Unified Development Ordinance - Currituck County Government

Chapter 7: Environmental ProtectionSECTION 7.3: STORMWATER MANAGEMENTSubsection 7.3.5: Alternative Stormwater PlansB. Allowable Deviations(1) Increased Lot CoverageA maximum 15 percent increase in lot coverage may be allowed for singlefamilydetached and duplex dwellings on lots in subdivisions that have a statepermitted and functional stormwater management system that specifiesallowable lot coverage, or for a single-family detached or duplex dwelling onan individual lot that implements adequate stormwater practices to captureand infiltrate stormwater runoff from all impervious surfaces from the firstfour inches of rain from any rainfall event.(2) Reduced Stormwater Detention RequirementsDevelopment subject to the standards in Section 7.3.3.B may reduce thedesign capacity of required stormwater management devices provided:(a)(b)An Alternative Stormwater Runoff Storage Analysis demonstrates theon-site soils have adequate storage capacity to capture and infiltratestormwater runoff from all impervious surfaces; orAn Alternative Downstream Drainage Capacity Analysis demonstratesthe downstrates the downstream drainage capacity exceeds the predevelopmentdischarge rate from the 24-hour storm event with a 2-year recurrence interval based on pre-development conditions from awooded site with Type A hydrologic soils.(3) Additional Fill or Land Disturbance ActivitiesA lot may be filled or graded higher than the average adjacent grade of thefirst 30 feet of adjoining property or to improve drainage for performance ofstormwater management devices, provided adequate stormwater practices areimplemented to capture and infiltrate stormwater runoff from all impervioussurfaces from the first four inches of rain from any rainfall event.(4) Low Impact DevelopmentThe use of low impact development techniques, including but not limited topervious pavements, cisterns, green roofs, and bio-retention islands may beused to reduce stormwater detention requirements or lower impervioussurface percentages.CURRITUCK COUNTY, NC UNIFIED DEVELOPMENT ORDINANCE7.19