15A NCAC 02H .1020. UNIVERSAL STORMWATER MANAGEMENT PROGRAM

(a)  Adoption of the Universal Stormwater Management Program (USMP) shall be made at the option of a local government by adopting an ordinance that complies with the requirements of this Rule and the requirements of 15A NCAC 02B .0104(f).  The Environmental Management Commission shall approve local ordinances if it determines that the requirements of the local ordinance equal or exceed the provisions of this Rule.  A model ordinance for the Universal Stormwater Management Program shall be available from the Division of Water Quality (DWQ).  Administration and implementation of the USMP shall be the responsibility of the adopting local government within its jurisdiction.  Local governments located within one of the 20 Coastal Counties may elect to have the Division of Water Quality administer and implement the Universal Stormwater Management Program, either whole or in part, within their jurisdiction following their adoption of the program.  Adoption of the USMP may not satisfy water quality requirements associated with the protection of threatened or endangered species or those requirements associated with a Total Maximum Daily Load (TMDL).  The requirements of the USMP shall supercede and replace all other existing post-construction stormwater requirements within that jurisdiction, as specified in Paragraph (b) of this Rule.

(b)  With the exceptions noted in Paragraph (c) of this Rule, the requirements specified in this Rule shall replace the following DWQ stormwater control requirements:

(1)           Water Supply (WS) Watershed II (WS II) (15A NCAC 02B .0214(3)(b)(i));

(2)           WS Watershed II Critical Area (WS II CA) (15A NCAC 02B .0214(3)(b)(ii));

(3)           WS Watershed III (WS III) (15A NCAC 02B .0215(3)(b)(i));

(4)           WS Watershed III Critical Area (WS III CA) (15A NCAC 02B .0215(3)(b)(ii));

(5)           WS Watershed IV (WS IV) (15A NCAC 02B .0216(3)(b)(i));

(6)           WS Watershed IV Critical Area (WS IV CA) (15A NCAC 02B .0216(3)(b)(ii));

(7)           High Quality Waters (HQW) for Freshwaters (15A NCAC 02H .1006);

(8)           High Quality Waters (HQW) for Saltwaters (15A NCAC 02H .1006);

(9)           Outstanding Resource Waters (ORW) for Freshwaters (15A NCAC 02H .1007);

(10)         Outstanding Resource Waters (ORW) for Saltwaters (15A NCAC 02H .1007);

(11)         Shellfishing (SA) (15A NCAC 02H .1005(2));

(12)         Post-Construction Requirements of the Phase 2 Program (S.L. 2006-246);

(13)         Coastal Counties Stormwater Requirements in 15A NCAC 02H .1005(3);

(14)         Stormwater Controls for 401 Certifications under 15A NCAC 02H .0500; 

(15)         Catawba Buffer Rules (15A NCAC 02B .0243 and 02B .0244); and

(16)         Urban Stormwater Management Requirements of the Randleman Lake Water Supply Watershed Rules (15A NCAC 02B .0251).

(c)  As mandated in 15A NCAC 02H .0506(b)(5) and (c)(5), the Division Director may review and require amendments to proposed stormwater control plans submitted under the provisions of the 401 Certification process in order to ensure that the proposed activity will not violate water quality standards.  Adoption of the Universal Stormwater Management Program does not affect the requirements specified in 15A NCAC 02B .0214(3)(b)(i)(I), 02B .0214(3)(b)(ii)(C) and (D), 15A NCAC 02B .0215(3)(b)(i)(I), 02B .0215(3)(b)(ii)(C) and (D), and 15A NCAC 02B .0216(3)(b)(ii)(C) and (D).  The Catawba Buffer Rules shall be superceded in those areas where the buffers are contained within the jurisdiction of another stormwater program listed in Paragraph (b) of this Rule and the requirements of that program are replaced by the USMP.  For the watershed that drains to Lake James, which is not contained within the jurisdiction of another stormwater program, the Catawba Buffer Rules shall be superceded if the USMP is implemented in the entire area within five miles of the normal pool elevation of Lake James.  The implementation of the USMP shall supercede the Urban Stormwater Management Requirements of the Randleman Lake Water Supply Watershed in 15A NCAC 02B .0251, but USMP implementation does not affect the Randleman Lake Water Supply Watershed; Protection and Maintenance of Riparian Areas requirements specified in 15A NCAC 02B .0250.

(d)  Coastal Counties Requirements.  All development activities located in one of the 20 Coastal Counties that disturb 10,000 square feet or more of land, including projects that disturb less than 10,000 square feet of land that are part of a larger common plan of development or sale, shall control the runoff from the first one and one half inch of rainfall to the level specified in Paragraph (f) of this Rule.  In addition, all impervious surfaces, except for roads, paths, and water dependent structures, shall be located at least 30 feet landward of all perennial and intermittent surface waters. In addition to the other requirements specified in this Paragraph, all development activities that are located within 575 feet of waters designated by the Environmental Management Commission as shellfishing waters shall be limited to a maximum impervious surface density of 36 percent.  Redevelopment activities that meet the provisions of 15A NCAC 02H .1002(14) shall not be required to comply with the requirements of this Paragraph. 

