WSMU_SMIT_WSWP Ordinance_20230613

-UNIFIED DEVELOPMENT ORDINANCE TOWN OF SMITHFIELD, NORTH CAROLINA
ARTICLE 10.-PERFORMANCE STANDARDS
PART IX.-OVERLAY DISTRICTS
Sec. 10.92.Water Supply Watershed Protection Overlay Districts.
Sec. 10.92. Water Supply Watershed Protection Overlay Districts.
10.92.1. Purpose.
The purpose of this section is to regulate development and land use activities in a manner which will limit exposure
of water supply watersheds to pollution.Sources of pollution include leachate from septic tank nitrification fields,
storm water runoff,accidental spillage from residential,commercial,and industrial activities, and discharge of
process and cooling water,among others.
As required by the Water Supply Watershed Protection Act of 1989,the State of North Carolina has reclassified
each of the state's drinking water supply watersheds to its most appropriate classification.The Neuse River
watershed is classified as WS-IV which are protected water supply watersheds which are generally moderate to
highly developed.Water supply watershed protection is a proactive approach to the preservation and treatment of
drinking water supplies rather than a reactive approach of treatment prior to consumption.
10.92.2. Authority.
Statutory authority for this section is derived from G.S. § 160D-702 and G.S. § 160D-703.
10.92.3.Jurisdiction.
The regulations established shall apply within areas designated as a Public Water Supply Watershed by the North
Carolina Environmental Management Commission and the boundaries of the watershed areas shall be as noted on
a map adopted in conjunction with these regulations.
10.92.4. Standards.
The standards of both the Water Supply Watershed Protection Overlay Districts and the underlying zoning district
shall apply.Where these standards differ,the standards of the Overlay Districts shall govern.
10.92.5. Establishment of Watershed Areas.
For the purposes of this section,the Town of Smithfield and its extraterritorial jurisdiction are divided into the
following Water Supply Watershed Protection Overlay Districts:
10.92.5.1.WS-IV-CA Critical Area Overlay District.
10.92.5.2.WS-IV-PA Protected Area Overlay District.
10.92.6. Development Regulations—WS-IV-CA District.
The following regulations shall apply within the WS-IV-CA:
10.92.6.1.Allowed Uses.
10.92.6.1.1.Agricultural uses are not subject to the stormwater requirements of this ordinance.
(Amended 10/3/2017)
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10.92.6.1.2.Silviculture, subject to the provisions of the Forest Practices Guidelines Related to Water
Quality.
10.92.6.1.3. Residential uses.
10.92.6.1.4. Expansions to existing nonresidential development in accordance with Section 10.92.9.
10.92.6.2. Density and Built-Upon Limits. (Amended 10/3/2017)
10.92.6.2.1.Single-Family Residential Minimum Lot Size.Where neither public water nor sewer are
available,the minimum lot size shall be forty thousand (40,000)square feet,or as determined by the
Johnston County Division of Environmental Health.Where either public water or sewer, or both,are
available,the minimum lot size shall be one-half(1/2)acre or twenty-one thousand seven hundred
eighty(21,780)square feet.
10.92.6.2.2. Impervious Surface Limitations. Development shall not exceed twenty-four(24) percent
built upon area on a project by project basis unless the high density option is utilized. For the purpose
of calculating the built upon area,total project area shall include the gross acreage in the tract on
which the project is to be developed.
10.92.6.2.3. High Density Option. Impervious surfaces may be increased up to a maximum of seventy(70) percent
subject to the following requirements:
10.92.6.2.3.1.Stormwater Control Requirements.Where development proposes intensity
greater than twenty-four(24) percent engineered stormwater controls shall be used to control
stormwater runoff from the first inch of rainfall in order to meet water quality concerns.
10.92.6.2.3.2.Ownership, Design, and Maintenance of Engineered Stormwater Controls.
10.92.6.2.3.2.1. Unless otherwise approved,ownership of the engineered stormwater
controls shall remain with the property owner or a property owners'association,which
shall be responsible for the continued care and maintenance of such controls.
