Post-Construction Ordinance

Mecklenburg County
Post-Construction Storm Water
Ordinance
1. Ordinance Goals
2. Ordinance Development Process
3. Proposed Ordinance Standards
4. Town & County Ordinances

Waters of Mecklenburg
Our Most Precious Natural Resource
Davidson
Cornelius
Huntersville
Charlotte
Mint Hill
Pineville
Matthews

Non-Point Source Pollutants
…of water
pollution in
Mecklenburg
County.
Sediment
Bacteria
Toxic & Mineral
Metals
Pesticides
Fertilizers
Petroleum Products
Storm water
runoff is the
biggest source…

Catawba
Cornelius
(2005)
Huntersville
(2005)
Charlotte
(1993)
Davidson
(2005)
Yadkin
Mint Hill
(2005)
Urbanized
areas must
obtain storm
water permits
that require
the control of
storm water
pollutants.
Pineville
(2005)
Matthews
(2005)

Storm Water
Permit Requirements
Public Education and Outreach
Public Involvement & Participation
Illicit Discharge Detection/Elimination
Construction Site Runoff Control
Post Construction Site Controls
Pollution Prevention/Good Housekeeping

Control non-point source pollutants, volume and velocity
during post-construction.
Deadline for County & Towns: July 1, 2007
Deadline for City of Charlotte: July 1, 2009

Joint Stakeholder Process by County, Towns & City
Prior to the initiation of the ordinance development process, staff
identified the goals they felt needed to be met by the ordinance.

Ordinance Goals (Staff)
Ensure compliance with all Federal and State requirements associated
with providing water and sewer services and protecting water quality in
our growing community.
1. Achieve compliance with the Phase I and Phase II
NPDES Storm Water Permit requirements.
2. Satisfactorily address the pollution control
criteria specified by NCWRC & USFWS for the
Yadkin Basin.
3. Satisfactorily address the causes of impairment
identified in the N.C. 2002 Integrated 305(b) and
303(d).
4. Satisfactorily address detention measures for the
control of storm water volumes and peaks.

1. Achieve compliance with Storm
Water Permit requirements.
• Manage storm water runoff from new
development and redevelopment that
disturb an acre or more of land surface.
• Ensure controls are in place to minimize
water quality impacts (State sets minimum
requirements).
• Provide a mechanism to require long term
operation and maintenance of control
measures.

2. Satisfactorily address the pollution control
criteria recommended by Wildlife agencies
Catawba
Yadkin
Goose
Creek
Six Mile
Creek
Carolina heelsplitter:
Endangered Species of
Freshwater Mussel

Good (Natural Condition)
Bad (Impacted by Development)
1. Limit impervious cover to 10% and less.
2. Maintain pre-development hydrograph.
3. Undisturbed buffers ranging up to 200 feet.

Impacts of the Heelsplitter
• Permits are required to provide water & sewer.
• Permits can’t be issued until EA / EIS results in FONSI.
• Wildlife agencies must be satisfied to reach FONSI.
• No FONSI = No water & sewer.
• Post-Construction Ordinance is meant to satisfy Wildlife agencies.
• Examples of Heelsplitter impacts to date:
- Franklin WTP expansion
- FERC Authorization to increase water withdrawal from MIL
- 3-County WWTP
- IBT Increase certification
- McDowell Creek WWTP expansion
- Reedy / McKee Creek sewer outfall
-McAlpine Creek Relief Sewer
-Reissuance of County & Towns’ Phase II Permit

Sugar Creek
Catawba
ba River Basin
Legend
Charlotte
Cornelius
Davidson
Huntersville
Matthews
Mint Hill
Pineville
McDowell Creek
Long Creek
Little Sugar Creek
Irwin Creek
Rocky River
Clarks Creek
73% of major streams are
impaired.
McAlpine Creek
3. Satisfactorily address the causes
of water quality impairment.
The primary source
of impairment is
storm water Catawba runoff Basin Yadkin Basin
Yadkin River Basin from Irwin new Creek McKee Creek
development.
Stewart Creek Rocky River
Yadkin
McKee Creek
Goose Creek
Clear Creek
N Fork Crooked Creek
N
Taggart Creek
Coffey Creek
Kings Branch
Sugar Creek
Briar Creek
Little Sugar Creek
McMullen Creek
Four Mile Creek
McAlpine Creek
Long Creek
McDowell Creek
McCullough Branch
Clarks Creek
Crooked Creek
Clear Creek
Goose Creek

Implications of Stream
Impairment
Storm Water Permits require the
restoration of impaired waters.

