Four flooding plan drafts under consideration for Chartiers Creek study
The U.S. Army Corps of Engineers held open houses last week in Carnegie and McKees Rocks to give West Hills residents a chance to provide feedback on a study underway to manage flooding along Chartiers Creek.
The study, done in partnership with the Southwestern Pennsylvania Commission, looks at alternative plans for flood management, with four potential plans under consideration to reduce flooding damage in Allegheny and Washington counties.
At the open houses, team members guided visitors through the study and proposed plans, encouraging residents to submit comments on a card or online via email or through a feedback form. Previously, the study team communicated with local municipalities about the project but had not held any public discussion until this most recent phase.
Members of the public can submit comments online until Friday, July 31. Residents along Chartiers Creek can also give feedback through comment boxes the study team will place at locations throughout the watershed, including the Carnegie Borough Building at 1 Veterans Way and the Sto-Rox Public Library at 420 Chartiers Ave.
Anthony Schneider, community planner and project manager for the study, said the Corps of Engineers plans to utilize the comments to better understand what people want for their community.
“We're going to use that, modify our plans to adjust based on that feedback, and then we'll come up with a final array of alternatives that we'll present to our leadership for their support on what we decide is our selected plan,” Schneider said.
The draft plans are organized by the number of structural and nonstructural measures they include. Structural measures include physical alterations that control the flow of floodwater, such as floodwalls, reservoirs or ponds and changes to the creek channel. Nonstructural measures aim to reduce flooding damage without altering the direction of floodwater, including alterations to existing buildings and flood warning systems.
The four alternative plans range from most to least structural measures:
- Cornerstone Max
- Life Safety Max
- Life Safety Focused
- Community Resilience
Schneider said the plans that were presented are still in a draft state.
“They're very much subject to change, which is why we wanted to present them to the public, so they have the power to affect change if there's something they're really concerned about within the whole process,” Schneider said.
In the Cornerstone Max Alternative — the plan with the largest number of structural measures — the study proposes the construction of levees or floodwalls along certain parts of Chartiers Creek in Carnegie and Rosslyn Farms, and the creation of a retention or detention pond in Crafton and Thornburg. The plan also proposes the creation of a levee or floodwall in McKees Rocks, where the creek flows into the Ohio River.
By contrast, the Life Safety Max Alternative only includes the proposed levees or floodwalls, without the retention or detention pond in Crafton and Thornburg. The Life Safety Focused Alternative includes only the levee or floodwall in McKees Rocks, and the Community Resilience Alternative has no structural measures. Instead, that alternative focuses on “nonstructural measures, nature-based solutions and emergency preparedness.”
In all the plans, plots of land around Chartiers Creek in Crafton, Thornburg and McKees Rocks are designated as Special Flood Hazard Areas by FEMA, where the study is considering nonstructural measures.
According to Schneider, the study team chose areas for potential floodwater prevention measures based on historic data from the U.S. Geological Survey and the National Weather Service, along with the team's existing models from FEMA and other local flood protection projects.
"What we presented is a rough, more of a tentative idea of where we think [floodwater measures] could possibly go,” Schneider said. “Our modeling will, once it's completed, inform where those selections are and where those inundation areas are.”
Carnegie Mayor Sam Bigham was unable to attend the Carnegie session due to work commitments but said he's pleased to see the Army Corps of Engineers and the Southwestern Pennsylvania Commission working proactively to address flooding in the watershed.
"We haven't had a major flood in Carnegie since 2004, but Campbells Run has had issues that we recently addressed by reinforcing the bank against erosion," he said. "Obviously preventing flooding should be the No. 1 priority but we should also reasonably work to protect the creek's ecosystem and make it accessible for recreation, like kayaking and fishing."
Moving forward, the study team hopes to compare the alternatives in July and select a recommended plan by August. A draft detailed project report is expected to be released by fall, which will then be put out for public review. Schneider anticipates hosting a virtual town hall so people can provide feedback on the final report before the design process officially starts.
After picking a plan, the team will iterate and refine the design through data collection and other assessment, including updating cost estimates and conceptual designs.
“Once we finish, we make our recommendation of a plan,” Schneider said. “We will then take that recommended plan to effectively what is a conceptual level of design, which usually includes some form of geotechnical exploration and helps us refine our quantities and the amount of material we're going to need, possible areas and things like that, so we have a better understanding of a more refined project cost for implementation at that process.”
Once the team produces a "35% design package” — the conceptual design for measures to be implemented along Chartiers Creek — it will bring the plan to the team's general and ultimately Congress for authorization and funding. The team hopes to finalize the 35% plan by 2028.
Those who could not attend last week’s workshops can submit comments online. For information, click here to email.
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