Beth Woodruff keeps a “go” bag packed in her home — spare clothing and essentials in case she has to flee at a moment’s notice. 

“Every time the weather radio goes off,” Woodruff said recently, “we start watching the river to see if it’s time to go.”Phil Nichols, Howard County’s assistant chief administrative officer, and Jim Caldwell, county chief of community sustainability, stand at an end of a culvert that carries Hudson Branch beneath Ellicott City’s Main Street. In a July 2016 flash flood, water overtopped the wall and culvert. The county has spent $8 million in repairs and rebuilding assistance since then, Nichols said. (Dave Harp)

Woodruff doesn’t live along the Atlantic Coast, and it’s not hurricanes that put her on edge. She’s a resident of Ellicott City, MD, at least 120 miles from the ocean and a dozen or more miles from the Chesapeake Bay. It’s sudden, severe downpours that worry her because in just a few minutes they can turn the stream in front of her house into a raging torrent, rising out of its banks to wash over her driveway and prevent escape by vehicle.

Nuisance flooding is a chronic problem around the Chesapeake Bay in historic ports such as Norfolk, Annapolis and Baltimore. It’s expected to worsen in the coming years, as climate change raises sea level and brings more erosion and intense storms to coastal communities.

But some communities well inland from the Bay are vulnerable to a different kind of flooding, one produced by heavy, flashy downpours that swell rivers beyond their banks and send runoff surging down streets and hillsides. It’s something expected to worsen in the future as the region’s rainfall is projected to continue to increase, as well as the intensity of storms. 

The vulnerability of old Ellicott City, a historic mill town on the banks of the Patapsco River west of Baltimore, illustrates the potential consequence.

Ellicott City is already what you might call flood-prone. Founded in 1772 to mill grain, it was an ideal spot to harness the power of fast-flowing water. Four streams converge there to form the Tiber River before emptying into the Patapsco. “Ellicott’s Mills,” as it was originally called, grew into a thriving burg, complete with the nation’s first railroad depot in 1830.

But some local residents had another name for the place — The Hollow — to describe the narrow valley bounded by steep granite cliffs in which they lived and worked. The water that powered the town’s mills could also wreak havoc. It’s done so dozens of times over the centuries.

“This town has flooded since the day it was created,” said Jim Caldwell, director of community sustainability for Howard County, MD. The Patapsco, which drains 586 square miles of land before reaching the Bay, often rose during tropical storms and prolonged rainy spells, inundating lower Main Street. But sudden downpours have also caused the streams running through town to jump their banks en route to the Patapsco. 

The Flood of 2016

The most recent flood was the most devastating in modern memory. On the night of July 30, 2016, 6.5 inches of rain fell in just a couple of hours. Meteorologists called it a “back-building” storm, a series of thunderstorms that hit essentially on top of each other.

Four streams draining the heights above historic Ellicott City converge along lower Main Street before emptying into the Patapsco River. Tiber Branch flows directly behind and even under some Main Street businesses. The wall here was rebuilt using reinforced concrete block. (Dave Harp)Main Street — a quaint strip of restaurants, studios, and antique and gift shops on one end, historic homes on the other — suddenly became a roiling sluiceway, as the Hudson Branch, which weaves back and forth under the roadway and beneath some buildings, climbed out of its banks. Water up to 6 feet deep in places washed dozens of vehicles into the Patapsco, ripped up brick sidewalks and broke through some buildings’ walls and windows, carrying off almost everything inside. 

The storm broke about 7 o’clock on a Saturday night, and restaurant patrons hadn’t paid much mind to the severe weather warnings issued shortly before. Some fled out the back of buildings, some retreated to upper floors. Emergency responders rescued dozens — but two people drowned. Almost as quickly as the water rose, it went down, leaving 90 businesses damaged, nearly 100 residents displaced and hundreds more unemployed.

