expanding your watershed toolbox - seswa - geiger...expanding your watershed toolbox october 18,...

Expanding Your Watershed Toolbox

October 18, 2012

Ron Geiger

Anthony Henry

2012 SESWA Conference

Chattanooga, TN

GIS and 2D Dynamic Modeling

The Evolution of Storm Water Engineeringhow far have we come…..The Evolution of Storm Water Engineeringhow far have we come…..

In the beginning….In the beginning….

• The Slide Rule

And then we became Rational….And then we became Rational….

• The Rational Method

Q = C I A

But we yearned for simpler tools….But we yearned for simpler tools….

• FHWA Nomo graphs

And then we invented the Spreadsheet….And then we invented the Spreadsheet….

• HGL• Detention Routing

But on the Seventh Day….But on the Seventh Day….

• Dynamic Modeling

AgendaAgenda

• Challenges of today’s storm water managers

• Common Tools that are a must have

• Options to consider in choosing the right tools

• Leveraging GIS and Dynamic Models

• Lessons Learned

Challenges of Today’s Storm Water ManagersChallenges of Today’s Storm Water Managers

• It’s more than flooding• Public is more demanding• Technology allows for more

questions, more detail• Not just where, but when,

and how much

Common Tools that are a Must HaveCommon Tools that are a Must Have

• Interactive HGL Analysis• GIS

• Physical Data on Drainage System• Land Use Data• Surface Terrain

• Eyewitnesses• Past problems documented/high water marks• Dates of flooding• Photos of overland flooding, surcharging

Options to Consider…Options to Consider…

• Traditional use of HGL

Options to Consider…Options to Consider…

• Dynamic Modeling with 2D capabilities

Not all 2D models are equalNot all 2D models are equal

• 1D SWMM – 2D TUFLOW• Grid

• 1D SIM (InfoWorks) – 2D InfoWorks 2D• Flexible triangular mesh

• 1D Mouse or Mike – 2D • Fixed or flexible Grid or triangular mesh

GIS and Dynamic ModelingGIS and Dynamic Modeling

• Process of building a model• 1D and 2D modeling• Mesh development• Common problems• Advantages• Examples in urban environments

Process of building a modelProcess of building a model

• GIS extension• Work in GIS directly

• External product with Import and Export of GIS data • Shape files or directly from Geodatabase

M-A-1

M-A-2

M-A-3

M-A-4

M-A-6

M-A-7

M-B-22

M-C-1

M-C-2

M-C-3

M-C-4

M-C-5

M-C-6

M-C-8

M-C-9

9463

9312

9125

8866

1D and 2D modeling1D and 2D modeling

• 1D for pipe and channel flow• Inlets and catchbasins• Pipe geometry• Open channel – natural or engineered• Ponds and detention basins

1D and 2D modeling1D and 2D modeling

• 2D for overland flow – flow out of channel• Down streets and over curbs• Between and through buildings• Across open land• Ponds and detention basins

Mesh developmentMesh development

• Surface terrain – Grid or TIN• DTM / DEM• LiDAR• Contours

• Surface features• Road curbs and centerlines• Buildings• Roughness polygons• Break lines and walls

Common problemsCommon problems

• GIS data may have holes or incorrectly entered data• Terrain data may need ‘scrubbing’ particularly for channels• Defining 2D surface appropriately• Interaction between 1D and 2D – Node or Line

AdvantagesAdvantages

• Better understanding of system• Identify causes of problems• Formulate workable solution

Example in urban environmentsExample in urban environments

• Old system

Irish Buffalo Trib O SoutheastAVI


• Detention pond

Tanglewood AVI


• Revenge of the creek

Washington Heights AVI

Lessons LearnedLessons Learned

• Existing GIS data is abundant• Learning curve in model building• Cost outweighed by flexibility and added benefits• Simple options may still be the best way

Hold on….Its about to get fun!!!Hold on….Its about to get fun!!!

Questions/CommentsQuestions/Comments

Ronald A. Geiger, PEWater Resources ManagerHDR Engineering, Inc.Charlotte, [email protected]

Anthony HenrySr. Hydraulic ModelerHDR Engineering, Inc.Austin, [email protected]

expanding your watershed toolbox - seswa - geiger...expanding your watershed toolbox october 18,...

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