10.92.6.2.3.2.2. Engineer stormwater controls shall be designed and constructed in accordance with standards and
specifications established by the Town of Smithfield and to the state's minimum standards.The BMP design
criteria shall require eighty-five(85) percent average annual removal of total suspended solids and the discharge
rate must meet one(1)of the following criteria:
10.92.6.2.3.2.2.1.The discharge rate following the one-inch design storm shall be
such that the runoff draws down to the pre-storm design within five(5)days, but not
less than two(2)days;or
10.92.6.2.3.2.2.2.The post development peak discharge rate shall equal the
predevelopment rate for the one-year,twenty-four-hour storm.
10.92.6.2.3.2.3. Except as allowed in paragraph 10.92.6.2.3.2.3.3 below, no building permit shall be issued for a
site proposed for development, until:
10.92.6.2.3.2.3.1. UDO Administrator has approved plans and specifications for the
proposed engineered stormwater controls and the property owner has entered into
an agreement and covenants or operation and maintenance agreement with the
town in accordance with the terms established by the town including being
referenced on a final plat which must be recorded along with the agreement in the
Johnston County Register of Deeds;and
10.92.6.2.3.2.3.2.The property owner has posted a performance bond,other surety
instrument, or other payment in acceptable form to the town in an amount
determined by the UDO Administrator as appropriate to assure construction,
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maintenance, repair, and/or reconstruction necessary for adequate performance of
the engineered stormwater controls.
10.92.6.2.3.2.3.3. For multi-family projects, building permits may be issued; but
construction drawing approval, or water and sewer permit approval,shall be
withheld until compliance with paragraphs 10.92.6.2.3.2.3.1 and 10.92.6.2.3.2.3.2
above.
10.92.6.2.3.2.3.4.The agreement and covenants or operation and maintenance
agreement required under paragraph 10.92.6.2.3.2.3.1 above, may be required prior
to site plan or preliminary plat approval.
10.92.6.2.3.2.4. No certificate of compliance/occupancy shall be issued for any structure
constructed within a site proposed for development,other than as allowed below, until the
UDO Administrator has approved construction of the engineered stormwater controls and
after review and approval of"as-built" drawings. Notwithstanding this requirement,the
UDO Administrator may allow for delay in approval of construction of stormwater controls
and submission and approval of as-built drawings for single-family housing and other
developments requiring multiple certificates of occupancy.
10.92.7. Development Regulations—WS-IV-PA District.
The following regulations shall apply within the WS-IV-PA:
10.92.7.1.Allowed Uses.
10.92.7.1.1.Agricultural uses are not subject to the stormwater requirements of this ordinance.
(Amended 10/3/2017)
10.92.7.1.2.Silviculture, subject to the provisions of the Forest Practices Guidelines Related to Water
Quality.
10.92.7.1.3. Residential development.
10.92.7.1.4. Nonresidential development,excluding storage of toxic and hazardous materials unless a
spill containment plan is implemented.
10.92.7.2. Density and Built-Upon Limits.(Amended 10/3/2017)
10.92.7.2.1.Single-Family Residential Minimum Lot Size.Where neither public water nor sewer are
available,the minimum lot size shall be forty thousand (40,000)square feet, or as determined by the
Johnston County Division of Environmental Health.Where either public water or sewer, or both,are
available,the minimum lot size shall be one-half(%)acre or twenty-one thousand seven hundred
eighty(21,780)square feet.
10.92.7.2.2. Impervious Surfaces. Development shall not exceed twenty-four(24) percent built upon
area on a project by project basis unless the high density option is utilized.
For the purpose of calculating the built upon area,total project area shall include the gross acreage in
the tract on which the project is to be developed.
10.92.7.2.3. High Density Option. Impervious surfaces may be increased up to a maximum of seventy(70) percent
subject to the following requirements:
10.92.7.2.3.1.Stormwater Control Requirements.Where development proposes intensity
greater than twenty-four(24) percent engineered stormwater controls shall be used to control
stormwater runoff from the first inch of rainfall in order to meet water quality concerns.
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10.92.7.2.3.2.Ownership, Design,and Maintenance of Engineered Stormwater Controls.
10.92.7.2.3.2.1. Unless otherwise approved,ownership of the engineered stormwater
controls shall remain with the property owner or a property owners'association,which
shall be responsible for the continued care and maintenance of such controls.
