ROANOKE VALLEY, VA – After months of dry conditions and growing concerns over low water levels at Smith Mountain Lake and Carvins Cove, this weekend’s heavy rainfall may have provided some much-needed relief to Southwest Virginia.
Rainfall totals from Sunday, October 11, show several communities receiving between 3 and 5 inches of rain, with some locations reporting even higher amounts.
Roanoke officially recorded 2.84 inches of rain, breaking the previous October 11 daily rainfall record of 2.66 inches set in 1983.
🌧️ RAINFALL TOTALS REPORTED AROUND OUR AREA:
- Floyd County (Check): 5.50 inches
- Roanoke County (Cloverdale): 5.10 inches
- Roanoke County (Laymantown): 5.10 inches
- Salem area: 5.00 inches
- Rocky Mount area: 4.82 inches
- Daleville area: 4.70 inches
- Stewartsville area: 4.26 inches
- Goodview area: 3.34 inches
- Roanoke Regional Airport: 2.84 inches
- Blacksburg area: 2.50 inches
- Forest area: 2.28 inches
- Bedford area: 2.03 inches
These are individual observations reported October 11. Rainfall varied by location.
💧 SO HOW MUCH DOES ALL THAT RAIN ACTUALLY HELP OUR LAKES?
Quite a bit potentially, but it’s not as simple as saying 3 inches of rain means a lake rises 3 inches.
Smith Mountain Lake receives water from a massive watershed, including the Roanoke and Blackwater rivers and their tributaries. Rain falling miles away can eventually make its way into the lake through streams, creeks and rivers.
As of Monday afternoon, October 12, Smith Mountain Lake was reported at approximately 790.58 feet, still about 4.42 feet below its normal full-pond elevation of 795 feet.
The recent rainfall has dramatically increased the amount of water moving through the region’s waterways, providing an opportunity for the lake to recover some of its lost elevation.
WHAT ABOUT CARVINS COVE?
Carvins Cove, an important drinking water source for the Roanoke Valley, has also experienced significant declines.
In a September 16 update, the Western Virginia Water Authority reported the reservoir was approximately 19.9 feet below full pond.
Although an updated post-storm level has not yet been confirmed, the recent rainfall across the surrounding watershed could help replenish the reservoir.
💦 HERE’S SOMETHING THAT PUTS ALL THIS RAIN INTO PERSPECTIVE:
Just ONE INCH of rain falling across ONE ACRE of land equals approximately 27,154 gallons of water.
Carvins Cove has a watershed covering approximately 11,200 acres.
If an average of 3 inches of rain fell evenly across that watershed, it would represent approximately 912 MILLION GALLONS OF RAINWATER!
Of course, that doesn’t mean 912 million gallons entered the reservoir. Some water soaks into the ground, some evaporates, and some flows elsewhere. But it demonstrates the enormous volume of water a single major storm can produce.
🌤️ DOES THIS MEAN THE DROUGHT IS OVER?
Unfortunately, not necessarily.
While the recent rainfall is certainly welcome news, months of dry weather cannot always be reversed by one weekend of heavy rain. Groundwater, streams, reservoirs and soil moisture can take additional time and rainfall to recover.
The good news is that some of the water flowing into Smith Mountain Lake and Carvins Cove may continue arriving even after the rain has stopped, as runoff works its way through the surrounding watersheds.
We’ll be watching for updated reservoir measurements to see just how much this storm helped.
🌧️ How much rain did you get over the weekend? Did you experience flooding, or did your area miss out on some of the heavier rainfall?