1. Description of Water Quality Buffers How they function
Why they are important
2. Types of Buffers N.C. buffer types
Charlotte-Mecklenburg buffer types
3. Buffer RequirementsWhere do they apply
Exemptions to applicability
Allowable uses
Measuring buffer widths
Diffuse flow
Water Quality Buffers
Long Creek in West Charlotte
Description of Water Quality BuffersVegetated, no-build area along the banks of surface waters for the protection
of water quality. The width of the buffer as well as the uses and vegetation
allowed in the buffer vary significantly depending on the purpose of the
buffer and the desired level of water quality protection.
Clear Creek at McManus Road in Southeast Mecklenburg County
How Water Quality Buffers Function
Buffer = Filter + Sponge
Surface
Water
1. Vegetation
filters
pollutants in
overland
sheet flow.
2. Permeable soil soaks up
runoff and filters pollutants
in subsurface flow. Some
water provides groundwater
recharge.3. Roots of vegetation absorb
nutrients and other
pollutants and release
moisture into atmosphere
through evapotranspiration.
Andrew D.
4. Roots of vegetation
stabilize banks
preventing erosion and
allowing the formation
of natural meanders.
5. Trees provide
shade lowering
water
temperatures
and increasing
dissolved
oxygen levels.
6. Vegetation
provides
habitat for
wildlife and
food for
aquatic
organisms.
7. Storage provided
for floodwaters.
Importance of Water Quality BuffersMost experts agree that a vegetated buffer is essential to the health of a
stream, providing its 1st line of protection against non-point source pollution.
Pesticides
Fertilizers
Bacteria
Sediment
Toxic & Mineral
Metals
Petroleum Products
N.C. Buffer Types
1. Neuse River Basin Buffer Rules (15A NCAC 02B .0233)
2. Tar-Pamlico River Basin Buffer Rules (15A NCAC 02B .0259)
3. Catawba River Basin Buffer Rules (15A NCAC 02B .0243)
4. Randleman Lake Water Supply Watershed Buffer Rules (15A
NCAC 02B .0250)
5. Goose, Six Mile & Waxhaw Creek Buffer Rules (15A NCAC 02B
.0600)
6. Jordan Lake Water Supply Watershed Buffer Rules (15A NCAC
02B .0267)
7. High Quality Waters (15A NCAC 02H .1006)
8. Outstanding Resource Waters (15A NCAC 02H .1007)
9. Water Supply Watersheds (15A NCAC 02B .0216)
10.Post-Construction Ordinance (15A NCAC 02H .1017(a)(2))
LEGEND
N.C. Areas With Water Quality Buffer Requirements
N.C. Catawba River Basin Buffer Rules
Purpose: Protect and preserve existing riparian buffers in order to maintain their pollutant removal
functions.
Applicability: Mainstem of the river measured from top of bank & mainstem of the lakes measured
from full pond.
Widths:
• Zone 1: 30-foot undisturbed forested area (closest to water)
• Zone 2: 20-foot vegetated area – can be disturbed and revegetated
N.C. Goose, Six Mile & Waxhaw Creek Buffer Rules
Purpose: Protect the freshwater
mussel called the Carolina
heelsplitter, which was
designated as a endangered
species by the U.S. Fish &
Wildlife Service in June 1993.
Applicability: Intermittent and
perennial waters located in the
Goose, Six Mile and Waxhaw
Creek watersheds.
Widths:
• 200-foot undisturbed
riparian buffers on all
perennial and intermittent
streams located in the
FEMA regulated floodplain
• 100-foot undisturbed
riparian buffers on all other
perennial and intermittent
streams.
Carolina Heelsplitter
Mecklenburg County
Union County
Watersheds with Carolina
Heelsplitter Buffer Requirements
Purpose: Protect drinking water
supplies.
Applicability: Perennial waters
located in Water Supply (WS)
watersheds.
Widths:
• 100-foot vegetative buffer for
all new development >24%
BUA
• 30-foot vegetative buffer for
all new development <24%
BUA
N.C. Water Supply Watershed Buffer Rules
Areas Covered by Water Supply
Water Rules
N.C. Post-Construction Buffer Rules
Areas Covered by Post-Construction
Ordinances
Purpose: Protect waters from new
development in urbanizing areas.
