A COMPREHENSIVE APPROACH TO PRIORITIZING STORMWATER INFRASTRUCTURE IMPROVEMENTS · 2017-10-17 ·...
Transcript of A COMPREHENSIVE APPROACH TO PRIORITIZING STORMWATER INFRASTRUCTURE IMPROVEMENTS · 2017-10-17 ·...
January 26, 2015
A COMPREHENSIVE APPROACH TO PRIORITIZING STORMWATER INFRASTRUCTURE IMPROVEMENTS Troy McPherson, PE, ENV SP Alan Davis, PE, ENV SP
ACKNOWLEDGEMENTS
Steve McLaughlin, PE (City of Virginia Beach) Stanley Smith, Jr. (City of Virginia Beach) Will Von Ohlen (City of Virginia Beach)
AGENDA
Background
Program Overview
Methodology
Implementation
Results
What’s Next?
City of Virginia Beach
Population – 450,000 250 Square Miles
5000 Outfalls 1200 miles of Stormwater Pipe 16 Stormwater Pump Stations
BACKGROUND
Stormwater Infrastructure
Specific Program
Funding Source
Cave-Ins Limited Resources
Condition Assessment
PROGRAM OVERVIEW
GOALS
1. METHODOLOGY
2. IMPLEMENT
3. RESULTS
4. APPLY
Reduce Cave-Ins Extend Useful Life Fiscally Focused
METHODOLOGY
Overall Pipe Rating =
Probability of Failure
Risk Modifier =
Magnitude of Loss
RISK BASED
CAVE-IN NOTIFICATION
METHODS
CITIZENS
CITY STAFF OTHER PROJECTS
METHODOLOGY
Prioritization Score Factors
ABOVE GROUND DEFECT CODES
PAVEMENT CONDITION
SURFACE CONDITION
STRUCTURE INTERFACE
DEFECT CORRELATION
Prioritization Score Factors
METHODOLOGY
CAVE-IN FAILURE FACTORS
WATER / SOIL INFILTRATION
HIGH WATER TABLE
TIDAL SYSTEMS
STRUCTURE INTERFACE
LIFTING HOLES
GASKET-LESS JOINTS
DEFLECTED JOINTS
Prioritization Score Factors
METHODOLOGY
RISK MODIFIERS
ROADWAY TYPE
GEOGRAPHIC
PIPE SIZE
PIPE MATERIAL
Prioritization Score Factors
METHODOLOGY
Segment Grade Score Defect Grade ∑ Defects per
Grade
Overall Pipe Rating
∑ Segment Grade Scores
Prioritization Score
Overall Pipe Rating
∑ Risk Modifiers
METHODOLOGY
Prioritization Threshold
Min. Grade 5 Effective
Grade ∑ Min. Risk Modifiers
METHODOLOGY
METHODOLOGY
METHODOLOGY
QUANTITATIVE RISK ANALYSIS
IMPROVEMENT PRIORITIZATION RISK THRESHOLD
IMPLEMENTATION
Residential Subdivision (Green Run) 100,000 LFT
Residential Subdivision (Glenwood) 100,000 LFT
Residential Subdivision (Pine Ridge) 40,000 LFT
GREEN RUN & GLENWOOD BASINS
Combined Total 200,000 LFT 15-24 Inch
Outfall to
BMPs
Field
2- Person Crew
Document Defects
Immediate Concerns
Daily Records
IMPLEMENTATION
ABOVE GROUND DEFECT CODES
Office - CCTV
5- Reviewers
In-House Review Software
Document Defects
Preliminary Repair Methods
IMPLEMENTATION
CAVE-IN FAILURE FACTORS
IMPLEMENTATION
Above Ground Defects
CCTV Defect Codes
IMPLEMENTATION
Above Ground Defects
CCTV Defect Codes
IMPLEMENTATION
RISK MODIFIERS
Office / Field
GIS Data
Field Observation
Institutional Knowledge
Preliminary Repair Methods
IMPLEMENTATION
DEFECTS PACP CODING SUPPLEMENTAL CODING
REHABILITATION RECOMMENDATIONS
IMPLEMENTATION
REHABILITATION METHODS
∑ Segment Costs
75% of CIPP (Lining Cost)
Full Length CIPP
(Lining)
RESULTS SUMMARY
17,928 LF
Unresolved
29,693 LF
Rehabilitation
55,247 LF No
Action
Green Run 100,000 LF
[VALUE] Unresolv
ed
[VALUE] Rehabilit
ation
[VALUE] No
Action
Glenwood 100,000 LF
$3,300,000 Savings
$1,900,000 Savings
WHAT’S NEXT?
Rehabilitation Green Run 43,561 LFT
Rehabilitation Glenwood 29,693 LFT
Condition Assessment Pine Ridge 40,000 LFT
THANK YOU…
QUESTIONS?