4. Satisfactorily address detention measures for
the control of storm water volumes and peaks.

• An inch of rainfall on an acre of woods in typical piedmont soils
produces no runoff.
• The same one inch of rainfall on one acre of asphalt will produce
over 27,000 gallons of runoff.

Volume + Velocity = Change in Natural Stream
Hydrology

14 feet
Channel Instability

Mayfly
Increased Turbidity

Flooding

Hiring of a Consultant
In March 2004 prior to the initiation of the stakeholders’
process, a private consultant (Tetra Tech) was hired to:
1. Develop a county-wide water quality model.
– Identify current water quality conditions.
– Set a baseline of water quality conditions to meet four (4)
goals.
– Predict future conditions based on land use plans.
– Identify the gap between current conditions, future
conditions and the baseline for goal compliance.
– Test ordinance scenarios developed by the stakeholders’
group and identify associated costs for closing the gap
between future conditions and the baseline.
– Confirm ordinance compliance with the four (4) goals.
2. Provide technical support during stakeholder deliberations.
3. Ensure that the ordinance is scientifically sound.

Ordinance Goals (Stakeholders)
1. Cost feasibility
2. Political feasibility
3. Administrative feasibility
4. Consistent with community values

Post-Construction Ordinance
Development Process
April 22, 2004 through September 22, 2005
Goal: To utilize a stakeholders’ process to reach
consensus on ordinance language to be considered
for adoption by elected officials for the purpose of
controlling storm water runoff in compliance with
the four (4) previously stated goals.

Stakeholder Representation
Dale Stewart
Mark Loflin
Tim Mead
Amy Ringwood
Steve Wilson
Rich Keagy
Dan Latta
Dan Duval
Tim Bahr
Curtis Trenkelbach
Lindsey Hobbs
Mark Cramer
Rick Roti
Merrie Salvo
Roy Alexander
Marc Houle
Jim Bowen
Charlotte Chamber
Char-Meck Planning Commission
Charlotte Property Owner
Charlotte Property Owner
CMU Advisory Committee
Home Builders Association
Home Builders Association
Marine Commissions
NAIOP/ Commercial Board of Realtors
NAIOP/ Commercial Board of Realtors
Northern Towns
REBIC
Sierra Club
Southern Towns
Storm Water Advisory Committee
Subdivision Steering Committee
UNC-Charlotte

Ordinance Development Process
Stakeholders were provided training and information
prior to the initiation of the consensus building process.
Phase I: Assess current & future water quality conditions
September 22, 2005: Reached full consensus – no minority report.
and compare to goals. How wide is the gap? November 2004
Phase II: Use water quality modeling to evaluate alternative
management scenarios for closing the gap. February 2005
Phase III: Translate the selected management scenario into
ordinance language. September 2005

Checking for Compliance with Goals
Modeling performed by a Tetra Tech confirmed the
following regarding the stakeholders’ ordinance:
• Fulfills all four (4) of the goals established by staff
• Addresses the stakeholder goals better than any of the
scenarios tested by:
– Significantly reducing costs while achieving the four
(4) primary goals.
– Allowing for more politically feasible.
– Providing for flexibility in design and implementation
and allowing for planned growth.
– Better addressing community values.

