Analysis & Alternatives Comparison

Pipe Surcharge State:

• <1 => Pipe is not surcharged

• 1.00 => Hydraulic gradient is less than or equal to pipe gradient

• 2.00 => Hydraulic gradient is greater than pipe gradient

Ground Level

Hydraulic

Gradient

Hydraulic

Gradient

HG

GL

HG

GL

Analysis & Alternatives Comparison

>A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 90>DWF>A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 80>DWF>A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 70>DWF

Level (m A D)Min

- 5 .298- 5 .299- 5 .298

Max- 0 .392- 1 .849- 3 .327

Multiple S imulations P lot P roduced by HabouchO M (9 /27 /2009 12 :10 :43 P M) P age 1 of 1S im: >A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 90>DWF (7 /29 /2009 1 :25 :11 P M)S im: >A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 80>DWF (7 /29 /2009 3 :50 :39 P M)S im: >A SP SU >Run Group_ 1>A lternatives>FP s added to P S 5 - 12 - 17_ 70>DWF (7 /29 /2009 8 :03 :38 P M)Selection Lis t: C us tom Selection

Trial3- 90% population

Trial2- 80% population

Trial1- 70% population

1ST Day 2nd Day 3rd Day

Case Studies

1. InfoWorks CS was used to:

• Model the full existing sewerage system of Sharjah City excluding the principal pumping stations and pipes with diameters less than 400mm.

• Study the performance of the existing system based on short (2010), medium (2020), and long (2027) terms.

• Evaluate options for proposed feasible enhancements.

2. Population data for a 20-year planning horizon was used in the model.

3. The model included:

• 65,349m of sewers

• 969 pipe (Dia ≥ 400mm)

• 995 manhole

• 13 Pumping station

Sharjah Sewerage and Stormwater Drainage Master Plan

Case Studies

Case Studies

Ajman Sewage Pumping Stations Upgrade

1. InfoWorks CS was used to:• Import the existing sewage system elements from ESRI Shape files and

CSV files. These files were exported from Mike Urban which was used to build the model originally by another consultant.

• Prepare the model physical elements to suit InfoWorks modelling environment.

• Check the assumptions and criteria adopted by the other consultant and amend wherever required.

• Study the performance of three existing principal pumping stations (17, 5 and 12) based on varying percentages (60 to 100%) of registered population with an eye on the remaining system elements.

• Evaluate options for proposed feasible enhancements utilizing RTCs, addition of future planned pumps, and replacement of pumps.

2. The model included:• 252,203m of sewers• 2,715 pipe (100 mm ≤ Dia ≤ 1100 mm)• 2,709 manhole• 21 Pumping station

Case Studies

PS5 PS17

PS12

Constrains when using InfoWorks

• InfoWorks requires validation through experimental data in order to be considered a reliable tool (Artina, 2007).

• It is used as a comprehensive analysis tool; however, it might be used as a design tool for small catchment or network provided that the user is experienced in modeling and sounds good technically.

• The software interface looks complex for new users; however, it will be very useful once the modeler gets hands on it.

• Some routines in the model are implemented in a way which can’t be expected by modeler so that a support from the software team might be required.

References

• Wastewater Planning Users Group. (2002). Code Of Practice For The Hydraulic Modelling Of Sewer Systems (Version 3.001 ed.). Retrieved from http://www.wapug.org.uk

• McMahon, M. (2008, April). Design Standard DS 520. In Design Standards (p. 26). Wessex Water

• Wallingford Software Ltd. (n.d.). InfoWorks CS - Software for Wastewater on Environmental Expert. Retrieved September 27, 2009, from Environmental Expert website: http://www.environmental-expert.com/stse_resulteach_product.aspx?cid=3919&idproduct=2243

• InfoWorks CS documentation.

• Lockie, T. (2007). Catchment Modelling Using SWMM. In The 49th Water New Zealand Annual Conference and Expo (pp. 1-9). Retrieved from http://www.waternz.org.nz/documents/sigs/modelling/ technical_articles_2007/lockie_t.pdf

Model Functionality Comparison

SWMM 5.0 MOUSE / MIKE URBAN INFOWORKS CSFlow Routing Dynamic Wave Dynamic Wave Dynamic Wave

Routing EngineExplicit numerical engine can have stability issues

if the model not constructed and reviewed carefully.

Implicit numerical engine, a stable and fast hydraulic engine. Though it is considered to be a

slightly slower engine than InfoWorks.

Implicit numerical engine. Generally considered the fastest and most stable fully dynamic engine.

Inlet Control No No YesDetention Storage Yes Yes Yes

RTC Yes Yes YesPumps Yes Yes Yes

Irregular XS Yes Yes Yes

Surface RunoffUtilizes a non-linear reservoir model to simulate

runoff.

Provides a number of surface runoff models, such as a time area method and a Kinematic wave

model (Non Linear Reservoir Model). This model behaves exactly the same as the SWMM non-linear

reservoir model

Provides a number of surface runoff models, including the SWMM non-linear reservoir model.

InfiltrationProvides three infiltration options, Curve Number,

Horton’s Equation and Green Ampt.

In addition to the RDII model (see below) MOUSE utilizes the Horton’s Equation or SCS Cur ve

Number to simulate infiltration.

Fixed PR Model (simple percentage), Green Ampt Model, Horton Infiltration Model, New UK PR Model, Wallingford Procedure Model, Constant Infiltration

Model, and US SCS Model.

RDII

Provides either unit hydrographs to simulate RDII or a groundwater infiltration module to simulate the influence of groundwater table on infiltration

flow.

MOUSE employs a complex RDII model.

Provides either unit hydrographs to simulate RDII or a groundwater infiltration module to simulate the

influence of groundwater table on infiltration flow. As per SWMM.

Continuous Simulation Yes Yes YesPollutant Build Up / Washoff Yes Yes Yes

Pollutants Modeled Yes Yes YesTreatment Yes Yes Yes

LTS - Job List NoYes - MOUSE provides a job list file which allows a

selected number of events to be run by the HD model.

No

Statistics Yes Yes YesUser Interface Basic user interface. Good user interface. Sophisticated user interface.

Data Management NoneReasonable data management with the scenar io

manager.Excellent data management.

Result Display Reasonable Good Excellent

SupportNo formal support, A SWMM Users List server,

allows subscribers to ask questions and exchange information.

Comprehensive Comprehensive

Purchase Cost Free~$15k to $40k dependant on pipe limitation and

modules selected.~$30k to $60k dependant on node limitation selected.

Maintenance Cost Free ~10% of the purchase price ~15% of the purchase price.

Miscellaneous

Use Ability

Price

ItemTopicModel

Hydraulics

Hydrology

Water Quality

* T. Lockie, 2007

Model Functionality Comparison*