In the aftermath, local, state and federal officials vowed to help Ellicott City rebuild as quickly as possible. The county kept Main Street closed for weeks while crews repaired and rebuilt damaged infrastructure — including an illegal sewer discharge that had gone undiscovered until it was exposed by the flood. Some things, like the brick sidewalks and Belgian block alleyway, got temporary patches of asphalt. But by October 2016, Main Street reopened, and businesses and residents started coming back.

Now, 19 months after the flood, by all outward appearances, the community has largely recovered. With the help of government and civic groups, residents and businesses have cleaned up the mud and reclaimed damaged structures; only a few buildings remain boarded or empty. Ninety-six percent of the businesses in the commercial district before the flood have come back, according to county officials. Residents haven’t been quite as quick — but 72 percent of those rendered homeless by the floodwaters have also returned, officials say.

The county, meanwhile, hired an engineering consultant to take a fresh look at the Tiber-Hudson watershed to see what might be done during storms to corral runoff, keep streams in their banks and reduce flooding. That poses real challenges, because the tiny, 4-square-mile watershed is about 65 percent covered with pavement and buildings. Caldwell calls Ellicott City suburban Howard County’s “little Baltimore,” because of its density of development.

The town has experienced about 50 floods of record since its founding, Caldwell said. Usually, they’ve been decades apart, but Ellicott City also got hit by Tropical Storm Lee in September 2011. Up to 6 feet of water flooded into shops in lower Main Street and homes in the West End.

Before July 2016, Caldwell said, he’d been focused on trying to put in “green infrastructure” that would beautify the town as well as reduce nutrient and sediment pollution from stormwater running off streets, parking lots and roofs. But since that disaster, he said, the community’s chief concern has shifted to controlling the quantity of runoff rather than its quality. 

Drafting a master plan

The county is drafting a master plan for Ellicott City and its watershed that aims to incorporate flood control measures into a long-term development plan for the community. In such a crowded area, there isn’t much open space in which to collect and hold water, particularly the immense quantities produced by intense or prolonged downpours. The engineering consultant proposed creating or expanding three large stormwater retention ponds, an underground “pipe farm” to hold more water in the densely developed area and a variety of other projects intended to keep streams in their banks. The estimated price tag for all 18 projects: $85 million. Jim Caldwell, Howard County’s director of community sustainability, recounts how flood waters surged up over stone walls and flooded parking lots. (Dave Harp)

“That’s money that’s not necessarily in anybody’s back pocket,” Caldwell said. “That’s the challenge we’re dealing with now.”

County Executive Allan Kittleman announced last summer that he would start with four of the flood mitigation projects, estimated to cost about $18 million in all, including stormwater retention facilities on three of the streams and upgrades to the stream channel and road culverts in the frequently flooded residential West End. Funds to start planning those are included in the county’s proposed fiscal 2019 capital budget.

Once complete, if the proposed projects work as designed, Caldwell said, they’ll significantly reduce flooding in Ellicott City, capturing enough runoff from a 100-year storm to make it more like a milder, 10-year storm. 

But the county official is frank to admit that all of the flood mitigation projects suggested so far can’t prevent the devastation wrought by the July 2016 storm. Meteorologists classified that storm as a 1,000-year flood, more powerful than a 100-year storm. That generally means there’s a one in 1,000 chance of it happening in any given year. But climate change could be shifting the storm-rating needle. The 2014 National Climate Assessment produced by the federal government predicts that “riverine” flooding is likely to increase along with coastal inundations. 

More severe storms

Studies show that rainfall in the Chesapeake region has been gradually increasing for nearly a century — and has risen by 3 percent in the most recent three decades, according to figures from the state-federal Bay Program partnership. That increase, coupled with more severe storms, will boost nitrogen runoff into the Bay by 9 million pounds more than once anticipated, according to recent computer model estimates.

