City%20of%20Austin%20Detention%20Ponds

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City of Austin Detention Ponds

• Desktop Field Analysis
• Laton Carr

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Detention Pond Classification

• Watershed Protection and Development Review
  (WPDR)
• Texas Commission of Environmental Quality (TCEQ)
• Project to classify detention ponds

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Building a Database

• Existing point feature class data base
• Electronic versions of maps
• Berm heights via memory
• (maintenance crew)
• Retrieval of any other existing maps
• Result Nearly empty data base

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Course of Action

• So what do you do?
• Send out the intern!

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Mission

• Berm or Dam?
• Berm/Dam dimensions
• Take image inside the pond
• Take image downstream
• Description of what lies 100 yds downstream

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Engineers Request

• Use of GIS to
• Find contributing drainage area into a pond
• Estimate volume of pond
• Estimate berm/dam height
• Delineate inundation area
• Determine what lies within this area

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Project Parts
Contributing Drainage Area
Pond Volume
Inundation Area
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Contributing Drainage Area

• Create base map

Gather data COA GIS
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Contributing Drainage Area

• Create base map

Gather data (DEM)
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Contributing Drainage Area

• Create base map

Building a geodatabase

• Geodatabase
• Feature Classes
• Note no feature data set.

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Contributing Drainage Area

• Create base map

Building a geodatabase
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Contributing Drainage Area

• Create base map

Projecting Data
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Contributing Drainage Area

• Create base map

Terrain Processing
fdr
Fac (boxed region detail)
Dem_aus
AgreeDem
fac
Dem_aus overlain by Creeks
fil
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Contributing Drainage Area

• Create base map

Adding Vector Data
Add Streets
Zoom to pond
Add Contours
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Contributing Drainage Area

• Analyze Map

Find drainage area at pond inlet.
Flow accumulation 2701 x (10 x 10) m2 x (1 km
/ 1000m)2 0.2701 km2
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Volume of Pond

• Analyze map

Create new polygon feature class
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Volume of Pond

• Analyze map

Export Table to .dbf file
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Volume of Pond

• Analyze map

Open in Excel and Run Macro
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Inundation Area

• Analyze map

Delineate inundation area
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Results

• Use of GIS to
• Find contributing drainage area into a pond
• Estimate volume of pond
• Estimate berm/dam height
• Delineate inundation area
• Determine what lies within this area

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Additional Work

• Use a new tool TIN Volume tool for calculating
  pond volume
• Finish procedure for estimating inundation area
• Automate more of the analysis
• Visual Basic
• Model Builder
• UML

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Thank youQuestions or Comments