Post-Construction Ordinance
• Applicability & Exemptions
• Administrative Manual
• Design Manual
• Storm Water Management Permit
• Storm Water Administrator
• Appeals & Variances
• Standards
• Mitigation
• Open Space
• Maintenance
• Enforcement

N
LAKE
NORMAN
ROCKY
RIVER
CENTRAL CATAWBA
WESTERN CATAWBA
YADKIN-SOUTHEAST CATAWBA
GOOSE CREEK
HUNTERSVILLE
LOWER
MTN
ISLAND
UPPER
MTN
ISLAND
McDOWELL
GAR
LONG
CLARKE
MALLARD
LOWER
CLARKE
Post-Construction
Ordinance Districts
BACK
CATAWBA
BEAVERDAM
LAKE
WYLIE
STEELE
PAW
SUGAR
IRWIN
UPPER
LITTLE
SUGAR
LOWER
LITTLE
SUGAR
BRIAR
McMULLEN
REEDY
McALPINE
FOUR MILE
CLEAR
GOOSE
CROOKED
TWELVE MILE
McKEE
CALDWELL
1. Most powerful
consensus
building tool.
2. Provides
significant
flexibility.
CLEM
SIX MILE
5 0 5 10 Miles

Criteria for Meeting Goals
1. Structural BMPs
2. Buffers
3. Detention
4. Open Space

Structural BMPs
Structural BMPs are Wetland
required Pond
at between 10% & 24%
BUA with either 85% Rain TSS Garden removal or both 85% TSS &
70% TP removal depending on the Watershed District.
Collect runoff and remove pollutants.

Buffers
S.W.I.M. plus 30-foot no build zone on intermittent
streams except Yadkin buffers at 50 feet for
intermittent and 100 feet for perennial or floodplain.
Buffers filter pollutants before
they enter surface waters.

Detention
Required based on BUA – Control volume for 1-yr,24-hr
storm – Control peak for 10-yr & 25-yr, 6-hr storms or for
residential perform downstream analysis; for commercial
control 10-yr, 6-hr storm and downstream analysis
Reduce volume and velocity of storm water runoff.

Open Space - Trees
Varies from 10% to 25% based on BUA – Greater BUA
less Open Space
Filter pollutants and reduce impervious area.

Mitigation
• The purpose of mitigation is to allow
flexibility in the administration of the
Ordinance and reduce compliance costs
while providing an equal or greater
protection of water quality.
• Applications/notifications must be submitted
for all forms of mitigation.
• If approved, mitigation is valid for three (3)
years.
• If denied, full compliance with the Ordinance
is required.

Types of Mitigation
1. TP Mitigation
• Off-Site Option
• Buy-Down Option
2. Development & Redevelopment Mitigation
• Buy-Right Mitigation Payment
3. Undisturbed Open Space Mitigation
• On-Site Option
• Off-Site Option
• Payment-In-Lieu Option
• Pre-Approved Options

Local Design Manual Goals
Completed in June 2007
• At least as protection as State Manual.
• Consider local conditions.
• Meet all post-construction goals.
• Recognize treatment train benefits.
• Provide design options (flexibility).

Local Design Manual Goals
Completed in June 2007
• Use existing monitoring data with
ability to incorporate future data.
• Easily implemented by the private
development community.
• Easily reviewed by local regulatory
staff.

September 8, 2006
• Commend the proposed measures in the
Yadkin-Southeast Catawba Watershed
District and believe that Charlotte and
Mecklenburg County should adopt this
ordinance.
• More protective measures needed in Goose
and Six Mile Creeks where the Carolina
heelsplitter is known to exist.

N.C. Division of Water Quality
June 2007: State approval received for all the Towns
and County
“The Division of Water Quality has reviewed the Phase
II Post-Construction ordinance and believes that the
ordinance, in conjunction with the technical design
storm water specifications found in the Charlotte-
Mecklenburg local storm water Best Management
Practices 9BMP) Design Manual, collectively meet the
requirements of the Phase II storm water program.”

Town & County Ordinances - June 30, 2007
• Cornelius: Modified stakeholder ordinance with
only one district, no open space, no TP removal
and Catawba buffers throughout.
• Davidson: Stakeholder ordinance.
• Huntersville: Updated existing LID Ordinance to
comply with Phase II requirements. More
protective than stakeholder ordinance.
• Matthews: Stakeholder ordinance.
• Mint Hill: Modified stakeholder ordinance with 3
districts and changes to Yadkin buffers.
• Pineville: Stakeholder ordinance.
• Mecklenburg County: Stakeholder ordinance.

City of Charlotte
Reconvened Stakeholders’ Group for Additional Information
September & October 2007

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For a copy of ordinances and other information:
http://stormwater.charmeck.org (select “Post-Construction Storm Water Programs”)