One of the most high-impact flood/flash flooding episodes in recent years in the Blacksburg Hydrologic Service Area (HSA) developed over a several day period but culminated September 29th. An unusual weather pattern became established around September 25th with very slow-moving and strong high pressure building across New England and low pressure over the southeastern U.S. combining to bring strong easterly flow into the southern Mid-Atlantic along with abundant moisture. Rainfall ending 12z on the 25th was generally confined to the southern portions of the HSA with up to 1 inch in parts of the North Carolina piedmont into southside Virginia. The rains became much heavier and widespread over the next two days with 1 to 4 inches ending at 12z on the 26th and another 1 to nearly 5 inches ending at 12z on the 27th. Over the next five days rainfall was nearly constant in some areas with pulses of heavier rainfall but with the heaviest amounts concentrating across the VA Blue Ridge mountains, mainly in Patrick, Floyd, Roanoke, Henry and Franklin counties. The maximum 5-day rainfall totals ending at 12Z (8 AM) on the 30th ranged from 10 to 16 inches in parts of Patrick and Floyd counties. Some of the higher totals equate to anywhere from a 100 to 500-year event per NOAA Atlas 14. The extremely wet soils set the stage for the severe flash flooding early on September 29th into the afternoon. Several bands of intense rainfall tracked across parts of the same counties mentioned above and also including Montgomery County over a 6 to 12 hour period from 0200 LST to 1400 lST (06z-18z) prompting the issuance of two Flash Flood Warnings for parts of eight counties and several cities at 943 AM (EDT) and 1019 (EDT) AM.  It was difficult to differentiate between the onset of flash flooding from the longer duration flooding that was developing or underway as well. No matter the type, by mid-morning numerous reports of flooding and several high water rescues had been reported across a wide area, but most notably in parts of Patrick, Floyd, Montgomery, Roanoke and Henry counties.  Local states of emergency were declared in Floyd and Patrick counties due to the widespread flood impacts with water rescues, some homes damaged and dozens of roads closed due to flooding or trees brought down in the saturated soil.

Flash Flood in RADFORD (C), VIRGINIA
From 29-SEP-15 07:00:00 to 29-SEP-15 15:00:00 (EST-5)
Location: RADFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Water was reported across Route 11 in Radford. The automated rain gage at the Radford River gage (RDFV2) measured 2.42 in one hour ending 0600 LST, which is very close to the 100-year recurrence interval (0.01 annual exceedance probability) for this location and duration.

Flash Flood in FLOYD, VIRGINIA
From 29-SEP-15 06:00:00 to 29-SEP-15 14:00:00 (EST-5)
Location: SHELORS MILL
Flood cause: Heavy Rain
Property damage: 3.10M
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flooding occurred across the county but was concentrated in Route 8 corridor. Several  swift water rescues were made and numerous roads were closed and many damaged. A van was swept off of Meadows Creek Road and the driver, a college student, was rescued. In addition, 13 homes were destroyed, 12 homes received major damage, 15 homes minor damage, and 42 other homes affected, for a total loss of $2.3 million dollars. The worst flooding appeared to be in the Sowers Mill Dam Road and Little River Road areas. According to county officials additional commercial and agricultural losses ran about $400,000. Road damage totaled an additional $400,000 per the Virginia Department of Transportation. Local officials described it as one of the worst weather disasters in county history. The Little River which runs through much of Floyd County was responsible for much of the damage. Residents in the Sowers Mill Dam Road area said the river rose 20 to 25 feet during the flood. The river gage on the Little River further downstream at Graysontown along the Pulaski-Montgomery county line reached a stage of 12.68 feet (flood stage = 8 ft), the 3rd highest at the current datum and highest since Hurricane Agnes in 1972.

Flash Flood in HENRY, VIRGINIA
From 29-SEP-15 10:00:00 to 29-SEP-15 18:00:00 (EST-5)
Location: SANVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flooding was reported along Morningside Drive west of Sanville. Blackberry Creek IFLOWS gage (BBBV2) rose from around 2 feet at 5AM to crest at 8.2 feet (Minor Flood Stage = 6 ft) by early early afternoon. Some crawl spaces were flooded along Blackberry Creek.

