Watershed Protection Overlay Standards

Sec. 8.7. Watershed Protection Overlay Standards

8.7.1. Applicability

The watershed All of the land area draining to a particular point on a water course or to a water body. protection overlay standards of this section shall apply to the Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlay as set forth in Sec. 4.11, Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlay.

8.7.2. General Requirements

A. Minimum Lot Size

1. In all Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlays, except F/J-B and E-B, the minimum lot sizes indicated in the following table shall be applied in all new subdivisions All divisions of a tract or parcel of land into two or more lots, building sites, or other divisions for the purpose of sale or building development (whether immediate or future) or any division of land involving the dedication of a new street or a change in existing streets. unless the subdivision All divisions of a tract or parcel of land into two or more lots, building sites, or other divisions for the purpose of sale or building development (whether immediate or future) or any division of land involving the dedication of a new street or a change in existing streets. uses the cluster provision in accordance with Sec. 6.7, Cluster Subdivision, or the conservation subdivision All divisions of a tract or parcel of land into two or more lots, building sites, or other divisions for the purpose of sale or building development (whether immediate or future) or any division of land involving the dedication of a new street or a change in existing streets. provisions of paragraph 6.2.4, Conservation Subdivision.

Minimum Lot Size

Overlay	Rural Tier	Rural Tier – Rural Village An area delineated on the Future Land Use Map, within the Rural Tier, that can include residential, commercial, office, institutional, and open space/recreation land uses.	Suburban Tier
M/LR-A	3 acres		20,000 square feet
M/LR-B	3 acres	1 acre	20,000 square feet
F/J-A	3 acres		1 acre
E-A; E-A(2)	Not Applicable		20,000 square feet

2. In the F/J-B and E-B overlays, developers Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. of single-family A residential use consisting of one dwelling unit per lot of record. As described in Sec. 7.1, Housing Types, includes: single-family detached house; zero lot line house; traditional house; or attached house. Not to include manufactured housing. subdivisions All divisions of a tract or parcel of land into two or more lots, building sites, or other divisions for the purpose of sale or building development (whether immediate or future) or any division of land involving the dedication of a new street or a change in existing streets. shall comply with the requirements of the underlying zoning district.

B. Impervious Surface Limits

1. Any development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. in a Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlay shall be subject to limits on the amount of impervious surfaces A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. permitted in accordance with the following table. Development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. plans, site plans An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development., preliminary plats A map indicating the proposed layout of a development and related information that is submitted for preliminary review., and final plats A map, chart or plan of a tract or parcel of land which is to be or which has been, subdivided. shall clearly identify the amount of existing and proposed impervious surfaces A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended..

Overlay	Low Density Option One of two approaches available for development in Watershed Protection Overlays that relies on non-structural means, specifically lower intensity limits, to minimize the risk of water pollution. Impervious Surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. Limit		High Density Option One of two approaches available for development in Watershed Protection Overlays. The high density option relies on impervious surface limits and engineered stormwater controls to minimize risk of water pollution. Impervious Surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. Limit
M/LR-A	6%		Not permitted
M/LR-B	Rural Tier	6%	Not permitted
M/LR-B	Rural Village An area delineated on the Future Land Use Map, within the Rural Tier, that can include residential, commercial, office, institutional, and open space/recreation land uses.	12%	24%
F/J-A	Within one-half mile of the normal pool: six percent; Between one-half and one mile from the normal pool: nine percent		Not permitted in the Rural Tier. 40%, for all areas not in the Rural Tier and for those uses allowed in Sec. 4.11.4, Nonresidential Land Use The purpose for which a building, structure, or area of land may be arranged or occupied or the activity conducted or proposed in a building, structure, or on an area of land. Restrictions; Nonresidential Land Use The purpose for which a building, structure, or area of land may be arranged or occupied or the activity conducted or proposed in a building, structure, or on an area of land. Restrictions, intensities greater than 25% shall require a Major Special Use The purpose for which a building, structure, or area of land may be arranged or occupied or the activity conducted or proposed in a building, structure, or on an area of land. Permit pursuant to Sec. 3.9, Special Use Permit.
F/J-B, E-B	24%		70%
E-A; E-A(2)	24%		Not permitted

