Carmel sewage could flow downriver to Indy. Here’s why.

After enduring historic flooding over the weekend, Indianapolis residents could face a new threat: raw sewage from Carmel.

Floodwaters from Blue Woods Creek in Carmel toppled a bridge on Hazell Dell Parkway and drained into the nearby Martin Marietta sand and gravel quarry. 

But Carmel officials say the quarry banks could fail and cause a chain reaction. The White River would be diverted into the quarry, which would overflow, potentially damage the nearby wastewater main near the bridge and send millions of gallons of raw sewage into the river toward Indy. 

E. Coli, salmonella and other harmful bacteria would flow downstream into Indianapolis waterways.

Carmel says crews are temporarily stabilizing the quarry banks to redirect the fast-moving water away from it. 

But what happens if their efforts fail?

We asked Citizens Energy Group, which handles drinking water and wastewater in Indianapolis, how they will deal with this polluted water if it makes its way to the city. We also asked how they deal with emergencies like the recent historic flooding, including how the DigIndy tunnel works. 

Can Citizens keep our drinking water clean?

Ben Easley, Citizens Energy Group’s corporate and public affairs coordinator, said the utility company is ready to handle Carmel’s polluted water if it comes our way.

“If wastewater flows into the White River, Citizens is fully equipped to ensure that finished water delivered to customers meets all Safe Drinking Water Act requirements,” Easley said in an email. “Citizens would enhance its upstream monitoring of the river water and make any necessary adjustments to treatment or supply before delivering finished water to customers.”

He’s confident Citizens could treat the extra wastewater in the river. The utility company uses both chlorine and ultraviolet light disinfection, both effective at killing microorganisms that can make people sick.

Citizens has 10 wastewater treatment plants across Indianapolis. According to Easley, Citizens facilities go beyond the minimum regulatory requirements for small particle removal. Those include biological waste and cyclospora, the parasite behind the recent multi-state outbreak. 

But, you might want to avoid directly touching the polluted water in the river for a while if the Carmel main does break. Unlike your drinking water, the river itself wouldn’t be treated.

How Citizens Energy prepares for emergencies

Easley said Citizen Energy’s facilities have emergency management plans, so they can adapt to bad weather conditions.

“When heavy rain is the forecast, we monitor conditions and execute these plans where needed, adapting operations to maintain critical infrastructure. Our employees also collaborate with county and state emergency managers to support the maintenance of critical utility infrastructure during disastrous weather events,” he said.

The company’s natural gas, water supply and wastewater service teams are put on standby to respond to flooding that damages roads or homes, which could also impact underground utility lines. 

While Indianapolis Department of Public Works crews place barriers and manage traffic, Citizens crews inspect infrastructure for blockages or breaks. 

Easley said some legacy sewer systems may not be designed to manage the volume of stormwater city residents experienced recently and could lead to flooded roads or wastewater backups.

He said Citizens Energy has seen several of the rain events that have happened this year, like the storms seen this past weekend or earlier this month. They dropped lots of rain in a very short amount of time, leading to high water in places that drain slowly.

Citizens also coordinates with DPW to ensure their flood control measures, like closing floodgates, doesn’t negatively affect operations.

“In recent days, DPW closed the water intake to the Central Canal in Broad Ripple as a flood protection measure,” Easley said. “This was communicated to Citizens and we then switched our water intake for our White River Water Treatment Plant (near 16th Street and Fall Creek) to an alternative intake near 30th Street.”

Citizens crews are also contracted to respond to issues in the separate stormwater system owned by the city. 

Part of the company’s planning is knowing when to take a piece off the board, like it did with parts of the White River North treatment plant along River Road just south of 122nd Street in Carmel. 

Some parts of the building were inundated with high water, leading Citizens to make the decision to isolate them and suspend operations there. 

“This type of event was unprecedented,” said Easley. “Citizens has never had to suspend operations at the White River North plant due to river levels.”

Citizens said residents felt no impact. The company was able to direct the water supply from other treatment facilities to continue serving their customers without interruption and without any water quality issues or boil water advisories.

What about the DigIndy Tunnel System?

During the historic flooding, some residents questioned on social media how the flooding could happen when the expensive DigIndy Tunnel System was operating.

The $2 billion tunnel system that came online last October was not designed to reduce flooding. Instead, its purpose is to prevent sewer overflows — wastewater from toilets and drains in homes and businesses — from entering local waterways.

That won’t help if the Carmel sewer main fails. 

The decision to build the DigIndy Tunnel came after former Mayor Bart Peterson signed an agreement in 2006 with the Environmental Protection Agency to settle a lawsuit that had alleged the city violated the U.S. Clean Water Act by allowing too much raw sewage into public waterways.

The agreement required the city to implement long-term plans to stop 97% of the sewage overflows in the Fall Creek watershed and 95% in the White River watershed.

When Citizens Energy bought Indianapolis’ water utility in 2011, it took on the obligation to fulfill the agreement. What resulted was the DigIndy Tunnel System, which began construction in 2012.

“Now fully in operation, DigIndy does not change the amount of water in waterways or offer flood protection,” Easley said. “Approaching 10 billion total gallons of captured and properly treated wastewater, we are proud that DigIndy has been successful in improving water quality in the White River.”

Turn those sprinklers off 

Citizens Energy is advising its customers to have a water conservation mindset. Heightened and unnecessary water demand for things like watering lawns can put unnecessary strain on the public water system.

For water conservation tips, check out the company’s WaterWise website.

Marion County residents should report high water issues and potential blockages by calling Citizens Energy at 317-924-3311.

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Mirror Indy reporter Enrique Saenz covers west Indianapolis. Contact him at 317-983-4203 or en***********@********dy.org. Follow him on Bluesky at @enriquesaenz.bsky.social.

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