All Cracked Up! Condition Assessment Protocols for Stormwater Infrastructure

Transcription

1 2014 HDR Architecture, 2014 HDR, Inc., all rights reserved.

2 Matthew Gustis, PE Charlotte-Mecklenburg Storm Water Services Ron Geiger, PE HDR, Inc. All Cracked Up! Condition Assessment Protocols for Stormwater Infrastructure 2014 HDR, Inc., all rights reserved.

3 State of the Stormwater Industry Assessment Protocols Case study on Condition Assessment Charlotte s Response

4 State of the Stormwater Industry

5 State of Stormwater Water Quality Integration o Green Infrastructure o Holistic Watershed Management Integrated Planning o TMDLs Risk-based Decision Making o Consequence of Failure o Triple Bottom Line

6 State of Stormwater Capacity strained from development o Increased runoff o Change in design standards Aging of Infrastructure o Pipe material life cycle o Poor installation o Structural failures

7 Assessment Protocols

8 6 th and Graham Project City of Charlotte CIP Project Downtown Charlotte Aging infrastructure Flooding of Buildings Public stormwater under high rise buildings Critical road network Risk to both public and private property

9 What can we learn from Wastewater Industry Condition issues with long term integrity and condition Capacity limitations from growth SSOs and impact to water quality NASSCO o National protocol for sanitary sewer condition assessment

10 NASSCO Standardize Defect Codes o o Severity Ratings o o o o o Manholes MACP Pipelines PACP Grade 5 Collapsed or collapse imminent Grade 4 Collapse likely in future Grade 3 Collapse unlikely in near future Grade 2 Minimal collapse risk Grade 1 Acceptable structural condition Protocols for Inspection (i.e. CCTV)

11 Translation to Stormwater Defect Codes specific to stormwater pipes o Shallow cover o Joint types/infiltration risk o Corrosion potential less o Different shapes present different defects Common Elements to Deterioration o Structural o Maintenance o Construction/Design

12 PACP Applied to Stormwater Inspection ID for each pipe reach Individual and Continuous Coding of Defects o Point features Joint separation o Linear features Longitudinal cracks Pipe Scoring summation of defects o Structural Pipe Rating (SPR) o Maintenance Pipe Rating (MPR) o Overall Pipe Rating (OPR) o Group Ratings within ranges for assessment

13 Case Study on Condition Assessment

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15 Sample Images of Main Drainage System Deformed Pipe Longitudinal Cracks Missing Pipe Sections Separated Joints

16 Sample Images of Main Drainage System Foreign Pipe Intrusion Tap in Break Deteriorated Stone Culvert Pipe Trenched in Top

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18 Translation to Stormwater Defect Codes specific to stormwater pipes o Shallow cover o Joint types/infiltration risk o Corrosion potential less o Different shapes present different defects Common Elements to Deterioration o Structural o Maintenance o Construction/Design

19 Charlotte s Response

20 Charlotte-Mecklenburg Storm Water Services (CMSWS) Charlotte: 308 square miles FEMA streams: 350 miles Drainage system length: 5,100 miles This includes systems on public and private property CMSWS established in 1993 to reduce flood risks and improve water quality Fee based and request driven 4 Tiers based on impervious area Revenue = $67M

21 CMSWS (Cont d.) Completed 74 capital improvement projects Closed out 33,000 requests since 1993 $475.1M in community investments Current Backlog Information o 1,209 high/medium priority and 6,001 low priority requests o 58 capital improvement projects o Storm Water fee has grown but has not kept pace with the rate of failing infrastructure o Long wait times

22 This image cannot currently be displayed. Capital Improvements Flood Control o Design Management (DM) o Storm Drainage Improvement (SDI) Projects prioritized based on severity of issues. o DM - AI, A or B depending of public safety risks o SDI - Structure/road flooding, requests and system failure o System condition is not quantitatively assessed

23 Charlotte-Mecklenburg Storm Water Services (CMSWS) Myth Storm water infrastructure requires no maintenance Out of sight out of mind

24 Challenges Increasing amount of infrastructure and runoff (development) o Increasing Backlog Increasing project costs o Poor installation practices o Aging infrastructure (failures) Lack of funding to maintain system Prioritization of work based on system condition o Lack of system condition information Extent of system responsibility

25 Increased Infrastructure Cumulative Miles of Drainage Pipe by Year Miles of Pipe Infrastructure has doubled over a 20 year period Year

26 Funding $5M Annual Increase Needed

27 What is Charlotte Doing? Increased level of field inspections Pipe video (CCTV) inspections Pipe rehabilitation versus replacement (new technologies) Reduction of standards Risk based assessments Asset Management (developing) o Infrastructure data collection Age, condition, material o Culvert inspections o Better project capital expenditures

28 Thank you! Matthew Gustis Charlotte-Mecklenburg Storm Water Services Ron Geiger HDR, Inc.