Conowingo water release may approach 'Agnes' proportions this weekend, dam owner warns

Brian Eddy of Forest Hill watches as the Little Gunpowder Falls continues to rise along Greene Road in Fallston early Wednesday evening.
Brian Eddy of Forest Hill watches as the Little Gunpowder Falls continues to rise along Greene Road in Fallston early Wednesday evening. (MATT BUTTON AEGIS STAFF, Patuxent Homestead)

Heavy rains Tuesday, Wednesday and Thursday led to flooding, road closures, the evacuation of Port Deposit, at least two swift water rescues in Harford County and warnings that expected water release through the Conowingo Dam this week could approach levels not seen since Tropical Storm Agnes 39 years ago.

The rains are expected to continue with flood warnings that are in effect through the end of the day and Conowingo Dam officials say they are expecting to open up to 50 crest gates by Saturday, which is likely to cause major flooding downriver.


As of midday Thursday, 32 of the dam's crest gates were open, according to Exelon Power, the dam's owner. By mid-morning, Route 1 across the dam was closed to traffic for an undetermined period. An Exelon spokesperson said the highway was closed so an additional crane could be moved into place on the dam.

The U.S. Army Corps of Engineers also announced Thursday morning it had sent engineers to dams along the Susquehanna in Pennsylvania and to Conowingo to monitor the flooding situation along the river. A news release from the corps said it has closed flood gates at several dams in New York and Pennsylvania in an effort to control downstream flooding.


Opening 32 gates at the dam is generally results in flooding in Port Deposit on the Cecil County shore of the river. Town officials said Wednesday they were preparing for the worst and had already canceled this week's riverfront festival that was to feature an appearance by county music legend George Jones. Port Deposit issued a mandatory evacuation order that was to take effect at 8 p.m. Thursday.

At about 10:30 a.m. Thursday, Harford County began relocating swift water rescue teams to the Port Deposit area, according to emergency radio broadcasts.

Dam officials said in a news release Thursday morning they expect to open 50 of the dam's 53 crest gates before the weekend ends. During the flooding caused by Agnes in June 1972, all 53 gates were opened.

River flows are expected to peak on Saturday at 6 a.m., according to the release.

It is a rare occurrence when more than 40 of the 83-year-old dam's 53 gates are open at the same time.

Record river flows through the dam were recorded during Tropical Storm Agnes on June 24, 1972, according to the U.S. Geological Service, or USGS, when the river crested at 36.8 feet.

Flood stage generally starts at 23.3 feet, Scott Hurst, the chief of the Susquehanna Hose Company in Havre de Grace, advised members following a conference call with Exelon officials and other emergency officials Wednesday evening.

Hurst e-mailed members that flows reaching 32 feet are expected through the dam by Saturday, but could reach 36 feet. He said dam officials explained the height of the water is the most critical factor in flooding, not the actual number of crest gates that are open at the dam.

Havre de Grace experienced major flooding during Agnes, Hurst noted; however, in the spring of 1996, when 46 gates were opened at the dam, it had "very little effect on Havre de Grace, but Port [Deposit] got it bad."

High water in Havre de Grace

In Havre de Grace, the Susquehanna River was brown and swollen, overflowing its banks in many parts of the city.

Public works officials gave the go-ahead to close the entrances to Tydings Park at about 9:45 a.m. Thursday.

The water there was already well into the parking lot, which was blocked off with police tape.

Tidewater Marina in the downtown area was also flooded, and several other waterfront parks, including Jean Roberts, Hutchins and North Park, were underwater, Havre de Grace Police Cpl. Neil Crouch said around that time.

Water Street was also shut down because of flooding, as was the public parking lot behind the water treatment plan.

NeighboringAberdeen seemed to be faring much better.

City Public Works Director Matt Lapinsky said Thursday morning no roads were closed or flooded.

"So far, so good – fingers crossed," he said.

The city reported only 0.3 inches of rain at about 9:15 a.m. that morning, although it had already gotten a total of about 4 inches from the storm.

Streams swell

Flood warnings were in effect in Harford County from 9:09 a.m. until 4 p.m. Thursday with flash flood warnings and watches periodically throughout the day, according to the National Weather Service.

Real time USGS data for several major streams in Harford showed water flow levels late Wednesday that were more than twice and in some cases three times higher than those recorded immediately after Hurricane Irene on Aug. 28. This was particularly true for Deer Creek in the Rocks area of northern Harford and Little Gunpowder Falls on the Harford and Baltimore County line in Fallston.

Harford County government said 16 county roads were closed as of 9:30 a.m. Thursday because of high water.

Water rescues

The heavy rains led to the first rescue after a woman became stranded in her car while driving through Rocks State Park Wednesday night.

Around 8:30 p.m., a Maryland State Police communications operator received a "frantic" 9-1-1 call from a woman who trapped in her vehicle that was becoming submerged after she drove into water flooding across the road, according to a release from state police.

The 49-year-old Pylesville woman drove into water flowing from Deer Creek onto Route 24 at St. Clair Bridge Road when she became stuck, according to the release.

Cpl. Ray Domico of the Bel Air Barrack was posted at Cherry Hill Road and Route 24, about two miles away, because of the road closure when the woman called 9-1-1.

While the communications officer kept the woman calm, Domico quickly went to the area and saw a sinking SUV in swift water. He judged there was little time to wait so he waded into the waist-deep water and helped the woman walk through the water to dry ground, according to the release.

Jarrettsville Volunteer Firefighters also responded to the call, but both Domico and the woman were out of the water by the time they arrived, according to Rich Gardiner, spokesman for Harford County Volunteer Fire and EMS Association.

Neither the woman nor Domico were injured. The vehicle was still in the flood waters Thursday morning, according to state police.

Early Wednesday around 2: 15 a.m., another call went out for a swift water rescue, Gardiner said.

Members of Darlington Volunteer Fire Company and the Technical Rescue and Dive Team were dispatched to Sandy Hook Road and Scarboro Road where they found one person trapped on top of a vehicle in high water along Deer Creek, Gardiner said.

The rescue lasted about 40 minutes.

State police and members of public safety agencies remind drivers to heed blockades blocking flooded roadways, not to drive into high waters and to use extra caution in the ongoing heavy rain.


Roads closed


As of Thursday morning, Carrs Mill Road in Fallston, Route 7 between Route 543 and My Lady Drive in Creswell, Route 24 between Cherry Hill Road and Coen Road in the Rocks area and Route 147 [Harford County] at the Baltimore County Line were all closed because of flooding.

Other closures by the county were reported on Pleasantville Road in Fallston from Route 152 to the Baltimore County line, Greene Road from Route 165 to Baltimore County in Upper Cross Roads and Pocock Road from Route 152 to Baltimore County, all affected the Little Gunpowder flooding.

Sandy Hook Road remained closed from the Deer Creek bridge to Gibson Road and from the bridge to Route 1, and Walters Mill Road was closed from Route 543 to Sandy Hook, according to the county.

Route 1 at Route 136, Route 165 at Route 24 and Route 543 between Route 1 bypass and Route 440, were all experiencing flooding issues, according to the State Highway Administration's website.

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