Helene in WNC could have been ‘exponentially worse,’ causing ‘annihilation.’ Here’s why

Clay Chandler, a spokesperson for Asheville’s Water Resources Department, offered chilling perspective on how much more lethal the already catastrophic Tropical Storm Helene could have been during an Oct. 25 briefing.

Buncombe County briefings provide updates on many pressing issues post-Helene, from relief sites to FEMA applications and beyond. Included under this umbrella are updates on the process of restoring water to the Asheville area.

During the Friday, Oct. 25 meeting, Chandler explained that previous improvements to the North Fork Dam very likely prevented “what is already a catastrophe from being exponentially worse.”

Here’s what we know about what could’ve happened, what prevented it and the current state of Asheville’s municipal water.

More: Helene recovery in Buncombe: Spectrum restoration delays, D-SNAP extension, more

What would happen if the North Fork Dam failed?

The North Fork Reservoir supplies water to roughly 80% of Asheville’s population. During Tropical Storm Helene, both of North Fork’s main transmission lines and a 36-inch bypass waterline were destroyed — and Chandler said that built-in safety mechanisms may have been partially responsible.

“It is entirely possible that water from one or both of the spillways at North Fork washed out our main transmission lines,” Chandler said.

Massive rainfall from the storm caused a torrent of water that eroded ground around pipes and pushed them apart. The excess rain that landed in the watershed and reservoir automatically flowed out of the emergency auxiliary spillway, funneling almost 18 inches of rain that landed in a 15,000-acre forested watershed downhill into a 355-acre lake.

However, the auxiliary spillway at North Fork created in anticipation of extreme weather events was also “almost certainly” the reason that the North Fork Dam did not fail.

The North Fork Dam Improvement Project

Chandler praised the prioritization of dam improvements by Asheville officials, without which Helene’s death count could have skyrocketed.

The North Fork Dam Improvement Project was operational in 2021 after three years of construction. The project, which received a Rehabilitation Project of the Year Award from the Association of Dam Safety Officials, added the following reinforcements to the dam:

• Raising the dam by 4 feet

• Improvements to the principal spillway and the addition of an auxiliary spillway

• Modifications to the raw water piping through the dam and to the water treatment plant

• Earth buttressing to reinforce the main dam and saddle dam for seismic stability

The auxiliary spillway was designed to begin trickling water at a 200-year storm event. The first fuse gate was designed to break out at just over a 1,000-year storm event. In order for all fuse gates to let go causing a dam failure, a 50,000-year storm event would need to occur.

Is it ok to drink Asheville tap water? Brush my teeth?

Under the current boil advisory, area residents must bring water to a full rolling boil for one minute, then allow the water to cool before use in order to safely consume it.

The same parameters apply for any water you ingest or place in your mouth — including water used for brushing your teeth.

Can I shower in Asheville water?

Unless the city issues a “Do Not Use” notification, tap water can currently be used by healthy individuals for showering, bathing and shaving. Ensure you don’t swallow any water and avoid shaving nicks.

The city recommends that children and disabled individuals should be supervised to ensure water is not ingested, and sponge bathing is advised. The city also suggests that anyone with open wounds, cuts, blisters or recent surgical wounds and people who are immunocompromised or suffer from chronic illness use only boiled and cooled water or water from an alternate source to bathe.

More: ‘Do not flush’: Helene destroyed Spruce Pine’s water treatment plant with no immediate fix

Can I wash dishes in Asheville water? Clothes?

Hand-washing dishes in unboiled Asheville water is not currently safe unless you rinse for a minute in dilute bleach (1 tablespoon of unscented bleach per gallon of water) after washing with detergent, and allow dishes to dry completely before use.

If your home dishwasher is at least 170 degrees and includes a full dry cycle, you can use it to safely wash dishes. However, the city warns that most home dishwashers do not reach this temperature.

Iris Seaton is the trending news reporter for the Asheville Citizen Times, part of the USA TODAY Network. Reach her at iseaton@citizentimes.com.

This article originally appeared on Asheville Citizen Times: Asheville water: North Fork dam break likely prevented by planning