Due to geography, flooding happens at same trouble spots with each significant storm

A county vehicle makes its way through flood waters covering Main Street in Union Bridge Oct. 30 following heavy rainfall associated with Hurricane Sandy.
A county vehicle makes its way through flood waters covering Main Street in Union Bridge Oct. 30 following heavy rainfall associated with Hurricane Sandy. (DAVE MUNCH/STAFF FILE PHOTO , Carroll County Times)

Built in a topographically low area, Union Bridge and the Md. 75 bridge over Little Pipe Creek regularly sees flooding.

You would think the residents of the town are used to it by now, but during Superstorm Sandy, when the creek flowed up over Md. 75 and about 18 inches high in Mayor Perry Jones Jr.'s service station near the bridge, the Union Bridge fire company still got six calls from residents who didn't know how to get out of town.

"It's been about 10 years now that Shepherds Mill [Road] was put in, and that's an access in and out of town when there's flooding," Jones said. "That's a big help."

Jones said he is working with Chad Green from the fire company to plan an emergency preparedness event for town residents to be held in the next month or two to prevent future panicked calls from residents.

But as for alleviating the flooding at the main entrance into town, there's not much more that can be done, Jones said. Like several other points in the county, some places are just prone to flooding or flash flooding, and unless the landscape was dramatically altered, it's probably going to stay that way.

"If you have a point where you're getting 2 or 3 inches of rain within seven or eight hours, yeah, we're going to have flooding, because the area is just so low," Jones said. "But it's a lot better than it used to be since they did the stream here."

About 10 or 12 years ago, the state did some reparation work on Little Pipe Creek, trying to remediate the erosion and flow patterns of the creek that exacerbated the flooding problem.

"They put some bends back in it, they put some riprap along the banks and things like that, and that's helped a lot for the flooding, because it takes a lot more rain now to flood than it used to," Jones said.

The creek does rise above the Md. 75 bridge during those extended rainstorms, but the state comes out and checks on the bridge a day or so after to make sure there isn't any significant damage. Jones said he has heard the state mention some plans to do improvements on the bridge, but as of now, he hasn't seen any formal plans.

Heather Keels, State Highway Administration community liaison for District 6 and 7, said there are no improvements for the Md. 75 bridge at this time.

Bruce Lockard, county roads operations bureau chief, said his crews spend a lot of time checking on roads and bridges the day after an area sees flooding.

"We have a critical list of structures that, after an event like that, we go through and look at to check on, and if we notice anything, we would have engineers look into them as a second check," he said. "When they flood like that, the flow is so intense going through them that they tend to scour, or erode around the footings and washout."

The majority of the flooding in the county happens in the northern and western areas, along the Monocacy River, Lockard said. When the Monocacy River water level rises, it causes four or five road closures from Keysville to Taneytown.

"There's very little that can be done to alleviate it - it's not like you could add a storm drain pipe and alleviate the problem, it would be more massive than that," Lockard said of the issues. "There are some areas that have low-lying roads where some construction work could be done to elevate the road maybe 12, 18 inches, and that would alleviate the road closure. It wouldn't stop the flooding, it would just stop the closing of the road."

Baptist Road in Taneytown is one road that the county has discussed possibly elevating the road to keep it above the lower levels of stream bank flooding, but to his knowledge, the project has not been evaluated for costs.

"As far as funding for alleviating or changing anything, that's all controlled by the board [of county commissioners]," Lockard said.

While the county road department does not have any major roadwork planned related to flooding, it has worked with the bureau of resource management to use stormwater management techniques to reduce flooding in some areas.

Gale Engles, county bureau chief of resource management, said one of the county's most successful recent projects was in the Patapsco area of Finksburg.

"Down in Patapsco, what we did was a series of stormwater management facilities that basically slow down the runoff rate and contain the drainage and the runoff and discharge it at a slower rate," Engles said. "That's basically what takes away the flooding problem."

In any stormwater project, the first priority is to see if the stormwater can be manipulated to infiltrate back into the ground, Engles said.

"If the soils are capable of doing that, we would put in a facility that had a series of [underground] drains that would infiltrate the water back into the ground, and what would discharge would be at a small rate, a 6- to 8-inch dewatering pipe," she said.

For larger facilities where infiltration is not possible, they design a detention facility that would still have a small discharge pipe, she said, but would hold the remaining water longer so that despite the volume of rain, the same amount of water is released from the pond.

Now that the work is completed, the Patapsco stormwater management system is working, Engles said, and no flooding problems have been reported in the two years since it was completed.

The bureau is not working with the roads department on any current projects, she said, but has been working on some projects in residential neighborhoods in Eldersburg where people were seeing flooding in their back yards.

"We did a pond recently in the Parrish Park development where we had flooding issues, and that pond finished up in late summer/early fall, and with the hurricane, we had no problems reported," she said.

The county owns about 180 stormwater management facilities, Engles said, out of a total of about 1,000 in the county.

"We have a list of ponds that we're retrofitting currently, but most of that has to do with our [stormwater discharge] permit, so we're looking at flooding as well as nutrient reductions and impervious treatment," Engles said.

Lockard said he remembers people talking about the great hurricanes and 100-year storms of the past, such as Agnes and Eloise. There would be lots of destruction, and then years of more normal weather.

"It does seem like these storms become more frequent - in my mind they have," Lockard said. "We don't go four or five years without having a heavy rain, it seems like almost annually we have at least one event come out through in the last five years."

With so many flood plain areas in the county, these frequent storms mean that flooding and road closures are just going to happen, he said.

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