Flood in SALEM (C), VIRGINIA
From 29-SEP-15 11:00:00 to 30-SEP-15 07:30:00 (EST-5)
Location: SALEM (C)
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Rainfall was generally 1 to 2 inches across the City of Salem during the day but the heavier rain upstream brought a significant flood wave was downstream along the mainstem Roanoke River through the City. The Salem Pump Station IFLOWS gage (SPSV2) on the Roanoke rose above flood stage (7 ft) on the 29th around 1100 LST, cresting at 13.8 feet (Moderate Flood Stage) at 2100 LST and falling below by 0730 LST on the 30th. This tied for the 4th highest on record at this gage with records dating back to the late 1970s.

Flood in ROANOKE (C), VIRGINIA
From 29-SEP-15 13:00:00 to 30-SEP-15 05:00:00 (EST-5)
Location: ROANOKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The Roanoke River flooded through the city of Roanoke due mainly to the very heavy rains across the upper basin. Rainfall in the city was generally around 1 inch during the day but up to 4 inches fell across the headwaters in Montgomery County. The USGS gage and NWS forecast point at Walnut Street (RONV2) rose very rapidly, reaching flood stage (10 ft) by early afternoon and cresting at 14.40 ft in the Moderate Flood Category and  the 10th highest stage on record (data at the current location since 1937). The recurrence interval per USGS data on the flooding at the Roanoke gage indicated approximately a 10-year event (0.1 annual exceedance probability). Several roads close to the Roanoke River were closed but no substantial damage was reported. Water rescues from three vehicles on Bennington Street were  performed during the evening of the 29th.

Flood in MONTGOMERY, VIRGINIA
From 29-SEP-15 10:00:00 to 29-SEP-15 20:00:00 (EST-5)
Location: PILOT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Flash flooding turned into river flooding across the eastern two-thirds of Montgomery County as runoff across the upper Roanoke River basin from the extremely heavy rainfall continued. Mean areal precipitation was a solid 2 to 4 inches across the South Fork Roanoke River basin and the gage at Shawsville (SHAV2) crested above the Major Flood Category (9 ft) at 9.32 feet (Flood Stage = 5 feet) the 2nd highest on record (since 1960) and highest since 1979 (9.27 ft). Precipitation was somewhat lower in the North Fork Roanoke River basin, generally 1 to 3 inches and the gage near Ironto (IROV2) crested at 10.1 feet (Flood Stage = 9 ft). On the mainstem Roanoke River at Lafayette (LAAV2) just below the confluence of the North and South Forks the crest reached 12.16 ft. in the Moderate Flood category and the 6th highest on record since 1944 and highest since the remains of Hurricane Jeanne in September, 2004. In addition numerous roads remained closed across the county into the late afternoon and evening due to slow to recede flood waters.

Flash Flood in FRANKLIN, VIRGINIA
From 29-SEP-15 11:00:00 to 29-SEP-15 20:00:00 (EST-5)
Location: ENDICOTT
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Rainfall of 1 to 2 inches by 8 AM (EST) across western Franklin County continued through early afternoon with an additional 1.5 to 3 inches in the far western sections. At least 8 roads mainly in the western sections of the county were reported to be closed by afternoon. These included Runnet Bag Road, Coles Creek Road, Madcap Road, Ruritan Road, Wades Gap Road, Boones Mill Road, Five Mile Mountain Road, Dillons Mill/Western Comer Road. The IFLOWS stream gage on Maggodee Creek (MGDV2) reached Action Stage of 5 feet by 1215 PM (EST) and crested at 1245 PM at 6.2 feet, just below Flood Stage of 7 feet.

Flash Flood in PATRICK, VIRGINIA
From 29-SEP-15 04:45:00 to 29-SEP-15 14:38:00 (EST-5)
Location: MEADOWS OF DAN
Flood cause: Heavy Rain
Property damage: 4.00M
Crop damage: 0.00K
Reported by: 911 Call Center

Flooding and flash flooding was widespread across Patrick County. Numerous creeks and rivers were reported out of banks with dozens of road closures across the county for much of the day. An apartment complex was evacuated due to a mudslide and multiple swift water rescues were carried out. Polebridge Creek west of Sanville was reported out of its banks and Big Ivy Creek flooded a portion of Route 58 southeast of Meadows of Dan. The Smith River gage at Woolwine (SMWV2) reached its highest crest on record (data only back to 1995) at 16.11 feet (6300 cfs) at 500 AM (EST) on the 29th (old record 12.20 ft. on 9/28/2004). This is a revised value based on a post-flood analysis by VA Department of Environmental Quality. The historic (1921) Bob White covered bridge over the Smith River near Woolwine was washed away as the river rose. Total damages in Patrick County were estimated at $4 million about half from road and infrastructure damage and half from agricultural losses.