10.92.7.2.3.2.2. Engineer stormwater controls shall be designed and constructed in accordance with standards and
specifications established by the Town of Smithfield and to the state's minimum standards.The BMP design
criteria shall require eighty-five(85) percent average annual removal of total suspended solids and the discharge
rate must meet one(1)of the following criteria:
10.92.7.2.3.2.2.1.The discharge rate following the one-inch design storm shall be
such that the runoff draws down to the pre-storm design within five(5)days, but not
less than two(2)days;or
10.92.7.2.3.2.2.2.The post development peak discharge rate shall equal the
predevelopment rate for the one-year,twenty-four-hour storm.
10.92.7.2.3.2.3. Except as allowed in paragraph 10.92.7.2.3.2.3.3 below, no building permit shall be issued for a
site proposed for development, until:
10.92.7.2.3.2.3.1. UDO Administrator has approved plans and specifications for the
proposed engineered stormwater controls and the property owner has entered into
an agreement and covenants or operation and maintenance agreement with the
town in accordance with the terms established by the town including being
referenced on a final plat which must be recorded along with the agreement in the
Johnston County Register of Deeds;and
10.92.7.2.3.2.3.2.The property owner has posted a performance bond,other surety
instrument, or other payment in acceptable form to the town in an amount
determined by the UDO Administrator as appropriate to assure construction,
maintenance, repair, and/or reconstruction necessary for adequate performance of
the engineered stormwater controls.
10.92.7.2.3.2.3.3. For office, institutional, commercial, industrial,and multi-family
projects, building permits may be issued; but construction drawing approval, or
water and sewer permit approval,shall be withheld until compliance with paragraphs
10.92.7.2.3.2.3.1 and 10.92.7.2.3.2.3.2 above.
10.92.7.2.3.2.3.4.The agreement and covenants or operation and maintenance
agreement required under paragraph 10.92.7.2.3.2.3.1 above, may be required prior
to site plan or preliminary plat approval.
10.92.7.2.3.2.4. No certificate of compliance/occupancy shall be issued for any structure
constructed within a site proposed for development,other than as allowed below, until the
UDO Administrator has approved construction of the engineered stormwater controls and
after review and approval of"as-built" drawings. Notwithstanding this requirement,the
UDO Administrator may allow for delay in approval of construction of stormwater controls
and submission and approval of as-built drawings for single-family housing and other
developments requiring multiple certificates of occupancy.
10.92.8. Impervious Surface Transfer Credit. (Amended 10/3/2017)
The impervious surface limit provisions of this section can be exceeded through an impervious surface credit
transfer. Credit for the impervious surfaces allowed on one(1)or more parcels("donor parcels")can be
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transferred to non-contiguous parcels("receiving parcels"), such that the amount of impervious surface available
for a development project would be the total of what is normally allowed on the receiving parcel plus what is
transferred from the donor parcel(s). Impervious surface credit transfer is subject to the following provisions:
10.92.8.1.The donor parcel and receiving parcel shall be located within the same water supply watershed.
10.92.8.2.The impervious surface credit transfer shall not be from a donor parcel in protected area to a
receiving parcel in critical area.
10.92.8.3.The portion of the donor parcel which is restricted from development as part of the impervious surface
credit transfer shall remain in a vegetated or natural.The portion of the donor site restricted from development
shall be protected from all future development through use of a permanent conservation easement in favor of
either:
10.92.8.3.1.Town of Smithfield; or
10.92.8.3.2.A land trust or similar conservation-oriented non-profit organization with legal authority
to accept such easements(the organization shall be bona fide and in perpetual existence and the
conveyance instruments shall contain an appropriate provision for retransfer to the town in the event
the organization becomes unable to carry out its functions). If the entity accepting the easement is not
the town then a third right of enforcement favoring the town shall be included in the easement.
10.92.8.4.The impervious surface credit transfer shall be reviewed and approved through use of the site
plan process.
10.92.8.5.The donor parcel shall be deemed appropriate for acceptance by the town under the Town of
Smithfield Review Criteria for Acceptance of Conservation Easements for Impervious Surface Transfer.
10.92.9. Buffer Areas Required. (Amended 10/3/2017)
For all new development activities proposed within the WS-IV-CA or WS-IV-PA Districts, a minimum fifty-feet
vegetative buffer is required, unless the high density option is utilized in which case the minimum buffer will be
one hundred (100)feet, adjacent to all perennial waters as indicated on the most recent versions of USGS 1:24,000
(7.5 minute)scale topographic maps or as determined by other reliable sources.Vegetation within such buffers
shall remain undisturbed except as permitted by state rules and as may be necessary to accommodate any of the
following uses:
10.92.9.1. Boat docks, ramps, piers,or similar structures.
10.92.9.2. Reconstruction, rehabilitation, or restoration of structures listed on the National Register of
Historic Places.