(e)  Non-Coastal Counties Requirements.  All residential development activity that is located in one of the 80 Non-Coastal Counties that disturbs one acre or more of land, including residential development that disturbs less than one acre of land that is part of a larger common plan of development or sale, and all non-residential development activity that is located in one of the 80 Non-Coastal Counties that disturbs ½ acre or more of land, including non-residential development that disturbs less than ½ acre of land that is part of a larger common plan of development or sale, shall control the runoff from the first one inch of rainfall as specified in Paragraph (f) of this Rule.  Except as allowed in this Paragraph, no new impervious or partially pervious surfaces, except for roads, paths, and water dependent structures, shall be allowed within the one percent Annual Chance Floodplain as delineated by the North Carolina Floodplain Mapping Program in the Division of Emergency Management.  For perennial and intermittent streams that do not have a floodplain delineated by the Floodplain Mapping Program, all development activities subject to this Rule shall be located at least 30 feet landward of all perennial and intermittent surface waters.  In addition to the other requirements specified in this Paragraph, all development activities that are located within the area designated by the Environmental Management Commission as a Critical Area of a Water Supply Watershed shall be limited to a maximum impervious surface density of 36 percent.  Redevelopment of residential structures within the one percent Annual Chance Floodplain that meets the provisions of 15A NCAC 02H .1002(14) is allowed.  Redevelopment of non-residential structures within the one percent Annual Chance Floodplain that meets the provisions of 15A NCAC 02H .1002(14) is allowed provided that less than ½ acre is disturbed during the redevelopment activity.  Redevelopment activities outside of the one percent Annual Chance Floodplain that meet the provisions of 15A NCAC 02H .1002(14) shall not be required to comply with the requirements of this Paragraph. 

(f)  Structural stormwater controls required under Paragraphs (d) and (e) shall meet the following criteria:

(1)           Remove an 85 percent average annual amount of Total Suspended Solids.

(2)           For detention ponds draw down the treatment volume no faster than 48 hours, but no slower than 120 hours.

(3)           Discharge the storage volume at a rate equal or less than the pre-development discharge rate for the 1-year, 24-hour storm.

(4)           Meet the General Engineering Design Criteria set forth in 15A NCAC 02H .1008(c).

(g)  For the purposes of this Rule, a surface water shall be present if the feature is shown on either the most recent complete version of the soil survey map prepared by the Natural Resources Conservation Service of the United States Department of Agriculture or the most recent version of the 1:24,000 scale (7.5 minute) quadrangle topographic maps prepared by the United States Geologic Survey (USGS).  Relief from this requirement shall be allowed when surface waters are not present in accordance with the provisions of 15A NCAC 02B .0233 (3)(a).

(h)  Local governments that implement the Universal Stormwater Management Program shall require recorded deed restrictions and protective covenants that ensure development activities will maintain the project consistent with approved plans.

(i)  Local governments that implement the Universal Stormwater Management Program shall require an operation and maintenance plan that ensures the operation of the structural stormwater control measures required by the program.  The operation and maintenance plan shall require the owner of each structural control to submit a maintenance inspection report on each structural stormwater control measure annually to the local program.

(j)  In addition to the other measures required in this Rule, all development activities located in one of the 20 Coastal Counties that disturb 10,000 square feet or more of land within ½ mile and draining to SA waters shall:

(1)           Use stormwater control measures that result in fecal coliform die off and that control to the maximum extent practicable sources of fecal coliform while incorporating the requirements specified in Paragraph (f) of this Rule. 

(2)           Prohibit new points of stormwater discharge to SA waters or expansion (increase in the volume of stormwater flow through conveyances or increase in capacity of conveyances) of existing stormwater conveyance systems that drain to SA waters.  Any modification or redesign of a stormwater conveyance system within the contributing drainage basin must not increase the net amount or rate of stormwater discharge through existing outfalls to SA waters.  Diffuse flow of stormwater at a non-erosive velocity to a vegetated buffer or other natural area capable of providing effective infiltration of the runoff from the 1-year, 24-hour storm shall not be considered a direct point of stormwater discharge.  Consideration shall be given to soil type, slope, vegetation, and existing hydrology when evaluating infiltration effectiveness.

(k)  In addition to the other measures required in this Rule, development activities draining to trout (Tr) waters shall use stormwater control measures that avoid an increase in the receiving water temperature, while still incorporating the requirements specified in Paragraph (f) of this Rule.

(l)  The Division, upon determination that a local government is failing to implement or enforce the approved local stormwater program, shall notify the local government in writing of the local program inadequacies.  If the local government has not corrected the deficiencies within 90 days of receipt of written notification from the Division, then the Division shall implement and enforce the provisions of this Rule.

(m)  Development activities conducted within a jurisdiction where the USMP has been implemented may take credit for the nutrient reductions achieved by utilizing diffuse flow in the one percent Annual Chance Floodplain to comply with the nutrient loading limits specified within NSW Rules where the one percent Annual Chance Floodplain exceeds the 50-foot Riparian Buffers.  Development activities occurring where the USMP has been implemented but there is no delineated one percent Annual Chance Floodplain may take credit for the nutrient reductions achieved by utilizing diffuse flow into a vegetated filter strip that exceeds the 50-foot Riparian Buffer by at least 30 feet and has a slope of five degrees, or less.

(n)  The following special provisions of the Universal Stormwater Management Program apply only to federal facilities and Department of Defense (DoD) installations.  Federal facilities and DoD installations may adopt the Universal Stormwater Management Program within their boundaries by submitting a letter to the Chairman of the Environmental Management Commission that states that the facility in question has adopted controls that comply with the requirements of this Rule and with the requirements of 15A NCAC 02B .0104(f).  In lieu of the protective covenants and deed restrictions required in Paragraph (h) of this Rule, federal facilities and DoD installations that choose to adopt the USMP within their boundaries shall incorporate specific restrictions and conditions into base master plans, or other appropriate instruments, to ensure that development activities regulated under this Rule will be maintained in a manner consistent with the approved plans.      

(o)  Implementation of this Universal Stormwater Management Program does not affect any other rule or requirement not specifically cited in this Rule.

 

History Note:        Authority G.S. 143-214.1; 143-214.7; 143-215.1; 143-215.3(a);

Eff. January 1, 2007.