Flash Flood in SALEM (C), VIRGINIA
From 29-SEP-15 10:00:00 to 29-SEP-15 16:00:00 (EST-5)
Location: SALEM (C)
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Rainfall was generally 1 to 2 inches across the City of Salem during the day. Several roads were reported closed in the City of Salem. A voluntary evacuation was made from Ramey Mobile Home Park along Mason Creek which crested at 7.5 ft (Flood Stage = 7 ft) at the upstream gage (MSCV2) in Roanoke County at 1400 LST.  Other road closures that continued into the evening included the low water bridge over the Roanoke River at Mill Lane, Texas Street at Carter Way,  East Riverside at Front Avenue, Eddy Street, Colorado Street, Apperson Drive, Mill Lane at Mountain Avenue, West Salem Mobile Home Park and West Riverside Mobile Home Village.

Flood in PATRICK, VIRGINIA
From 29-SEP-15 14:39:00 to 29-SEP-15 22:39:00 (EST-5)
Location: VESTA
Flood cause: Heavy Rain
Property damage: 1.00M
Crop damage: 0.00K
Reported by: Trained Spotter

Flooding continued much of the day across Patrick County. Dozens of roads remained closed by late afternoon. U.S. Route 58 and VA State Highway 8 both major thoroughfares were under 2 to 3 feet of water around 400 PM. Several businesses in downtown Stuart were flooded and several other businesses on U.S. 58 were flooded including the W and W produce store and Wal Mart.

Flood in ROANOKE, VIRGINIA
From 29-SEP-15 11:30:00 to 30-SEP-15 04:30:00 (EST-5)
Location: KUMIS
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

Numerous roads were closed throughout the day across parts of Roanoke County as 1 to 3 inches of rain, with isolated 4 inch amounts from early on the 29th through midday. A water rescue from a car was needed along Bent Mountain Road. The Roanoke River at Glenvar gage (GNVV2) rose to 16.53 feet during the afternoon of the 29th due to the very heavy rain across the upper Roanoke River basin. This stage was above the defined Major Flood Category (16 ft) and the 4th highest crest since records began in 1992 on this gage. It was slightly below a 10-year recurrence interval (0.1 annual exceedance probability). Several roads near the river were closed due to the flood waters. Mason Creek (MSCV2) north of Salem in the county crested at 7.5 ft (Flood Stage = 7 ft)  at 1400 LST.

Flash Flood in MONTGOMERY, VIRGINIA
From 29-SEP-15 07:30:00 to 29-SEP-15 14:50:00 (EST-5)
Location: RINER
Flood cause: Heavy Rain
Property damage: 1.00M
Crop damage: 0.00K
Reported by: Public

There were numerous reports of roads flooded and some badly damaged across Montgomery County. The biggest impacts were in the western half of the county where 3 to 5 inches of rain fell in a 6-hour period between 0700 LST and 1300 LST. The asphalt on Laurel Mill Ridge road was reportedly washed away. Meadow Creek Road had at least one foot of water rushing over it. Duck Pond Road was closed from Oak Lane to Smithfield. Radford Road was closed, Route 8 in Riner was partially flooded and an earth retaining wall gave way. Toms Creek was flooding a portion of Mt. Zion Road near Brooksfield Road. Plantation was closed due to 6 to 12 inches of water over the road.

Flood in PULASKI, VIRGINIA
From 29-SEP-15 05:45:00 to 29-SEP-15 18:45:00 (EST-5)
Location: SIMPKINSTOWN
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Department of Highways

Rainfall of 4 to 7 inches across the area caused several roads to be closed due to flooding in eastern Pulaski County. Route 605 was closed in several locations along with portions of Routes 665, 613 and 626. The river gage on the Little River further  at Graysontown (GRYV2) along the Pulaski-Montgomery county line reached a stage of 12.68 feet (flood stage = 8 ft), the 3rd highest at the current datum and highest since Hurricane Agnes in 1972. The discharge of 23100 cubic feet per second equated to approximately a 50-year recurrence interval per USGS information.