Applicability: Intermittent and
perennial waters located within
new development projects in
Phase I and Phase II jurisdictions
that disturb one acre or more of
land, including projects that
disturb less than one acre of land
that are part of a larger common
plan of development or sale.
Widths:
• Built-upon area must be 30
foot landward of all perennial
and intermittent waters.
Union
Mecklenburg
Lincoln
Gaston
Iredell
RowanBurke
Cleveland
Catawba
Caldwell AlexanderDavie
Cabarrus
Charlotte-Mecklenburg Buffer Types
1. Water Supply Watershed –Adopted by 5 jurisdictions from
June 1993 through October 2001
2. Surface Water Improvement & Management (S.W.I.M.) –
Adopted by 8 jurisdictions from November 1999 through
June 2001
3. Goose Creek (Undisturbed) –Adopted by 2 jurisdictions in
March 2010
4. Post-Construction –Adopted by 8 jurisdictions in June 2007
and July 2008
Lake Norman
Mountain
Island Lake
Lake
Wylie
Charlotte-Mecklenburg Water Supply Watershed Buffer
Rules
Purpose: Protect drinking
water supplies.
Applicability: Perennial
waters located in Water Supply
(WS) watersheds.
Widths:
• One zone, undisturbed
buffer varying in width
from 30, 40, 50 and 100
feet or the entire FEMA
floodplain depending on
the density of the
development and its
location in the watershed.
Charlotte-Mecklenburg Surface Water Improvement
& Management (S.W.I.M.) Buffer Rules
Purpose: Ensure that streams and adjacent lands fulfill their natural functions, including protecting
water quality by filtering pollutants; providing storage for floodwaters; allowing channels to meander
naturally; and providing suitable habitats for wildlife.
Applicability: Streams draining >100 acres in Charlotte, Mecklenburg County & Pineville; >50 acres
in Cornelius, Davidson, Matthews & Mint Hill.
Widths:
• 3 zone buffer (with some disturbances allowed) varying in width from 35, 50 and 100 feet or the
entire FEMA floodplain depending on the size of the upstream drainage area.
Charlotte-Mecklenburg Goose & Six Mile Creek
(Carolina heelsplitter) Buffer Rules
For protection of Carolina
heelsplitter. Same as
State.
Charlotte-Mecklenburg Post-Construction Buffer Rules
Purpose: Protect waters from new
development in urbanizing areas.
Applicability: Intermittent and
perennial waters located within new
developments that disturb more than
one acre; or residential developments
that cumulatively create more than
24% built upon area; or commercial
developments that cumulatively create
more than 20,000 square feet of built
upon area.
Widths:
• In most jurisdictions, a 30-foot
vegetated buffer extends upstream
of the 50 and 100 acre drainage
area cutoff for the S.W.I.M.
buffers.
S.W.I.M.
Buffer
Post-
Construction
Buffer
Buffer RequirementsWhere Do N.C. Buffer Rules Apply?
1. Surface water shown on either the most recent version of the Natural Resources
Conservation Service (NCRS) Soil Survey Map or the United States Geologic
Survey (USGS) Quadrangle Topographic Maps.
2. When a landowner or other affected party believes a map is inaccurate, they can
consult the Division or the appropriate delegated local authority and an on-site
determination will be made.
3. Surface waters that appear on the maps shall not be subject to this Rule if an on-
site determination shows that they fall into one of the following categories.
• Ditches and manmade conveyances other than modified natural streams
unless constructed for navigation or boat access.
• Manmade ponds and lakes that are located outside natural drainage ways.
• Ephemeral (storm water) streams.
1 1
2 2
3
3
NRCS Soil Survey Map USGS Quadrangle Topographic Map
Goose Creek in Mint Hill
Buffer Type Final Determination Requirement
Water Supply Watershed Latest version of the applicable USGS quadrangle
map
S.W.I.M Mecklenburg County GIS (POLARIS)
http://polaris.mecklenburgcountync.gov/
Post-Construction POLARIS and certified professional using approved
State methodology
Goose & Six Mile
(Undisturbed)
Same as State
Buffer RequirementsWhere Do Charlotte-Mecklenburg Buffer Rules Apply?
