Maryland undertakes multimillion-dollar fish passage restoration project Patapsco to be model for other sites

The rushing 450-foot long cascade at the abandoned Daniels dam in the Patapsco River Valley has been "drydocked" recently, another sideshow in a multimillion-dollar bioengineering spectacle that will continue at least until 1994.

The dam, a popular fishing spot, was de-watered as part of the state's fish passage restoration project. Its waters have been jetting through a 4-foot sluice gate beside the new fish passage canal.


There is a 6-foot drop behind the 27-foot-high dam where the water is usually about 12 feet deep, the result of years of sediment accumulating since the mill dams were first built.

At the foot of the dam, water has worn a 6- to 12-foot-deep pool, which was pumped dry to allow structural reinforcement work to proceed. The fishway, which will include an observation window for underwater viewing, will be completed by mid-December.


"It's history repeating itself," observed Jay O'Dell, manager of the fish passage project. "We have this major move now to promote the future of shad and herring just as they were doing exactly 100 years ago."

Concern over dams and the decline of shad and herring, a staple food for colonists and natives, dates back to the 1768 law of fish passage, the first of many laws requiring fishways or regulating the proximity of grist mill dams on the river.

But the major barriers were the nine dams of the Industrial Revolution located between Elkridge and Daniels, which made the Patapsco River industries world-famous and helped to give the river its nickname, "Maryland's River of History."

Three of these remain today -- Daniels, Union and Simkins. Bloede, near the site of the old Orange Grove Flour Mill dam, made technological history when it was built in 1906, the world's first underwater hydroelectric plant. It, too, is getting a fishway. Only Simkins, which is privately owned, is actively used today.

Remnants of old fish ladders have been found at Daniels, as well as at many other local dam sites on both the Patapsco and the Patuxent rivers, some probably the result of state-funded work done in the 1890s by MacDonald's Fishway Co., Mr. O'Dell speculated. Fishways were legally required in 1874 on the Patapsco by an early Howard County law.

"They had virtually nil success because technology was so crude," he said. Today's fish canals, however, are underpinned by sophisticated research, Mr. O'Dell said.

O'Dell has spent 25 years researching the project, which included locating over 1,000 dam sites blocking Maryland rivers.

The fishways at Daniels and Bloede are using what is called the "Denil design," which has a slope and water velocity that matches the biological requirements of the shad and river herring. Other migrating species, white and yellow perch, large- and small-mouth bass and the American eel, (considered a great delicacy overseas and good crab bait), will also benefit. All are valued for both commercial and recreational fishing.


Target species were determined by biological sampling at the foot of Bloede, now the first dam that blocks further migration up to 23 miles of historical spawning habitat ending at Liberty Dam.

Some of the Patapsco fish populations had plummeted by more than 90 percent in the past 25 years because of the barriers, pollution and overfishing. American shad fishing was closed in 1980; hickory shad in 1981; other species such as the bass have a short season.

"Twenty years ago the river changed color every day due to

chemical pollution, paper waste and

sewage . . . and you could see raw paper and raw sewage on the rocks of the river," Mr. O'Dell said.

The Patapsco River Plan is based on cooperative efforts by government and private groups and is expected to serve as a model for other blocked river systems feeding into the Chesapeake.


Soon there will be only one dam blocking the migration passage -- Simkins Dam in Ellicott City, whose construction is under negotiation. Mr. O'Dell hopes work will be completed before the first pioneer fish begin their runs, probably in 1994. Two dams, Stony Run and Deep Run, located on Patapsco tributaries, were removed.

Though there will be no fish runs to see for a few years, there will be biologists in waders with electroshock guns, traps and nets monitoring the river and canals with fish counts, as often as twice a week during spawning season from early March to May.

Each spring, as they have since 1990, truckloads of ripe, egg-carrying fish (plus mature males) will be driven down from the Conowingo Dam on the Susquehanna River and be released along the Upper Patapsco as part of the restocking phase of the program.

"That's the key to the restoration program," O'Dell said.

Always a crowd-pleaser, there will be a 3-by-5-foot window for public viewing of the migrating fish at Daniels, as well as for scientific observation; spectators can also look down into the stepped-ramp structure from an overlook above the canal.

But the best show of all will be the spring runs, with silverbacked fish churning from shore to shore, heading up the river. It starts around St. Patrick's Day with yellow perch when the water temperature hits 46 degrees.


The iridescent schools of river herring spawn at 54 degrees; the shad run when the delicate shadblow tree blooms, usually when the waters hit 50 degrees. Then, males and females will strike both lures and flies.

Improved recreational fishing along the Patapsco's shores, as well as Maryland's other rivers, is a major goal of the fish-restoration program. Hopefully, bans on endangered fish will eventually be lifted.

Fisherman and fish, the great blue heron that nests above the Daniels dam, kingfishers, turtles, raccoons and other wildlife should all benefit from the opening of the river's lifeline.

There is even the possibility, according to Mr. O'Dell, that the rare, mammoth sturgeon, which can live 150 years and grow to several hundred pounds, may one day return to parts of the Patapsco.

The once-industrialized "river of history" is now making ecological history.