Stormwater for Elected Officials
Failing Infrastructure
March 31, 2015
Date
Agenda
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Overview Stormwater Infrastructure
– Open and Closed drainage
Design Standards
– Design Standards
– Product Standards
– Future versus Past Land Use
– Service Life
Failing Infrastructure and Challenges
– Failing Infrastructure (Examples)
– Challenges
What is Charlotte Doing
– Thorough Assessment
– Prioritize Work (severity/risk)
– Organize Resolution (Maintenance versus Design)
– Utilize Rehabilitation Techniques
Cost
– Project Cost
Overview Stormwater
Infrastructure
Open Systems
Closed Pipe Systems
Design Standards
Design Storms
Rainfall
Product Standards
Past, Present and Future Land Use
Development Conditions
Natural Conditions
Service Life - Infrastructure
Stormwater Infrastructure Last
Forever………
Myth?
Out of sight out of mind……
Failing Infrastructure
Service Life Expectations (Based on installation, environmental
conditions, soils, ground water, etc.)
• Reinforced Concrete Pipe (RCP) – 100+ years
• High Density Polyethylene Pipe (HDPE) – 50 years + TBD
• Corrugated Metal Pipe (CMP) – 25-30 years
• Aluminum (coatings) Corrugated Pipe – 75 years +
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Life Expectancy comes from different sources ACPA, FHWA, FLH, NASPD, local experience, etc.
assumes appropriate installation.
RCP
HDPE
CMP
Failing Infrastructure
Examples
1526 Alleghany St
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6969 Haines Mill Rd
– Faulty installation of
seal material
– Access for repairs
– Sinkholes
Failed pipe joint
Leaking grout in structure
Traffic and safety concerns
Roadway collapse
Failing Infrastructure
Examples
• 106 S Sycamore St
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Corrugated Metal Pipe
Corroded Pipe (bottom)
Loss of backfill material
Ground collapse (sinkholes)
Repair or replace
Road Closures
Challenges
• Amount of system in place
• Infrastructure continues to age (life cycle material specific)
• Increased runoff (development/size of systems)
• Increase in system inventory (development)
• Increase in underground utilities (power,
communication, gas, others)
• Traffic Inconvenience (roadway closures)
• Asset Management (the need)
• Cost (increases annually)
What is Charlotte Storm Water Doing
Accurate Classification of
Request/Problems
• Helps prioritize work
• Improves communication with
customer
• Captures historical information
• Organize work into resolution
types (maintenance/design
efficiency)
What is Charlotte Storm Water Doing
• Utilizing alternatives to
rehabilitate in lieu of
replace
• Enhanced Construction
Inspection
• Utilization of CCTV
inspections (post
construction)
• Warranty on
construction
• Asset
Management/Inventory
• Cost/benefit approach
to resolution (cost,
inconvenience, traffic)
• New Development
(inheritance)
CIPP Lining
CCTV Inspection
Maintenance and Repair Project
428 N. Poplar Street
Problem
• Sinkhole over a storm drain pipe under street
caused by a broken pipe.
Design and Construction
• Repair pipe joints in system.
• $16,300.00 construction cost.
• 7 Days to construct.
Constraints
• Traffic.
• Utilities.
Finished Project
Maintenance and Repair Project
7707 Bridle Court
Problem
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Sinkhole over a storm drain pipe in a yard due to a
joint failure.
Design and Construction
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Repair separated joint and seal 8 additional joints
$14,208.00 Construction Cost.
9 Days to construct.
Constraints
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Utilities.
Design Project
201 Crompton Street
Problem
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Roadway and shoulder caving in
due to defective corrugated pipe
culverts under street.
Constraints and Hurdles
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Need to get the road re-opened expedited design.
Interrupted industrial traffic and
emergency access.
Railroad in project area.
Utility conflicts.
USGS Rain Gage Station in project area.
Design Project
201 Crompton Street (continued)
Railroad between
both culverts
Design and Construction
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Replaced 4 corrugated culverts with 2
concrete box culverts (1 each side of
Railroad).
$183,889.00 Construction Costs.
1 Month to construct.
Completed Project
Design Project
4706 Sahalee Lane
Problem
– Sinkhole caused by a collapsed 42
inch HDPE pipe installed during
original development (year 2000).
Design Project
4705 Sahalee Lane (continued)
House Foundation Protection
Finished Project
Design and Construction
– Replaced failed 42 inch HDPE pipe with 42 inch concrete pipe.
– Construction Cost $67,150.00.
– 3 days to construct.
Constraints and Hurdles
– House Foundation
– Fence.
Design Project
Sam Drenan Road
Problem
– Metal Pipe Culvert failed under a
major street (Install approx. 1961).
Design Project
Sam Drenan Road (continued)
Design Consideration
– Replaced Dual 48”
corrugated metal culvert
with 10.0’x6.5’ and
6.0’x7.5’ Dual Concrete
Box Culvert.
