GIS for Small Communities Ohio Water Environment Association Collection System Specialty Conference May 10, 2012 Christopher Heltzel, GISP
GIS for Small Communities
Ohio Water Environment Association Collection System Specialty
Conference May 10, 2012
Christopher Heltzel, GISP
Agenda
• What is GIS
• How Does GIS Compare to CADD
• Benefits of GIS
• How to Develop a GIS
• Case Study – Harrison, OH
• Geographic
– Coordinate Projection Round Earth vs. Flat Screen
• Information System
– Database (Geodatabase)
What is GIS? Geographic Information System
GIS vs. CADD
• GIS is Data-Centric CADD is Paper-Centric
• GIS is Strong at Large Scales (mapping over kilometers and designed to address projection issues) CADD is Detail Oriented (sub-millimeter accuracy and dimensioning)
• GIS Includes Standard Connectivity/Topology Rules
Benefits of GIS
• A single seamless representation of information that can be displayed on a map
• Sharing information
– Aerial Photos
– Parcels
– Streets
– Water Bodies
– Topography
GIS for Public Utility Management
Geographic Information System (GIS)
Asset Inventory
Projects Condition
Assessment Capacity Modeling
Maintenance Management
Capital Infrastructure
Planning
Financial Management
Linear Asset Inventory
• Assets Distributed Throughout a City, County or Larger Region
• Connected Network
• Flow Tracing
• Physical Characteristics – Material
– Diameter
– Length
– Depth
Status Diameter Feet Miles
Active 6 48.32 0.01
Active 8 92,559.60 17.53
Active 10 10,087.85 1.91
Active 12 54,925.84 10.40
Active 15 28,189.26 5.34
Active 16 2,069.47 0.39
Active 18 9,226.99 1.75
Active 24 6,575.80 1.25
Active 36 7,171.11 1.36
Proposed 8 35,259.25 6.68
Proposed 12 5,475.57 1.04
Proposed 18 8,192.87 1.55
Proposed 24 8,560.26 1.62
268,342 50.82
Development of a GIS
• Identify Near-Term Needs and Long-Term Goals
• Catalog Currently Available Data Sources
• Prioritize Data Sources by Accuracy and Importance
• Create Initial GIS with Available Data, Targeting Near-Term Needs
• Perform Data Gap Analysis
• Develop Field Data Collection Program to Support Near and Long-Term Goals
Level of Accuracy
• It is better to now the approximate location of all assets than the specific location of half the assets
• A complete inventory supports a data refinement plan
• Prioritize field data collection to maximize the benefit
Case Study – Harrison, OH
• Population
– City About 10,000
– Township About 3,000
• 1.15 MGD Average / 5.36 MGD Peak Wastewater Flow
• 43.5 miles of Sanitary Sewer and Force Main ranging from 6 to 36-inches in diameter
• Sewer materials are typically vitrified clay and concrete in older sewers and PVC for sewers constructed in the last 10 years.
Wastewater Master Plan
• WW Master Plan
• SewerGEMS Collection System Model
• No Existing Model
• Existing Documentation
• CADD and Paper Sewer Atlases
• 10 Years of Plan and Profile Drawings
Import CADD Data
• Locations
• Diameters
• Flow Direction Arrows
• Some Inverts
• Missing Material
• Improperly Segmented
• Inconsistently Drawn Flow Direction
Digitize From Paper Drawings
Additional Data Processing
• Assign Manhole Rim Elevation Based on 2-foot Contours
• Assign Unique Asset ID
– “MH” Prefix
– Sequential Number
Sewer System Results
• Gravity Mains
• Pump Stations
• Force Mains
• Manholes
• Treatment Plant
• Flow Arrow
• Trace
• Basins
Results with Background Layers
• Rail Roads
• Water Bodies
• Parcels
• Streets
• Buildings
• Aerial Photography
SewerGEMS
• Export Sewer Network
– Valid Connectivity
– Pipe Diameters
– Pipe Lengths
– Pipe Inverts
• Results Can be Returned to GIS for Mapping
Maps – Existing and Future
Effort and Time
• WW Master Plan
• $50k Total
• Less than $20k for GIS Model Network
• Less than 9 Months
• GIS Software
– ArcGIS Reader (no cost)
Next Steps
Geographic Information System (GIS)
Asset Inventory
Projects Condition
Assessment Capacity Modeling
Maintenance Management
Capital Infrastructure
Planning
Financial Management