Others have reached similar conclusions about future rainfall patterns. High-intensity, heavy rainfall events have already increased in frequency in the Northeast by 71 percent from 1958 to 2012, and are likely to increase even more, according to the Maryland Commission on Climate Change. When combined with the lack of open ground in most urban areas to absorb such rainfall, the commission warned that “large quantities of runoff may quickly overwhelm the capacity of stormwater drainage systems.”

A Bay Program management strategy for climate adaptation warned that runoff controls designed to handle once-normal amounts of rainfall will likely need to be designed to be “climate smart” in the future to handle greater volumes. That’s something Ellicott City has already learned.

“These storms we’re having are not the storms that we had in the past,” Caldwell acknowledged. “We had Tropical Storm Lee, we had this microburst, back-building thunderstorm, so things are changing, and the stormwater designs we have today are obviously not going to control these storms.“

If flooding continues to become more frequent and severe, Caldwell added, it will pose heightened risks to many more places than Ellicott City.

Washington, DC, also has suffered repeated “interior” or flash floods, damaging homes and displacing residents and forcing the shutdown of a metro station during rush hour. A 2006 deluge displaced the Internal Revenue Service and damaged other government buildings, and there have been other, less severe inundations in recent years. An interagency task force formed to look at what to do about such floods warned that there’ll be more, noting that “today’s 100-year storm is projected to be equivalent to a 15-year storm by the 2080s.”

Rebuilding to anticipate storms

Many residents and employees in the community see development, rather than climate change, as the chief culprit for the flooding. Caldwell acknowledges that development has aggravated flooding, but he points out that two thirds of the watershed was built before 1985, before any stormwater management was required. And in 1994, the county went beyond state standards to mandate that any new Ellicott City development after that be built to control runoff from 100-year storms. 

Those who’ve returned to live and work in Ellicott City say they cherish its historic character and the tight-knit community relationships they’ve formed there. Despite suffering two major floods in five years, they say they didn’t really consider moving away. Four streams draining the heights above historic Ellicott City converge along lower Main Street before emptying into the Patapsco River. Tiber Branch flows directly behind and even under some Main Street businesses. The wall here was rebuilt using reinforced concrete block. (Dave Harp)

“There was not even a second thought,” said Don Reuwer, a Howard County developer who owns a significant portion of Main Street. Instead, he said, when weighing what to do with his damaged buildings, his prompt response was, “Yes, let’s put ‘em back as fast as we can, better than ever.”

With some flooded structures, Reuwer said he didn’t replace damaged wood flooring and drywall, opting instead for waterproof concrete floors and wall paneling that can weather future inundation. Electrical outlets and related infrastructure have been elevated to limit loss.

Floodwaters broke through walls of two of Reuwer’s buildings that loom over the Tiber River — the old Caplan’s department store and the former Taylor’s department store, just up Main Street. In both cases, he said he rebuilt the damaged walls using concrete blocks filled with cement and fortified with steel rebar. Of Caplan’s, he said, “It’s built like a dam, nothing’s going to hurt it.”

Flood-proofing homes and buildings may be the only way to safeguard people and property, given the inability of even upgraded stormwater retention measures to hold back extreme storms like the 2016 deluge.

The U.S. Army Corps of Engineers brought in a team of experts to study the town’s buildings, and its report, presented in late February, lays out a menu of “dry” and “wet” flood-proofing measures that property owners can take. They range from installing flood-proof doors and removable door and window flood panels to elevating structures, at costs just as varied, from $10,000 per measure to around $200,000 and, in one case, more than $300,000. 

“It’s all based on what people can afford and what they can manage,” said Marco Ciarla, project manager for the flood-proofing study in the Corps’ Baltimore District office. He acknowledged that cost and the desire to maintain Ellicott City’s historic appearance could make it a challenge to institute many measures. There are some government funds to help with flood hazard mitigation, but they’re limited.

Limiting the damage

Ciarla also cautioned that the flood-proofing measures recommended by the study team would help prevent or limit damage in many cases, but still might fail in a flood as fierce as the one in 2016. Even so, he said, the steep expense may prove worth it if the county’s flood mitigation projects do succeed in reducing the impact of intense storms.

