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?