– $800,000.00 cost
Low Flow Barrel
High Flow Barrel
Design Requirement
– State permitting required a
low flow barrel (on left) and
high flow barrel (on right).
Cost
• Average Project Cost
(Charlotte)
– Project costs have many
variables ($1M - $1K)
– $88,000 average (design and
construction)
– 4-6 months to construct
average
– 200 projects completed on
average per year
– 800 projects on the wait list
(growing by 260 per year)
Questions?
Stormwater Fees
Daryl Hammock
Assistant Manager
City of Charlotte, Storm Water Services Division
Why develop a stormwater fee?
• Competition with other community needs
• Lack of consistent funding
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Prevents staff development
Limits proactive capital program
Reduces O&M Activities
• New funding requirements
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Higher citizen expectations
Stormwater permit compliance
From Stephen R. Lienhart, P.E.
Why develop a stormwater fee?
Why Develop a stormwater fee?
Stormwater Program Concepts
Extent of service (where provided)
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City limits, or other district
Downspouts
• ‘Public water’
• Within the right-of-way
Level of service (how much provided)
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Comprehensive (surface water quality
& flooding)
Surface water quality only
Maintenance, flooding only
50 year pipe replacement cycle
Cost of service
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Based on above decisions
Revenue must equal cost to provide
the service NCGS 160A-314
Develop a funding strategy
Can be fees, debt, taxes
(82%, 18%, 0%)
Fees
• Typically based on contribution,
not benefit (pollutants, flow)
• Usually varies but can be flat rate
• Impervious area, gross parcel
area, or combination of both
Funding of Stormwater Utilities in
the Southeast
Fee vs. Tax Illustration
Commercial accounts generating $54,000 revenue
Customer
Uptown hi-rise
(2 acres, $88M)
Strip mall,
outskirts of City
Monthly Fee
$300
$4,200
Property Tax
$47,500
$6,500
(28 acres, $12M)
Premise:
• Distribute costs to rate payers based on their contribution
to problems
• Logical in terms of flooding, EPA compliance
Stormwater Utilities in Southeast
Some Regulatory costs and FEMA
related costs are not as strongly
tied to impervious.
Increasing Infrastructure
Cumulative Miles of
Storm Drainage Pipe
2000
Miles of pipe
1800
1600
1400
1200
1000
800
600
400
200
0
1900
1913
1923
1933
1943
1953
1963
1973
1983
1993
2003
2013
Year
• Mileage of pipe doubled from 1994 to 2014
• Pipes may need to be replaced after 20, 50 or 100 years
• Local Development regulations/inspections are a key to
your long term financial success
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Population Growth
Expect growth of
drainage problems,
and expect them at
an increasing rate
Maintenance & Repair Backlog
Charlottes fee has grown (20
increases), but has not kept
pace with rate of failing
infrastructure
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Mistakes That Can Be Avoided
• A new fee raises citizen expectations above
which existed pre-fee – Increases your work
• Align program with State legislation;
– http://NCLEG.net NCGS 153A-274
(Durham Case)
• Specific long term plans rarely hold true
– Plan on “Adaptive Management” (rainy years)
• Things are going to cost more than you think
Allow cushion
– - retrofitting, easements, citizen support
Successes
• Helps to have combination of
flooding/infrastructure drivers in addition to
federal Clean Water Act drivers
• Citizen Advisory Committee
– Citizen group
– Helps build, and with a goal to maintain public trust
• Clearly defined Extent and Level of Service
• Simple and strong qualification system – Say no
to squeaky wheels
• Impervious basis to fee
Success: Balanced Portfolio Strategy
• Repairs to storm drains including ditches, creeks
• Flood Control
• Collaboration:
– Neighborhood Projects
– Transit/Transportation Projects
– Economic Development Projects
• Watershed Restoration
– Streams, ponds, pollution
removal devices
Resources
Resources
UNC Environmental Finance Center:
http://www.efc.sog.unc.edu/
http://NCLEG.net
NCGS 153A-274
http://stormwater.charmeck.org
Fees & Billing
Daryl Hammock
Assistant Manager
City of Charlotte, Storm Water
Services Division
704-336-2167
[email protected]
Current Fee/Rate Structure
Major
System
(County)
Minor
System
(City)
Billing
Process
Fee
Total
Detached Single-Family Residential
Tier I
$0.77
$5.52
$0.85
$7.14
Tier II
$1.20
$8.13
$0.85
$10.18
Tier III
$1.73
$8.13
$0.85
$10.71
Tier IV
$2.96
$8.13
$0.85
$11.94
< 2,000 sq ft
2,000 to <3,000 sq ft
3,000 to <5,000 sq ft
5,000 sq ft & up
Attached Single-Family Residential and all other nonresidential
Per
Impervious
Acre
$20.00
$135.56
$0.85
$156.41
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Storm Water Utility Survey