2. The impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. limit provisions of this section can be exceeded through an impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. credit transfer. Credit for the impervious surfaces A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. allowed on one or more parcels See “Lot of record.” (“donor parcels See “Lot of record.””) can be transferred to non-contiguous parcels See “Lot of record.” (“receiving parcels See “Lot of record.””), such that the amount of impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. available for a development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. project would be the total of what is normally allowed on the receiving parcel See “Lot of record.” plus what is transferred from the donor parcel See “Lot of record.”(s). Impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. credit transfer is subject to the following provisions:

a. The donor parcel See “Lot of record.” and receiving parcel See “Lot of record.” shall be located within the same water supply watershed All of the land area draining to a particular point on a water course or to a water body..

b. The impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. credit transfer shall not be from a donor parcel See “Lot of record.” in Area B to a receiving parcel See “Lot of record.” in Area A, or from a donor parcel See “Lot of record.” in an F/J-A area with a nine percent limit to a receiving parcel See “Lot of record.” in an F/J-A area with a six percent limit.

c. The portion of the donor parcel See “Lot of record.” which is restricted from development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. as part of the impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. credit transfer shall remain in a vegetated or natural state or used for crop Cultivated plants or agricultural produce, such as but not limited to grain, vegetables, or fruit. production or pasture provided that best management practices (BMPs) as developed Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. by the Soil and Water Conservation District are utilized. The portion of the donor site restricted from development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. shall be protected from all future development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. through use of a permanent conservation easement A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. in favor of either:

(1) Durham County or the City of Durham; or

(2) A land trust or similar conservation-oriented non-profit organization with legal authority to accept such easements A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. (the organization shall be bona fide and in perpetual existence and the conveyance instruments shall contain an appropriate provision for retransfer to the County or City, as appropriate, in the event the organization becomes unable to carry out its functions). If the entity accepting the easement A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. is not the County or City, then a third right of enforcement favoring the County or City, as appropriate, shall be included in the easement A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes..

d. The impervious surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. credit transfer shall be reviewed and approved through use of the final plat The final map of all or a portion of a subdivision which is presented for final approval. process pursuant to Sec. 3.6, Subdivision Review, or the site plan An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. process pursuant to Sec. 3.7, Site Plan Review, as applicable.

e. The donor parcel See “Lot of record.” shall be deemed appropriate for acceptance by the County or City, as appropriate, under the Durham County Review Criteria for Acceptance of Conservation Easements A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. for Impervious Surface A surface composed of any material that impedes or prevents natural infiltration of water into the soil and qualifies as “built-upon area” as defined by NCGS 143-214.7, as amended. Transfer.

C. Stormwater Control Requirements

Where development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. proposes intensity greater than the maximum authorized by the Low Density Option One of two approaches available for development in Watershed Protection Overlays that relies on non-structural means, specifically lower intensity limits, to minimize the risk of water pollution., engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls shall be used to control stormwater runoff The direct runoff of water resulting from precipitation in any form. from the first inch of rainfall in order to meet water quality concerns.

D. Ownership, Design, and Maintenance of Engineered Stormwater Controls

1. Unless otherwise approved, ownership of the engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls shall remain with the property owner Any person having charge of any real property according to the records held by the Register of Deeds. or a property owner Any person having charge of any real property according to the records held by the Register of Deeds.'s association, which shall be responsible for the continued care and maintenance of such controls.

2. Engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls shall be designed and constructed in accordance with standards and specifications established by the City Public Works Director or County Engineer, or their designees, as appropriate.

3. Except as allowed in paragraph c below, no building permit A permit issued by the Inspections Department in conformance with the State Building Code. shall be issued for a site proposed for development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land., until:

a. The City Public Works Director or County Engineer, or their designees, as appropriate, has approved plans and specifications for the proposed engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls and the property owner Any person having charge of any real property according to the records held by the Register of Deeds. has entered into an Agreement and Covenants or Operation and Maintenance Agreement with the City or County, as appropriate, in accordance with the terms established by either the City Public Works Director or County Engineer, or their designees, as appropriate; and

b. The property owner Any person having charge of any real property according to the records held by the Register of Deeds. has posted a performance bond, other surety instrument, or other payment satisfactory to the City or County, as appropriate, in an amount determined by the City Public Works Director or County Engineer, or their designees, as appropriate to assure construction, maintenance, repair, and/or reconstruction necessary for adequate performance of the engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls.

c. For office A room, group of rooms, or building whose primary use is the conduct of a business, professional service, or governmental activity of a non-retail nature; including administration, record keeping, clerical work, and similar functions. This definition is not meant to include manufacturing, processing, repair, or storage of materials or products., institutional, commercial, industrial, and multifamily A residential use consisting of at least three dwelling units. As described in Sec. 7.1, Housing Types, includes: townhouse; detached rowhouse; multiplex; or apartment. projects, building As defined in the North Carolina Building Code, as amended, or the North Carolina Residential Code for One and Two-Family Dwellings, as amended, as applicable. permits may be issued; but construction drawing approval, or water or sewer permit approval, shall be withheld until compliance with paragraphs a and b above.

d. The Agreement and Covenants or Operation and Maintenance Agreement required under paragraph a, above, may be required prior to site plan An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. or preliminary plat A map indicating the proposed layout of a development and related information that is submitted for preliminary review. approval.

