The engineering firm hired by Howard County to study flooding in Ellicott City said community concern over the impact of development following the deadly Memorial Day weekend storm may come from misunderstanding data.
Models in McCormick Taylor’s analysis, released following the fatal 2016 flood, found undeveloped land, in some cases, produced roughly half the amount of runoff as developed parcels. Christopher Brooks, director of water resources engineering for McCormick Taylor, said he understands people who don’t understand the technicalities may reach the conclusion development is the primary culprit for flooding, but he warned the problem isn’t linear.
“Fifty percent less runoff does not mean 50 percent less flood damage, necessarily,” Brooks said during a briefing with reporters on Friday morning. “Because there’s a lot of other factors that are in play. I think what this community has working against it, particularly in the low areas, are the topography … even if you got a significant reduction (in discharge) … you’re still funneling all that water down into that area of town.”
Sunday’s storm dropped more than eight inches of rain on the area in a matter of hours. As a result, a river of muddy water rushed down Main Street, killing one man, destroying businesses, and sweeping away cars. Old Ellicott City dates back to the 1770s when it was built as a mill town. It’s situated in the Tiber-Hudson watershed along the Patapsco River and has historically been flood-prone. Under modern building standards most construction in the area would be prohibited.
The area around old Ellicott City has been subject to intense development over the last 50 years as demand for suburban residential and commercial property increased. Some residents and activists attribute the two most recent floods, which have killed three people, to the aggressive building in the area southwest of Baltimore. McCormick Taylor’s analysis acknowledges development in the area “plays a role” in flooding, but found the reasons for the flooding are varied and complicated.
McCormick Taylor’s analysis includes recommendations for 18 projects, at an estimated cost of $84 million, intended to blunt the impact of flooding. Howard County’s current cap on general obligation debt is $95 million annually.
Phil Nichols, Howard County’s assistant chief administrative officer, said the jurisdiction has already allocated funds for the construction of some of those recommendations, such as stormwater ponds along the Route 40 and Route 29 interchange.
Additional solutions suggested by McCormick Taylor include digging tunnels on either side of Main Street to divert flood flows; building underground storm water management pipes and vaults; and creating natural stormwater management tools.
Some experts have said the county needs to consider radical options for rebuilding along Main Street in old Ellicott City. Those options include removing residential and commercial buildings and replacing them with park land.
“They need to be told by leaders it’s not OK to rebuild again,” Hye Yeong Kwon, executive director of the Center for Watershed Protection, said earlier this week.
Brooks said the proposed solutions included in the analysis were limited to what was considered feasible, and wouldn’t affect area merchants.
“Within our study we looked to do things that were feasible without directly impacting businesses in the commercial district of Main Street, but recognizing there are other options that could be looked at in the future,” Brooks said.
Following the briefing, Columbia resident Barb Stanley was upset by what she heard from Brooks and Nichols. She said the area shouldn’t have been rebuilt after the flood nearly two years ago. She supports turning the area into a park named after Eddison Hermond, 39, who died in the most recent flooding. Hermond, Stanley said, should be the last person to lose his or her life to sentimentality.
“The historical aspect (of the Main Street retail district) outweighed public safety,” Stanley said.