Maryland town turns flood zone into a tourist attraction

Prone to flooding, Carroll Creek flows through Frederick, Md., on its way to the Monocacy River, which empties into the Potomac River. A major storm 50 years ago left the streets of the historic city several feet underwater. When it happened again just four years later, officials began to search for a solution.

An early proposal centered around an open cement trough cutting through town. It would have solved the flooding problem but would also have left an unsightly scar across a city dominated by early 19th-century Federal and Greek Revival architecture, primarily rendered in brick. The plan that was ultimately adopted was much more ambitious: moving stormwater underground through two pairs of concrete conduits more than a mile long, each of them big enough to drive a bus through. Combined, the conduits can hold up to 5.7 million cubic feet of water. Levees, floodwalls and four pumping stations are also part of the system.

Nestled above and between the pairs of conduits, a shallow, 40-foot-wide canal serves as the new version of Carroll Creek, which is flanked by wide brick pathways, landscaping, fountains, several pedestrian bridges and a 350-seat amphitheater. Costing $60 million, construction on the flood control project commenced in 1985 and took eight years to complete. The $15 million linear park that sits atop the underground conduits wasn't dedicated until the summer of 2006, 28 years since its conception in the 1970s.

With flooding no longer a threat, more than 400 buildings in the area were declared free from the floodplain, spurring millions of dollars in private investment. What was once a moribund industrial area has been transformed into office, retail, residential and community gathering space as well as a major tourist attraction, with Carroll Creek Linear Park as its centerpiece. But for all the time and money expended on the public works project, it took the efforts of an army of volunteers to make the park and its surroundings the success that it is.

While water moved as intended beneath the new park's wide sidewalks, the decorative canal above presented an unforeseen problem. The low flow rate, shallow depth and abundance of nutrients from upstream runoff resulted in a creek filled with algae blooms and a foul smell. The problem persisted for years, in spite of the city's many attempts to clear the water.

Dr. Peter Kremers, a member of the local Men's Garden Club, has been an avid water gardener for some time, building a garden pond beside his home. "I kept reading in the paper about all the issues here with the algae," he says. "I thought, why don't we just turn this into a water garden?"

He approached the city in 2012 with his idea of a floating canopy of plants that would block the sunlight that algae needs to grow. Once Kremers was given permission to proceed, he and his friend Lisa Collins placed 20 pots of aquatic plants in the creek as an experiment.

"Nobody wanted to be down here because it was gross," says Collins.

The experiment was a success. That fall, "Color on the Creek" was established as a nonprofit entity tasked with beautifying the creek, while ridding it of algae. The next step was to scale it up, replacing the cinder blocks used to prop up the test plants. Kremers designed metal stands that were strong enough to hold the pots, and could also be easily moved around in the rock-strewn streambed. "A lot of the plant material is depth sensitive," he says. "Some plants need three inches. Other stuff wants to be two feet down." In the following spring, with help from the garden club and the Rotary Club of Carroll Creek, more than 1,000 plants were established in 380 stands spread along the creek. This past summer there were more than 5,000 plants in 450 containers, covering 30,000 square feet of water and stretching more than a quarter of a mile.

After three years, testing performed by students at a local college verified the water garden's effectiveness at reducing algae. "Visually, it was pretty obvious," says Kremers.

Every aspect of Color on the Creek's operation is performed by volunteers and paid for with donations. Days devoted to spring cleanup and planting find 60 or more volunteers at the creek. Over the course of the year, 250 people will typically come out to help, many of them teenagers. "I'm one of the youngest guys in the garden club," says Kremers. "Most of them just can't do the physical stuff. So it's really good to see the kids out there."

"Once the plants get going in the summer, there's not that much to do," says Collins. "We've got a couple guys that get in and they pick up any trash and cut off the dead stuff and keep it pretty. But once it's in and going, it's not too bad."

Stargazer was set afloat to much fanfare. A day later it capsized, done in by too much wind and not enough ballast. "So what we've learned is how to keep them upright," Kremers says. "And how to keep water from coming through the hull and coming through the top. They're out there for three months. No sane sailor launches a boat in November, through the worst of the winter."

The next year, six more boats joined Stargazer. New boats have been added to the armada every year since. This winter at least two dozen scaled-down vessels are anchored in the park's waterway, including three-masted schooners, a frigate, tugboat, aircraft carrier, pirate ship and a stern-wheel paddle boat. The flotilla draws a crowd, especially at night when their lights come on. The eclectic collection of boats on Carroll Creek is now known as "Sailing Through the Winter Solstice," drawing crowds to downtown Frederick in the worst of weather.

Before the boats depart in March, everyone is encouraged to vote for their favorite vessel online. Each vote costs a dollar and the money raised goes to a charity designated by the boat's sponsor. "You can vote as many times as you want for your favorite boat, your favorite charity," says Collins. "I think last year we raised about $50,000."

A month later, volunteers are back in the water, straightening the plant stands that have been knocked over by the boats and preparing for another summer of Color on the Creek. "The most gratifying thing for me in this whole project has been how willing people are to step up and have fun," says Kremers . "If I ask someone for help, 90 percent of the time they say yes." Apart from a brief lawyerly recalcitrance over putting boats in the creek, the city has been a willing partner with Color on the Creek. "It's not that they just got out of the way," he says. "They actually are very helpful. They give us a lot of support."

Frederick has benefited in many ways from the efforts of Kremers and his crew of volunteers, beyond just beautifying its newest park. "People come into town, we see it all the time. I'd be in the water. I'd talk to people, and a lot of them come to see the boats or come to see the lily garden. And then they shop, and they eat at the restaurants."