4. No certificate of compliance A statement, signed by an administrative officer, setting forth that a building, structure, or use complies with this Ordinance and Building Codes and that the same may be used for the purposes stated on the permit. shall be issued for any structure A walled or roofed constructed object that is principally above ground; vertical projections meeting the definition of antenna-supporting or wireless support structures; or, when used in reference to Sec. 8.4, Floodplain and Flood Damage Protection Standards, a gas or liquid storage tank that is principally above ground. Included in this definition are extensions or additions which are covered by a roof supported by walls or columns, such as but not limited to porte cocheres, carports, covered or screened porches, and breezeways. constructed within a site proposed for development Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land., other than as allowed below, until the City Public Works Director or County Engineer, or their designees, as appropriate, has approved construction of the engineered stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls and after review and approval of submitted “as-built” drawings. Notwithstanding this requirement, the Stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. Division of the City may allow for delay in approval of construction of stormwater The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. controls and submission and approval of as-built drawings for single family One or more individuals residing in a dwelling unit, living as a single housekeeping unit, and complying with the following rules: A. Any number of individuals related by blood, marriage, or adoption may occupy a dwelling unit; B. Where some or all of the occupants are unrelated by blood, marriage, or adoption, the total number of occupants that are unrelated, shall not exceed six. In applying this provision, children who are under the age of 23 and who are children of the owner or a person renting an entire dwelling unit from the owner shall be counted as a single occupant. In addition, in all cases, the limitation set out in subsection C. below shall apply. C. Where a reasonable accommodation has been approved. D. The presence of household employees or children in foster care shall not disqualify any premises otherwise satisfying the above rules. housing, duplexes, townhouses A building made up of three or more attached dwelling units (except when otherwise allowed) where each unit is on an individual lot and the units are lined up in a row and share side walls., and detached rowhouses) and other developments Pursuant to NCGS 160D-102, any of the following: a. The construction, erection, alteration, enlargement, renovation, substantial repair, movement to another site, or demolition of any structure. b. The excavation, grading, filling, clearing, or alteration of land. c. The subdivision of land as defined in G.S. 160D-802. d. The initiation or substantial change in the use of land or the intensity of use of land. requiring multiple certificates of occupancy in accordance with adopted policies of the City.

E. Riparian Buffers

Riparian buffers are required in accordance with Sec. 8.5, Riparian Buffer Protection Standards.

F. Wastewater Treatment and Facilities

1. Wastewater Treatment

Wastewater treatment facilities shall be allowed if approved by the State of North Carolina. Individual on-site ground absorption systems shall be permitted, subject the State of North Carolina, as applicable.

2. Sanitary Sewer Services

a. Except in the Rural Tier, public and private sanitary sewer lines, force mains, and pump stations shall be permitted within all Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlays. Public and private pump stations shall be equipped with the following safety features:

(1) Battery-backed alarm systems activated by pump failure or power outage, connected by an automatic dialer to a 24-hour maintenance service approved by the City Public Works Director or County Engineer, or their designees, as appropriate.

(2) Provision for connection of a portable generator. The City Public Works Director or County Engineer, or their designees, as appropriate, may require the pump station to be equipped with on-site, stand-by power.

b. Within the Rural Tier, new public or private sanitary sewer lines or outfalls, including necessary force mains and pump stations, may be permitted within the Watershed All of the land area draining to a particular point on a water course or to a water body. Protection Overlays subject to City Council or Board of Commissioners approval, as appropriate:

(1) To serve an existing use or structure A walled or roofed constructed object that is principally above ground; vertical projections meeting the definition of antenna-supporting or wireless support structures; or, when used in reference to Sec. 8.4, Floodplain and Flood Damage Protection Standards, a gas or liquid storage tank that is principally above ground. Included in this definition are extensions or additions which are covered by a roof supported by walls or columns, such as but not limited to porte cocheres, carports, covered or screened porches, and breezeways. for which a health hazard has been documented by the County Health Department or the State of North Carolina; or

(2) If associated with a wastewater treatment facility permitted pursuant to paragraph 1, Wastewater Treatment, above.

c. In considering such extensions, all reasonable alternatives shall be considered prior to a decision to extend the sewer services. All service connections, installed in accordance with the North Carolina Plumbing Code, shall be permitted only in accordance with Article III, Water and Sewer Main Extensions, of Chapter 70, Utilities, of the Durham City Code.

