Gunpowder River’s wild brown trout fishery a short drive from downtown Baltimore

Below Prettyboy Reservoir in Baltimore County, the Gunpowder River flows through forested rock ledges and supports a wild brown trout fishery. And it’s happening about 20 minutes from downtown Baltimore.

“It feels like you’re a lot farther away than you actually are,” said Rob Lepczyk, a fly fishing guide for Great Feathers fly shop in Sparks, Maryland. “We’re in horse country with beautiful rolling hills, farms and big stone houses. It’s beautiful country.”

To top that off, “the fishing is actually pretty damn good,” Lepczyk said.

And it’s a fishery that didn’t exist 30 years ago. The Gunpowder River between Prettyboy and Loch Raven reservoirs — both city-owned water supply reservoirs — was a marginal stream until the mid-’80s, when Trout Unlimited, City of Baltimore and the state came to an agreement on a minimum flow release from Prettyboy Dam. A few years of stocking brown trout was all it took for the species to take hold in the new steady supply of cold water.

The Gunpowder River’s tailwater fishery is a “legitimate success story,” according to Clark Howells, watershed section manager for the city’s Department of Public Works. “It’s really something that should be celebrated and we’re proud of it,” he said.

Though the original agreement only covered the minimum flow, the city has also made an effort to keep the Gunpowder River below 68 degrees year-round. They’ve largely succeeded, thanks in part to the design of the deep, steep-sided reservoir that allows for plenty of cold water storage below the thermocline.

“It gave us the natural capacity to be able to make this cold water release,” Howells said. “Other reservoirs in the region don’t have the same volume of cold water to be able to support a fishery as effectively as we do.”

The cold water also supports “some really good bugs,” Lepcyzk said, including sulphers, Hendricksons, and a trico hatch that lasts much further into the fall and winter than most rivers. Caddisflies, golden stoneflies and midges throughout the winter also add to the mix.

The Gunpowder River below Prettyboy Dam is some of the only public water in the area. (Credit: Rob Lepczyk)

There are anglers out there who say the city could be even more effective in supporting the fishery, including Lepczyk. The criticism stems from the fact that the city operates Prettyboy Reservoir exclusively as a water supply that provides the majority of the Baltimore metropolitan area’s drinking water. That means keeping the reservoir as full as possible. Sometimes that leads to high flows after a heavy rainfall when the reservoir is full. Other times, when the city needs to bring the water levels up, the flows will drop. Though flows don’t drop as low as the minimum set out in the original agreement, they can fall below levels anglers like Lepczyk like to see.

“I’m not asking for 300 cfs all day long, but 75 would be great,” he said.

For their part, the city says they do everything they can to balance protecting the fishery with protecting the public water supply.

“We try to balance things, and sometimes nature does cooperate with us the way we want it to,” said DPW spokesman Kurt Kocher.