10.92.9.3. Roads, provided they cross the buffer at a horizontal angle of at least sixty(60)degrees.
10.92.9.4.Other public projects,where no practical alternative exists.
10.92.10. Existing Single-Family Development Exempt.
Existing single-family dwelling units or proposed additions or expansions to existing single-family dwelling units
shall be exempt from these regulations.
10.92.11. Other Existing Development.
Existing development as defined herein (other than single-family residential development)which does not
currently comply with these provisions, may be continued and maintained without penalty. Proposed expansions
to structures classified as existing development, including nonresidential development within the critical area,
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which would qualify as permitted uses within the underlying zoning district may be allowed but shall be required
to comply fully with these requirements.The existing built-upon area shall not be required to be included when
calculating permissible density.
10.92.12. Existing Vacant Lots.
Existing vacant lots,for which plats or deeds have been recorded in the Johnston County Register of Deeds office
prior to the adoption of these regulations, may be used for any of the permissible uses allowed in the watershed
area in which it is located, provided that whenever two(2) or more contiguous residential lots of record are in
single ownership at any time after the adoption of this ordinance and such lots individually have less area than the
minimum requirements for residential purposes for the watershed area in which such lots are located,then such
lots shall be considered as a single property for the purpose of compliance with these requirements.
10.92.13. Occupied Lots.
Lots occupied for residential purposes at the effective date of these regulations may continue to be used, provided
that whenever two (2)or more contiguous lots of record, one(1)of which is occupied, are in single ownership on
the effective date of these regulations,and such lots individually or together have less area than required by the
minimum standards,then such lots shall be considered as a single property for the purpose of compliance with
these requirements.
10.92.14. Swale Street Systems.
Within the WS-IV-CA and WS-IV-PA Districts,the Town Council may authorize development which would utilize a
swale rather than a curb and gutter street system provided such streets are designed and constructed in
accordance with the NCDOT Division of Highways manual entitled "Minimum Constructions Standards for
Subdivision Roads,"as amended, or its successor document,for the classification of street proposed.Additionally,
best management practices(BMPs)as prescribed in the NCDOT manual "Water Supply Watershed Best
Management Practices" shall be utilized for all new roadway construction within watershed areas.
10.92.15. Planned Unit Development within Watershed Areas.
For planned unit developments proposed within water supply watershed areas, development densities shall
comply with the regulations established under this section.
10.92.16. Variances.
10.92.16.1.Whenever an application is filed for a variance to the provisions contained in this section the
town shall notify the other local governments having jurisdiction within the watershed and any entity using
the water supply for consumption purposes to allow these parties an opportunity to comment on the
application.
10.92.16.2.The Board of Adjustment shall conduct a hearing on the application in accordance with the
procedures established under this ordinance.The Board of Adjustment shall have the power to authorize, in
specific cases, minor variances, as defined herein,from the terms of this section as will not be contrary to the
public interest.
10.92.16.3. If the application for a variance calls for the granting of a major variance,as defined herein,and if the
Board of Adjustment decides in favor of granting the variance, a preliminary record of the hearing shall be
prepared within thirty(30)days.The preliminary record shall include:
10.92.16.3.1.The variance application;
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10.92.16.3.2.The hearing notices;
10.92.16.3.3.The evidence presented;
10.92.16.3.4. Proposed findings and exceptions;
10.92.16.3.5.The proposed decision, including any conditions proposed to be added to the permit.
10.92.16.4.The preliminary record shall be sent to the(EMC)for review as follows:
10.92.16.4.1. If the EMC concludes from the preliminary record that the variance qualifies as a major
variance and that(a)the property owner can secure no reasonable return from nor make any
proposed variance is granted,and (b)the variance, if granted,will not result in a threat to the water
supply,then the EMC shall approve the variance as proposed or approve the proposed variance with
conditions.