G. Hazardous and Nuclear Materials

1. Prior to site plan An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. approval, an Emergency Contingency Plan shall be prepared and submitted through the Planning Department to the Durham County Fire Marshall and the Water Management Director for review and approval. The Emergency Contingency Plan shall be prepared in accordance with the requirements in the Superfund Amendments and Reauthorization Act (SARA), Title III and shall be updated annually. In addition, the Emergency Contingency Plan shall include:

a. A site plan An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. showing buildings and the locations of points of storage, transfer and use of nuclear and hazardous materials Materials, or mixtures containing those materials, which pose a physical, environmental or health hazard by virtue of their carcinogenic, corrosive, highly toxic, irritant, sensitizing or toxic properties as defined in 29 CFR 1910.1200. Included in this definition are materials included in EPA's most recent Priority Pollutants List and substances which are regulated, or caused to be regulated, under provisions of the Resource Conservation and Recovery Act (RCRA); the Comprehensive Emergency Response, Compensation and Liability Act (CERCLA); the Superfund Amendments and Reauthorization Act (SARA); or any subsequent amendments of these Acts. Hazardous materials shall include hazardous wastes, which are the byproducts resulting from the use of hazardous materials, materials which have been used to clean up spills of hazardous materials, and hazardous materials which have reached their shelf-life or have been used or contaminated. Also included in this definition are hazardous wastes regulated, or caused to be regulated by the Resource Conservation and Recovery Act (40 CFR 261, Subpart C and Subpart B);

b. A list of nuclear and hazardous materials Materials, or mixtures containing those materials, which pose a physical, environmental or health hazard by virtue of their carcinogenic, corrosive, highly toxic, irritant, sensitizing or toxic properties as defined in 29 CFR 1910.1200. Included in this definition are materials included in EPA's most recent Priority Pollutants List and substances which are regulated, or caused to be regulated, under provisions of the Resource Conservation and Recovery Act (RCRA); the Comprehensive Emergency Response, Compensation and Liability Act (CERCLA); the Superfund Amendments and Reauthorization Act (SARA); or any subsequent amendments of these Acts. Hazardous materials shall include hazardous wastes, which are the byproducts resulting from the use of hazardous materials, materials which have been used to clean up spills of hazardous materials, and hazardous materials which have reached their shelf-life or have been used or contaminated. Also included in this definition are hazardous wastes regulated, or caused to be regulated by the Resource Conservation and Recovery Act (40 CFR 261, Subpart C and Subpart B) kept on-site in any quantities;

c. The location of spill control valves on any bridges and causeways; and

d. The person Any individual, partnership, firm, association, joint venture, public or private corporation, trust, estate, commission, board, public or private institution, utility, cooperative, interstate body, or other legal entity. responsible for on-site spill control and containment, and the appropriate means of contacting that person Any individual, partnership, firm, association, joint venture, public or private corporation, trust, estate, commission, board, public or private institution, utility, cooperative, interstate body, or other legal entity. on a 24-hour basis.

2. Any container or tank used to store hazardous materials Materials, or mixtures containing those materials, which pose a physical, environmental or health hazard by virtue of their carcinogenic, corrosive, highly toxic, irritant, sensitizing or toxic properties as defined in 29 CFR 1910.1200. Included in this definition are materials included in EPA's most recent Priority Pollutants List and substances which are regulated, or caused to be regulated, under provisions of the Resource Conservation and Recovery Act (RCRA); the Comprehensive Emergency Response, Compensation and Liability Act (CERCLA); the Superfund Amendments and Reauthorization Act (SARA); or any subsequent amendments of these Acts. Hazardous materials shall include hazardous wastes, which are the byproducts resulting from the use of hazardous materials, materials which have been used to clean up spills of hazardous materials, and hazardous materials which have reached their shelf-life or have been used or contaminated. Also included in this definition are hazardous wastes regulated, or caused to be regulated by the Resource Conservation and Recovery Act (40 CFR 261, Subpart C and Subpart B) shall be equipped with leak detection devices and shall be double-walled or have other secondary containment features.