“It’s a classic case, if a community wants to spend a lot of money, they can reduce risk from many storm events in the future, but they can’t eliminate risk entirely to folks at the bottom of the hill,” said Tom Schueler, executive director of the Chesapeake Stormwater Network, a nonprofit that trains and advises government and private entities on how to better manage runoff. His offices in Ellicott City were above street level, so they were spared flood damage, but they were forced to work from home for three months during cleanup and the initial rebuilding.

Schueler said that with today’s knowledge, it’s clear Ellicott City wouldn’t be built where or how it is now.

“It’s not a spot, if you had to do it all over again, you would want to locate a charming community, but it does have historical roots,” he said. For all of the rebuilding done so far, he said, “we’re still, I think, hydrologically vulnerable…We have a lot more work to do.”

Gayle Killen’s stone and frame home in the West End definitely has historical roots. It was built in 1809 to serve as an icehouse. Killen said she bought it in 2010, in time to experience flooding in 2011 and 2016. But she said there’s flooding even during less severe downpours.

“We are inundated by an everyday rainstorm,” she said. Though the Hudson Branch flows behind her house, she said, runoff from uphill is a more frequent threat. “It’s literally coming down the hillside, eating through walls.” She has sandbags around her front door, she pointed out, to keep out runoff from the sidewalk.

In 2016, floodwater tore up the street in front of her house, took away the concrete flood barriers shielding her coal chute and began pouring into her house. When it receded, she was left with two to three feet of muddy sediment to clean out.

Given what’s happened so far, Killen thinks the county ought to be planning to deal with floods brought by more than 100-year storms.

“The storm intensity is increasing, we know this. We don’t need to fight about that,” she said, adding that the 2016 deluge was no surprise to her. “I didn’t know when, but I knew it was coming.”

Despite that, she said, she’s not about to move away. 

“I came to this town knowing its problems,” she said, adding that she thought she could help. Now, she’s determined to protect her house, putting in flood-proof doors, window panels and whatever else she thinks it’ll take. And she said she’s not going to wait for permission from the historic preservation authorities — the “aesthetics police,” she calls them. 

“This is my forever home,” she said. “What I’m going for is ultimate resilience, come hell and high water.” In the meantime, she said, she’s going to keep the sandbags around her front door.

A community responds

It seems the devastation wrought by the 2016 storm has engaged the community in a way that earlier ones did not. After the 2011 flood, a county workgroup called for short– and long-range measures to enhance stormwater retention in the watershed. Very little of that 2015 report got acted on before the flash flood hit eight months later, said Lori Lilly, executive director of the nonprofit Howard EcoWorks, who served on the study. 

Now, with a $154,000 grant from the National Fish and Wildlife Foundation, Howard EcoWorks has a campaign called “Ellicott City - Soak It Up” aimed at enlisting 500 residents and businesses in putting in rain gardens, forest buffers and other things on their properties to reduce runoff.  With 80 residents signed up so far, Lilly said, one of her long-term goals is to replace 700 acres of turf grass in the watershed with deeper-rooted native plants that can soak up more rainfall. 

“It’s not a flood mitigation solution,” Lilly said, given the degree of impervious development in the watershed.  Rather, she said, it’s intended to make residents aware that “there are things they can do to help be a part of solution.”

Beth Woodruff welcomes anything that can engage her upstream neighbors. She was away during the July 2016 flood, and returned to find her home intact, though some floors were warped by water that got in the crawlspace. Her yard, though, had a “sedan-sized” chunk eroded out of it, and her driveway was gone and her sewer line severed. 

Unlike Killen, her neighbor, Woodruff said she’s hopeful that the projects the county is planning will reduce flooding along the Hudson Branch, which wends its way back and forth under Main Street.

But given the uncertainty of when the next storm will hit, she said she won’t feel more comfortable until they’re actually built. 

“These solutions really can’t come fast enough for our community.”