10.92.16.4.2. If the EMC concludes from the preliminary record that the variance qualifies as a major
variance and that(a)the property owner can secure a reasonable return from or make a practical use
of the property without the variance or, (b)the variance, if granted,will result in a serious threat to the
water supply,then the EMC shall deny approval of the variance as proposed.
10.92.16.5.The EMC shall prepare a final Commission decision relative to the proposed variance and
transmit it to the Board of Adjustment.The Board shall advise the applicant for the proposed variance of the
FMC's final decision.
10.92.16.6.A record of all variances granted during a calendar shall be transmitted to the Division of
Environmental Management on or before January 1st of the following year.
10.92.17. Cluster Subdivisions. (Amended 10/3/2017)
Cluster development is allowed in all watershed areas under the following conditions:
10.92.17.1. Minimum lot sizes are not applicable to single family cluster development projects; however,the
total number of lots shall not exceed the number of lots allowed for single family detached developments in
Sections 10.92.6.2.1 and 10.92.7.2.1. Density or built-upon area for the project shall not exceed that allowed
for the critical area, balance of watershed or protected area,whichever applies.
10.92.17.2.All built-upon area shall be designed and located to minimize stormwater runoff impact to the
receiving waters and minimize concentrated stormwater flow, maximize the use of sheet flow through
vegetated areas,and maximize the flow length through vegetated areas.
10.92.17.3.Areas concentrated density development shall be located in upland area and away,to the
maximum extent practicable,from surface waters and drainage ways.
10.92.17.4.The remainder of the tract shall remain in a vegetated or natural state.The title to the open
space area shall be conveyed to an incorporated Homeowners'association for management;to the Town of
Smithfield for preservation as a park or open space;or to a conservation organization for preservation in a
permanent easement.Where a property association is not incorporated, a maintenance agreement shall be
filed with the property deeds.
Cluster developments that meet the applicable low density requirements shall transport stormwater runoff by
vegetated conveyances to the maximum extent practicable.
10.92.18. Amendments to Water Supply Watershed Protection Regulations.
The Town Council may,on its own motion or upon a properly filed petition, amend,supplement,or modify the
watershed regulations set forth under this section in accordance with the procedures established under Article 4 of
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this ordinance, provided that no amendments shall be adopted which shall cause these regulations to violate the
minimum watershed protection rules adopted by the North Carolina Environmental Management Commission.All
amendments shall subsequently be filed with the North Carolina Division of Environmental Management,the
North Carolina Division of Environmental Health,and the North Carolina Division of Community Assistance.
10.92.19. Summary of Water Supply Watershed Protection Rules.
The following table summarizes the water supply watershed protection regulations contained herein,which were
adopted by the Smithfield Town Council on August 2, 2017;to become effective and in force from that day
forward.
Classifications Dischargers Residential Nonresidential Sludge Landfills Hazardous Sewer
Density Low Development Application Materials Lines
Density
Option
WS-IV None 2du/lac** No new None None None Allow
Critical Area development
Protected Area Domestic and Same Allow None None Inventory Allow
Industrial maximum 24% spill/failure
built-upon
NOTES:
** Minimum lot size where public water or sewer is not available shall be forty thousand(40,000)square feet.
(1) Critical area is one(1)mile draining to river intake or to the ridgeline,whichever is greater.
(2) Protected area is ten(10)miles upstream draining to river intake or to the ridgeline,whichever is greatest.
(3) For residential and nonresidential development,a minimum buffer width of fifty(50)feet shall be provided adjacent to all perennial waters.
(4) Spill containment structures are required for new industry where hazardous materials are used,stored,or manufactured.
(5) Storm water control structures shall not be employed within the critical or protected portion of the watershed as a means to exceed the minimum criteria
established herein.
(6) Agricultural activities are subject to provisions of the Food Security Act of 1985 and the Food,Agriculture,Conservation,and Trade Act of 1990.In critical area
agricultural activities must maintain a ten-foot vegetated buffer or equivalent control.Animal operations with greater than one hundred(100)animals must
use BMPs as determined by the Soil and Water Conservation Commission.
(7) Forestry activities are subject to the provisions of the forest practices guidelines related to water quality(15A NCAC 11.0101-.0209).
(8) The Department of Transportation must use BMPs as described in their document,"Water Supply Watershed Best Management Practices."
(9) Swale street systems constructed in accordance with NCDOT standards may be permissible within the critical and protected areas.
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