Buffer RequirementsExemptions from N.C. Buffer Requirements
Uses existing as of the effective date of the
ordinance are exempt from ordinance
requirements. Converting to a different use
requires compliance with buffer rules, which
includes:
Adding impervious area to the buffer
Going from agriculture to non-agriculture
Ceasing to maintain a lawn in the riparian buffer
Unnecessary hardship.
Lack of practical alternatives for a road
crossing, railroad crossing, bridge, airport
facility, or utility crossing as long as it is
located, designed, constructed, and maintained
to minimize disturbance, provide maximum
nutrient removal, protect against erosion and
sedimentation, have the least adverse effects on
aquatic life and habitat, and protect water
quality to the maximum extent practicable
through the use of BMPs.
Goose Creek Buffer Exemption
for an Existing Use
Buffer RequirementsExemptions from Charlotte-Mecklenburg Buffer
Requirements
Buffer Type Exemptions
Water Supply Watershed Existing development; obtain variance
S.W.I.M Existing development; valid building permit;
subdivided by recorded subdivision plat, valid
preliminary subdivision plan; obtain variance
Post-Construction Same as S.W.I.M.; obtain variance
Goose & Six Mile (Undisturbed) Same as State.
A Table of Uses sets out the uses and their designation under many of the N.C. buffer rules as exempt, allowable, allowable with mitigation, or prohibited.
EXEMPT. Use allowed.
ALLOWABLE. Use may proceed provided there are no practical alternatives to the requested use.
ALLOWABLE WITH MITIGATION. Uses may proceed provided there are no practical alternatives to the requested use and an appropriate mitigation strategy has been approved.
PROHIBITED. Use may not proceed unless a variance is granted.
Buffer RequirementsAllowable Uses in N.C. Buffers (Catawba & Goose only)
Exempt AllowableAllowable with
MitigationProhibited
Road crossings of streams and other surface waters
subject to this Rule:
• Road crossings that impact equal to or less than 40
linear feet of riparian buffer
• Road crossings that impact greater than 40 linear
feet but equal to or less than 150 linear feet or one-
third of an acre of riparian buffer
• Road crossings that impact greater than 150 linear
feet or one-third of an acre of riparian buffer
X
X
X
Buffer RequirementsAllowable Uses in N.C. Buffers (Watershed & Post-
Construction)
Buffer Type Allowable Uses
Water Supply Watershed Water dependent structures, or other structures, such as flag
poles, signs and security lights, which result in only minimal
increases in impervious area and public projects such as road
crossings and greenways may be allowed where no practicable
alternative exists. These activities shall minimize built-upon
surface area, divert runoff away from surface waters and
maximize the utilization of BMPs.
Post-Construction None specified.
Buffer RequirementsAllowable Uses in Charlotte-Mecklenburg Buffers
Buffer Type Allowable Uses
Water Supply Watershed Same as State; removal of trees <2 inch caliper
allowed following approval
S.W.I.M Uses vary based on zone as described in table; other
uses allowed following approval & mitigation
Post-Construction Same as S.W.I.M.
Goose & Six Mile
(Undisturbed)
Same as State.
Channel
Buffer widths must be measured
horizontally on a line perpendicular
to the surface water.
Buffer Requirements Measuring Buffer Widths (N.C. & Charlotte-Mecklenburg)
Water quality buffers are measured horizontally on a line perpendicular to the surface water. For lakes, this measurement is
made landward from the full pond elevation established by Duke Energy. For streams and the ponds that they intersect, buffers
are measured landward from the top of the bank on both sides of the stream.
Buffer Requirements Diffuse Flow (N.C. & Charlotte-Mecklenburg)
Diffuse flow of runoff must be
maintained in the riparian buffer by
dispersing concentrated.
Concentrated runoff from new
ditches or manmade conveyances
must be converted to diffuse flow
before the runoff enters the buffer.
Periodic corrective action to restore
diffuse flow shall be taken if
necessary to impede the formation
of erosion gullies.
Overhead View of a Level Spreader with
Vegetated Filter Strip (LS-VFS)
Flow Splitter
Forebay
Water QualityBuffer
Questions?
• For more information on the Charlotte-Mecklenburg buffer requirements, go to
http://stormwater.charmeck.org (select “Regulations” and select “Buffers”)
• For more information regarding the N.C. buffer requirements, access the rules on
the internet.
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