SW3240802_Stormwater Narrative_20240820

McKIM&CREED ENGINEERS
SURVEYORS
PLANNERS
LUNA ESTATES SUBDIVISION
STORMWATER NARRATIVE
Luna Estates Subdivision is a proposed 18-lot single-family subdivision located on+/-30
acres in Weddington,Union County,North Carolina. The existing site conditions include
mostly forested area,and no wetlands/streams are on-site.The predominant soil types
according to the USDA Soil Survey are Cecil gravelly sandy clay loam and Helena fine
sandy loam,which have Hydrologic Soil Group ratings of"B" and"D".The proposed
area of disturbance for the project is 26.0 acres. The site is in the Sixmile Creek
watershed,within the Catawba River Basin.The development will be located off
Weddington-Mattews Road,approximately 1.0 mile east of the NC-16 and NC-84
intersection.
Stormwater management for the project is designed in accordance with the NCDEQ
Minimum Design Criteria(MDC).Over 200,000 square feet of new impervious will be
created as part of the Luna Estates development,therefore the project is considered high-
density.One wet pond is proposed as a permanent SCM.A wet pond was determined to
be the most suitable SCM due to the large drainage area,which exceeds the
recommended drainage area size for most infiltration-type BMP's.The main pool surface
area and volume are sized using the SA/DA and Average Depth Method.The proposed
SCMs are designed to meet all the Town of Weddington design requirements for pre-
development vs.post-development flows,as well as safely pass the 100-year,24-hour
storm event through the emergency spillway.
8020 Tower Point Drive
Charlotte, NC 28227
704.841 .2588
Fax [phone]
www.mckimcreed.com