How the flood of 1976 changed Frederick: Carroll Creek flood control project is one of a kind

Oct. 09--Walking along Carroll Creek in downtown Frederick, few visitors might realize they're walking atop a buried concrete river, created to avoid a potentially catastrophic 100-year flood.

Heralded as a "gem" of downtown, the redeveloped Carroll Creek has attracted no shortage of acclaim and attention.

Much of the praise centers on the visible elements: landscaping, park beautification, and the commercial and residential buildings the project has spawned.

Below the surface of the creek lies the oft-overlooked, vitally important flood control system designed and built in the wake of the 1976 flood.

How it works

The innovative system relies on a series of four underground conduits running below the artificial creek. When water collects in Baker Park, the conduits prevent flooding by channeling the flow of water east toward the Monocacy River.

Each 20-by-20-foot conduit -- large enough to drive a bus through -- can hold up to 1.4 million cubic feet of water, according to Tracy Coleman, a city engineer. The four together hold a combined 5.7 million cubic feet of water.

Baker Park, by comparison, can hold up to 580,000 cubic feet of water, Coleman wrote in an email.

As she noted, however, stormwater doesn't sit still. The flood control system also uses a series of pumps that regulate how much water enters the conduits. Flap valves in the conduit walls push standing water through the 1.3-mile pipe system and out to the Monocacy River, according to a 1992 article in The Frederick News-Post Leader.

The system as a whole effectively prevents a 100-year storm event -- a rainfall that has a 1 percent chance of happening in any given year -- from flooding as it did in 1976, when 7 inches of rainfall drenched downtown in less than 16 hours.

The project also removed about 130 acres in downtown from a 100-year floodplain, relieving property owners in that area from mandatory flood insurance required by the Federal Emergency Management Agency.

An innovative solution

The 1976 flood devastated much of downtown Frederick, causing between $5 million and $25 million in damage, according to estimates published by The News-Post.

To state Sen. Ron Young, D-District 3, the city's mayor at the time of the flood, the need to take preventative measures was apparent. Exactly what those measures would be, however, was less clear.

The best option from a functional standpoint was akin to a giant sewer system running through the heart of downtown. Although the system effectively moved flood water, it was unattractive.

"It was very ugly," Young recalled Tuesday in a phone interview. "It did nothing for downtown."

Young, working with various architects and design firms, instead proposed covering the underground conduit system with a shallow manmade creek channel. The body of water comes from the natural creek, but is controlled to contain a constant amount of water.

The upper artificial creek was inspired by the River Walk in San Antonio, Texas. But the combination of the above-ground waterway and subterranean flood control system was original.

Many communities locally and nationwide have looked to Frederick's design as a model for their own flooding solutions, most recently those from Ellicott City, according to Richard Griffin, the city's economic development director.

Conceptual plans emerged by the late 1970s, but construction didn't begin until 1985. Part of the delay stemmed, in part, from raising the money necessary to pay for the $60 million project.

Young described financing as "the most daunting" part of the project, noting that initial cost estimates were four times the city's operating budget. Working with the Frederick County delegation and state legislators, he successfully pitched a $2 million contribution from the state budget the first year, with subsequent $2 million allocations in the next three fiscal years.

Once Gov. William Donald Schaefer was elected, he helped Young secure additional state dollars, which were combined with city and county contributions.

Young chalked up the success of his legislative request, in part, to the way he pitched the project. Neither flood control nor park beautification was enough to convince state legislators at the time, he said.

Instead, he sold the project on economic development.

Economic benefits

Many of the direct and intangible economic benefits of the project are still to come.

Construction of the flood control system ended in 1993. Although a master plan for the linear park to rest atop the flood control was adopted in 1991, park development didn't begin until 2005.

Young lost his 1989 bid for reelection. According to Young, the project also lost momentum under new leadership. He said if he had won reelection, the entire project would have finished by 1995.

He said he was thankful subsequent administrations eventually resumed his efforts. The $10.6 million first phase of park improvements, spanning from Court to Carroll streets, ended in 2006. The $15.8 million second phase of improvements along the eastern portion of the creek was earlier this year.

Despite the delays, Young called the end result "beautiful."

Several significant projects have been completed. Griffin noted that the first phase of park improvements coincided with about $35 million of new construction in four new buildings along the creek, bringing about 80 new residential units and 110,000 square feet of office and retail space.

Griffin named renovations to the C. Burr Artz Public Library and improved pedestrian and bicycle connections through downtown as additional benefits.

The various projects in the pipeline including a proposed downtown hotel and conference center that, once finished, would add $100,000 to $150,000 more in private investment, according to Griffin.

The circle of positive impacts surrounding the creek will continue to widen with time, project by project, block by block, he said.

Staff writer Danielle E. Gaines contributed to this story

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