Challenges in Building Water Distribution Models one-to-one with GIS

Ben Chenevey, PE

Outline

Introduction

WDS Modeling Overview

Challenges w/ Building

Challenges w/ Updating

Summary & Conclusions

Outline

Introduction

WDS Modeling Overview

Challenges w/ Building

Challenges w/ Updating

Summary & Conclusions

What is a Distribution System Model?

Pipe

s

Junc

tions

Valv

es

Pum

ps

Tank

s

Res

ervo

irs

Hydraulic representation of actual system

Infrastructure Operations Demands

Evaluate Complex Hydraulics

• Seasonal demands

• Fire flow analysis• Main breaks• Surge analysis

Test Out Alternatives

• Operational changes

• Future service areas

Plan for Growth

• New demands• New supplies

Analyze Water Quality

• Tank cycling / mixing

• Water age• Chlorine residual

Summary of Model Uses

Annual Average Net Demand Within Water Distribution System

Advanced Modeling Applications

Improving capabilities change our questions

Advanced applications require advanced calibration

Advanced calibration requires advanced modeling expertise

Typical Demand Within A Zone/Through a Pumping

Station

Demand at this address

On this day of the year

Hydraulic Model Components

1st Step in Model Building• Latest available CAD/GIS maps for the

system• Provides Model Spatial Information &

Attributes

Model Often Changes After GIS Import• Facilities Modeling• Calibration

GIS & Modeling

One-To-One Modeling

Goal: Direct Link between GIS and

Model ID

Purpose: Improve Model Updates &

GIS Analytics

InfoWater• Modeling Software• Add-On for ESRI ArcGIS

GIS & Modeling

Infowater• GIS Gateway

GIS & Modeling

Introduction

WDS Modeling Overview

Challenges w/ Building

Challenges w/ Updating

Summary & Conclusions

Outline

Challenges w/ Building Models One-to-One

1 All GIS is Different (YMMV)

2 Planning is Key

3 Interaction between GIS & the Model

4 100% is Rarely Achieved

Example Challenges - Connectivity

Extent of WDS in GIS

• Pipes, Valves, Fixtures, Appurtenances

• Topology of Layers

Model Connectivity

• Pipes - Junctions• Fill Connectivity• Orphan Pipes & Nodes

Example Challenges - Connectivity

Model has different & advanced requirements

GIS deficiencies often found during model build

Can be hard to find

• Network Traces

How to account for

• Fix GIS• Add new Pipes in

Model

Pipe not split by cross connections

Example Challenges - Facilities

Pump Stations often represented as point in GIS• May be connected or end at building• Expanded to include interior piping and pumps in the model

GIS Representation Model Representation

Example Challenges - Facilities

Even if captured in GIS, Models need additional information• Pumps & Valves• Minor Loses• Operational Controls• Closed Valves• Calibration

Outline

Introduction

WDS Modeling Overview

Challenges w/ Building

Challenges w/ Updating

Summary & Conclusions

Challenges w/ Updating Models

1 Continuous Model Updates

2 Keep Same Conventions as Original Build

3 Has Model Influenced GIS?

4 Updated Model vs. New Model

Example Challenges – Updating Models

New PipesCreating

New Records

Replaced Pipes or New Information

Update Existing Records

Abandon Pipes

Delete Non-Matching (?)

GIS Attribute

Large West Coast Utility• Update a One-to-One Model w/ Latest GIS• Use GIS Exchange Wisely

Example Challenges – Zone Based UpdatesLarge Midwest Utility• Converting to One-to-One with GIS is possible• For active model, Zone based upgrade may be ideal

Isolate Zone

• Select Zone Layers

• Delete from Model

Update Zone

• Import from GIS

• Follow a Routine

Finalize• Boundaries• Facilities• Calibrate

Example Challenges – Retroactive Alignment

Model was spatially inconsistent

No impact on Hydraulics

Asset Management Team wanted model results

GIS – Model Link Identified

GIS Spatial Information Updated in

Model

Previous Model Layout vs GIS

Updated Model Layout vs GIS

Flint, Michigan• Hydraulic Modeling Project• Asset Management Project

Outline

Introduction

WDS Modeling Overview

Challenges w/ Building

Challenges w/ Updating

Summary & Conclusions

Summary / Takeaways

• Improve Model Update Frequency and Level of Effort• Help get Model Results into GIS

Model that is One-to-One with GIS can:

• Usually 100% (but that’s ok!)

Model that is One-to-One is NOT:

• Consider the specific GIS (YMMV)• Create & Follow a Plan during model build

Proper Implementation Requires to:

• Understand how new or revised elements will be handled during model build• Incremental Updates for Models are possible

Model Updates create unique challenges:

Akron, Ohio+1 330 515 5749

ben.chenevey@arcadis.com

BEN CHENEVEY, PEStaff Water Engineer, Arcadis